:root {
    --primary: #4F46E5;
    --primary-light: #818CF8;
    --primary-dark: #3730A3;
    --secondary: #8B5CF6;
    --accent: #06B6D4;
    --bg-light: #F8FAFC;
    --bg-dark: #0F172A;
    --surface-light: #FFFFFF;
    --surface-dark: #1E293B;
    --text-primary: #1E293B;
    --text-light: #1E293B;
    --text-dark: #F1F5F9;
    --text-muted: #64748B;
    --success: #10B981;
    --error: #EF4444;
    --warning: #F59E0B;
    --border-light: #E2E8F0;
    --border-dark: #334155;
    --border: #E2E8F0;
    --card-bg: #FFFFFF;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.07);
    --gradient: linear-gradient(135deg, #4F46E5, #8B5CF6);
    --gradient-accent: linear-gradient(135deg, #4F46E5 0%, #8B5CF6 50%, #06B6D4 100%);
    --shadow-sm: 0 2px 8px rgba(79, 70, 229, 0.08);

/* Hide empty ad spaces - hidden by default, show when ad code is added */
.ad-banner {
    margin-top: 70px;
    background: var(--surface-light);
    border-bottom: 1px solid var(--border-light);
    display: flex;
    justify-content: center;
    padding: 10px;
}

.ad-banner.hidden {
    display: none !important;
    margin: 0 !important;
    padding: 0 !important;
    border: none !important;
}

.ad-banner.has-ad {
    display: flex;
}

.ad-placeholder {
    width: 728px;
    max-width: 100%;
    height: 90px;
    background: linear-gradient(135deg, rgba(79, 70, 229, 0.1), rgba(139, 92, 246, 0.1));
    border: 1px dashed var(--border-light);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    font-size: 0.875rem;
}

[data-theme="dark"] .ad-banner {
    background: var(--surface-dark);
    border-bottom-color: var(--border-dark);
}
    --shadow-md: 0 10px 40px rgba(79, 70, 229, 0.15);
    --shadow-lg: 0 20px 60px rgba(79, 70, 229, 0.2);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'DM Sans', sans-serif;
}

[data-theme="dark"] {
    --bg-light: #0F172A;
    --bg-dark: #020617;
    --surface-light: #1E293B;
    --surface-dark: #0F172A;
    --text-primary: #F1F5F9;
    --text-light: #F1F5F9;
    --text-muted: #94A3B8;
    --border-light: #334155;
    --border: #334155;
    --card-bg: #1E293B;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    background-color: var(--bg-light);
    color: var(--text-light);
    line-height: 1.6;
    overflow-x: hidden;
    transition: var(--transition);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

main {
    flex: 1;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 5%;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

input, select {
    font-family: inherit;
    font-size: 1rem;
}

.header {
    position: fixed !important;
    top: 0 !important;
    left: 0 !important;
    right: 0 !important;
    height: 70px;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-light);
    z-index: 10000 !important;
    transition: var(--transition);
}

.rating-strip {
    position: fixed !important;
    top: 70px !important;
    left: 0 !important;
    right: 0 !important;
    background: linear-gradient(90deg, #4F46E5, #8B5CF6, #EC4899, #4F46E5);
    background-size: 300% 100%;
    padding: 10px 0 !important;
    z-index: 9999 !important;
    overflow: hidden !important;
    animation: gradientShift 8s ease infinite;
}

@keyframes gradientShift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.rating-strip-inner {
    display: flex;
    align-items: center;
    animation: scrollLeft 30s linear infinite;
    white-space: nowrap;
}

@keyframes scrollLeft {
    0% { transform: translateX(0); }
    100% { transform: translateX(-50%); }
}

.rating-strip-item {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin: 0 40px;
    color: white;
    font-weight: 500;
    font-size: 0.95rem;
}

.rating-strip-item .avatar {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: white;
    color: #4F46E5;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.75rem;
}

.rating-strip-item .stars {
    color: #FFD700;
    font-size: 0.9rem;
}

.rating-strip-item .rating-value {
    color: #FFD700;
    font-weight: 700;
}

body {
    padding-top: 110px;
}

body.no-strip {
    padding-top: 70px;
}

[data-theme="dark"] .header {
    background: rgba(15, 23, 42, 0.85);
    border-bottom-color: var(--border-dark);
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 5%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    width: 40px;
    height: 40px;
}

.logo-text {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-list {
    display: flex;
    gap: 32px;
}

.nav-link {
    font-weight: 500;
    color: var(--text-light);
    position: relative;
    padding: 8px 0;
    transition: var(--transition);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient);
    transition: var(--transition);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-link:hover {
    color: var(--primary);
}

.nav-highlight {
    color: var(--primary) !important;
    font-weight: 600;
    background: linear-gradient(135deg, rgba(79, 70, 229, 0.1), rgba(139, 92, 246, 0.1));
    padding: 8px 16px !important;
    border-radius: 20px;
    transition: all 0.3s ease;
}

.btn-logout {
    background: none;
    border: none;
    font-weight: 500;
    color: var(--text-light);
    padding: 8px 16px;
    cursor: pointer;
    transition: var(--transition);
    font-family: inherit;
    font-size: inherit;
}

.btn-logout:hover {
    color: #ef4444;
}

.nav-highlight:hover {
    background: linear-gradient(135deg, rgba(79, 70, 229, 0.2), rgba(139, 92, 246, 0.2));
}

.nav-highlight::after {
    display: none;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

.theme-toggle {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--surface-light);
    border: 1px solid var(--border-light);
    transition: var(--transition);
}

.theme-toggle:hover {
    transform: rotate(15deg);
    box-shadow: var(--shadow-sm);
}

.theme-toggle svg {
    width: 20px;
    height: 20px;
    color: var(--text-light);
    transition: var(--transition);
}

.sun-icon {
    display: none;
}

[data-theme="dark"] .sun-icon {
    display: block;
}

[data-theme="dark"] .moon-icon {
    display: none;
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
    cursor: pointer;
    background: none;
    border: none;
}

@media (max-width: 768px) {
    .hamburger {
        display: flex !important;
    }
    
    .header .hamburger {
        display: flex !important;
        visibility: visible !important;
        opacity: 1 !important;
    }
}

.hamburger span {
    width: 24px;
    height: 2px;
    background: var(--text-light);
    transition: var(--transition);
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

.mobile-menu {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--surface-light);
    border-bottom: 1px solid var(--border-light);
    padding: 0;
    max-height: 0;
    overflow: hidden;
    transition: var(--transition);
    z-index: 999;
}

