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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #f8f9fa;
}

/* Header */
.header {
    background: #fff;
    border-bottom: 1px solid #e9ecef;
    padding: 1rem 2rem;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1400px;
    margin: 0 auto;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: #2563eb;
    text-decoration: none;
}

.logo span {
    color: #64748b;
    font-weight: 400;
}

.header-nav {
    display: flex;
    gap: 2rem;
}

.header-nav a {
    color: #64748b;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.header-nav a:hover {
    color: #2563eb;
}

/* Main Layout */
.main-container {
    display: flex;
    max-width: 1400px;
    margin: 0 auto;
    min-height: calc(100vh - 80px);
}

/* Sidebar */
.sidebar {
    width: 280px;
    background: #fff;
    border-right: 1px solid #e9ecef;
    padding: 2rem 0;
    overflow-y: auto;
    position: sticky;
    top: 80px;
    height: calc(100vh - 80px);
}

.sidebar-section {
    margin-bottom: 1.5rem;
}

.sidebar-title {
    padding: 0.5rem 1.5rem;
    font-size: 0.875rem;
    font-weight: 600;
    color: #374151;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: space-between;
    transition: background-color 0.2s ease;
}

.sidebar-title:hover {
    background-color: #f3f4f6;
}

.sidebar-title::after {
    content: "\25BC";
    font-size: 0.75rem;
    transition: transform 0.3s ease;
}

.sidebar-title.collapsed::after {
    transform: rotate(-90deg);
}

.sidebar-menu {
    list-style: none;
    padding: 0;
    margin: 0;
    transition: max-height 0.3s ease, opacity 0.3s ease;
    overflow: hidden;
}

.sidebar-menu.collapsed {
    max-height: 0;
    opacity: 0;
}

.sidebar-menu:not(.collapsed) {
    max-height: 500px;
    opacity: 1;
}

.sidebar-menu li {
    margin: 0;
}

.sidebar-menu a {
    display: block;
    padding: 0.75rem 1.5rem;
    color: #64748b;
    text-decoration: none;
    transition: all 0.2s ease;
    border-left: 3px solid transparent;
    font-size: 0.9rem;
}

.sidebar-menu a:hover {
    background-color: #f8fafc;
    color: #2563eb;
    border-left-color: #2563eb;
}

.sidebar-menu a.active {
    background-color: #eff6ff;
    color: #2563eb;
    border-left-color: #2563eb;
    font-weight: 600;
}

.sidebar-submenu {
    list-style: none;
    padding: 0;
    margin: 0;
}

.sidebar-submenu a {
    padding-left: 3rem;
    font-size: 0.85rem;
}

/* Content Area */
.content {
    flex: 1;
    padding: 2rem;
    background: #fff;
    margin: 1rem;
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

/* Welcome Section */
.welcome-hero {
    text-align: center;
    padding: 4rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 12px;
    margin-bottom: 3rem;
}

.welcome-hero h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.welcome-hero p {
    font-size: 1.2rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto;
}

/* Quick Start Cards */
.quick-start-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.quick-start-card {
    background: #fff;
    border: 1px solid #e5e7eb;
    border-radius: 12px;
    padding: 2rem;
    transition: all 0.3s ease;
    cursor: pointer;
}

.quick-start-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    border-color: #2563eb;
}

.card-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 0.5rem;
}

.card-description {
    color: #6b7280;
    line-height: 1.6;
}

/* Documentation Sections */
.doc-section {
    margin-bottom: 3rem;
}

.doc-section h2 {
    font-size: 1.875rem;
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid #e5e7eb;
}

.doc-list {
    list-style: none;
    padding: 0;
}

.doc-list li {
    background: #f9fafb;
    margin-bottom: 0.5rem;
    border-radius: 8px;
    transition: all 0.2s ease;
}

.doc-list li:hover {
    background: #f3f4f6;
    transform: translateX(4px);
}

.doc-list a {
    display: block;
    padding: 1rem 1.5rem;
    color: #374151;
    text-decoration: none;
    font-weight: 500;
}

.doc-list a:hover {
    color: #2563eb;
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .header {
        padding: 1rem;
    }

    .main-container {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        position: static;
        height: auto;
        border-right: none;
        border-bottom: 1px solid #e9ecef;
    }

    .content {
        margin: 0;
        border-radius: 0;
    }

    .welcome-hero {
        padding: 2rem 0;
        margin: 0 0 2rem 0;
        border-radius: 0;
    }

    .welcome-hero h1 {
        font-size: 2rem;
    }

    .quick-start-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
}

/* Search Bar */
.search-container {
    padding: 1rem 1.5rem;
    border-bottom: 1px solid #e9ecef;
}

.search-input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid #d1d5db;
    border-radius: 8px;
    font-size: 0.9rem;
    transition: border-color 0.2s ease;
}

.search-input:focus {
    outline: none;
    border-color: #2563eb;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}