/* ScanStudy - Modern Educational Platform */
/* Design System: Indigo Ink with Academic Focus */

:root {
    /* Primary Colors - Indigo Ink Palette */
    --color-bg-primary: #1B0A3C;
    --color-bg-secondary: #3D1E7C;
    --color-bg-tertiary: #2A1A5E;
    --color-accent: #7B68EE;
    --color-accent-light: #9B8AF5;
    --color-text-primary: #E8E0F0;
    --color-text-secondary: #B8A8D8;
    --color-text-muted: #8B7CB8;
    
    /* Supporting Colors */
    --color-success: #4ADE80;
    --color-warning: #FBBF24;
    --color-error: #F87171;
    --color-info: #60A5FA;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #7B68EE 0%, #9B8AF5 100%);
    --gradient-hero: linear-gradient(160deg, #1B0A3C 0%, #3D1E7C 50%, #2A1A5E 100%);
    --gradient-card: linear-gradient(145deg, rgba(123, 104, 238, 0.1) 0%, rgba(61, 30, 124, 0.2) 100%);
    
    /* Typography */
    --font-display: 'DM Serif Display', serif;
    --font-body: 'Plus Jakarta Sans', sans-serif;
    
    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2rem;
    --space-xl: 3rem;
    --space-2xl: 4rem;
    --space-3xl: 6rem;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(123, 104, 238, 0.15);
    --shadow-md: 0 4px 20px rgba(123, 104, 238, 0.25);
    --shadow-lg: 0 8px 40px rgba(123, 104, 238, 0.35);
    --shadow-glow: 0 0 60px rgba(123, 104, 238, 0.4);
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* Reset & Base */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    background: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
}

/* Noise Texture Overlay */
.noise-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1000;
    opacity: 0.03;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-md) var(--space-xl);
    background: rgba(27, 10, 60, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(123, 104, 238, 0.1);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    font-family: var(--font-display);
    font-size: 1.5rem;
    color: var(--color-text-primary);
}

.logo-icon {
    color: var(--color-accent);
    font-size: 1.75rem;
}

.logo-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav {
    display: flex;
    gap: var(--space-lg);
}

.nav-link {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: var(--transition-fast);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: var(--transition-fast);
}

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

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

/* Hero Section */
.hero {
    min-height: 100vh;
    display: grid;
    grid-template-columns: 1fr 1fr;
    align-items: center;
    gap: var(--space-3xl);
    padding: calc(var(--space-3xl) + 80px) var(--space-xl) var(--space-3xl);
    background: var(--gradient-hero);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 800px;
    height: 800px;
    background: radial-gradient(circle, rgba(123, 104, 238, 0.15) 0%, transparent 70%);
    border-radius: 50%;
    animation: pulse-glow 8s ease-in-out infinite;
}

@keyframes pulse-glow {
    0%, 100% { transform: scale(1); opacity: 0.5; }
    50% { transform: scale(1.1); opacity: 0.8; }
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 600px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-xs) var(--space-md);
    background: rgba(123, 104, 238, 0.15);
    border: 1px solid rgba(123, 104, 238, 0.3);
    border-radius: var(--radius-xl);
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--color-accent-light);
    margin-bottom: var(--space-lg);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.badge-dot {
    width: 8px;
    height: 8px;
    background: var(--color-accent);
    border-radius: 50%;
    animation: pulse-dot 2s ease-in-out infinite;
}

@keyframes pulse-dot {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.5; transform: scale(0.8); }
}

.hero-title {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, 5vw, 4rem);
    line-height: 1.1;
    margin-bottom: var(--space-md);
    color: var(--color-text-primary);
}

.title-accent {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-xl);
    line-height: 1.7;
}

.hero-actions {
    display: flex;
    gap: var(--space-md);
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-lg);
    font-family: var(--font-body);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-normal);
    border: none;
    text-decoration: none;
}

.btn-icon {
    font-size: 1.2rem;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: transparent;
    color: var(--color-text-primary);
    border: 2px solid rgba(123, 104, 238, 0.5);
}

.btn-secondary:hover {
    background: rgba(123, 104, 238, 0.1);
    border-color: var(--color-accent);
}

.btn-camera {
    background: rgba(123, 104, 238, 0.2);
    color: var(--color-text-primary);
    border: 1px solid rgba(123, 104, 238, 0.3);
    padding: var(--space-sm) var(--space-md);
    font-size: 0.9rem;
}

.btn-camera:hover {
    background: rgba(123, 104, 238, 0.3);
}

.btn-capture {
    background: var(--color-accent);
    color: white;
    padding: var(--space-md) var(--space-xl);
    font-size: 1.1rem;
}