@media (max-width: 768px) {
    .mobile-menu {
        display: block !important;
        position: fixed !important;
        top: 60px !important;
        left: 0 !important;
        right: 0 !important;
        width: 100% !important;
        height: calc(100vh - 60px) !important;
        max-height: none !important;
        overflow-y: auto !important;
        overflow-x: hidden !important;
        background: var(--bg-light, #fff) !important;
        z-index: 9998 !important;
        padding: 20px !important;
        transform: translateX(-100%) !important;
        transition: transform 0.3s ease, visibility 0.3s ease !important;
        visibility: hidden !important;
        pointer-events: none !important;
    }
    
    .mobile-menu.active {
        transform: translateX(0) !important;
        visibility: visible !important;
        pointer-events: auto !important;
    }
    
    .mobile-menu .mobile-nav-list {
        list-style: none;
        padding: 0;
        margin: 0;
    }
    
    .mobile-menu .mobile-nav-list li {
        margin-bottom: 10px;
    }
    
    .mobile-menu .mobile-nav-link {
        display: block;
        padding: 14px 18px;
        font-size: 16px;
        font-weight: 500;
        color: var(--text-primary, #333);
        text-decoration: none;
        border-radius: 10px;
        background: var(--bg-light, #f5f5f5);
        border-bottom: none;
    }
    
    .mobile-menu .mobile-nav-link:hover,
    .mobile-menu .mobile-nav-link:active,
    .mobile-menu .mobile-nav-link.active {
        background: var(--primary, #4F46E5);
        color: white;
    }
}

[data-theme="dark"] .mobile-menu {
    background: var(--surface-dark);
    border-bottom-color: var(--border-dark);
}

.mobile-menu.active {
    max-height: 300px;
    padding: 20px 5%;
}

.mobile-nav-link {
    display: block;
    padding: 12px 0;
    font-weight: 500;
    border-bottom: 1px solid var(--border-light);
    transition: var(--transition);
}

[data-theme="dark"] .mobile-nav-link {
    border-bottom-color: var(--border-dark);
}

.mobile-nav-link:hover {
    color: var(--primary);
    padding-left: 8px;
}

/* Hero Section */
.hero {
    min-height: calc(100vh - 110px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px 5% 30px;
    position: relative;
    overflow: hidden;
    border-bottom: none;
    margin-bottom: 0;
}

@media (max-width: 768px) {
    .hero {
        min-height: calc(100vh - 106px);
        padding: 15px 4% 20px;
    }
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at 30% 20%, rgba(79, 70, 229, 0.15) 0%, transparent 50%),
                radial-gradient(ellipse at 70% 80%, rgba(139, 92, 246, 0.1) 0%, transparent 50%);
    z-index: -1;
}

[data-theme="dark"] .hero-bg {
    background: radial-gradient(ellipse at 30% 20%, rgba(79, 70, 229, 0.2) 0%, transparent 50%),
                radial-gradient(ellipse at 70% 80%, rgba(139, 92, 246, 0.15) 0%, transparent 50%);
}

/* Two-column hero grid */
.hero-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    max-width: 1200px;
    width: 100%;
}

.hero-content {
    animation: fadeInUp 0.8s ease-out;
}

.hero-title {
    font-family: var(--font-heading);
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.02em;
    margin-bottom: 24px;
    background: linear-gradient(135deg, var(--text-light) 0%, var(--primary) 50%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--text-muted);
    margin-bottom: 32px;
    line-height: 1.7;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(255,255,255,0.2), transparent);
    opacity: 0;
    transition: var(--transition);
}

.btn:hover::before {
    opacity: 1;
}

.btn-primary {
    background: var(--gradient);
    color: white;
    box-shadow: 0 4px 20px rgba(79, 70, 229, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(79, 70, 229, 0.4);
}

.btn-primary:active {
    transform: translateY(0) scale(0.98);
}

.btn-secondary {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}

.btn-secondary:hover {
    background: var(--primary);
    color: white;
}

.hero-cta svg {
    width: 20px;
    height: 20px;
    transition: var(--transition);
}

.btn:hover .hero-cta svg {
    transform: translateX(4px);
}

.hero-stats {
    display: flex;
    gap: 40px;
    margin-top: 48px;
}

.stat-item {
    display: flex;
    flex-direction: column;
}

.stat-number {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    font-weight: 700;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
    animation: fadeInRight 0.8s ease-out 0.2s both;
}

.calculator-3d {
    perspective: 1000px;
}

.calc-body {
    width: 280px;
    height: 350px;
    background: var(--gradient);
    border-radius: var(--radius-lg);
    padding: 20px;
    box-shadow: 0 30px 60px rgba(79, 70, 229, 0.3);
    transform: rotateY(-10deg) rotateX(5deg);
    animation: float 4s ease-in-out infinite;
}

.calc-screen {
    width: 100%;
    height: 60px;
    background: #1a1a2e;
    border-radius: var(--radius-sm);
    margin-bottom: 20px;
    box-shadow: inset 0 2px 10px rgba(0,0,0,0.3);
}

.calc-buttons {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.btn-row {
    display: flex;
    gap: 10px;
}

.btn-row span {
    flex: 1;
    height: 40px;
    background: rgba(255,255,255,0.2);
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.btn-row span:hover {
    background: rgba(255,255,255,0.4);
}

@keyframes float {
    0%, 100% { transform: rotateY(-10deg) rotateX(5deg) translateY(0); }
    50% { transform: rotateY(-10deg) rotateX(5deg) translateY(-10px); }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.search-section {
    padding: 20px 5%;
    background: var(--surface-light);
    border-bottom: 1px solid var(--border-light);
}

[data-theme="dark"] .search-section {
    background: var(--surface-dark);
    border-bottom-color: var(--border-dark);
}

.search-box {
    max-width: 500px;
    margin: 0 auto 24px;
    position: relative;
}

.search-box svg {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    width: 20px;
    height: 20px;
    color: var(--text-muted);
}

.search-box input {
    width: 100%;
    padding: 16px 16px 16px 48px;
    border: 2px solid var(--border-light);
    border-radius: var(--radius-lg);
    background: var(--bg-light);
    color: var(--text-light);
    font-size: 1rem;
    transition: var(--transition);
}

[data-theme="dark"] .search-box input {
    border-color: var(--border-dark);
    background: var(--bg-dark);
}

.search-box input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(79, 70, 229, 0.1);
}

.category-filters {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
}

.filter-btn {
    padding: 10px 20px;
    border-radius: var(--radius-xl);
    font-weight: 500;
    color: var(--text-muted);
    background: var(--bg-light);
    border: 1px solid var(--border-light);
    transition: var(--transition);
}

[data-theme="dark"] .filter-btn {
    background: var(--bg-dark);
    border-color: var(--border-dark);
    color: var(--text-muted);
}

.filter-btn:hover {
    color: var(--primary);
    border-color: var(--primary);
}

.filter-btn.active {
    background: var(--gradient);
    color: white;
    border-color: transparent;
}

