:root {
  --edu-bg: #f8fafc;
  --edu-surface: #ffffff;
  --edu-text: #0f172a;
  --edu-muted: #475569;
  --edu-line: #cbd5e1;
  --edu-brand: #047857;
  --edu-brand-dark: #065f46;
  --edu-soft: #ecfdf5;
}

html.dark {
  --edu-bg: #0b1120;
  --edu-surface: #111827;
  --edu-text: #f1f5f9;
  --edu-muted: #cbd5e1;
  --edu-line: #334155;
  --edu-brand: #34d399;
  --edu-brand-dark: #6ee7b7;
  --edu-soft: #052e2b;
}

* { box-sizing: border-box; }
body { margin: 0; background: var(--edu-bg); color: var(--edu-text); font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; line-height: 1.65; }
a { color: var(--edu-brand-dark); text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
a:focus-visible, button:focus-visible { outline: 3px solid #f59e0b; outline-offset: 3px; }
.edu-shell { width: min(100% - 32px, 1080px); margin-inline: auto; }
.edu-header { background: #020617; color: #fff; border-bottom: 3px solid #10b981; }
.edu-header-row { min-height: 72px; display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.edu-brand { color: #fff; text-decoration: none; font-weight: 900; font-size: 1.3rem; letter-spacing: -.03em; }
.edu-brand span { color: #34d399; }
.edu-nav { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 8px 16px; }
.edu-nav a { color: #e2e8f0; font-weight: 700; font-size: .92rem; text-decoration: none; }
.edu-nav a:hover { color: #6ee7b7; }
.edu-breadcrumb { padding: 14px 0; color: var(--edu-muted); font-size: .9rem; }
.edu-breadcrumb a { font-weight: 700; }
.edu-main { padding: 20px 0 64px; }
.edu-hero { padding: clamp(24px, 6vw, 56px); border: 1px solid var(--edu-line); border-radius: 24px; background: var(--edu-surface); box-shadow: 0 18px 45px rgba(15, 23, 42, .08); }
.edu-kicker { margin: 0 0 8px; color: var(--edu-brand); font-size: .8rem; font-weight: 900; letter-spacing: .08em; text-transform: uppercase; }
h1 { margin: 0; max-width: 850px; font-size: clamp(2rem, 7vw, 4rem); line-height: 1.05; letter-spacing: -.045em; }
.edu-lead { max-width: 800px; margin: 22px 0 0; color: var(--edu-muted); font-size: clamp(1.05rem, 2vw, 1.3rem); }
.edu-answer { margin-top: 24px; padding: 18px 20px; border-left: 5px solid #10b981; border-radius: 12px; background: var(--edu-soft); font-size: 1.05rem; }
.edu-grid { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 32px; margin-top: 32px; align-items: start; }
.edu-article, .edu-card { min-width: 0; padding: clamp(20px, 4vw, 36px); border: 1px solid var(--edu-line); border-radius: 20px; background: var(--edu-surface); }
.edu-article h2 { margin: 34px 0 12px; font-size: clamp(1.45rem, 4vw, 2rem); line-height: 1.2; }
.edu-article h2:first-child { margin-top: 0; }
.edu-article h3 { margin: 24px 0 8px; font-size: 1.2rem; }
.edu-article p, .edu-article li { color: var(--edu-muted); }
.edu-article strong { color: var(--edu-text); }
.edu-table-wrap { max-width: 100%; overflow-x: auto; margin: 20px 0; border: 1px solid var(--edu-line); border-radius: 14px; }
.edu-table { width: 100%; min-width: 560px; border-collapse: collapse; background: var(--edu-surface); }
.edu-table th, .edu-table td { padding: 12px 14px; border-bottom: 1px solid var(--edu-line); text-align: left; vertical-align: top; }
.edu-table th { background: var(--edu-soft); color: var(--edu-text); }
.edu-card { position: sticky; top: 20px; padding: 22px; }
.edu-card h2, .edu-card h3 { margin-top: 0; line-height: 1.25; }
.edu-card ul { padding-left: 20px; }
.edu-card li { margin: 10px 0; }
.edu-cta { display: inline-flex; align-items: center; justify-content: center; min-height: 48px; padding: 12px 18px; border-radius: 12px; background: #047857; color: #fff; font-weight: 800; text-decoration: none; text-align: center; }
.edu-cta:hover { background: #065f46; }
.edu-related { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; margin-top: 24px; }
.edu-related article { min-width: 0; padding: 20px; border: 1px solid var(--edu-line); border-radius: 16px; background: var(--edu-surface); }
.edu-related h2, .edu-related h3 { margin: 0 0 8px; font-size: 1.1rem; }
.edu-related p { margin: 0; color: var(--edu-muted); }
.edu-faq details { margin: 12px 0; padding: 16px 18px; border: 1px solid var(--edu-line); border-radius: 12px; background: var(--edu-surface); }
.edu-faq summary { cursor: pointer; font-weight: 800; }
.edu-footer { padding: 28px 0; border-top: 1px solid var(--edu-line); color: var(--edu-muted); font-size: .9rem; }
.edu-footer-row { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; }
.edu-meta { color: var(--edu-muted); font-size: .9rem; }

@media (max-width: 760px) {
  .edu-grid { grid-template-columns: 1fr; }
  .edu-card { position: static; }
  .edu-related { grid-template-columns: 1fr; }
}

@media (max-width: 420px) {
  .edu-shell { width: min(100% - 16px, 1080px); }
  .edu-header-row { align-items: flex-start; flex-direction: column; padding: 14px 0; }
  .edu-nav { justify-content: flex-start; gap: 8px 12px; }
  .edu-hero, .edu-article { border-radius: 16px; }
  h1 { overflow-wrap: anywhere; }
}

@media (max-width: 359px) {
  .edu-header .edu-nav > a { display: inline-block !important; }
  .edu-nav { gap: 6px 10px; }
  .edu-nav a { font-size: .82rem; }
}

@media print {
  html, body { background: #fff !important; color: #000 !important; }
  .edu-header, .edu-breadcrumb, .edu-card, .edu-related, .edu-footer { display: none !important; }
  .edu-shell { width: 100%; }
  .edu-main, .edu-hero, .edu-article { padding: 0; border: 0; box-shadow: none; }
  .edu-grid { display: block; }
  a { color: #000 !important; text-decoration: none; }
}