/* ===== CSS Variables & Reset ===== */
:root {
    /* Colors - HSL for better manipulation */
    --color-bg: #0a0a0b;
    --color-bg-elevated: #141416;
    --color-bg-card: rgba(26, 26, 30, 0.7);
    --color-surface: rgba(255, 255, 255, 0.03);
    --color-border: rgba(255, 255, 255, 0.08);
    --color-border-hover: rgba(255, 255, 255, 0.15);

    --color-text-primary: #ffffff;
    --color-text-secondary: rgba(255, 255, 255, 0.65);
    --color-text-tertiary: rgba(255, 255, 255, 0.45);

    /* Accent Colors */
    --color-accent: #6366f1;
    --color-accent-light: #818cf8;
    --color-accent-dark: #4f46e5;

    /* Gradient */
    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #d946ef 100%);
    --gradient-glow: radial-gradient(ellipse at center, rgba(99, 102, 241, 0.15) 0%, transparent 70%);
    --gradient-card: linear-gradient(135deg, rgba(255, 255, 255, 0.05) 0%, rgba(255, 255, 255, 0.02) 100%);

    /* Typography */
    --font-sans: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.5rem;
    --font-size-5xl: 3.5rem;
    --font-size-6xl: 4.5rem;

    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    --space-24: 6rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 16px 64px rgba(0, 0, 0, 0.6);
    --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.3);

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-base: 0.25s ease;
    --transition-slow: 0.4s ease;
    --transition-spring: 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-sans);
    background: var(--color-bg);
    color: var(--color-text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

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

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

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

/* ===== Language Switch ===== */
.lang-switch {
    position: relative;
    display: flex;
    align-items: center;
    background: #1a1a1e;
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-full);
    padding: 2px;
    margin-left: var(--space-4);
    height: 32px;
}

.lang-switch-bg {
    position: absolute;
    left: 2px;
    top: 2px;
    width: calc(50% - 2px);
    height: calc(100% - 4px);
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    transition: transform var(--transition-base);
    z-index: 1;
}

.lang-btn {
    position: relative;
    z-index: 2;
    padding: 0 var(--space-3);
    height: 100%;
    font-size: var(--font-size-xs);
    font-weight: 500;
    color: var(--color-text-secondary);
    border-radius: var(--radius-full);
    transition: color var(--transition-fast);
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 48px;
}

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

.lang-btn.active {
    color: white;
}

/* Toggle Logic in CSS (handled by JS toggling 'active' class on btn, we use that to move bg) */
.lang-switch:has(.lang-btn:last-child.active) .lang-switch-bg {
    transform: translateX(100%);
}

/* ===== Navigation ===== */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: var(--space-4) var(--space-8);
    background: rgba(10, 10, 11, 0.8);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--color-border);
}

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

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    font-weight: 700;
    font-size: var(--font-size-lg);
}

.nav-logo img {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-md);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--space-8);
}

.nav-links a {
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-text-secondary);
    transition: var(--transition-fast);
}

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

.nav-github {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    transition: var(--transition-fast);
}

.nav-github:hover {
    background: var(--color-bg-card);
    border-color: var(--color-border-hover);
    transform: scale(1.05);
}

/* ===== Hero Section ===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--space-24) var(--space-8) var(--space-16);
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    overflow: hidden;
}

.hero-glow {
    position: absolute;
    top: -30%;
    left: 50%;
    transform: translateX(-50%);
    width: 140%;
    height: 80%;
    background: var(--gradient-glow);
    filter: blur(80px);
    animation: pulse 8s ease-in-out infinite;
}

@keyframes pulse {

    0%,
    100% {
        opacity: 0.5;
        transform: translateX(-50%) scale(1);
    }

    50% {
        opacity: 0.8;
        transform: translateX(-50%) scale(1.1);
    }
}

.hero-grid {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
    background-size: 64px 64px;
    mask-image: radial-gradient(ellipse at center, black 0%, transparent 70%);
}

.hero-content {
    position: relative;
    z-index: 10;
    text-align: center;
    max-width: 800px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-6);
    animation: fadeInUp 0.6s ease;
}