.btn-capture:hover {
    background: var(--color-accent-light);
}

.btn-cancel {
    background: rgba(248, 113, 113, 0.2);
    color: var(--color-error);
    border: 1px solid var(--color-error);
}

.btn-cancel:hover {
    background: rgba(248, 113, 113, 0.3);
}

/* Hero Visual */
.hero-visual {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.scan-frame {
    position: relative;
    width: 400px;
    height: 300px;
    background: rgba(61, 30, 124, 0.3);
    border: 2px solid rgba(123, 104, 238, 0.5);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-glow);
}

.scan-line {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--gradient-primary);
    box-shadow: 0 0 20px var(--color-accent);
    animation: scan 2s ease-in-out infinite;
    z-index: 10;
}

@keyframes scan {
    0% { top: 0; opacity: 0; }
    10% { opacity: 1; }
    90% { opacity: 1; }
    100% { top: 100%; opacity: 0; }
}

.scan-corner {
    position: absolute;
    width: 30px;
    height: 30px;
    border: 3px solid var(--color-accent);
}

.scan-corner.tl { top: -2px; left: -2px; border-right: none; border-bottom: none; }
.scan-corner.tr { top: -2px; right: -2px; border-left: none; border-bottom: none; }
.scan-corner.bl { bottom: -2px; left: -2px; border-right: none; border-top: none; }
.scan-corner.br { bottom: -2px; right: -2px; border-left: none; border-top: none; }

.scan-content {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100%;
    padding: var(--space-lg);
}

.math-equation {
    font-family: 'Times New Roman', serif;
    font-size: 2rem;
    color: var(--color-text-primary);
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    flex-wrap: wrap;
    justify-content: center;
}

.eq-part {
    opacity: 0;
    animation: fade-in-up 0.5s ease forwards;
}

.eq-part:nth-child(1) { animation-delay: 0.1s; }
.eq-part:nth-child(2) { animation-delay: 0.2s; }
.eq-part:nth-child(3) { animation-delay: 0.3s; }
.eq-part:nth-child(4) { animation-delay: 0.4s; }
.eq-part:nth-child(5) { animation-delay: 0.5s; }
.eq-part:nth-child(6) { animation-delay: 0.6s; }
.eq-part:nth-child(7) { animation-delay: 0.7s; }

@keyframes fade-in-up {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.floating-card {
    position: absolute;
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-md);
    background: rgba(27, 10, 60, 0.9);
    border: 1px solid rgba(123, 104, 238, 0.3);
    border-radius: var(--radius-md);
    backdrop-filter: blur(10px);
    animation: float 6s ease-in-out infinite;
}

.card-1 {
    top: 10%;
    right: -20px;
    animation-delay: 0s;
}

.card-2 {
    bottom: 20%;
    left: -40px;
    animation-delay: 3s;
}

.card-icon {
    font-size: 1.2rem;
}

.card-text {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--color-text-primary);
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-15px); }
}

/* Scanner Section */
.scanner-section {
    padding: var(--space-3xl) var(--space-xl);
    background: var(--color-bg-primary);
}

.scanner-container {
    max-width: 800px;
    margin: 0 auto;
}

.scanner-header {
    text-align: center;
    margin-bottom: var(--space-2xl);
}

.scanner-header h2 {
    font-family: var(--font-display);
    font-size: 2.5rem;
    margin-bottom: var(--space-sm);
    color: var(--color-text-primary);
}

.scanner-header p {
    color: var(--color-text-secondary);
    font-size: 1.1rem;
}

.scanner-interface {
    background: var(--gradient-card);
    border: 1px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    position: relative;
}

.upload-zone {
    border: 2px dashed rgba(123, 104, 238, 0.4);
    border-radius: var(--radius-lg);
    padding: var(--space-3xl);
    text-align: center;
    cursor: pointer;
    transition: var(--transition-normal);
}

.upload-zone:hover {
    border-color: var(--color-accent);
    background: rgba(123, 104, 238, 0.05);
}

.upload-icon {
    color: var(--color-accent);
    margin-bottom: var(--space-md);
}

.upload-text {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--space-xs);
}

.upload-subtext {
    color: var(--color-text-muted);
    margin-bottom: var(--space-lg);
}

.camera-preview {
    position: relative;
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.camera-preview video {
    width: 100%;
    height: auto;
    display: block;
    border-radius: var(--radius-lg);
}

.camera-controls {
    display: flex;
    justify-content: center;
    gap: var(--space-md);
    margin-top: var(--space-lg);
}

.preview-area {
    text-align: center;
}

.preview-area img {
    max-width: 100%;
    border-radius: var(--radius-lg);
    margin-bottom: var(--space-lg);
}

