/* ========================================
   DailyHangeul - Modern Landing Page CSS
   ======================================== */

:root {
    /* Colors */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #f97316;
    --accent: #10b981;

    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;

    --white: #ffffff;
    --black: #000000;

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    --gradient-secondary: linear-gradient(135deg, #f97316 0%, #fb923c 100%);
    --gradient-accent: linear-gradient(135deg, #10b981 0%, #34d399 100%);
    --gradient-hero: linear-gradient(135deg, #667eea 0%, #764ba2 100%);

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

    /* Spacing */
    --container-max: 1200px;
    --section-padding: 100px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: 16px;
    line-height: 1.6;
    color: var(--gray-700);
    background: var(--white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a {
    color: inherit;
    text-decoration: none;
    transition: color 0.2s ease;
}

img {
    max-width: 100%;
    height: auto;
}

ul, ol {
    list-style: none;
}

.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
}

/* ========================================
   Navigation
   ======================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 20px 0;
    transition: all 0.3s ease;
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    box-shadow: var(--shadow-md);
    padding: 16px 0;
}

.nav-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--gray-900);
}

.logo-img {
    width: 40px;
    height: 40px;
    border-radius: 12px;
    object-fit: cover;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-links a {
    font-weight: 500;
    color: var(--gray-600);
    transition: color 0.2s ease;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--primary);
}

.nav-cta {
    background: var(--gradient-primary);
    color: var(--white) !important;
    padding: 10px 24px;
    border-radius: 100px;
    font-weight: 600;
}

.nav-cta:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

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

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--gray-700);
    border-radius: 2px;
    transition: all 0.3s ease;
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 100px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: -1;
}

.hero-gradient {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, #f5f3ff 0%, #ede9fe 50%, #fdf4ff 100%);
}

.hero-pattern {
    position: absolute;
    inset: 0;
    background-image: radial-gradient(circle at 1px 1px, var(--gray-200) 1px, transparent 0);
    background-size: 40px 40px;
    opacity: 0.5;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--white);
    padding: 8px 16px;
    border-radius: 100px;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--primary);
    box-shadow: var(--shadow-md);
    margin-bottom: 24px;
}

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

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.hero-title {
    font-size: 3.75rem;
    font-weight: 800;
    line-height: 1.1;
    color: var(--gray-900);
    margin-bottom: 24px;
    letter-spacing: -0.02em;
}

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

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--gray-600);
    margin-bottom: 32px;
    max-width: 520px;
    line-height: 1.7;
}

.hero-cta {
    display: flex;
    gap: 16px;
    margin-bottom: 48px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 14px 28px;
    border-radius: 14px;
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.2s ease;
    cursor: pointer;
    border: none;
}

.btn-lg {
    padding: 16px 32px;
    font-size: 1.0625rem;
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--white);
    box-shadow: 0 4px 14px rgba(99, 102, 241, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.5);
}

.btn-secondary {
    background: var(--white);
    color: var(--gray-700);
    border: 2px solid var(--gray-200);
}

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

.hero-stats {
    display: flex;
    align-items: center;
    gap: 32px;
}

.stat {
    text-align: left;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 800;
    color: var(--gray-900);
}

.stat-label {
    font-size: 0.875rem;
    color: var(--gray-500);
}

.stat-divider {
    width: 1px;
    height: 48px;
    background: var(--gray-200);
}

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

.phone-mockup {
    position: relative;
    width: 320px;
    background: var(--gray-900);
    border-radius: 40px;
    padding: 12px;
    box-shadow: var(--shadow-2xl);
}

.phone-screen {
    background: var(--white);
    border-radius: 32px;
    overflow: hidden;
}

.app-preview {
    padding: 24px 20px;
}

.app-header {
    margin-bottom: 24px;
}

.app-greeting {
    display: block;
    font-size: 0.875rem;
    color: var(--gray-500);
}

