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

html {
    scroll-behavior: smooth;
}

:root {
    --primary-color: #FF9900;
    --secondary-color: #1A1A1A;
    --background-color: #FAFAFA;
    --text-color: #222222;
    --card-background: #ffffff;
    --border-color: #E0E0E0;
    --hover-color: #FF8800;
    --shadow: 0 2px 8px rgba(0,0,0,0.06);
    --shadow-hover: 0 4px 12px rgba(0,0,0,0.12);
    --sidebar-width: 280px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Floating Sidebar Navigation */
.floating-nav {
    position: fixed;
    left: 0;
    top: 80px;
    width: var(--sidebar-width);
    height: calc(100vh - 100px);
    background: var(--card-background);
    box-shadow: 2px 0 12px rgba(0,0,0,0.08);
    border-radius: 0 12px 12px 0;
    z-index: 999;
    overflow-y: auto;
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    padding: 20px 0;
}

.floating-nav.collapsed {
    transform: translateX(calc(-1 * var(--sidebar-width) + 40px));
}

.nav-toggle {
    position: absolute;
    right: 10px;
    top: 10px;
    background: var(--primary-color);
    color: white;
    border: none;
    width: 32px;
    height: 32px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.nav-toggle:hover {
    background: var(--hover-color);
    transform: scale(1.1);
}

.nav-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--secondary-color);
    padding: 0 20px 15px 20px;
    border-bottom: 2px solid var(--border-color);
    margin-bottom: 10px;
}

.nav-items {
    list-style: none;
    padding: 0;
}

.nav-item {
    padding: 0;
    margin: 0;
}

.nav-item a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 20px;
    color: #444444;
    text-decoration: none;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    border-left: 3px solid transparent;
    font-size: 0.95rem;
}

.nav-item a:hover {
    background: #F5F5F5;
    color: var(--primary-color);
    border-left-color: var(--primary-color);
}

.nav-item a.active {
    background: #FFF5E6;
    color: var(--primary-color);
    border-left-color: var(--primary-color);
    font-weight: 600;
}

.nav-item a:active {
    transform: scale(0.98);
}

.nav-item i {
    font-size: 1.1rem;
    width: 20px;
    text-align: center;
}

/* Navbar */
.navbar {
    background: var(--card-background);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
}

.logo {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--secondary-color);
    gap: 10px;
}

.logo i {
    font-size: 2rem;
    color: var(--primary-color);
}

.nav-links {
    display: flex;
    gap: 30px;
}

.nav-links a {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

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

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #FF9900 0%, #FF7700 100%);
    color: white;
    padding: 60px 20px;
    text-align: center;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 15px;
    font-weight: 600;
    text-shadow: 1px 1px 3px rgba(0,0,0,0.1);
}

.hero .subtitle {
    font-size: 1.3rem;
    margin-bottom: 12px;
    opacity: 0.95;
    font-weight: 400;
}

.hero .description {
    font-size: 1rem;
    margin-bottom: 25px;
    opacity: 0.9;
}

.search-box {
    display: flex;
    max-width: 500px;
    margin: 0 auto;
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

.search-box input {
    flex: 1;
    border: none;
    padding: 12px 20px;
    font-size: 0.95rem;
    outline: none;
    color: var(--text-color);
    transition: background 0.3s ease;
}

.search-box input:focus {
    background: #FAFAFA;
}

.search-box button {
    background: var(--primary-color);
    border: none;
    padding: 12px 25px;
    color: white;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.search-box button:hover {
    background: var(--hover-color);
}

.search-box button:active {
    transform: scale(0.95);
}

/* Topics Section */
.topics {
    padding: 60px 0;
}

.topics h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 50px;
    color: var(--secondary-color);
}

.topic-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-bottom: 60px;
}

.topic-card {
    background: var(--card-background);
    border-radius: 12px;
    padding: 25px;
    box-shadow: var(--shadow);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    border: 1px solid var(--border-color);
}

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

.topic-card:active {
    transform: translateY(-2px);
    transition: transform 0.1s;
}

.topic-card .icon {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.topic-card h3 {
    font-size: 1.3rem;
    margin-bottom: 12px;
    color: var(--secondary-color);
    font-weight: 600;
}

.topic-card p {
    color: #555555;
    line-height: 1.6;
    font-size: 0.95rem;
}

/* Content Section */
.content-section {
    padding: 40px 0;
    min-height: 400px;
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.content-section.fade-out {
    opacity: 0;
    transform: translateY(-10px);
}

.content-section.fade-in {
    opacity: 1;
    transform: translateY(0);
}

.welcome-content {
    background: var(--card-background);
    padding: 35px;
    border-radius: 12px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.welcome-content h2 {
    color: var(--secondary-color);
    font-size: 1.8rem;
    margin-bottom: 25px;
    font-weight: 600;
}

.intro-box h3 {
    color: var(--secondary-color);
    font-size: 1.3rem;
    margin: 25px 0 12px 0;
    font-weight: 600;
}

.intro-box p {
    margin-bottom: 18px;
    line-height: 1.8;
    color: #444444;
}

.intro-box ul, .intro-box ol {
    margin: 18px 0;
    padding-left: 40px;
}

.intro-box li {
    margin: 8px 0;
    line-height: 1.8;
    color: #444444;
}

.intro-box strong {
    color: var(--primary-color);
    font-weight: 600;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 25px;
    margin-top: 30px;
}

.feature-item {
    text-align: center;
    padding: 20px;
    background: #F5F5F5;
    border-radius: 8px;
}

.feature-item i {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 12px;
}

.feature-item h4 {
    color: var(--secondary-color);
    margin-bottom: 8px;
    font-weight: 600;
    font-size: 1rem;
}

