/* ===== CSS Variables ===== */
:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --accent-color: #ec4899;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --border-color: #e2e8f0;
    --sidebar-width: 280px;
    --topbar-height: 70px;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.15);
    --transition: all 0.3s ease;
}

/* Dark Mode */
[data-theme="dark"] {
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --border-color: #334155;
}

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

body {
    font-family: 'Inter', sans-serif;
    color: var(--text-primary);
    background: var(--bg-secondary);
    line-height: 1.6;
    overflow-x: hidden;
}

code, pre {
    font-family: 'Fira Code', monospace;
}

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

/* ===== Layout ===== */
.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    width: var(--sidebar-width);
    height: 100vh;
    background: var(--bg-primary);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    z-index: 1000;
    transition: var(--transition);
}

.sidebar-header {
    padding: 2rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 1rem;
}

.sidebar-header i {
    font-size: 2.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.sidebar-header h1 {
    font-size: 1.1rem;
    font-weight: 700;
    line-height: 1.3;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.sidebar-nav {
    flex: 1;
    padding: 1.5rem 0;
    overflow-y: auto;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 0.875rem;
    padding: 0.875rem 1.5rem;
    color: var(--text-secondary);
    transition: var(--transition);
    cursor: pointer;
    border-left: 3px solid transparent;
}

.nav-item:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.nav-item.active {
    background: var(--bg-secondary);
    color: var(--primary-color);
    border-left-color: var(--primary-color);
    font-weight: 600;
}

.nav-item i {
    font-size: 1.125rem;
    width: 20px;
    text-align: center;
}

.sidebar-footer {
    padding: 1.5rem;
    border-top: 1px solid var(--border-color);
    text-align: center;
}

.sidebar-footer p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

.github-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--bg-secondary);
    border-radius: 6px;
    font-size: 0.875rem;
    transition: var(--transition);
}

.github-link:hover {
    background: var(--bg-tertiary);
    transform: translateY(-2px);
}

/* ===== Main Content ===== */
.main-content {
    margin-left: var(--sidebar-width);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.top-bar {
    height: var(--topbar-height);
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    padding: 0 2rem;
    display: flex;
    align-items: center;
    gap: 1.5rem;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-primary);
    cursor: pointer;
}

.search-box {
    flex: 1;
    max-width: 500px;
    position: relative;
}

.search-box i {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
}

.search-box input {
    width: 100%;
    padding: 0.75rem 1rem 0.75rem 2.75rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 0.9375rem;
    transition: var(--transition);
}

.search-box input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.top-actions {
    display: flex;
    gap: 0.75rem;
}

.theme-toggle {
    width: 40px;
    height: 40px;
    border: 1px solid var(--border-color);
    background: var(--bg-secondary);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
    color: var(--text-secondary);
}

.theme-toggle:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

/* ===== Content Area ===== */
.content-area {
    flex: 1;
    padding: 2.5rem;
}

.page-section {
    display: none;
    animation: fadeIn 0.3s ease;
}

.page-section.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===== Hero Section ===== */
.hero {
    text-align: center;
    padding: 3rem 0 4rem;
}

.hero-icon {
    font-size: 4rem;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

/* ===== Buttons ===== */
.btn {
    padding: 0.875rem 1.75rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
}

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

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

.btn-secondary:hover {
    background: var(--bg-secondary);
    transform: translateY(-2px);
}

/* ===== Feature Grid ===== */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin: 3rem 0;
}

.feature-card {
    background: var(--bg-primary);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

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

.feature-icon {
    width: 60px;
    height: 60px;
    border-radius: 12px;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(139, 92, 246, 0.1));
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.25rem;
}

.feature-icon i {
    font-size: 1.75rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

/* ===== Quick Start ===== */
.quick-start {
    background: var(--bg-primary);
    padding: 2.5rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    margin: 3rem 0;
}

.quick-start h2 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
}

/* ===== Code Block ===== */
.code-block {
    background: #1e293b;
    border-radius: 8px;
    overflow: hidden;
    margin: 1rem 0;
}

.code-header {
    background: #0f172a;
    padding: 0.75rem 1.25rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid #334155;
}

.code-header span {
    color: #94a3b8;
    font-size: 0.875rem;
    font-weight: 500;
}

.copy-btn {
    background: #334155;
    border: none;
    padding: 0.375rem 0.75rem;
    border-radius: 4px;
    color: #94a3b8;
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.875rem;
}

.copy-btn:hover {
    background: #475569;
    color: #f1f5f9;
}

.code-block pre {
    padding: 1.5rem;
    overflow-x: auto;
    margin: 0;
}

.code-block code {
    color: #e2e8f0;
    font-size: 0.875rem;
    line-height: 1.7;
}

/* ===== Tech Stack ===== */
.tech-stack {
    text-align: center;
    padding: 3rem 0;
}

.tech-stack h2 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
}

.tech-badges {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    justify-content: center;
}

.badge {
    padding: 0.625rem 1.25rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
    transition: var(--transition);
}

.badge-ts { background: #3178c6; color: white; }
.badge-node { background: #339933; color: white; }
.badge-playwright { background: #2EAD33; color: white; }
.badge-openai { background: #10a37f; color: white; }
.badge-react { background: #61dafb; color: #000; }
.badge-ast { background: #f59e0b; color: white; }

.badge:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* ===== Footer ===== */
.footer {
    background: var(--bg-primary);
    border-top: 1px solid var(--border-color);
    padding: 1.5rem 2rem;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .sidebar {
        transform: translateX(-100%);
    }

    .sidebar.active {
        transform: translateX(0);
    }

    .main-content {
        margin-left: 0;
    }

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

@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }

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

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

    .content-area {
        padding: 1.5rem;
    }

    .search-box {
        display: none;
    }

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