.preview-actions {
    display: flex;
    justify-content: center;
    gap: var(--space-md);
}

/* Text Input Area */
.text-input-area {
    background: var(--color-bg-secondary);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    margin-top: var(--space-xl);
}

.input-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-md);
}

.input-header h3 {
    font-family: var(--font-display);
    font-size: 1.5rem;
}

.btn-close {
    background: none;
    border: none;
    color: var(--color-text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    transition: var(--transition-fast);
}

.btn-close:hover {
    color: var(--color-text-primary);
}

#questionInput {
    width: 100%;
    min-height: 120px;
    padding: var(--space-md);
    background: rgba(27, 10, 60, 0.5);
    border: 1px solid rgba(123, 104, 238, 0.3);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    font-family: var(--font-body);
    font-size: 1rem;
    resize: vertical;
    margin-bottom: var(--space-md);
}

#questionInput:focus {
    outline: none;
    border-color: var(--color-accent);
}

.input-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--space-md);
    flex-wrap: wrap;
}

.subject-select {
    padding: var(--space-sm) var(--space-md);
    background: rgba(27, 10, 60, 0.5);
    border: 1px solid rgba(123, 104, 238, 0.3);
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    font-family: var(--font-body);
    font-size: 0.95rem;
    cursor: pointer;
}

.subject-select:focus {
    outline: none;
    border-color: var(--color-accent);
}

/* Result Section */
.result-section {
    padding: var(--space-3xl) var(--space-xl);
    background: var(--color-bg-primary);
}

.result-container {
    max-width: 900px;
    margin: 0 auto;
}

.result-header {
    text-align: center;
    margin-bottom: var(--space-2xl);
}

.subject-badge {
    display: inline-block;
    padding: var(--space-xs) var(--space-md);
    background: var(--gradient-primary);
    border-radius: var(--radius-xl);
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--space-md);
}

.result-header h2 {
    font-family: var(--font-display);
    font-size: 2.5rem;
    color: var(--color-text-primary);
}

.result-content {
    background: var(--gradient-card);
    border: 1px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    margin-bottom: var(--space-xl);
}

.question-display, .answer-display, .steps-display, .related-questions {
    margin-bottom: var(--space-xl);
}

.question-display h3, .answer-display h3, .steps-display h3, .related-questions h3 {
    font-family: var(--font-display);
    font-size: 1.3rem;
    margin-bottom: var(--space-md);
    color: var(--color-accent-light);
}

.question-display p {
    font-size: 1.1rem;
    color: var(--color-text-primary);
    padding: var(--space-md);
    background: rgba(27, 10, 60, 0.5);
    border-radius: var(--radius-md);
    border-left: 3px solid var(--color-accent);
}

#answerContent {
    font-size: 1.2rem;
    color: var(--color-text-primary);
    padding: var(--space-lg);
    background: rgba(74, 222, 128, 0.1);
    border: 1px solid rgba(74, 222, 128, 0.3);
    border-radius: var(--radius-md);
}

.step-item {
    display: flex;
    gap: var(--space-md);
    margin-bottom: var(--space-md);
    padding: var(--space-md);
    background: rgba(27, 10, 60, 0.3);
    border-radius: var(--radius-md);
}

.step-number {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    border-radius: 50%;
    font-weight: 700;
    font-size: 0.9rem;
    flex-shrink: 0;
}

.step-content {
    color: var(--color-text-secondary);
    line-height: 1.7;
}

.related-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-md);
}

.related-card {
    padding: var(--space-md);
    background: rgba(27, 10, 60, 0.5);
    border: 1px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition-normal);
}

.related-card:hover {
    border-color: var(--color-accent);
    transform: translateY(-2px);
}

.related-card h4 {
    font-size: 0.95rem;
    color: var(--color-text-primary);
    margin-bottom: var(--space-xs);
}

.related-card p {
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

.result-actions {
    display: flex;
    justify-content: center;
    gap: var(--space-md);
}

/* Features Section */
.features {
    padding: var(--space-3xl) var(--space-xl);
    background: var(--color-bg-secondary);
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-2xl);
}

.section-label {
    display: inline-block;
    padding: var(--space-xs) var(--space-md);
    background: rgba(123, 104, 238, 0.15);
    border: 1px solid rgba(123, 104, 238, 0.3);
    border-radius: var(--radius-xl);
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-accent-light);
    margin-bottom: var(--space-md);
}

.section-header h2 {
    font-family: var(--font-display);
    font-size: 2.5rem;
    color: var(--color-text-primary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-lg);
    max-width: 1200px;
    margin: 0 auto;
}