.tools-section {
    padding: 40px 5%;
}

.section-header {
    text-align: center;
    margin-bottom: 30px;
}

.section-header h2 {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.section-header p {
    color: var(--text-muted);
    font-size: 1.125rem;
}

.tools-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

@media (max-width: 768px) {
    .tools-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }
}

.tool-card {
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 32px;
    transition: var(--transition);
    animation: fadeInUp 0.6s ease-out both;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.tool-card .btn {
    justify-content: center;
}

[data-theme="dark"] .tool-card {
    background: rgba(30, 41, 59, 0.8);
    border-color: var(--border-dark);
}

.tool-card:nth-child(1) { animation-delay: 0.1s; }
.tool-card:nth-child(2) { animation-delay: 0.15s; }
.tool-card:nth-child(3) { animation-delay: 0.2s; }
.tool-card:nth-child(4) { animation-delay: 0.25s; }
.tool-card:nth-child(5) { animation-delay: 0.3s; }
.tool-card:nth-child(6) { animation-delay: 0.35s; }
.tool-card:nth-child(7) { animation-delay: 0.4s; }
.tool-card:nth-child(8) { animation-delay: 0.45s; }

.tool-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.tool-card.hidden {
    display: none;
}

.tool-icon {
    width: 60px;
    height: 60px;
    background: var(--gradient);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.tool-icon svg {
    width: 28px;
    height: 28px;
    color: white;
}

.tool-card h3 {
    font-family: var(--font-heading);
    font-size: 1.375rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.tool-card p {
    color: var(--text-muted);
    font-size: 0.9375rem;
    margin-bottom: 20px;
    line-height: 1.6;
}

.tool-btn {
    width: 100%;
    justify-content: center;
}

.tool-btn.clicked {
    animation: buttonClick 0.3s ease-in-out;
}

@keyframes buttonClick {
    0% { transform: scale(1); }
    50% { transform: scale(0.95); background: var(--primary-dark); }
    100% { transform: scale(1); }
}

.mid-ad {
    margin-top: 0;
    border-bottom: none;
}

.about-section {
    padding: 40px 5%;
    background: var(--surface-light);
}

[data-theme="dark"] .about-section {
    background: var(--surface-dark);
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.about-content p {
    color: var(--text-muted);
    font-size: 1.0625rem;
    margin-bottom: 20px;
    line-height: 1.8;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 24px;
    margin-top: 48px;
}

.feature-item {
    padding: 24px;
    background: var(--bg-light);
    border-radius: var(--radius-lg);
    text-align: center;
    transition: var(--transition);
}

[data-theme="dark"] .feature-item {
    background: var(--bg-dark);
}

.feature-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.feature-item svg {
    width: 40px;
    height: 40px;
    color: var(--primary);
    margin-bottom: 16px;
}

.feature-item h4 {
    font-family: var(--font-heading);
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.feature-item p {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.seo-content {
    padding: 60px 5%;
    background: linear-gradient(180deg, var(--bg-light) 0%, var(--surface-light) 100%);
}

[data-theme="dark"] .seo-content {
    background: linear-gradient(180deg, var(--bg-dark) 0%, var(--surface-dark) 100%);
}

.seo-content h2 {
    font-family: var(--font-heading);
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 20px;
    text-align: center;
    color: var(--text-light);
    margin-top: 40px;
}

.seo-content h3 {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 12px;
    margin-top: 30px;
    color: var(--text-light);
}

.seo-content p {
    color: var(--text-muted);
    line-height: 1.8;
    margin-bottom: 16px;
    text-align: justify;
}

.seo-content strong {
    color: var(--primary);
}

.seo-content ul, .seo-content ol {
    margin: 20px 0;
    padding-left: 24px;
}

.seo-content li {
    color: var(--text-muted);
    line-height: 1.8;
    margin-bottom: 10px;
}

.seo-content .formula {
    background: linear-gradient(135deg, rgba(79, 70, 229, 0.1), rgba(139, 92, 246, 0.1));
    padding: 20px;
    border-radius: var(--radius-md);
    font-family: 'Courier New', monospace;
    font-size: 1.1rem;
    text-align: center;
    margin: 20px 0;
    color: var(--primary);
    font-weight: 600;
}

/* Content Section - Article/Documentation Style */
.content-section,
.tool-page .seo-content-section {
    padding: 30px 4%;
    background: #F8F7FF;
    border-top: 1px solid #E5E7EB;
    max-width: 960px;
    margin: 0 auto;
}

[data-theme="dark"] .content-section,
[data-theme="dark"] .tool-page .seo-content-section {
    background: #1a1a2e;
    border-top-color: #374151;
}

.content-section h1,
.tool-page .seo-content-section h1 {
    font-family: 'DM Sans', 'Nunito', 'Plus Jakarta Sans', sans-serif;
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 24px;
    text-align: center;
    color: #2D2B8F;
    line-height: 1.3;
}

.content-section h2,
.tool-page .seo-content-section h2 {
    font-family: 'DM Sans', 'Nunito', 'Plus Jakarta Sans', sans-serif;
    font-size: 1.4rem;
    font-weight: 700;
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: #1a1a3e;
    padding-bottom: 8px;
    border-bottom: 3px solid #4F46E5;
    display: inline-block;
    width: fit-content;
}

.content-section h3,
.tool-page .seo-content-section h3 {
    font-family: 'DM Sans', 'Nunito', 'Plus Jakarta Sans', sans-serif;
    font-size: 1.2rem;
    font-weight: 600;
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    color: #1a1a3e;
}

.content-section p,
.tool-page .seo-content-section p {
    font-family: 'DM Sans', 'Nunito', 'Plus Jakarta Sans', sans-serif;
    font-weight: 400;
    font-size: 1.05rem;
    color: #374151;
    line-height: 1.8;
    margin-bottom: 1.25rem;
    text-align: left;
    max-width: 900px;
}

.content-section ul,
.content-section ol,
.tool-page .seo-content-section ul,
.tool-page .seo-content-section ol {
    margin: 20px 0;
    padding-left: 28px;
    max-width: 900px;
}

.content-section li,
.tool-page .seo-content-section li {
    font-family: 'DM Sans', 'Nunito', 'Plus Jakarta Sans', sans-serif;
    font-weight: 400;
    font-size: 1.05rem;
    color: #374151;
    line-height: 1.8;
    margin-bottom: 12px;
}

.content-section li strong,
.tool-page .seo-content-section li strong {
    color: #3B31CC;
    font-weight: 600;
}