.app-date {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--gray-900);
}

.word-card {
    background: linear-gradient(135deg, #f5f3ff 0%, #ede9fe 100%);
    border-radius: 20px;
    padding: 24px;
    text-align: center;
    margin-bottom: 20px;
}

.word-korean {
    font-size: 2rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 8px;
}

.word-romanization {
    font-size: 0.875rem;
    color: var(--gray-500);
    margin-bottom: 4px;
}

.word-english {
    font-size: 1rem;
    color: var(--gray-600);
    margin-bottom: 16px;
}

.word-actions {
    display: flex;
    justify-content: center;
    gap: 12px;
}

.action-btn {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    border: none;
    font-size: 1.25rem;
    cursor: pointer;
    transition: transform 0.2s ease;
}

.action-btn.listen {
    background: var(--white);
    box-shadow: var(--shadow-md);
}

.action-btn.speak {
    background: var(--gradient-primary);
}

.action-btn:hover {
    transform: scale(1.1);
}

.score-display {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px;
    background: var(--white);
    border-radius: 16px;
    box-shadow: var(--shadow-sm);
}

.score-circle {
    width: 56px;
    height: 56px;
    background: var(--gradient-accent);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.score-value {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--white);
}

.score-label {
    font-weight: 600;
    color: var(--accent);
}

.floating-card {
    position: absolute;
    background: var(--white);
    padding: 12px 20px;
    border-radius: 16px;
    box-shadow: var(--shadow-xl);
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
    font-size: 0.875rem;
    animation: float 3s ease-in-out infinite;
}

.floating-card .card-emoji {
    font-size: 1.25rem;
}

.card-1 {
    top: 15%;
    left: -20%;
    animation-delay: 0s;
}

.card-2 {
    bottom: 20%;
    right: -15%;
    animation-delay: 1.5s;
}

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

/* ========================================
   Features Section
   ======================================== */
.features {
    padding: var(--section-padding) 0;
    background: var(--white);
}

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 60px;
}

.section-tag {
    display: inline-block;
    background: var(--gradient-primary);
    color: var(--white);
    padding: 6px 16px;
    border-radius: 100px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 16px;
}

.section-title {
    font-size: 2.75rem;
    font-weight: 800;
    color: var(--gray-900);
    margin-bottom: 16px;
    letter-spacing: -0.02em;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--gray-500);
    line-height: 1.7;
}

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

.feature-card {
    background: var(--gray-50);
    border-radius: 24px;
    padding: 32px;
    transition: all 0.3s ease;
}

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

.feature-card.feature-main {
    grid-column: span 2;
    background: linear-gradient(135deg, #f5f3ff 0%, #ede9fe 100%);
}

.feature-icon {
    width: 56px;
    height: 56px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.icon-ai { background: var(--gradient-primary); color: var(--white); }
.icon-daily { background: var(--gradient-secondary); color: var(--white); }
.icon-scenarios { background: var(--gradient-accent); color: var(--white); }
.icon-tutor { background: linear-gradient(135deg, #ec4899 0%, #f472b6 100%); color: var(--white); }
.icon-progress { background: linear-gradient(135deg, #3b82f6 0%, #60a5fa 100%); color: var(--white); }
.icon-levels { background: linear-gradient(135deg, #f59e0b 0%, #fbbf24 100%); color: var(--white); }

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 12px;
}

.feature-card p {
    color: var(--gray-600);
    line-height: 1.6;
}

.feature-preview {
    margin-top: 24px;
}

.ai-feedback {
    background: var(--white);
    border-radius: 16px;
    padding: 16px;
    box-shadow: var(--shadow-md);
}

.feedback-header {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
    font-weight: 600;
    font-size: 0.875rem;
    color: var(--gray-700);
}

.ai-avatar {
    font-size: 1.25rem;
}

.ai-feedback p {
    font-size: 0.9375rem;
    font-style: italic;
}

/* ========================================
   How It Works Section
   ======================================== */
.how-it-works {
    padding: var(--section-padding) 0;
    background: var(--gray-50);
}

