:root {
    /* Colors - Light Theme */
    --background: oklch(1 0 0);
    --foreground: oklch(0.141 0.005 285.823);
    --card: oklch(1 0 0);
    --card-foreground: oklch(0.141 0.005 285.823);
    --primary: oklch(0.71 0.20 58);
    --primary-foreground: oklch(0.98 0.016 73.684);
    --secondary: oklch(0.967 0.001 286.375);
    --secondary-foreground: oklch(0.21 0.006 285.885);
    --muted: oklch(0.967 0.001 286.375);
    --muted-foreground: oklch(0.552 0.016 285.938);
    --accent: oklch(0.967 0.001 286.375);
    --border: oklch(0.92 0.004 286.32);
    --radius: 0.65rem;
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
}

.dark {
    /* Colors - Dark Theme */
    --background: oklch(0.141 0.005 285.823);
    --foreground: oklch(0.985 0 0);
    --card: oklch(0.21 0.006 285.885);
    --card-foreground: oklch(0.985 0 0);
    --primary: oklch(0.71 0.20 58);
    --primary-foreground: oklch(0.98 0.016 73.684);
    --secondary: oklch(0.274 0.006 286.033);
    --secondary-foreground: oklch(0.985 0 0);
    --muted: oklch(0.274 0.006 286.033);
    --muted-foreground: oklch(0.705 0.015 286.067);
    --accent: oklch(0.274 0.006 286.033);
    --border: oklch(1 0 0 / 10%);
    --shadow: 0 10px 15px -3px rgb(0 0 0 / 0.3), 0 4px 6px -4px rgb(0 0 0 / 0.3);
}

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

body {
    font-family: Arial, Helvetica, sans-serif;
    background-color: var(--background);
    color: var(--foreground);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Header */
header {
    background-color: var(--card);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 50;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    height: 4rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.header-left {
    display: flex;
    align-items: center;
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-icon {
    width: 2.5rem;
    height: 2.5rem;
    border-radius: 9999px;
    background: linear-gradient(135deg, var(--primary) 0%, oklch(0.65 0.18 45) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-foreground);
    font-weight: 700;
    font-size: 1.25rem;
}

.logo-text {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--foreground);
}

.header-right {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.language-selector {
    background-color: var(--card);
    border: 1px solid var(--border);
    color: var(--foreground);
    padding: 0.5rem;
    border-radius: var(--radius);
    cursor: pointer;
    font-size: 0.875rem;
    transition: all 0.2s;
}

.language-selector:hover {
    background-color: var(--accent);
}

.language-selector:focus {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

.theme-toggle {
    background-color: transparent;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: var(--radius);
    color: var(--foreground);
    transition: background-color 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    background-color: var(--accent);
}

.light .moon-icon {
    display: none;
}

.dark .sun-icon {
    display: none;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary) 0%, oklch(0.65 0.18 45) 100%);
    color: var(--primary-foreground);
    padding: 4rem 0;
    text-align: center;
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.hero-description {
    font-size: 1.25rem;
    opacity: 0.95;
    max-width: 800px;
    margin: 0 auto;
}

/* Sections */
.section {
    padding: 4rem 0;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--foreground);
    margin-bottom: 2rem;
    text-align: center;
}

.section-subtitle {
    text-align: center;
    font-size: 1.125rem;
    color: var(--muted-foreground);
    margin-bottom: 3rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* Card Component */
.card {
    background-color: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 1.5rem;
    transition: box-shadow 0.2s;
}

.card:hover {
    box-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
}

.card-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--foreground);
    margin-bottom: 1rem;
}

.card-description {
    font-size: 1rem;
    color: var(--muted-foreground);
    line-height: 1.7;
}

/* Grid */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

/* Feature Cards */
.feature-card {
    text-align: center;
    padding: 2rem 1.5rem;
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: var(--primary);
}

.feature-icon i {
    display: inline-block;
}

.feature-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--foreground);
    margin-bottom: 0.5rem;
}

.feature-description {
    font-size: 0.875rem;
    color: var(--muted-foreground);
    line-height: 1.6;
}

/* Architecture Section */
.architecture-image {
    margin: 1.5rem 0;
    text-align: center;
}

.architecture-image img {
    max-width: 100%;
    border-radius: var(--radius);
    border: 1px solid var(--border);
}

.architecture-list {
    margin-top: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.architecture-item {
    display: flex;
    gap: 1rem;
    padding: 1rem;
    background-color: var(--accent);
    border-radius: calc(var(--radius) - 2px);
    transition: background-color 0.2s;
}

.architecture-item:hover {
    background-color: var(--muted);
}

.architecture-item-icon {
    font-size: 2rem;
    flex-shrink: 0;
    color: var(--primary);
    width: 3rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.architecture-item-icon i {
    display: inline-block;
}

.architecture-item-content h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--foreground);
    margin-bottom: 0.25rem;
}

.architecture-item-content p {
    font-size: 0.875rem;
    color: var(--muted-foreground);
    line-height: 1.5;
}

/* CTA Section */
.cta-section {
    background-color: var(--muted);
}

.cta-card {
    text-align: center;
    padding: 3rem 2rem;
}

.cta-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--foreground);
    margin-bottom: 1rem;
}

.cta-description {
    font-size: 1.125rem;
    color: var(--muted-foreground);
    margin-bottom: 2rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

/* Button Component */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    padding: 0.625rem 1.25rem;
    border: none;
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
}

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

.btn-primary:hover {
    opacity: 0.9;
    transform: translateY(-1px);
    box-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.2);
}

/* Footer */
footer {
    background-color: var(--card);
    border-top: 1px solid var(--border);
    padding: 2rem 0;
    margin-top: 4rem;
}

footer p {
    text-align: center;
    color: var(--muted-foreground);
    font-size: 0.875rem;
}

/* Responsive */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2rem;
    }

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

    .section-title {
        font-size: 1.5rem;
    }

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

    .cta-title {
        font-size: 1.5rem;
    }

    .cta-description {
        font-size: 1rem;
    }

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

/* Video Section */
.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.video-card {
    display: flex;
    flex-direction: column;
    padding: 1.5rem;
}

.video-card:hover {
    box-shadow: 0 8px 16px -4px rgb(0 0 0 / 0.15);
    transform: translateY(-2px);
    transition: all 0.3s ease;
}

.video-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--foreground);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.video-title i {
    color: var(--primary);
}

.video-container {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%; /* 16:9 aspect ratio */
    background-color: var(--muted);
    border-radius: calc(var(--radius) - 2px);
    overflow: hidden;
    margin-bottom: 1rem;
}

.video-container video {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: calc(var(--radius) - 2px);
}

.video-container img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: calc(var(--radius) - 2px);
}

.video-description {
    font-size: 0.875rem;
    color: var(--muted-foreground);
    line-height: 1.5;
}

.text-orange {
    color: oklch(0.71 0.20 58);
}