.content-section .formula,
.tool-page .seo-content-section .formula {
    background: linear-gradient(135deg, rgba(79, 70, 229, 0.08), rgba(139, 92, 246, 0.08));
    padding: 24px 32px;
    border-radius: 8px;
    font-family: 'Courier New', monospace;
    font-size: 1.15rem;
    text-align: center;
    margin: 24px 0;
    color: #3B31CC;
    font-weight: 600;
    border: 1px solid rgba(79, 70, 229, 0.15);
    display: inline-block;
}

@media (max-width: 768px) {
    .content-section,
    .tool-page .seo-content-section {
        padding: 40px 1.25rem;
        max-width: 100%;
        overflow-x: hidden;
    }
    
    .content-section h1,
    .tool-page .seo-content-section h1 {
        font-size: clamp(1.5rem, 5vw, 2.2rem);
        word-wrap: break-word;
    }
    
    .content-section h2,
    .tool-page .seo-content-section h2 {
        font-size: clamp(1.1rem, 4vw, 1.4rem);
        width: 100%;
        display: block;
    }
    
    .content-section h3,
    .tool-page .seo-content-section h3 {
        font-size: 1.05rem;
    }
    
    .content-section p,
    .tool-page .seo-content-section p {
        font-size: 0.95rem;
        line-height: 1.7;
        word-wrap: break-word;
        overflow-wrap: break-word;
    }
    
    .content-section li,
    .tool-page .seo-content-section li {
        font-size: 0.95rem;
        line-height: 1.7;
        word-wrap: break-word;
    }
    
    .content-section .formula,
    .tool-page .seo-content-section .formula {
        font-size: 1rem;
        padding: 16px 20px;
        word-wrap: break-word;
        max-width: 100%;
        overflow-x: auto;
    }
    
    .content-section ul,
    .content-section ol,
    .tool-page .seo-content-section ul,
    .tool-page .seo-content-section ol {
        padding-left: 20px;
    }
}

/* Scroll to top button */
.scroll-top-btn {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: #4F46E5;
    color: white;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(79, 70, 229, 0.3);
    transition: all 0.3s ease;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
}

.scroll-top-btn.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-top-btn:hover {
    background: #3B31CC;
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(79, 70, 229, 0.4);
}

.scroll-top-btn svg {
    width: 24px;
    height: 24px;
}

/* ==================== PROFESSIONAL FOOTER ==================== */
.footer {
    background: linear-gradient(180deg, #1a1a2e 0%, #0f0f1a 100%);
    color: #e2e8f0;
    padding: 0;
    margin-top: auto;
    border-top: none;
    width: 100%;
    position: relative;
    
}

.footer-main {
    padding: 60px 5% 40px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 40px;
}

/* Brand Column */
.footer-brand {
    padding-right: 20px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
    text-decoration: none;
}

.footer-logo .logo-icon {
    width: 40px;
    height: 40px;
}

.footer-logo .logo-text {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 700;
    background: linear-gradient(135deg, #4F46E5, #8B5CF6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.footer-desc {
    color: #94a3b8;
    font-size: 0.9375rem;
    line-height: 1.7;
    margin-bottom: 24px;
}

/* Newsletter */
.footer-newsletter {
    background: rgba(79, 70, 229, 0.1);
    border: 1px solid rgba(79, 70, 229, 0.2);
    border-radius: 12px;
    padding: 20px;
}

.footer-newsletter h4 {
    color: #fff;
    font-size: 1rem;
    margin-bottom: 8px;
}

.footer-newsletter p {
    color: #94a3b8;
    font-size: 0.875rem;
    margin-bottom: 16px;
}

.newsletter-form {
    display: flex;
    gap: 10px;
}

.newsletter-form input {
    flex: 1;
    padding: 10px 14px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.1);
    color: #fff;
    font-size: 0.875rem;
}

.newsletter-form input::placeholder {
    color: #94a3b8;
}

.newsletter-form input:focus {
    outline: none;
    border-color: #4F46E5;
}

.newsletter-form .btn {
    padding: 10px 16px;
    font-size: 0.875rem;
}

/* Footer Columns */
.footer-col h4 {
    color: #fff;
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 20px;
    position: relative;
}

.footer-col h4::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 30px;
    height: 2px;
    background: linear-gradient(90deg, #4F46E5, #8B5CF6);
    border-radius: 2px;
}

.footer-links {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a {
    color: #94a3b8;
    text-decoration: none;
    font-size: 0.9375rem;
    transition: color 0.25s ease, transform 0.25s ease, background-color 0.25s ease, box-shadow 0.25s ease;
    display: inline-block;
    position: relative;
    padding: 6px 10px 6px 0;
    border-radius: 10px;
}

.footer-links a::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    width: 0;
    height: 100%;
    border-radius: inherit;
    background: linear-gradient(90deg, rgba(79, 70, 229, 0.16), rgba(139, 92, 246, 0.08));
    transform: translateY(-50%);
    transition: width 0.25s ease;
    z-index: -1;
}

.footer-links a:hover {
    color: #c4b5fd;
    transform: translateX(6px);
    box-shadow: 0 8px 20px rgba(79, 70, 229, 0.12);
}

.footer-links a:hover::before {
    width: 100%;
}

.footer-links a:focus-visible {
    outline: 2px solid rgba(129, 140, 248, 0.8);
    outline-offset: 3px;
    color: #ddd6fe;
}

.footer-links a:focus-visible::before {
    width: 100%;
}

/* Social Links */
.footer-social {
    display: flex;
    gap: 12px;
    margin-top: 8px;
}

.social-link {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    color: #94a3b8;
}

.social-link svg {
    width: 18px;
    height: 18px;
}

.social-link:hover {
    background: linear-gradient(135deg, #4F46E5, #8B5CF6);
    color: #fff;
    transform: translateY(-3px);
}

/* Footer Bottom */
.footer-bottom {
    padding: 24px 5%;
    background: rgba(0, 0, 0, 0.2);
}

.footer-bottom-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-bottom p {
    color: #64748b;
    font-size: 0.875rem;
    margin: 0;
}

.footer-made-with {
    color: #64748b;
    font-size: 0.875rem;
}

.footer-made-with span {
    color: #e11d48;
}

/* Mobile Responsive Footer */
@media (max-width: 1024px) {
    .footer-container {
        grid-template-columns: 1fr 1fr;
        gap: 32px;
    }
    
    .footer-brand {
        grid-column: span 2;
        padding-right: 0;
    }
}

@media (max-width: 640px) {
    .footer-main {
        padding: 40px 5% 30px;
    }
    
    .footer-container {
        grid-template-columns: 1fr;
        gap: 28px;
    }
    
    .footer-brand {
        grid-column: span 1;
        text-align: center;
    }
    
    .footer-logo {
        justify-content: center;
    }
    
    .footer-col {
        text-align: center;
    }
    
    .footer-col h4::after {
        left: 50%;
        transform: translateX(-50%);
    }
    