.feature-card {
    padding: var(--space-xl);
    background: var(--gradient-card);
    border: 1px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-xl);
    transition: var(--transition-normal);
}

.feature-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-accent);
    box-shadow: var(--shadow-md);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: var(--space-md);
}

.feature-card h3 {
    font-family: var(--font-display);
    font-size: 1.3rem;
    margin-bottom: var(--space-sm);
    color: var(--color-text-primary);
}

.feature-card p {
    color: var(--color-text-secondary);
    line-height: 1.6;
}

/* Subjects Section */
.subjects {
    padding: var(--space-3xl) var(--space-xl);
    background: var(--color-bg-primary);
}

.subjects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-lg);
    max-width: 1200px;
    margin: 0 auto;
}

.subject-card {
    padding: var(--space-xl);
    background: var(--gradient-card);
    border: 1px solid rgba(123, 104, 238, 0.2);
    border-radius: var(--radius-xl);
    text-align: center;
    cursor: pointer;
    transition: var(--transition-normal);
}

.subject-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-accent);
    box-shadow: var(--shadow-md);
}

.subject-icon {
    font-size: 3rem;
    margin-bottom: var(--space-md);
}

.subject-card h3 {
    font-family: var(--font-display);
    font-size: 1.3rem;
    margin-bottom: var(--space-xs);
    color: var(--color-text-primary);
}

.subject-card p {
    color: var(--color-text-muted);
    font-size: 0.9rem;
}

/* Stats Section */
.stats {
    padding: var(--space-3xl) var(--space-xl);
    background: var(--color-bg-secondary);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-xl);
    max-width: 1000px;
    margin: 0 auto;
    text-align: center;
}

.stat-item {
    padding: var(--space-lg);
}

.stat-number {
    display: block;
    font-family: var(--font-display);
    font-size: 3rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--space-xs);
}

.stat-label {
    color: var(--color-text-secondary);
    font-size: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Footer */
.footer {
    padding: var(--space-3xl) var(--space-xl) var(--space-xl);
    background: var(--color-bg-primary);
    border-top: 1px solid rgba(123, 104, 238, 0.1);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr repeat(3, 1fr);
    gap: var(--space-2xl);
    max-width: 1200px;
    margin: 0 auto var(--space-2xl);
}

.footer-brand p {
    color: var(--color-text-secondary);
    margin-top: var(--space-md);
    line-height: 1.6;
}

.footer-column h4 {
    font-family: var(--font-display);
    font-size: 1.1rem;
    margin-bottom: var(--space-md);
    color: var(--color-text-primary);
}

.footer-column a {
    display: block;
    color: var(--color-text-secondary);
    text-decoration: none;
    margin-bottom: var(--space-sm);
    transition: var(--transition-fast);
}

.footer-column a:hover {
    color: var(--color-accent-light);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--space-xl);
    border-top: 1px solid rgba(123, 104, 238, 0.1);
}

.footer-bottom p {
    color: var(--color-text-muted);
    font-size: 0.9rem;
}

/* Scanning Overlay */
.scanning-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(27, 10, 60, 0.95);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.scanning-animation {
    text-align: center;
}

.scanner-laser {
    width: 200px;
    height: 4px;
    background: var(--gradient-primary);
    margin: 0 auto var(--space-lg);
    border-radius: 2px;
    box-shadow: 0 0 20px var(--color-accent);
    animation: laser-scan 1.5s ease-in-out infinite;
}

@keyframes laser-scan {
    0%, 100% { transform: scaleX(0.5); opacity: 0.5; }
    50% { transform: scaleX(1); opacity: 1; }
}

.scanning-text {
    font-size: 1.2rem;
    color: var(--color-text-primary);
    animation: pulse-text 1.5s ease-in-out infinite;
}

@keyframes pulse-text {
    0%, 100% { opacity: 0.6; }
    50% { opacity: 1; }
}

/* Responsive Design */
@media (max-width: 968px) {
    .hero {
        grid-template-columns: 1fr;
        text-align: center;
        padding-top: calc(var(--space-2xl) + 80px);
    }
    
    .hero-content {
        max-width: 100%;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .hero-visual {
        order: -1;
    }
    
    .scan-frame {
        width: 300px;
        height: 225px;
    }
    
    .math-equation {
        font-size: 1.5rem;
    }
    
    .floating-card {
        display: none;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

@media (max-width: 640px) {
    .header {
        padding: var(--space-sm) var(--space-md);
    }
    
    .nav {
        display: none;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
    
    .features-grid,
    .subjects-grid {
        grid-template-columns: 1fr;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .input-actions {
        flex-direction: column;
    }
    
    .subject-select {
        width: 100%;
    }
}