/* Crawlable course introductions share the classroom's green and warm yellow palette. */
:root { --seo-green: #234b38; --seo-muted: #5d7064; --seo-border: #dce6d8; --seo-yellow: #f5d66f; }
:is(.seo-main, .seo-section, .seo-topbar, .seo-footer, .seo-page) { min-width: 0; }
:is(.seo-main, .seo-section, .seo-topbar, .seo-footer, .seo-page) *,
:is(.seo-main, .seo-section, .seo-topbar, .seo-footer, .seo-page) *::before,
:is(.seo-main, .seo-section, .seo-topbar, .seo-footer, .seo-page) *::after { box-sizing: border-box; }
:is(.seo-main, .seo-section, .seo-topbar, .seo-footer, .seo-page) :is(h1, h2, h3, p, a, li, dt, dd) { overflow-wrap: anywhere; }
.seo-main { width: 100%; max-width: 1180px; margin: 0 auto; padding: 42px 28px 70px; }
.seo-topbar { display: flex; align-items: center; justify-content: space-between; gap: 24px; padding: 16px max(5%, calc((100vw - 1180px) / 2)); background: #fff; border-bottom: 1px solid var(--seo-border); }
.seo-brand { display: flex; align-items: center; gap: 12px; min-width: 0; color: var(--seo-green); text-decoration: none; font-size: 17px; font-weight: 750; line-height: 1.4; }
.seo-brand img { flex-shrink: 0; width: 48px; height: 48px; border-radius: 12px; object-fit: contain; }
.seo-brand small { display: block; margin-top: 4px; color: var(--seo-muted); font-size: 11px; font-weight: 500; }
.seo-topbar nav { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 6px; }
.seo-topbar nav a { padding: 9px 12px; border-radius: 8px; color: var(--seo-green); font-size: 14px; font-weight: 650; text-decoration: none; }
.seo-topbar nav a:hover { background: #edf4e8; }
.seo-breadcrumb, .seo-breadcrumbs { display: flex; flex-wrap: wrap; gap: 6px 10px; margin: 0 0 24px; color: var(--seo-muted); font-size: 13px; }
.seo-breadcrumb a, .seo-breadcrumbs a { color: var(--seo-green); }
.seo-hero { padding: clamp(24px, 4vw, 42px); border: 1px solid var(--seo-border); border-radius: 20px; background: linear-gradient(125deg, #edf4e8, #fff9e7); }
.seo-hero h1 { max-width: 920px; margin: 0; color: var(--seo-green); font-size: clamp(28px, 4vw, 42px); line-height: 1.4; }
.seo-hero > p, .seo-intro { max-width: 900px; color: var(--seo-muted); font-size: 16px; line-height: 1.85; }
.seo-kicker, .seo-course-school { margin: 0 0 8px; color: #557448; font-size: 13px; font-weight: 700; line-height: 1.6; }
.seo-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 12px; margin-top: 22px; }
.seo-button { display: inline-flex; align-items: center; justify-content: center; flex-shrink: 0; max-width: 100%; padding: 10px 16px; border: 1px solid #a38425; border-radius: 9px; background: var(--seo-yellow); color: var(--seo-green); font-size: 14px; font-weight: 700; text-decoration: none; text-align: center; }
.seo-button:hover { background: #f2cc4f; }
.seo-section { margin: 34px 0 0; }
.seo-section > h2 { margin: 0 0 18px; color: var(--seo-green); font-size: clamp(23px, 3.5vw, 32px); line-height: 1.45; }
.seo-grid, .seo-course-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; }
.seo-card, .seo-course-card { min-width: 0; padding: 24px; border: 1px solid var(--seo-border); border-top: 4px solid #829d6b; border-radius: 14px; background: #fff; }
.seo-course-card:nth-child(even) { border-top-color: #cfac3f; background: #fff9e7; }
/* 首頁課程卡依社大上色，用的是「你在哪一所社大上課？」同一組顏色（course-planner.css
   的 .school-huwei / .school-hai）。原本的 :nth-child(even) 是按位置交錯，同一所海線社大
   的上、下課會一白一黃，看起來像兩所不同的社大。山線沿用底色白＋綠上框。 */
.seo-card.school-huwei { background: #eef4e8; }
.seo-card.school-hai { border-top-color: #cfac3f; background: #fff8e4; }
.seo-card h3, .seo-course-card h2, .seo-course-card h3 { margin: 0 0 12px; color: var(--seo-green); font-size: 21px; line-height: 1.55; }
.seo-card p:not(.seo-kicker), .seo-course-card p:not(.seo-course-school) { margin: 10px 0; color: var(--seo-muted); font-size: 15px; line-height: 1.8; }
.seo-card a, .seo-course-card a { display: inline-block; margin-top: 7px; color: var(--seo-green); font-size: 14px; font-weight: 650; line-height: 1.8; text-underline-offset: 4px; }
.seo-note { padding: 15px 18px; margin: 0 0 24px; border-left: 3px solid #d5b75a; border-radius: 0 10px 10px 0; background: #fff9e7; color: var(--seo-muted); font-size: 14px; line-height: 1.8; overflow-wrap: anywhere; }
.seo-note a { color: var(--seo-green); }
.seo-list, .seo-question-list { padding-left: 23px; color: var(--seo-muted); font-size: 16px; line-height: 1.85; }
.seo-list li, .seo-question-list li { margin: 10px 0; padding-left: 3px; }
.seo-prose { max-width: 900px; color: var(--seo-muted); font-size: 16px; line-height: 1.9; }
.seo-materials { display: grid; gap: 18px; margin-top: 22px; }
.seo-materials > .public-material-card { min-width: 0; }
.seo-faq { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; margin: 0; }
.seo-faq > div { min-width: 0; padding: 23px; border: 1px solid var(--seo-border); border-radius: 14px; background: #fff; }
.seo-faq dt { margin: 0 0 12px; color: var(--seo-green); font-size: 18px; font-weight: 700; line-height: 1.6; }
.seo-faq dd { margin: 0; color: var(--seo-muted); font-size: 15px; line-height: 1.85; }
.seo-faq a { color: var(--seo-green); }
.seo-footer { padding: 24px max(5%, calc((100vw - 1180px) / 2)); border-top: 1px solid var(--seo-border); background: #fff; color: var(--seo-muted); font-size: 13px; }
.seo-footer a { color: var(--seo-green); }
.course-home .seo-discovery { margin-top: 48px; padding-top: 0; }
.course-home .seo-faq-section { padding-top: 0; }
:is(.seo-main, .seo-topbar, .seo-section, .seo-footer) :is(a, button):focus-visible { outline: 3px solid #977000; outline-offset: 4px; }
@media (max-width: 720px) {
  .seo-main { padding: 30px 20px 50px; }
  .seo-topbar { align-items: flex-start; flex-direction: column; gap: 14px; padding: 16px 20px; }
  .seo-topbar nav { justify-content: flex-start; }
  .seo-hero { padding: 24px 20px; border-radius: 16px; }
  .seo-grid, .seo-course-grid, .seo-faq { grid-template-columns: minmax(0, 1fr); }
  .seo-card, .seo-course-card, .seo-faq > div { padding: 20px; }
  .seo-section { margin-top: 28px; }
  .seo-discovery .course-section-heading { flex-direction: column; gap: 14px; }
  .seo-note { padding: 13px 15px; }
}