:root {
    --primary: #2563eb;
    --secondary: #059669;
    --background: #ffffff;
    --text: #1f2937;
    --text-secondary: #4b5563;
    --card-bg: #f8fafc;
    --card-border: #e2e8f0;
    --hover-bg: #f1f5f9;
    --gradient-start: #2563eb;
    --gradient-end: #059669;
}

[data-theme="dark"] {
    --background: #1e293b;
    --text: #f1f5f9;
    --text-secondary: #cbd5e1;
    --card-bg: #334155;
    --card-border: #475569;
    --hover-bg: #2d3a4f;
    --gradient-start: #1e40af;
    --gradient-end: #047857;
}

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

body {
    font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background-color: var(--background);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

/* Hero Section */
.hero {
    padding: 6rem 0;
    margin-bottom: 3rem;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    border-radius: 1rem;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="100" height="100" viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg"><circle cx="50" cy="50" r="40" stroke="rgba(255,255,255,0.1)" stroke-width="2" fill="none"/></svg>') repeat;
    opacity: 0.1;
}

.hero-content {
    position: relative;
    z-index: 1;
    color: white;
    text-align: center;
    padding: 0 2rem;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    background: linear-gradient(to right, #ffffff, #e2e8f0);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.9);
    max-width: 800px;
    margin: 0 auto;
}

/* Features Section */
.features-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.feature-box {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 0.75rem;
    padding: 1.5rem;
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-box:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.feature-icon {
    font-size: 1.5rem;
    padding: 0.75rem;
    background: var(--hover-bg);
    border-radius: 0.5rem;
    flex-shrink: 0;
    color: var(--primary);
    transition: transform 0.3s ease;
}

.feature-box:hover .feature-icon {
    transform: scale(1.1);
}

.feature-content {
    flex: 1;
}

.feature-content h4 {
    margin: 0 0 0.5rem 0;
    color: var(--text);
    font-size: 1.25rem;
}

/* Guide Section */
.section-guide {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 0.75rem;
    padding: 2rem;
    margin: 2rem 0;
}

.guide-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin: 2rem 0;
}

.guide-step {
    background: var(--background);
    border: 1px solid var(--card-border);
    border-radius: 0.75rem;
    padding: 2rem;
    position: relative;
    transition: all 0.3s ease;
    text-align: center;
}

.guide-step:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.step-number {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
    width: 3rem;
    height: 3rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    margin: 0 auto 1rem;
    font-size: 1.25rem;
}

.guide-step h3 {
    margin: 1rem 0;
    font-size: 1.5rem;
    color: var(--text);
}

.guide-step .feature-icon {
    font-size: 2.5rem;
    margin: 1rem auto;
    display: block;
}

/* Tables */
.table-container {
    overflow-x: auto;
    margin: 2rem 0;
    border-radius: 0.75rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

table {
    width: 100%;
    border-collapse: collapse;
    background: var(--card-bg);
    border: 1px solid var(--card-border);
}

th {
    background: var(--hover-bg);
    font-weight: 600;
    text-align: left;
    padding: 1rem;
    border-bottom: 2px solid var(--card-border);
}

td {
    padding: 1rem;
    border-bottom: 1px solid var(--card-border);
}

tr:last-child td {
    border-bottom: none;
}

/* Typography */
h2 {
    font-size: 2rem;
    margin: 3rem 0 1.5rem;
    color: var(--text);
    border-bottom: 2px solid var(--primary);
    padding-bottom: 0.5rem;
    display: inline-block;
}

h3 {
    font-size: 1.5rem;
    margin: 2rem 0 1rem;
    color: var(--text);
}

p, ul, ol {
    margin-bottom: 1.5rem;
    text-align: left;
    line-height: 1.8;
}

ul, ol {
    padding-left: 1.5rem;
}

li {
    margin-bottom: 0.75rem;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: var(--secondary);
    text-decoration: none;
}

/* Theme Toggle */
.theme-toggle {
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 1000;
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    padding: 0.75rem;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.theme-toggle:hover {
    background: var(--hover-bg);
    transform: rotate(180deg);
}

/* Footer */
.footer {
    background-color: var(--card-bg);
    border-top: 1px solid var(--card-border);
    padding: 3rem 0;
    margin-top: 6rem;
    text-align: center;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    text-align: center;
}

.footer-content p {
    color: var(--text-secondary);
    margin: 0.5rem 0;
    font-size: 0.875rem;
    text-align: center;
}

.footer-content a {
    color: var(--primary);
    text-decoration: none;
}

.footer-content a:hover {
    color: var(--secondary);
}

/* Highlight */
.highlight {
    background: linear-gradient(120deg, rgba(37, 99, 235, 0.1) 0%, rgba(5, 150, 105, 0.1) 100%);
    padding: 0.2em 0.4em;
    border-radius: 0.25rem;
    font-weight: 500;
}

/* Buttons */
.btn, .cta-button {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
    border-radius: 0.5rem;
    font-weight: 500;
    text-decoration: none;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.btn:hover, .cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    color: white;
}

/* Animations */
@keyframes float {
    0% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-10px);
    }
    100% {
        transform: translateY(0px);
    }
}

.floating {
    animation: float 3s ease-in-out infinite;
}

/* Responsiveness */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .guide-grid {
        grid-template-columns: 1fr;
    }
    
    .features-container {
        grid-template-columns: 1fr;
    }
    
    .container {
        padding: 1rem;
    }
}

/* Model Cards */
.model-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 0.75rem;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.model-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.model-card h3 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
    color: var(--primary);
}

.model-card h3 .feature-icon {
    background: none;
    padding: 0;
}