    .footer-links a:hover {
        transform: none;
    }
    
    .footer-social {
        justify-content: center;
    }
    
    .newsletter-form {
        flex-direction: column;
    }
    
    .footer-bottom-container {
        flex-direction: column;
        gap: 12px;
        text-align: center;
    }
}

@media (max-width: 640px) {
    .footer-main {
        padding: 32px 16px 24px;
    }

    .footer-container {
        gap: 16px;
    }

    .footer-brand,
    .footer-col {
        text-align: left;
        padding: 20px;
        background: rgba(255, 255, 255, 0.03);
        border: 1px solid rgba(148, 163, 184, 0.14);
        border-radius: 18px;
        backdrop-filter: blur(12px);
    }

    .footer-logo {
        justify-content: flex-start;
    }

    .footer-col h4::after {
        left: 0;
        transform: none;
    }

    .footer-links {
        display: grid;
        gap: 10px;
    }

    .footer-links li {
        margin-bottom: 0;
    }

    .footer-links a {
        display: block;
        padding: 10px 12px;
        border-radius: 10px;
        background: rgba(255, 255, 255, 0.04);
    }

    .footer-social {
        justify-content: flex-start;
        flex-wrap: wrap;
    }

    .footer-newsletter {
        padding: 16px;
    }

    .newsletter-form input,
    .newsletter-form button {
        width: 100%;
    }

    .footer-bottom {
        padding: 18px 16px calc(18px + env(safe-area-inset-bottom));
    }

    .footer-bottom-container {
        align-items: flex-start;
        gap: 10px;
        text-align: left;
    }
}

.scroll-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    background: #4F46E5;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(79, 70, 229, 0.3);
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all 0.3s ease;
    z-index: 1000;
    border: none;
    cursor: pointer;
}

.scroll-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.scroll-top:hover {
    background: #3B31CC;
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(79, 70, 229, 0.4);
}

.scroll-top svg {
    width: 24px;
    height: 24px;
    color: white;
}

/* Back to Home Button */
.back-to-home {
    position: fixed;
    bottom: 100px;
    left: 20px;
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 20px;
    background: linear-gradient(135deg, #4F46E5 0%, #8B5CF6 100%);
    color: white;
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    font-size: 14px;
    box-shadow: 0 4px 15px rgba(79, 70, 229, 0.4);
    z-index: 999;
    transition: all 0.3s ease;
}

.back-to-home:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(79, 70, 229, 0.5);
}

.back-to-home svg {
    width: 18px;
    height: 18px;
}

/* Mobile: smaller button */
@media (max-width: 768px) {
    .back-to-home {
        bottom: 80px;
        left: 16px;
        padding: 10px 16px;
        font-size: 13px;
    }
    
    .back-to-home span {
        display: none;
    }
    
    .back-to-home {
        width: 44px;
        height: 44px;
        padding: 0;
        justify-content: center;
        border-radius: 50%;
    }
}

.modal-overlay {
    position: fixed;
    top: 0 !important;
    left: 0 !important;
    right: 0 !important;
    bottom: 0 !important;
    width: 100% !important;
    height: 100% !important;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    display: flex !important;
    align-items: center;
    justify-content: center;
    padding: 20px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
    z-index: 99999;
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal {
    background: var(--surface-light);
    border-radius: var(--radius-xl);
    max-width: 500px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    transform: translateY(30px);
    transition: var(--transition);
}

[data-theme="dark"] .modal {
    background: var(--surface-dark);
}

.modal-overlay.active .modal {
    transform: translateY(0);
}

.modal-close {
    position: absolute;
    top: 16px;
    right: 16px;
    width: 36px;
    height: 36px;
    background: var(--bg-light);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    z-index: 10;
}

[data-theme="dark"] .modal-close {
    background: var(--bg-dark);
}

.modal-close:hover {
    background: var(--error);
    color: white;
}

.modal-close svg {
    width: 20px;
    height: 20px;
}

.modal-clear-history {
    position: absolute;
    top: 16px;
    right: 60px;
    width: 36px;
    height: 36px;
    background: var(--bg-light);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    z-index: 10;
    cursor: pointer;
    border: none;
    color: var(--text-primary);
}

[data-theme="dark"] .modal-clear-history {
    background: var(--bg-dark);
}

.modal-clear-history:hover {
    background: var(--error);
    color: white;
}

.modal-clear-history svg {
    width: 18px;
    height: 18px;
}

.modal-content {
    padding: 40px 32px 32px;
}

.modal h2 {
    font-family: var(--font-heading);
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 24px;
    text-align: center;
}

.calc-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-weight: 500;
    font-size: 0.9375rem;
}

.form-group input,
.form-group select {
    padding: 14px 16px;
    border: 2px solid var(--border-light);
    border-radius: var(--radius-md);
    background: var(--bg-light);
    color: var(--text-light);
    transition: var(--transition);
}

[data-theme="dark"] .form-group input,
[data-theme="dark"] .form-group select {
    border-color: var(--border-dark);
    background: var(--bg-dark);
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(79, 70, 229, 0.1);
}

.form-group input.error {
    border-color: var(--error);
}

.error-message {
    color: var(--error);
    font-size: 0.8125rem;
    display: none;
}

.error-message.show {
    display: block;
}

.unit-toggle {
    display: flex;
    gap: 12px;
    margin-bottom: 8px;
}

.unit-toggle-btn {
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    background: var(--bg-light);
    border: 1px solid var(--border-light);
    color: var(--text-muted);
    transition: var(--transition);
}

[data-theme="dark"] .unit-toggle-btn {
    background: var(--bg-dark);
    border-color: var(--border-dark);
}

.unit-toggle-btn.active {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

.form-row {
    display: flex;
    gap: 16px;
}

.form-row .form-group {
    flex: 1;
}

.calc-result {
    background: linear-gradient(135deg, rgba(79, 70, 229, 0.1), rgba(139, 92, 246, 0.1));
    border-radius: var(--radius-md);
    padding: 20px;
    margin-top: 8px;
    text-align: center;
    display: none;
}

[data-theme="dark"] .calc-result {
    background: linear-gradient(135deg, rgba(79, 70, 229, 0.15), rgba(139, 92, 246, 0.15));
}

.calc-result.show {
    display: block;
    animation: fadeInUp 0.4s ease-out;
}

.result-label {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-bottom: 4px;
}

.result-value {
    font-family: var(--font-heading);
    font-size: 1.75rem;
    font-weight: 700;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.result-details {
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid var(--border-light);
}

[data-theme="dark"] .result-details {
    border-top-color: var(--border-dark);
}

.result-detail-item {
    display: flex;
    justify-content: space-between;
    font-size: 0.875rem;
    padding: 4px 0;
}