.feature-item p {
    color: #555555;
    font-size: 0.9rem;
}

/* Page Content Styles */
.page-content {
    background: var(--card-background);
    padding: 35px;
    border-radius: 12px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    animation: slideInUp 0.4s ease;
}

@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.page-content h2 {
    color: var(--secondary-color);
    font-size: 2rem;
    margin-bottom: 25px;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 12px;
    font-weight: 600;
}

.page-content h3 {
    color: var(--secondary-color);
    font-size: 1.5rem;
    margin: 35px 0 18px 0;
    border-left: 4px solid var(--primary-color);
    padding-left: 12px;
    font-weight: 600;
}

.page-content h4 {
    color: var(--secondary-color);
    font-size: 1.2rem;
    margin: 25px 0 12px 0;
    font-weight: 600;
}

.page-content p {
    margin-bottom: 18px;
    line-height: 1.8;
    color: #444444;
}

.page-content ul, .page-content ol {
    margin: 18px 0;
    padding-left: 40px;
}

.page-content li {
    margin: 8px 0;
    line-height: 1.8;
    color: #444444;
}

.page-content strong {
    color: var(--primary-color);
    font-weight: 600;
}

.page-content code {
    background: #F5F5F5;
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'SF Mono', Monaco, 'Courier New', monospace;
    color: #e83e8c;
    font-size: 0.9em;
}

.page-content pre {
    background: #2d2d2d;
    color: #f8f8f2;
    padding: 18px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 18px 0;
}

.page-content pre code {
    background: none;
    color: inherit;
    padding: 0;
}

.info-box {
    background: #e3f2fd;
    border-left: 5px solid #2196F3;
    padding: 20px;
    margin: 25px 0;
    border-radius: 5px;
}

.warning-box {
    background: #fff3e0;
    border-left: 5px solid #ff9800;
    padding: 20px;
    margin: 25px 0;
    border-radius: 5px;
}

.success-box {
    background: #e8f5e9;
    border-left: 5px solid #4caf50;
    padding: 20px;
    margin: 25px 0;
    border-radius: 5px;
}

.example-box {
    background: #f5f5f5;
    border: 2px dashed var(--border-color);
    padding: 20px;
    margin: 25px 0;
    border-radius: 8px;
}

.example-box h4 {
    color: var(--primary-color);
    margin-top: 0;
}

.back-button {
    display: inline-block;
    background: var(--primary-color);
    color: white;
    padding: 10px 25px;
    border-radius: 8px;
    text-decoration: none;
    margin-bottom: 25px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border: none;
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: 500;
}

.back-button:hover {
    background: var(--hover-color);
    transform: translateX(-3px);
}

.back-button:active {
    transform: translateX(-1px);
}

.table-container {
    overflow-x: auto;
    margin: 25px 0;
}

table {
    width: 100%;
    border-collapse: collapse;
    background: white;
}

th, td {
    padding: 12px;
    text-align: left;
    border: 1px solid var(--border-color);
}

th {
    background: var(--primary-color);
    color: white;
    font-weight: 600;
}

tr:nth-child(even) {
    background: #f9f9f9;
}

/* Footer */
footer {
    background: #1A1A1A;
    color: #CCCCCC;
    text-align: center;
    padding: 25px 20px;
    margin-top: 50px;
    border-top: 1px solid var(--border-color);
}

footer p {
    margin: 8px 0;
    font-size: 0.95rem;
}

.disclaimer {
    font-size: 0.85rem;
    opacity: 0.7;
}

/* Responsive */
@media (max-width: 768px) {
    .floating-nav {
        width: 250px;
        --sidebar-width: 250px;
        top: 60px;
    }

    .floating-nav.collapsed {
        transform: translateX(calc(-1 * var(--sidebar-width) + 35px));
    }

    .nav-toggle {
        right: 8px;
        top: 8px;
    }

    .hero h1 {
        font-size: 1.8rem;
    }

    .hero .subtitle {
        font-size: 1.1rem;
    }

    .hero {
        padding: 40px 20px;
    }

    .topics h2 {
        font-size: 1.8rem;
    }

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

    .nav-links {
        gap: 15px;
        font-size: 0.9rem;
    }

    .page-content {
        padding: 20px;
    }

    .page-content h2 {
        font-size: 1.6rem;
    }

    .page-content h3 {
        font-size: 1.3rem;
    }

    .welcome-content {
        padding: 25px;
    }

    .logo {
        font-size: 1.2rem;
    }

    .logo span {
        display: none;
    }
}

@media (max-width: 480px) {
    .floating-nav {
        width: 220px;
        --sidebar-width: 220px;
    }

    .nav-item a {
        padding: 10px 15px;
        font-size: 0.9rem;
    }

    .nav-title {
        font-size: 1rem;
        padding: 0 15px 12px 15px;
    }
}

/* Loading Animation */
.loading {
    text-align: center;
    padding: 60px 40px;
    font-size: 1.2rem;
    color: var(--primary-color);
    animation: fadeIn 0.3s ease;
}

.loading i {
    font-size: 2rem;
    margin-bottom: 10px;
    display: block;
}

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

/* Scrollbar styles for floating nav */
.floating-nav::-webkit-scrollbar {
    width: 6px;
}

.floating-nav::-webkit-scrollbar-track {
    background: #F5F5F5;
}

.floating-nav::-webkit-scrollbar-thumb {
    background: #CCCCCC;
    border-radius: 3px;
}

.floating-nav::-webkit-scrollbar-thumb:hover {
    background: #AAAAAA;
}