/* CSS Variables for Theme */
:root {
    --primary: #ff6b6b;
    --primary-dark: #ee5a52;
    --secondary: #10b981;
    --dark: #1e293b;
    --dark-light: #334155;
    --gray: #64748b;
    --gray-light: #cbd5e1;
    --bg: #fafaf9;
    --bg-card: #ffffff;
    --text: #1e293b;
    --text-light: #64748b;
    --border: #e2e8f0;
    --shadow: rgba(30, 41, 59, 0.08);
    --shadow-hover: rgba(30, 41, 59, 0.16);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Navigation */
.nav {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(250, 250, 249, 0.8);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: all 0.3s ease;
}

.nav.scrolled {
    background: rgba(250, 250, 249, 0.95);
    box-shadow: 0 4px 16px var(--shadow);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 20px;
    font-weight: 700;
    color: var(--dark);
    text-decoration: none;
    transition: opacity 0.2s;
}

.logo:hover {
    opacity: 0.8;
}

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

.nav-links a {
    color: var(--text);
    text-decoration: none;
    font-weight: 500;
    font-size: 15px;
    transition: color 0.2s;
}

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

.btn-auth-nav {
    padding: 8px 20px !important;
    background: var(--primary) !important;
    color: white !important;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.2s;
}

.btn-auth-nav:hover {
    background: var(--primary-dark) !important;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(255, 107, 107, 0.3);
}

/* Language Selector */
.lang-selector {
    position: relative;
}

.lang-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 12px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--bg-card);
    color: var(--text);
    font-weight: 500;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s;
}

.lang-btn:hover {
    border-color: var(--gray-light);
    background: var(--bg);
}

.lang-dropdown {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    min-width: 140px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    box-shadow: 0 8px 24px var(--shadow);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: all 0.2s;
}

.lang-dropdown.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.lang-dropdown button {
    display: block;
    width: 100%;
    padding: 12px 16px;
    text-align: left;
    border: none;
    background: none;
    color: var(--text);
    font-weight: 500;
    font-size: 14px;
    cursor: pointer;
    transition: background 0.2s;
}

.lang-dropdown button:first-child {
    border-radius: 12px 12px 0 0;
}

.lang-dropdown button:last-child {
    border-radius: 0 0 12px 12px;
}

.lang-dropdown button:hover {
    background: var(--bg);
}

/* Mobile Menu */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background: var(--dark);
    border-radius: 2px;
    transition: all 0.3s;
}

/* Hero Section */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(135deg, var(--bg) 0%, #fff5f5 100%);
}

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

.hero-title {
    font-size: 56px;
    font-weight: 700;
    line-height: 1.1;
    color: var(--dark);
    margin-bottom: 24px;
}

.hero-subtitle {
    font-size: 20px;
    color: var(--text-light);
    margin-bottom: 32px;
    line-height: 1.6;
}

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

.btn {
    padding: 14px 28px;
    border-radius: 12px;
    font-weight: 600;
    font-size: 16px;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: all 0.2s;
    cursor: pointer;
    border: none;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(255, 107, 107, 0.3);
}

.btn-secondary {
    background: var(--bg-card);
    color: var(--dark);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    border-color: var(--gray-light);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px var(--shadow);
}

.btn-large {
    padding: 18px 36px;
    font-size: 18px;
}

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

/* Demo Upload Card */
.hero-demo-upload {
    margin-top: 48px;
}

.demo-upload-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 32px;
    margin-bottom: 24px;
}

.demo-header {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    margin-bottom: 24px;
}

.upload-icon-hero {
    color: var(--primary);
    flex-shrink: 0;
}

.demo-header h3 {
    font-size: 22px;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 4px;
    line-height: 1.3;
}

.demo-header p {
    font-size: 15px;
    color: var(--text-light);
    line-height: 1.5;
    margin: 0;
}

/* Tabs */
.demo-tabs {
    display: flex;
    gap: 8px;
    margin-bottom: 24px;
    background: var(--bg);
    padding: 4px;
    border-radius: 12px;
}

.demo-tab {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 16px;
    border: none;
    background: none;
    border-radius: 8px;
    font-weight: 600;
    font-size: 15px;
    color: var(--text-light);
    cursor: pointer;
    transition: all 0.2s;
}

.demo-tab.active {
    background: var(--bg-card);
    color: var(--dark);
    box-shadow: 0 2px 8px var(--shadow);
}

.demo-tab svg {
    width: 18px;
    height: 18px;
}

/* Tab Content */
.demo-content {
    display: none;
}

.demo-content.active {
    display: block;
}

.btn-upload-large {
    width: 100%;
    padding: 16px 24px;
    font-size: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.youtube-input-group {
    display: flex;
    gap: 12px;
}