.result-detail-item span:first-child {
    color: var(--text-muted);
}

.result-detail-item span:last-child {
    font-weight: 600;
}

.bmi-category {
    display: inline-block;
    padding: 4px 12px;
    border-radius: var(--radius-xl);
    font-size: 0.875rem;
    font-weight: 600;
    margin-top: 8px;
}

.bmi-category.underweight { background: #FEF3C7; color: #92400E; }
.bmi-category.normal { background: #D1FAE5; color: #065F46; }
.bmi-category.overweight { background: #FED7AA; color: #9A3412; }
.bmi-category.obese { background: #FECACA; color: #991B1B; }

.form-actions {
    display: flex;
    gap: 12px;
    margin-top: 8px;
}

.form-actions .btn {
    flex: 1;
    justify-content: center;
}

.scientific-display {
    background: #1a1a2e;
    border-radius: var(--radius-md);
    padding: 16px;
    margin-bottom: 20px;
}

.scientific-expression {
    font-family: 'Courier New', monospace;
    font-size: 1rem;
    color: rgba(255,255,255,0.7);
    text-align: right;
    min-height: 24px;
    word-break: break-all;
}

.scientific-result {
    font-family: 'Courier New', monospace;
    font-size: 2rem;
    font-weight: 700;
    color: white;
    text-align: right;
}

.scientific-buttons {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 8px;
}

.sci-btn {
    padding: 14px 8px;
    border-radius: var(--radius-sm);
    font-size: 0.9375rem;
    font-weight: 600;
    background: var(--bg-light);
    color: var(--text-light);
    border: 1px solid var(--border-light);
    transition: var(--transition);
}

[data-theme="dark"] .sci-btn {
    background: var(--bg-dark);
    border-color: var(--border-dark);
    color: var(--text-dark);
}

.sci-btn:hover {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

.sci-btn.operator {
    background: var(--gradient);
    color: white;
    border: none;
}

.sci-btn.equals {
    background: var(--success);
    color: white;
    border: none;
}

.sci-btn.equals:hover {
    background: #059669;
}

.sci-btn.clear {
    background: var(--error);
    color: white;
    border: none;
}

.sci-btn.clear:hover {
    background: #DC2626;
}

.unit-category-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 20px;
}

.unit-tab {
    padding: 8px 16px;
    border-radius: var(--radius-xl);
    font-size: 0.875rem;
    font-weight: 500;
    background: var(--bg-light);
    border: 1px solid var(--border-light);
    color: var(--text-muted);
    transition: var(--transition);
}

[data-theme="dark"] .unit-tab {
    background: var(--bg-dark);
    border-color: var(--border-dark);
}

.unit-tab.active {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

.unit-converter-form {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 16px;
    align-items: end;
}

.unit-swap {
    width: 44px;
    height: 44px;
    background: var(--gradient);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 8px;
    transition: var(--transition);
}

.unit-swap:hover {
    transform: rotate(180deg);
}

.unit-swap svg {
    width: 20px;
    height: 20px;
    color: white;
}

.unit-converter-form .form-group {
    flex: 1;
}

.unit-result-display {
    background: linear-gradient(135deg, rgba(79, 70, 229, 0.1), rgba(139, 92, 246, 0.1));
    border-radius: var(--radius-md);
    padding: 20px;
    margin-top: 16px;
    text-align: center;
}

[data-theme="dark"] .unit-result-display {
    background: linear-gradient(135deg, rgba(79, 70, 229, 0.15), rgba(139, 92, 246, 0.15));
}

@media (max-width: 1024px) {
    .hero {
        padding: 100px 5% 60px;
    }
    
    .hero-grid {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
    }
    
    .hero-content {
        order: 1;
    }
    
    .hero-visual {
        order: 2;
        margin-top: 0;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 32px;
    }
}

@media (max-width: 768px) {
    .nav {
        display: none;
    }
    
    .hamburger {
        display: flex;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-stats {
        gap: 24px;
        justify-content: center;
    }
    
    .stat-number {
        font-size: 2rem;
    }
    
    .calc-body {
        width: 220px;
        height: 280px;
    }
    
    .tools-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }
    
    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
    
    .ad-placeholder {
        width: 100%;
        max-width: 320px;
        height: 50px;
    }
    
    .form-row {
        flex-direction: column;
    }
    
    .unit-converter-form {
        grid-template-columns: 1fr;
    }
    
    .unit-swap {
        margin: 0 auto;
        transform: rotate(90deg);
    }
    
    .unit-swap:hover {
        transform: rotate(270deg);
    }
    
    .scientific-buttons {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .modal {
        max-height: 100vh;
        border-radius: var(--radius-lg) var(--radius-lg) 0 0;
        margin-top: auto;
    }
    
    .modal-overlay {
        align-items: flex-end;
        padding: 0;
    }
}

@media (max-width: 480px) {
    body {
        padding-top: 106px;
    }
    
    body.no-strip {
        padding-top: 60px;
    }
    
    .header {
        height: 60px !important;
    }
    
    .rating-strip {
        top: 60px !important;
        padding: 6px 0 !important;
    }
    
    .hero {
        padding: 15px 4% 20px;
        min-height: calc(100vh - 106px);
    }
    
    .btn {
        padding: 12px 20px;
        font-size: 0.9375rem;
    }
    
    .section-header h2 {
        font-size: 1.75rem;
    }
    
    .search-box input {
        padding: 14px 14px 14px 44px;
    }
    
    .category-filters {
        gap: 8px;
    }
    
    .filter-btn {
        padding: 8px 14px;
        font-size: 0.8125rem;
    }
    
    .tools-section,
    .about-section,
    .seo-content {
        padding: 60px 4%;
    }
}

/* ==========================================
   Expert Calculator - Loading Screen
   ========================================== */

.loader-overlay {
    position: fixed;
    inset: 0;
    background: linear-gradient(135deg, #f0f1fa 0%, #e8e6f6 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 99999;
    opacity: 1;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

.loader-overlay.hidden {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

[data-theme="dark"] .loader-overlay {
    background: linear-gradient(135deg, #0f172a 0%, #1e1b4b 100%);
}

.loader-content {
    text-align: center;
    padding: 40px;
}

.loader-logo {
    width: 80px;
    height: 80px;
    margin: 0 auto 24px;
    animation: loaderPulse 2s ease-in-out infinite;
}

.loader-logo svg {
    width: 100%;
    height: 100%;
    filter: drop-shadow(0 8px 20px rgba(79, 70, 229, 0.4));
}

@keyframes loaderPulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

.loader-title {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, #4F46E5, #8B5CF6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 24px;
}

.loader-progress {
    width: 200px;
    height: 4px;
    background: rgba(79, 70, 229, 0.2);
    border-radius: 2px;
    overflow: hidden;
    margin: 0 auto;
}

[data-theme="dark"] .loader-progress {
    background: rgba(139, 92, 246, 0.3);
}