.badge-icon {
    font-size: var(--font-size-base);
}

.hero-title {
    font-size: var(--font-size-6xl);
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.03em;
    margin-bottom: var(--space-6);
    animation: fadeInUp 0.6s ease 0.1s both;
}

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

.hero-desc {
    font-size: var(--font-size-xl);
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto var(--space-10);
    animation: fadeInUp 0.6s ease 0.2s both;
}

.hero-actions {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-4);
    margin-bottom: var(--space-12);
    animation: fadeInUp 0.6s ease 0.3s both;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-4) var(--space-6);
    font-size: var(--font-size-base);
    font-weight: 600;
    border-radius: var(--radius-xl);
    transition: var(--transition-base);
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 0 60px rgba(99, 102, 241, 0.4);
}

.btn-secondary {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    color: var(--color-text-primary);
}

.btn-secondary:hover {
    background: var(--color-bg-card);
    border-color: var(--color-border-hover);
}

.hero-stats {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-8);
    animation: fadeInUp 0.6s ease 0.4s both;
}

.stat {
    text-align: center;
}

.stat-value {
    display: block;
    font-size: var(--font-size-2xl);
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
}

.stat-divider {
    width: 1px;
    height: 40px;
    background: var(--color-border);
}

.hero-image {
    position: relative;
    z-index: 10;
    margin-top: var(--space-16);
    animation: fadeInUp 0.8s ease 0.5s both;
}

.hero-device {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
}

.device-frame {
    position: relative;
    border-radius: var(--radius-2xl);
    overflow: hidden;
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-xl);
}

.device-screen {
    width: 100%;
    display: block;
}

.device-reflection {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

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

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===== Section Commons ===== */
.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto var(--space-16);
}

.section-badge {
    display: inline-block;
    padding: var(--space-2) var(--space-4);
    background: var(--gradient-primary);
    font-size: var(--font-size-xs);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    border-radius: var(--radius-full);
    margin-bottom: var(--space-4);
}

.section-title {
    font-size: var(--font-size-4xl);
    font-weight: 800;
    letter-spacing: -0.02em;
    margin-bottom: var(--space-4);
}

.section-desc {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
}

/* ===== Features Section ===== */
.features {
    padding: var(--space-24) var(--space-8);
    background: var(--color-bg);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-6);
    max-width: 1200px;
    margin: 0 auto;
}

.feature-card {
    position: relative;
    padding: var(--space-8);
    background: var(--gradient-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-2xl);
    transition: var(--transition-base);
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
}

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

.feature-large {
    grid-column: span 2;
}

.feature-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    height: 56px;
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    margin-bottom: var(--space-6);
    color: white;
}

.feature-card h3 {
    font-size: var(--font-size-xl);
    font-weight: 700;
    margin-bottom: var(--space-3);
}

.feature-card p {
    font-size: var(--font-size-base);
    color: var(--color-text-secondary);
    line-height: 1.7;
}

.feature-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
    margin-top: var(--space-6);
}

.feature-tags span {
    padding: var(--space-1) var(--space-3);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
}

/* ===== Screenshots Section ===== */
.screenshots {
    padding: var(--space-24) var(--space-8);
    background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-bg-elevated) 100%);
}

.screenshots-carousel {
    max-width: 1400px;
    margin: 0 auto;
}

.carousel-track {
    display: flex;
    gap: var(--space-6);
    overflow-x: auto;
    scroll-snap-type: x mandatory;
    scrollbar-width: none;
    -ms-overflow-style: none;
    padding: var(--space-4) 0;
}

.carousel-track::-webkit-scrollbar {
    display: none;
}

.screenshot-card {
    flex: 0 0 auto;
    width: 340px;
    scroll-snap-align: center;
    transition: var(--transition-base);
}

.screenshot-card:hover {
    transform: scale(1.02);
}

.screenshot-image {
    position: relative;
    border-radius: var(--radius-xl);
    overflow: hidden;
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    margin-bottom: var(--space-4);
}

.screenshot-image img {
    width: 100%;
    aspect-ratio: 16/10;
    object-fit: cover;
    transition: var(--transition-slow);
}

.screenshot-card:hover .screenshot-image img {
    transform: scale(1.05);
}

.screenshot-info h4 {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--space-1);
}

