:root {
    --primary: #0d3b2e;
    --primary-light: #1b5e4a;
    --secondary: #2d6a4f;
    --accent: #95d5b2;
    --accent-soft: #d8f3dc;
    --gold: #c9a227;
    --text: #1a1a1a;
    --text-muted: #4a5568;
    --bg: #f0f4f1;
    --card: #ffffff;
    --border: #e2e8f0;
    --shadow: 0 10px 40px -10px rgba(13, 59, 46, 0.15);
    --shadow-lg: 0 25px 50px -12px rgba(13, 59, 46, 0.2);
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
    font-family: 'Segoe UI', system-ui, -apple-system, BlinkMacSystemFont, 'Helvetica Neue', sans-serif;
    line-height: 1.7;
    color: var(--text);
    background: linear-gradient(160deg, #e8f5e9 0%, #f0f4f1 40%, #e3f2fd 100%);
    min-height: 100vh;
    padding: 40px 20px;
}
.container {
    max-width: 920px;
    margin: 0 auto;
    background: var(--card);
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}
.hero {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 50%, var(--secondary) 100%);
    color: white;
    padding: 48px 48px 40px;
    position: relative;
}
.hero::after {
    content: '';
    position: absolute;
    bottom: 0; left: 0; right: 0;
    height: 6px;
    background: linear-gradient(90deg, var(--gold), var(--accent), var(--gold));
}
.hero h1 {
    font-size: 2.35rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 12px;
    line-height: 1.25;
}
.hero-sub {
    font-size: 1.1rem;
    opacity: 0.92;
    max-width: 640px;
}
.content { padding: 40px 48px 48px; }
.intro-lead {
    font-size: 1.15rem;
    color: var(--text-muted);
    background: linear-gradient(135deg, var(--accent-soft), #e8f5e9);
    padding: 22px 26px;
    border-radius: 14px;
    border-left: 5px solid var(--primary);
    margin-bottom: 28px;
    box-shadow: 0 4px 12px rgba(13, 59, 46, 0.06);
}
h2 {
    color: var(--primary);
    font-size: 1.45rem;
    margin: 42px 0 16px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--accent);
    display: flex;
    align-items: center;
    gap: 10px;
}
h2::before {
    content: '';
    width: 8px; height: 8px;
    background: var(--gold);
    border-radius: 50%;
    flex-shrink: 0;
}
p { margin-bottom: 16px; font-size: 1.05rem; color: var(--text); }
ul { padding-left: 0; list-style: none; margin: 18px 0; }
li {
    position: relative;
    padding-left: 28px;
    margin-bottom: 14px;
    font-size: 1.05rem;
}
li::before {
    content: '';
    position: absolute;
    left: 0; top: 9px;
    width: 10px; height: 10px;
    background: var(--secondary);
    border-radius: 3px;
    transform: rotate(45deg);
}
strong { color: var(--primary); font-weight: 600; }
pre.diagram {
    background: linear-gradient(180deg, #0f1f1a, #1a2f28);
    color: #7dcea0;
    padding: 28px 24px;
    border-radius: 14px;
    overflow-x: auto;
    font-family: 'SF Mono', 'Fira Code', 'Courier New', monospace;
    font-size: 0.82rem;
    line-height: 1.35;
    margin: 24px 0;
    box-shadow: inset 0 2px 12px rgba(0,0,0,0.3);
    border: 1px solid #2d4a3e;
}
table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    margin: 28px 0;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
}
th, td { padding: 14px 18px; text-align: left; }
th {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: #fff;
    font-weight: 600;
    font-size: 0.95rem;
    letter-spacing: 0.02em;
}
td { border-bottom: 1px solid var(--border); font-size: 0.98rem; }
tr:last-child td { border-bottom: none; }
tr:nth-child(even) td { background: #f8faf9; }
tr:hover td { background: var(--accent-soft); transition: background 0.2s; }
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 18px;
    margin: 24px 0;
}
.feature-card {
    background: linear-gradient(145deg, #ffffff, #f7faf8);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 22px;
    box-shadow: 0 4px 16px rgba(13, 59, 46, 0.06);
    transition: transform 0.2s, box-shadow 0.2s;
}
.feature-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow);
}
.feature-card h3 {
    color: var(--primary);
    font-size: 1.05rem;
    margin-bottom: 8px;
}
.feature-card p { font-size: 0.95rem; color: var(--text-muted); margin: 0; }
.highlight-box {
    background: linear-gradient(135deg, #0d3b2e 0%, #1b5e4a 100%);
    color: #e8f5e9;
    padding: 28px 30px;
    border-radius: 16px;
    margin: 28px 0;
    box-shadow: var(--shadow);
}
.highlight-box h3 {
    color: var(--gold);
    font-size: 1.15rem;
    margin-bottom: 12px;
}
.highlight-box p { color: #d8f3dc; font-size: 1rem; }
.summary {
    background: linear-gradient(135deg, var(--accent-soft), #c8e6c9);
    border-radius: 16px;
    padding: 28px 30px;
    margin-top: 36px;
    border: 1px solid #a5d6a7;
}
.summary h2 { border: none; margin-top: 0; }
.summary h2::before { display: none; }
@media (max-width: 640px) {
    .hero, .content { padding: 28px 22px; }
    .hero h1 { font-size: 1.75rem; }
    pre.diagram { font-size: 0.7rem; padding: 16px; }
}