:root {
    --bg: #ffffff;
    --bg-alt: #f6f8fb;
    --ink: #16202b;
    --ink-soft: #5a6b7b;
    --line: #e4e9f0;
    --brand: #1463ff;
    --brand-dark: #0d47c0;
    --accent: #ff7a18;
    --radius: 14px;
    --shadow: 0 6px 24px rgba(18,40,80,.08);
    --max: 1120px;
    font-synthesis: none;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    color: var(--ink);
    background: var(--bg);
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
}
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; }
h1, h2, h3 { line-height: 1.2; color: var(--ink); }

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 20px; }
.section { padding: 48px 20px; }
.section--center { text-align: center; }

/* Header */
.site-header {
    position: sticky; top: 0; z-index: 30;
    background: rgba(255,255,255,.9);
    backdrop-filter: saturate(180%) blur(10px);
    border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { font-weight: 800; font-size: 1.35rem; letter-spacing: -.02em; }
.brand-mark { color: var(--brand); }
.brand-rest { color: var(--ink); }
.brand:hover { text-decoration: none; }
.main-nav { display: flex; gap: 26px; }
.main-nav a { color: var(--ink-soft); font-weight: 600; font-size: .98rem; }
.main-nav a:hover { color: var(--brand); text-decoration: none; }

/* Hero */
.hero {
    background: radial-gradient(1200px 500px at 80% -10%, #e8f0ff 0%, transparent 60%),
                linear-gradient(180deg, var(--bg-alt), var(--bg));
    padding: 72px 0 56px;
    border-bottom: 1px solid var(--line);
}
.hero-kicker {
    display: inline-block; margin: 0 0 14px;
    color: var(--brand-dark); font-weight: 700; font-size: .82rem;
    letter-spacing: .08em; text-transform: uppercase;
    background: #e8f0ff; padding: 6px 14px; border-radius: 999px;
}
.hero h1 { font-size: clamp(2rem, 5vw, 3.2rem); margin: 0 0 18px; letter-spacing: -.025em; max-width: 16ch; }
.hero-lead { font-size: 1.18rem; color: var(--ink-soft); max-width: 60ch; margin: 0 0 30px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; }

.btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 13px 24px; border-radius: 999px;
    font-weight: 700; font-size: 1rem; cursor: pointer;
    transition: transform .12s ease, box-shadow .12s ease;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary { background: var(--brand); color: #fff; box-shadow: 0 8px 20px rgba(20,99,255,.3); }
.btn-primary:hover { background: var(--brand-dark); }
.btn-ghost { background: #fff; color: var(--ink); border: 1px solid var(--line); }
.btn-ghost:hover { border-color: var(--brand); color: var(--brand); }

/* Pillars */
.pillars { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.pillar {
    display: block; padding: 30px 26px; border-radius: var(--radius);
    background: #fff; border: 1px solid var(--line);
    color: var(--ink); transition: transform .15s, box-shadow .15s, border-color .15s;
}
.pillar:hover { text-decoration: none; transform: translateY(-4px); box-shadow: var(--shadow); border-color: #cdd8ea; }
.pillar-num { font-size: .8rem; font-weight: 800; color: var(--accent); letter-spacing: .1em; }
.pillar h2 { font-size: 1.4rem; margin: 8px 0 10px; }
.pillar p { color: var(--ink-soft); margin: 0 0 16px; font-size: .98rem; }
.pillar-link { font-weight: 700; color: var(--brand); }

/* Section head */
.section-head { display: flex; align-items: baseline; justify-content: space-between; margin-bottom: 26px; }
.section-head h2 { font-size: 1.7rem; margin: 0; }
.section-more { font-weight: 700; }

/* Cards */
.card-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.card {
    background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
    overflow: hidden; transition: transform .15s, box-shadow .15s;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.card-link { color: var(--ink); display: block; }
.card-link:hover { text-decoration: none; }
.card-thumb { height: 168px; background-size: cover; background-position: center; background-color: var(--bg-alt); }
.card-thumb--empty { display: flex; align-items: center; justify-content: center; background: linear-gradient(135deg, #1463ff, #0d47c0); }
.card-thumb--empty span { color: rgba(255,255,255,.8); font-weight: 800; letter-spacing: .05em; }
.card-body { padding: 18px 20px 22px; }
.card-date { font-size: .8rem; color: var(--ink-soft); }
.card-body h3 { font-size: 1.1rem; margin: 6px 0 8px; }
.card-body p { color: var(--ink-soft); font-size: .92rem; margin: 0; }

/* Guide cards */
.card--guide { background: linear-gradient(180deg, #fff, var(--bg-alt)); }
.card-tag {
    display: inline-block; margin-bottom: 8px; padding: 3px 11px;
    background: #e8f0ff; color: var(--brand-dark);
    font-size: .72rem; font-weight: 800; letter-spacing: .06em; text-transform: uppercase;
    border-radius: 999px;
}
.card--guide h3 { font-size: 1.15rem; margin: 0 0 8px; }