.steps {
    display: flex;
    flex-direction: column;
    gap: 32px;
    max-width: 800px;
    margin: 0 auto;
}

.step {
    display: grid;
    grid-template-columns: auto 1fr auto;
    gap: 32px;
    align-items: center;
    background: var(--white);
    padding: 32px;
    border-radius: 24px;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
}

.step:hover {
    transform: translateX(8px);
    box-shadow: var(--shadow-xl);
}

.step-number {
    font-size: 3rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.step-content h3 {
    font-size: 1.375rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 8px;
}

.step-content p {
    color: var(--gray-600);
}

.step-visual {
    width: 80px;
    height: 80px;
    background: var(--gray-100);
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.step-icon {
    font-size: 2rem;
}

/* ========================================
   Download Section
   ======================================== */
.download {
    padding: var(--section-padding) 0;
    background: var(--gray-900);
    text-align: center;
}

.download-title {
    font-size: 2.75rem;
    font-weight: 800;
    color: var(--white);
    margin-bottom: 16px;
}

.download-subtitle {
    font-size: 1.125rem;
    color: var(--gray-400);
    margin-bottom: 40px;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.download-buttons {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.store-btn {
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--white);
    color: var(--gray-900);
    padding: 14px 28px;
    border-radius: 14px;
    transition: all 0.2s ease;
}

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

.store-text {
    text-align: left;
}

.store-label {
    display: block;
    font-size: 0.75rem;
    color: var(--gray-500);
}

.store-name {
    font-size: 1.125rem;
    font-weight: 700;
}

.download-features {
    display: flex;
    justify-content: center;
    gap: 32px;
    flex-wrap: wrap;
}

.download-feature {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--gray-400);
    font-size: 0.9375rem;
}

.download-feature svg {
    color: var(--accent);
}

/* ========================================
   Footer
   ======================================== */
.footer {
    padding: 60px 0 40px;
    background: var(--gray-900);
    border-top: 1px solid var(--gray-800);
}

.footer-content {
    display: grid;
    grid-template-columns: 1.5fr repeat(3, 1fr);
    gap: 48px;
    margin-bottom: 48px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--white);
    margin-bottom: 16px;
}

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

.footer-tagline {
    color: var(--gray-400);
    font-size: 0.9375rem;
    max-width: 280px;
}

.footer-column h4 {
    color: var(--white);
    font-size: 0.875rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 20px;
}

.footer-column a {
    display: block;
    color: var(--gray-400);
    font-size: 0.9375rem;
    margin-bottom: 12px;
    transition: color 0.2s ease;
}

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

.footer-bottom {
    padding-top: 32px;
    border-top: 1px solid var(--gray-800);
    text-align: center;
    color: var(--gray-500);
    font-size: 0.875rem;
}

/* ========================================
   Legal Pages
   ======================================== */
.legal-page .navbar {
    background: var(--white);
    box-shadow: var(--shadow-sm);
}

.legal-content {
    padding-top: 120px;
    padding-bottom: 80px;
    min-height: 100vh;
    background: var(--gray-50);
}

.legal-header {
    text-align: center;
    margin-bottom: 48px;
}

.legal-badge {
    display: inline-block;
    background: var(--gradient-primary);
    color: var(--white);
    padding: 6px 16px;
    border-radius: 100px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 16px;
}

.legal-header h1 {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--gray-900);
    margin-bottom: 12px;
}

.legal-updated {
    color: var(--gray-500);
    font-size: 0.9375rem;
}

.legal-body {
    max-width: 800px;
    margin: 0 auto;
    background: var(--white);
    padding: 48px;
    border-radius: 24px;
    box-shadow: var(--shadow-md);
}

.legal-intro {
    font-size: 1.125rem;
    color: var(--gray-600);
    padding-bottom: 32px;
    border-bottom: 1px solid var(--gray-200);
    margin-bottom: 32px;
}