.youtube-input {
    flex: 1;
    padding: 14px 16px;
    border: 1px solid var(--border);
    border-radius: 10px;
    font-size: 15px;
    font-family: 'Inter', sans-serif;
    background: var(--bg);
}

.youtube-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(255, 107, 107, 0.1);
}

.demo-note {
    display: block;
    margin-top: 12px;
    font-size: 13px;
    color: var(--text-light);
    text-align: center;
    line-height: 1.5;
}

/* Divider */
.demo-divider {
    text-align: center;
    position: relative;
    margin: 24px 0;
}

.demo-divider span {
    background: var(--bg);
    padding: 0 16px;
    color: var(--text-light);
    font-size: 14px;
    font-weight: 600;
    position: relative;
    z-index: 1;
}

.demo-divider::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    height: 1px;
    background: var(--border);
}

.btn-block {
    width: 100%;
    text-align: center;
    justify-content: center;
}

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

.stat {
    text-align: left;
}

.stat-number {
    font-size: 36px;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 4px;
}

.stat-label {
    font-size: 14px;
    color: var(--text-light);
    font-weight: 500;
}

/* Hero Visual */
.hero-visual {
    position: relative;
}

.visual-card {
    background: var(--bg-card);
    border-radius: 24px;
    padding: 32px;
    box-shadow: 0 24px 48px var(--shadow);
    border: 1px solid var(--border);
}

.waveform {
    display: flex;
    gap: 4px;
    align-items: flex-end;
    height: 80px;
    margin-bottom: 24px;
    padding: 16px;
    background: linear-gradient(135deg, rgba(255, 107, 107, 0.1) 0%, rgba(16, 185, 129, 0.1) 100%);
    border-radius: 12px;
}

.waveform span {
    flex: 1;
    background: var(--primary);
    border-radius: 4px;
    animation: wave 1.5s ease-in-out infinite;
}

.waveform span:nth-child(1) { height: 30%; animation-delay: 0s; }
.waveform span:nth-child(2) { height: 50%; animation-delay: 0.1s; }
.waveform span:nth-child(3) { height: 70%; animation-delay: 0.2s; }
.waveform span:nth-child(4) { height: 45%; animation-delay: 0.3s; }
.waveform span:nth-child(5) { height: 60%; animation-delay: 0.4s; }
.waveform span:nth-child(6) { height: 35%; animation-delay: 0.5s; }
.waveform span:nth-child(7) { height: 80%; animation-delay: 0.6s; }
.waveform span:nth-child(8) { height: 55%; animation-delay: 0.7s; }
.waveform span:nth-child(9) { height: 40%; animation-delay: 0.8s; }
.waveform span:nth-child(10) { height: 65%; animation-delay: 0.9s; }
.waveform span:nth-child(11) { height: 50%; animation-delay: 1s; }
.waveform span:nth-child(12) { height: 75%; animation-delay: 1.1s; }
.waveform span:nth-child(13) { height: 45%; animation-delay: 1.2s; }
.waveform span:nth-child(14) { height: 60%; animation-delay: 1.3s; }
.waveform span:nth-child(15) { height: 35%; animation-delay: 1.4s; }

@keyframes wave {
    0%, 100% { transform: scaleY(1); }
    50% { transform: scaleY(1.3); }
}

.transcript-preview {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.transcript-line {
    display: flex;
    gap: 12px;
    padding: 12px;
    background: var(--bg);
    border-radius: 8px;
    align-items: center;
}

.timestamp {
    font-size: 12px;
    font-weight: 600;
    color: var(--primary);
    min-width: 36px;
}

.text {
    color: var(--text);
    font-size: 14px;
}

/* Features Section */
.features {
    padding: 100px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 64px;
}

.section-header h2 {
    font-size: 42px;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 16px;
}

.section-header p {
    font-size: 18px;
    color: var(--text-light);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.feature-card {
    padding: 32px;
    background: var(--bg-card);
    border-radius: 16px;
    border: 1px solid var(--border);
    transition: all 0.3s;
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 16px 32px var(--shadow-hover);
    border-color: var(--gray-light);
}

.feature-icon {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, rgba(255, 107, 107, 0.1) 0%, rgba(16, 185, 129, 0.1) 100%);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 20px;
    font-weight: 600;
    color: var(--dark);
    margin-bottom: 12px;
}

.feature-card p {
    color: var(--text-light);
    font-size: 15px;
    line-height: 1.6;
}

/* How It Works */
.how-it-works {
    padding: 100px 0;
    background: linear-gradient(135deg, #fff5f5 0%, var(--bg) 100%);
}