.screenshot-info p {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
}

.carousel-nav {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-6);
    margin-top: var(--space-10);
}

.carousel-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    color: var(--color-text-secondary);
    transition: var(--transition-fast);
}

.carousel-btn:hover {
    background: var(--color-surface);
    border-color: var(--color-border-hover);
    color: var(--color-text-primary);
}

.carousel-dots {
    display: flex;
    gap: var(--space-2);
}

.carousel-dot {
    width: 8px;
    height: 8px;
    background: var(--color-border);
    border-radius: var(--radius-full);
    transition: var(--transition-fast);
    cursor: pointer;
}

.carousel-dot.active {
    width: 24px;
    background: var(--gradient-primary);
}

/* ===== Download Section ===== */
.download {
    position: relative;
    padding: var(--space-24) var(--space-8);
    overflow: hidden;
}

.download-bg {
    position: absolute;
    inset: 0;
}

.download-glow {
    position: absolute;
    bottom: -50%;
    left: 50%;
    transform: translateX(-50%);
    width: 100%;
    height: 100%;
    background: var(--gradient-glow);
    filter: blur(100px);
}

.download-content {
    position: relative;
    z-index: 10;
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.download-icon {
    display: inline-flex;
    margin-bottom: var(--space-8);
}

.download-icon img {
    width: 80px;
    height: 80px;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
}

.download-title {
    font-size: var(--font-size-4xl);
    font-weight: 800;
    margin-bottom: var(--space-4);
}

.download-desc {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-10);
}

.download-buttons {
    display: flex;
    justify-content: center;
    gap: var(--space-4);
    margin-bottom: var(--space-8);
}

.download-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-3);
    padding: 6px var(--space-6);
    background: var(--color-text-primary);
    color: var(--color-bg);
    border-radius: var(--radius-xl);
    transition: var(--transition-base);
}

.download-btn:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-lg);
}

.download-btn-disabled {
    background: var(--color-bg-card);
    color: var(--color-text-secondary);
    border: 1px solid var(--color-border);
    cursor: not-allowed;
    pointer-events: none;
    opacity: 0.7;
}

.download-btn-disabled:hover {
    transform: none;
    box-shadow: none;
}

.download-btn-text {
    text-align: left;
}

.download-btn-label {
    display: block;
    font-size: var(--font-size-xs);
    opacity: 0.7;
}

.download-btn-platform {
    display: block;
    font-size: var(--font-size-lg);
    font-weight: 700;
}

.download-info {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-3);
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
}

.download-divider {
    opacity: 0.3;
}

/* ===== Footer ===== */
.footer {
    padding: var(--space-12) var(--space-8);
    border-top: 1px solid var(--color-border);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--space-6);
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    font-weight: 600;
}

.footer-brand img {
    width: 28px;
    height: 28px;
    border-radius: var(--radius-sm);
}

.footer-links {
    display: flex;
    gap: var(--space-6);
}

.footer-links a {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
    transition: var(--transition-fast);
}

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

.footer-copyright {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
}

/* ===== Responsive Design ===== */
@media (max-width: 1024px) {
    .hero-title {
        font-size: var(--font-size-5xl);
    }

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

    .feature-large {
        grid-column: span 2;
    }
}

@media (max-width: 768px) {
    :root {
        --font-size-6xl: 3rem;
        --font-size-5xl: 2.5rem;
        --font-size-4xl: 2rem;
    }

    .nav {
        padding: var(--space-4);
    }

    .nav-links {
        gap: var(--space-4);
    }

    .hero {
        padding: var(--space-20) var(--space-4) var(--space-12);
    }

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

    .hero-stats {
        flex-wrap: wrap;
        gap: var(--space-4);
    }

    .stat-divider {
        display: none;
    }

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

    .feature-large {
        grid-column: span 1;
    }

    .screenshot-card {
        width: 280px;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }

    .lang-switch {
        top: var(--space-4);
        right: var(--space-4);
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: var(--font-size-3xl);
    }

    .section-title {
        font-size: var(--font-size-2xl);
    }

    .download-title {
        font-size: var(--font-size-2xl);
    }
}