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

body {
    font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: #f8fafc;
    color: #0f172a;
    line-height: 1.5;
    scroll-behavior: smooth;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
}

.header {
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    color: white;
    border-radius: 2rem;
    padding: 2rem 2rem 2rem 2rem;
    margin-bottom: 2.5rem;
    box-shadow: 0 20px 35px -12px rgba(0,0,0,0.2);
}

.header h1 {
    font-size: 2.4rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 0.5rem;
}

.header p {
    font-size: 1.1rem;
    opacity: 0.85;
    max-width: 80%;
}

.badge {
    display: inline-block;
    background: #3b82f6;
    padding: 0.2rem 0.8rem;
    border-radius: 2rem;
    font-size: 0.8rem;
    font-weight: 500;
    margin-top: 1rem;
}

.jump-links {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
    background: white;
    padding: 1rem 1.5rem;
    border-radius: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: 0 4px 12px rgba(0,0,0,0.03);
    border: 1px solid #e2e8f0;
}

.jump-links a {
    text-decoration: none;
    font-weight: 500;
    background: #f1f5f9;
    padding: 0.4rem 1rem;
    border-radius: 2rem;
    font-size: 0.85rem;
    color: #1e293b;
    transition: all 0.2s;
}

.jump-links a:hover {
    background: #3b82f6;
    color: white;
    transform: translateY(-2px);
}

.section-card {
    background: white;
    border-radius: 1.75rem;
    padding: 1.8rem 2rem;
    margin-bottom: 2.5rem;
    box-shadow: 0 8px 20px rgba(0,0,0,0.02), 0 2px 4px rgba(0,0,0,0.02);
    border: 1px solid #eef2ff;
    transition: box-shadow 0.2s;
}

.section-card:hover {
    box-shadow: 0 20px 30px -12px rgba(0,0,0,0.08);
}

h2 {
    font-size: 1.8rem;
    font-weight: 700;
    letter-spacing: -0.01em;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    border-left: 5px solid #3b82f6;
    padding-left: 1rem;
}

h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin: 1.5rem 0 0.8rem 0;
    color: #0f172a;
}

h4 {
    font-weight: 600;
    font-size: 1rem;
    margin: 1rem 0 0.3rem 0;
    color: #334155;
}

pre {
    background: #0f172a;
    color: #e2e8f0;
    padding: 1rem 1.2rem;
    border-radius: 1rem;
    overflow-x: auto;
    font-family: 'SF Mono', 'Fira Code', monospace;
    font-size: 0.85rem;
    margin: 1rem 0;
    white-space: pre-wrap;
    word-break: break-word;
}

code {
    background: #eef2ff;
    padding: 0.2rem 0.4rem;
    border-radius: 0.5rem;
    font-family: monospace;
    font-size: 0.85rem;
    color: #1e40af;
}

.tip {
    background: #ecfdf5;
    border-left: 4px solid #10b981;
    padding: 1rem 1.2rem;
    border-radius: 1rem;
    margin: 1rem 0;
}

.warning {
    background: #fffbeb;
    border-left: 4px solid #f59e0b;
    padding: 1rem 1.2rem;
    border-radius: 1rem;
    margin: 1rem 0;
}

.step-list {
    list-style-type: none;
    counter-reset: step-counter;
    margin: 1rem 0;
}

.step-list li {
    counter-increment: step-counter;
    margin-bottom: 1rem;
    padding-left: 2rem;
    position: relative;
}

.step-list li::before {
    content: counter(step-counter);
    background: #3b82f6;
    color: white;
    font-weight: bold;
    width: 1.5rem;
    height: 1.5rem;
    border-radius: 2rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    position: absolute;
    left: 0;
    top: 0;
}

hr {
    margin: 1rem 0;
    border: 0;
    height: 1px;
    background: #e2e8f0;
}

footer {
    text-align: center;
    margin-top: 2rem;
    padding: 1.5rem;
    color: #64748b;
    font-size: 0.85rem;
    border-top: 1px solid #e2e8f0;
}

@media (max-width: 640px) {
    .container { padding: 1rem; }
    .section-card { padding: 1.2rem; }
    h2 { font-size: 1.5rem; }
    .header p { max-width: 100%; }
}