.steps {
    display: grid;
    grid-template-columns: 1fr auto 1fr auto 1fr;
    gap: 32px;
    align-items: center;
    margin-top: 48px;
}

.step {
    text-align: center;
    padding: 32px;
    background: var(--bg-card);
    border-radius: 16px;
    border: 1px solid var(--border);
}

.step-number {
    width: 64px;
    height: 64px;
    background: var(--primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    font-weight: 700;
    margin: 0 auto 20px;
}

.step h3 {
    font-size: 22px;
    font-weight: 600;
    color: var(--dark);
    margin-bottom: 12px;
}

.step p {
    color: var(--text-light);
    font-size: 15px;
    line-height: 1.6;
}

.step-connector {
    width: 48px;
    height: 2px;
    background: linear-gradient(90deg, var(--primary) 0%, var(--secondary) 100%);
}

/* Use Cases */
.use-cases {
    padding: 100px 0;
}

.use-cases-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.use-case {
    padding: 32px;
    background: var(--bg-card);
    border-radius: 16px;
    border: 1px solid var(--border);
    text-align: center;
    transition: all 0.3s;
}

.use-case:hover {
    transform: translateY(-4px);
    box-shadow: 0 16px 32px var(--shadow-hover);
}

.use-case-emoji {
    font-size: 48px;
    margin-bottom: 20px;
}

.use-case h3 {
    font-size: 20px;
    font-weight: 600;
    color: var(--dark);
    margin-bottom: 12px;
}

.use-case p {
    color: var(--text-light);
    font-size: 15px;
    line-height: 1.6;
}

/* CTA Section */
.cta-section {
    padding: 100px 0;
    background: linear-gradient(135deg, var(--dark) 0%, var(--dark-light) 100%);
    color: white;
}

.cta-content {
    text-align: center;
    max-width: 700px;
    margin: 0 auto;
}

.cta-content h2 {
    font-size: 42px;
    font-weight: 700;
    margin-bottom: 20px;
}

.cta-content p {
    font-size: 18px;
    opacity: 0.9;
    margin-bottom: 32px;
}

.cta-note {
    margin-top: 16px;
    font-size: 14px;
    opacity: 0.7;
}

/* Footer */
.footer {
    padding: 60px 0 32px;
    background: var(--bg-card);
    border-top: 1px solid var(--border);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 48px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 18px;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 16px;
}

.footer-column p {
    color: var(--text-light);
    font-size: 15px;
    line-height: 1.6;
}

.footer-column h4 {
    font-size: 16px;
    font-weight: 600;
    color: var(--dark);
    margin-bottom: 16px;
}

.footer-column a {
    display: block;
    color: var(--text-light);
    text-decoration: none;
    font-size: 15px;
    margin-bottom: 12px;
    transition: color 0.2s;
}

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

.footer-bottom {
    padding-top: 32px;
    border-top: 1px solid var(--border);
    text-align: center;
    color: var(--text-light);
    font-size: 14px;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .hero .container {
        grid-template-columns: 1fr;
        gap: 48px;
    }

    .hero-title {
        font-size: 48px;
    }

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

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

    .step-connector {
        width: 2px;
        height: 48px;
        margin: 0 auto;
    }

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

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

@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        background: var(--bg-card);
        border-bottom: 1px solid var(--border);
        flex-direction: column;
        padding: 24px;
        gap: 16px;
        transform: translateY(-100%);
        opacity: 0;
        transition: all 0.3s;
    }

    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
    }

    .mobile-menu-btn {
        display: flex;
    }

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

    .mobile-menu-btn.active span:nth-child(2) {
        opacity: 0;
    }

    .mobile-menu-btn.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -7px);
    }

    .hero {
        padding: 100px 0 60px;
    }

    .hero-title {
        font-size: 36px;
    }

    .hero-subtitle {
        font-size: 18px;
    }

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

    .btn {
        justify-content: center;
    }

    .hero-stats {
        gap: 32px;
    }

    .stat-number {
        font-size: 28px;
    }

    .section-header h2 {
        font-size: 32px;
    }

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

    .use-cases-grid {
        grid-template-columns: 1fr;
    }

    .cta-content h2 {
        font-size: 32px;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 32px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .hero-title {
        font-size: 32px;
    }

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

    .demo-upload-card {
        padding: 24px 16px !important;
    }

    .youtube-input-group {
        flex-direction: column;
    }

    .youtube-input-group .btn {
        width: 100%;
    }

    .demo-header {
        flex-direction: column;
        text-align: center;
        gap: 12px !important;
    }
}