.loader-progress-bar {
    height: 100%;
    background: linear-gradient(90deg, #4F46E5, #8B5CF6);
    border-radius: 2px;
    width: 0%;
    transition: width 0.3s ease;
    position: relative;
    overflow: hidden;
}

.loader-progress-bar::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
    animation: loaderShimmer 1.5s infinite;
}

@keyframes loaderShimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

@media (max-width: 480px) {
    .loader-content {
        padding: 30px 20px;
    }
    
    .loader-logo {
        width: 60px;
        height: 60px;
    }
    
    .loader-title {
        font-size: 1.25rem;
    }
    
    .loader-progress {
        width: 150px;
    }
}

/* ==========================================
   Assignment Row Styles
   ========================================== */

.assignment-row {
    
    .loader-tagline {
        font-size: 0.875rem;
    }
}

.assignment-row {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 10px;
    margin-bottom: 10px;
    align-items: center;
}

.assignment-row input {
    padding: 10px 12px;
    border: 2px solid var(--border-light);
    border-radius: var(--radius-sm);
    background: var(--bg-light);
    color: var(--text-light);
    font-size: 0.875rem;
    transition: var(--transition);
}

[data-theme="dark"] .assignment-row input {
    border-color: var(--border-dark);
    background: var(--bg-dark);
}

.assignment-row input:focus {
    outline: none;
    border-color: var(--primary);
}

@media (max-width: 480px) {
    .assignment-row {
        grid-template-columns: 1fr;
    }
}

.tip-presets {
    display: flex;
    gap: 8px;
    margin-bottom: 12px;
    flex-wrap: wrap;
}

.tip-btn {
    padding: 8px 16px;
    border-radius: var(--radius-xl);
    font-size: 0.875rem;
    font-weight: 500;
    background: var(--bg-light);
    border: 1px solid var(--border-light);
    color: var(--text-muted);
    transition: var(--transition);
}

[data-theme="dark"] .tip-btn {
    background: var(--bg-dark);
    border-color: var(--border-dark);
}

.tip-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.tip-btn.active {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

.range-value {
    display: inline-block;
    margin-left: 12px;
    font-weight: 600;
    color: var(--primary);
}

.password-options {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
    margin-bottom: 20px;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    padding: 10px;
    background: var(--bg-light);
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-light);
    transition: var(--transition);
}

[data-theme="dark"] .checkbox-label {
    background: var(--bg-dark);
    border-color: var(--border-dark);
}

.checkbox-label:hover {
    border-color: var(--primary);
}

.checkbox-label input {
    width: 18px;
    height: 18px;
    accent-color: var(--primary);
}

.password-result {
    display: flex;
    gap: 10px;
    margin-top: 20px;
}

.password-result input {
    flex: 1;
    padding: 14px 16px;
    border: 2px solid var(--border-light);
    border-radius: var(--radius-md);
    background: var(--bg-light);
    color: var(--text-light);
    font-family: 'Courier New', monospace;
    font-size: 1rem;
}

[data-theme="dark"] .password-result input {
    border-color: var(--border-dark);
    background: var(--bg-dark);
}

.btn-copy {
    width: 50px;
    height: 50px;
    background: var(--gradient);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    flex-shrink: 0;
}

.btn-copy:hover {
    transform: scale(1.05);
}

.btn-copy.copied {
    background: var(--success);
}

.btn-copy svg {
    width: 22px;
    height: 22px;
    color: white;
}

.password-strength {
    margin-top: 16px;
}

.strength-bar {
    height: 6px;
    border-radius: 10px;
    background: var(--border-light);
    margin-bottom: 8px;
    transition: var(--transition);
}

.strength-bar.weak { background: var(--error); width: 30%; }
.strength-bar.medium { background: var(--warning); width: 60%; }
.strength-bar.strong { background: #22c55e; width: 80%; }
.strength-bar.very-strong { background: var(--success); width: 100%; }

.strength-text {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-muted);
}

@media (max-width: 480px) {
    .password-options {
        grid-template-columns: 1fr;
    }
    
    .tip-presets {
        justify-content: center;
    }
}

/* Tool Page Styles */
.tool-page {
    padding: 40px 20px 60px;
    min-height: calc(100vh - 200px);
}

.tool-page-container {
    max-width: 1200px;
    margin: 0 auto;
}

.tool-page-header {
    text-align: center;
    margin-bottom: 40px;
}

.breadcrumb {
    display: none;
}

.breadcrumb a {
    color: var(--primary);
    text-decoration: none;
    transition: var(--transition);
}

.breadcrumb a:hover {
    color: var(--primary-dark);
}

.breadcrumb-separator {
    color: var(--text-muted);
}

.tool-page-title {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.tool-page-description {
    font-size: 1.125rem;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.6;
}

.tool-page-content {
    display: grid;
    grid-template-columns: 1fr 320px;
    gap: 32px;
    margin-bottom: 48px;
}

.tool-form-section {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 32px;
    box-shadow: var(--shadow);
}

.tool-info-sidebar {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.info-card {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 24px;
    box-shadow: var(--shadow);
}

.info-card h3 {
    font-family: var(--font-heading);
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.info-card ol, .info-card ul {
    margin: 0;
    padding-left: 20px;
}

.info-card li {
    margin-bottom: 8px;
    color: var(--text-muted);
    line-height: 1.5;
}

.info-card li:last-child {
    margin-bottom: 0;
}

.related-tools {
    margin-top: 48px;
    padding-top: 48px;
    border-top: 1px solid var(--border);
}

.related-tools h2 {
    font-family: var(--font-heading);
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    text-align: center;
    margin-bottom: 32px;
}

.related-tools-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.related-tool-card {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 24px;
    text-decoration: none;
    transition: var(--transition);
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.related-tool-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.1);
}

.related-tool-icon {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
}

.related-tool-icon svg {
    width: 28px;
    height: 28px;
    color: white;
}

.related-tool-card h3 {
    font-family: var(--font-heading);
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.related-tool-card p {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin: 0;
}

@media (max-width: 1024px) {
    .tool-page-content {
        grid-template-columns: 1fr;
    }
    
    .tool-info-sidebar {
        flex-direction: row;
        flex-wrap: wrap;
    }
    
    .info-card {
        flex: 1;
        min-width: 280px;
    }
    
    .related-tools-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 640px) {
    .tool-page {
        padding: 24px 16px 40px;
    }
    
    .tool-page-title {
        font-size: 1.75rem;
    }
    
    .tool-page-description {
        font-size: 1rem;
    }
    
    .tool-form-section {
        padding: 24px 20px;
    }
    
    .info-card {
        min-width: 100%;
    }
    
    .related-tools-grid {
        grid-template-columns: 1fr;
    }
}

/* Content Sections & SEO Content */
.content-section {
    margin-top: 48px;
    padding-top: 48px;
    border-top: 1px solid var(--border);
}