.legal-section {
    margin-bottom: 40px;
}

.legal-section h2 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 16px;
}

.legal-section h3 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--gray-800);
    margin-top: 24px;
    margin-bottom: 12px;
}

.legal-section h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--gray-700);
    margin-bottom: 8px;
}

.legal-section p {
    margin-bottom: 16px;
    line-height: 1.7;
}

.legal-section ul {
    list-style: disc;
    margin-left: 24px;
    margin-bottom: 16px;
}

.legal-section ul li {
    margin-bottom: 8px;
    line-height: 1.6;
}

.legal-section ul.dont-list {
    list-style: none;
    margin-left: 0;
}

.legal-section ul.dont-list li {
    position: relative;
    padding-left: 28px;
}

.legal-section ul.dont-list li::before {
    content: "✕";
    position: absolute;
    left: 0;
    color: #ef4444;
    font-weight: 700;
}

.legal-section a {
    color: var(--primary);
    text-decoration: underline;
}

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

.highlight-box {
    background: var(--gray-50);
    border-left: 4px solid var(--primary);
    padding: 20px 24px;
    border-radius: 0 12px 12px 0;
    margin: 20px 0;
}

.highlight-box.premium {
    border-left-color: var(--accent);
    background: linear-gradient(135deg, #ecfdf5 0%, #d1fae5 100%);
}

.highlight-box.warning {
    border-left-color: var(--secondary);
    background: linear-gradient(135deg, #fff7ed 0%, #ffedd5 100%);
}

.service-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin: 20px 0;
}

.service-item {
    background: var(--gray-50);
    padding: 16px;
    border-radius: 12px;
}

.service-item h4 {
    margin-bottom: 4px;
}

.service-item p {
    font-size: 0.875rem;
    color: var(--gray-500);
    margin: 0;
}

.contact-info {
    background: var(--gray-50);
    padding: 24px;
    border-radius: 16px;
    margin-top: 16px;
}

.contact-info p {
    margin-bottom: 8px;
}

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-text {
        order: 1;
    }

    .hero-visual {
        order: 2;
        margin-top: 40px;
    }

    .hero-subtitle {
        margin-left: auto;
        margin-right: auto;
    }

    .hero-cta {
        justify-content: center;
    }

    .hero-stats {
        justify-content: center;
    }

    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .feature-card.feature-main {
        grid-column: span 2;
    }

    .footer-content {
        grid-template-columns: 1fr 1fr;
        gap: 40px;
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 60px;
    }

    .nav-links {
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background: var(--white);
        flex-direction: column;
        justify-content: center;
        gap: 32px;
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
    }

    .nav-links.active {
        opacity: 1;
        visibility: visible;
    }

    .nav-links a {
        font-size: 1.5rem;
    }

    .nav-toggle {
        display: flex;
        z-index: 1001;
    }

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

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

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

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-stats {
        flex-wrap: wrap;
        gap: 24px;
    }

    .stat-divider {
        display: none;
    }

    .phone-mockup {
        width: 280px;
    }

    .floating-card {
        display: none;
    }

    .section-title {
        font-size: 2rem;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .feature-card.feature-main {
        grid-column: span 1;
    }

    .step {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .step-number {
        font-size: 2rem;
    }

    .step-visual {
        margin: 0 auto;
    }

    .download-title {
        font-size: 2rem;
    }

    .download-buttons {
        flex-direction: column;
        align-items: center;
    }

    .store-btn {
        width: 100%;
        max-width: 280px;
        justify-content: center;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .footer-brand {
        margin-bottom: 32px;
    }

    .footer-tagline {
        max-width: none;
    }

    .footer-logo {
        justify-content: center;
    }

    .legal-body {
        padding: 32px 24px;
    }

    .legal-header h1 {
        font-size: 2rem;
    }

    .service-list {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .btn-lg {
        padding: 14px 24px;
        font-size: 1rem;
    }

    .hero-cta {
        flex-direction: column;
    }

    .download-features {
        flex-direction: column;
        gap: 16px;
    }
}