/* Author box */
.author-box {
    display: flex; gap: 26px; align-items: center;
    background: var(--bg-alt); border: 1px solid var(--line);
    border-radius: var(--radius); padding: 32px;
}
.author-avatar {
    flex: 0 0 84px; width: 84px; height: 84px; border-radius: 50%;
    background: linear-gradient(135deg, var(--brand), var(--brand-dark));
    color: #fff; font-weight: 800; font-size: 1.6rem;
    display: flex; align-items: center; justify-content: center;
}
.author-label { font-size: .8rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--accent); }
.author-text h2 { font-size: 1.5rem; margin: 4px 0 8px; }
.author-text p { color: var(--ink-soft); margin: 0 0 16px; max-width: 65ch; }
.footer-author { margin-top: 10px !important; font-size: .9rem; }
.footer-author a { color: #fff; font-weight: 600; }
@media (max-width: 640px) { .author-box { flex-direction: column; text-align: center; } }

/* Category cloud */
.cat-cloud { display: flex; flex-wrap: wrap; gap: 10px; }
.cat-cloud--filter { margin-bottom: 32px; }
.cat-chip {
    display: inline-flex; align-items: center; gap: 7px;
    padding: 8px 15px; border-radius: 999px;
    background: var(--bg-alt); border: 1px solid var(--line);
    color: var(--ink); font-weight: 600; font-size: .9rem;
}
.cat-chip span { color: var(--ink-soft); font-size: .8rem; font-weight: 700; }
.cat-chip:hover { text-decoration: none; border-color: var(--brand); color: var(--brand); }
.cat-chip.is-active { background: var(--brand); color: #fff; border-color: var(--brand); }
.cat-chip.is-active span { color: rgba(255,255,255,.8); }

/* Article */
.article { max-width: 800px; padding-top: 40px; padding-bottom: 56px; }
.article-head { margin-bottom: 28px; }
.breadcrumb { font-size: .85rem; color: var(--ink-soft); margin: 0 0 14px; }
.article-head h1 { font-size: clamp(1.8rem, 4vw, 2.6rem); margin: 0 0 10px; letter-spacing: -.02em; }
.article-intro { font-size: 1.12rem; color: var(--ink-soft); margin: 0; }
.article-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; color: var(--ink-soft); font-size: .9rem; margin-top: 12px; }
.meta-cat { background: var(--bg-alt); padding: 4px 12px; border-radius: 999px; font-weight: 600; }
.article-hero { width: 100%; border-radius: var(--radius); margin: 8px 0 28px; }

.prose { font-size: 1.06rem; }
.prose p { margin: 0 0 1.1em; }
.prose h2 { font-size: 1.5rem; margin: 1.8em 0 .5em; }
.prose h3 { font-size: 1.2rem; margin: 1.5em 0 .4em; }
.prose ul, .prose ol { margin: 0 0 1.2em; padding-left: 1.4em; }
.prose li { margin-bottom: .5em; }
.prose img { border-radius: 10px; }
.prose iframe { max-width: 100%; border-radius: 10px; margin: 1em 0; }
.prose a { font-weight: 600; }

.glossary ul { list-style: none; padding: 0; }
.glossary li {
    padding: 12px 16px; margin-bottom: 8px;
    background: var(--bg-alt); border-radius: 10px; border-left: 3px solid var(--brand);
}
.glossary strong { color: var(--ink); }

/* Next box */
.next-box { margin-top: 40px; padding: 26px; background: var(--bg-alt); border-radius: var(--radius); }
.next-box h3 { margin: 0 0 14px; }
.next-links { display: flex; flex-wrap: wrap; gap: 14px; }
.next-links a { font-weight: 600; padding: 10px 16px; background: #fff; border: 1px solid var(--line); border-radius: 10px; }
.next-links a:hover { border-color: var(--brand); text-decoration: none; }

/* Pager */
.pager { display: flex; align-items: center; justify-content: center; gap: 20px; margin-top: 44px; }
.pager a { font-weight: 700; padding: 10px 18px; border: 1px solid var(--line); border-radius: 999px; }
.pager a:hover { border-color: var(--brand); text-decoration: none; }
.pager-info { color: var(--ink-soft); font-size: .9rem; }

/* Footer */
.site-footer { background: #0f1722; color: #c4cedb; margin-top: 60px; padding: 48px 0 0; }
.footer-inner { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 30px; padding-bottom: 36px; }
.footer-col strong { color: #fff; font-size: 1.2rem; }
.footer-col p { color: #8a98a8; margin: 8px 0 0; }
.footer-head { display: block; color: #fff; font-weight: 700; margin-bottom: 12px; }
.footer-col a { display: block; color: #c4cedb; padding: 4px 0; }
.footer-col a:hover { color: #fff; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.08); padding: 18px 20px; font-size: .85rem; color: #8a98a8; }

/* Responsive */
@media (max-width: 900px) {
    .pillars, .card-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-inner { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
    .pillars, .card-grid { grid-template-columns: 1fr; }
    .main-nav { gap: 16px; }
    .main-nav a { font-size: .9rem; }
    .footer-inner { grid-template-columns: 1fr; }
    .hero { padding: 48px 0 40px; }
}