.content-section h2 {
    font-family: var(--font-heading);
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.content-section h3 {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-top: 32px;
    margin-bottom: 12px;
}

.content-section h4 {
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.content-section p {
    color: var(--text-muted);
    line-height: 1.7;
    margin-bottom: 16px;
}

.content-section ul {
    margin-bottom: 16px;
    padding-left: 24px;
}

.content-section li {
    color: var(--text-muted);
    line-height: 1.6;
    margin-bottom: 8px;
}

.formula-box {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 20px;
    border-left: 4px solid var(--primary);
    box-shadow: var(--shadow);
}

.formula-box h4 {
    color: var(--primary);
    margin-bottom: 12px;
}

.formula-box .formula {
    font-family: 'Courier New', monospace;
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    background: var(--bg-light);
    padding: 12px 16px;
    border-radius: 8px;
    margin-bottom: 12px;
}

.formula-box p {
    margin-bottom: 0;
    font-size: 0.875rem;
}

.faq-section {
    margin-top: 24px;
}

.faq-item {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 16px;
    box-shadow: var(--shadow);
}

.faq-item h4 {
    color: var(--text-primary);
    margin-bottom: 8px;
}

.faq-item p {
    margin-bottom: 0;
    font-size: 0.9375rem;
}

/* GST Presets */
.gst-presets {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 16px;
}

.gst-btn {
    padding: 8px 14px;
    border: 2px solid var(--border);
    border-radius: 8px;
    background: var(--card-bg);
    color: var(--text-primary);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.gst-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.gst-btn.active {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

/* User Auth Styles */
.user-nav-item {
    display: flex;
    align-items: center;
    padding: 4px !important;
}

.user-avatar,
.user-avatar-placeholder {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    object-fit: cover;
}

.user-avatar-placeholder {
    background: var(--primary);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 14px;
}

.tool-rating-section {
    background: var(--card-bg);
    padding: 40px 5%;
    margin-top: 40px;
    border-top: 1px solid var(--border-light);
}

.tool-rating-section h2 {
    text-align: center;
    margin-bottom: 24px;
    font-size: 1.5rem;
}

.tool-rating-section h3 {
    font-size: 1.1rem;
    margin-bottom: 16px;
    color: var(--text-muted);
}

.rating-container {
    max-width: 500px;
    margin: 0 auto 30px;
    text-align: center;
}

.stars-display {
    font-size: 2.5rem;
    margin-bottom: 12px;
}

.stars-display .star {
    color: #fbbf24;
    cursor: default;
}

.rating-text {
    font-size: 1.1rem;
    color: var(--text-muted);
}

.rating-input {
    margin-top: 20px;
}

.login-prompt-rating {
    color: var(--text-muted);
}

.login-prompt-rating a {
    color: var(--primary);
    font-weight: 600;
}

.rating-interactive {
    display: flex;
    justify-content: center;
    gap: 8px;
}

.rating-interactive .star {
    font-size: 2rem;
    cursor: pointer;
    color: #d1d5db;
    transition: color 0.2s, transform 0.2s;
}

.rating-interactive .star:hover,
.rating-interactive .star.active {
    color: #fbbf24;
    transform: scale(1.1);
}

.rating-submit-btn {
    margin-top: 16px;
    padding: 10px 24px;
}

.top-ratings {
    max-width: 600px;
    margin: 0 auto;
    padding-top: 30px;
    border-top: 1px solid var(--border-light);
}

.top-ratings h3 {
    text-align: center;
    margin-bottom: 20px;
}

.ratings-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.rating-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px;
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
}

.rating-item .stars {
    color: #fbbfbf24;
    font-size: 0.9rem;
}

.rating-item .rating-comment {
    flex: 1;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.rating-item .rating-date {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.rating-popup {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.6);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.rating-popup.show {
    opacity: 1;
    visibility: visible;
}

.rating-popup-content {
    background: white;
    border-radius: 20px;
    padding: 40px;
    max-width: 420px;
    width: 90%;
    text-align: center;
    transform: scale(0.8);
    transition: transform 0.3s ease;
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.3);
}

.rating-popup.show .rating-popup-content {
    transform: scale(1);
}

.rating-popup h2 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.rating-popup p {
    color: var(--text-muted);
    margin-bottom: 20px;
}

.rating-popup .stars-popup {
    font-size: 2.5rem;
    margin-bottom: 20px;
    cursor: pointer;
}

.rating-popup .stars-popup span {
    color: #d1d5db;
    transition: color 0.2s;
    margin: 0 3px;
}

.rating-popup .stars-popup span:hover,
.rating-popup .stars-popup span.active {
    color: #fbbf24;
}

.rating-popup input[type="text"] {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--border-light);
    border-radius: var(--radius-md);
    font-size: 1rem;
    margin-bottom: 16px;
    box-sizing: border-box;
}

.rating-popup input[type="text"]:focus {
    outline: none;
    border-color: var(--primary);
}

.rating-popup .btn-group {
    display: flex;
    gap: 12px;
    justify-content: center;
}

.rating-popup .btn-skip {
    background: transparent;
    color: var(--text-muted);
    border: 2px solid var(--border-light);
    padding: 12px 24px;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition);
}

.rating-popup .btn-skip:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.rating-popup .fake-ratings {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--border-light);
}

.rating-popup .fake-ratings p {
    font-size: 0.9rem;
    margin-bottom: 8px;
    color: var(--text-muted);
}

.rating-popup .fake-rating-item {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 8px;
    font-size: 0.9rem;
}

.rating-popup .fake-rating-item .avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--gradient);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.8rem;
}

.rating-popup .fake-rating-item .stars {
    color: #fbbf24;
    font-size: 0.85rem;
}

@media (max-width: 480px) {
    .rating-popup-content {
        padding: 30px 20px;
    }
    
    .rating-popup h2 {
        font-size: 1.25rem;
    }
    
    .rating-popup .btn-group {
        flex-direction: column;
    }
    
    .rating-strip {
        top: 60px;
        padding: 6px 0;
    }
    
    .rating-strip-item {
        font-size: 0.7rem;
        margin: 0 20px;
    }
    
    .rating-strip-item .avatar {
        width: 20px;
        height: 20px;
        font-size: 0.6rem;
    }
    
    body {
        padding-top: 106px;
    }
    
    .header {
        height: 60px;
    }
}

@media (max-width: 768px) {
    .footer {
        padding: 40px 4% 20px;
    }
    
    .footer-bottom {
        padding-top: 20px;
        margin-top: 20px;
    }
}

.no-ratings {
    text-align: center;
    color: var(--text-muted);
    padding: 20px;
}