@font-face {
  font-family: "Learning Sans";
  src: url("/assets/learning/NotoSansSC-poster-subset.woff2") format("woff2");
  font-style: normal;
  font-weight: 100 900;
  font-display: swap;
}

:root {
  --paper: #f5f1e9;
  --paper-deep: #ebe5da;
  --surface: #fffdf8;
  --ink: #171916;
  --ink-soft: #5f625c;
  --line: #cbc5ba;
  --accent: #a8431f;
  --accent-soft: #f0ddd3;
  --teal: #174e56;
  --night: #071827;
  --cyan: #68d4f7;
  --gold: #f0b85d;
  --max: 1180px;
}

* { box-sizing: border-box; }

html {
  color-scheme: light;
  scroll-behavior: smooth;
  background: var(--paper);
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Learning Sans", "Microsoft YaHei", "PingFang SC", sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: inherit; text-decoration: none; }
button { font: inherit; }

.learning-shell {
  width: min(var(--max), calc(100% - 48px));
  margin: 0 auto;
}

.learning-nav {
  position: sticky;
  top: 0;
  z-index: 20;
  min-height: 68px;
  padding: 0 max(24px, calc((100% - var(--max)) / 2));
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  border-bottom: 1px solid rgba(203, 197, 186, .9);
  background: rgba(245, 241, 233, .94);
  backdrop-filter: blur(14px);
}

.learning-brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  flex: none;
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: 18px;
  font-weight: 700;
}

.learning-brand > span {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
}

.learning-nav nav {
  display: flex;
  align-items: stretch;
  align-self: stretch;
}

.learning-nav nav a {
  min-width: 72px;
  padding: 0 16px;
  display: grid;
  place-items: center;
  color: var(--ink-soft);
  border-bottom: 2px solid transparent;
  font-size: 14px;
}

.learning-nav nav a:hover,
.learning-nav nav a:focus-visible,
.learning-nav nav a[aria-current="page"] {
  color: var(--accent);
  border-bottom-color: var(--accent);
  outline: none;
}

.learning-hero {
  padding: 92px 0 78px;
  border-bottom: 1px solid var(--line);
}

.learning-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(320px, .85fr);
  gap: 80px;
  align-items: end;
}

.learning-kicker {
  margin: 0 0 16px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0;
}

.learning-hero h1 {
  margin: 0;
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: 82px;
  line-height: 1.05;
  font-weight: 500;
  letter-spacing: 0;
}

.learning-intro {
  margin: 0 0 5px;
  max-width: 520px;
  color: var(--ink-soft);
  font-size: 20px;
  line-height: 1.85;
}

.learning-catalog { padding: 78px 0 100px; }

.catalog-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 36px;
  margin-bottom: 42px;
}

.catalog-heading h2 {
  margin: 0;
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: 38px;
  line-height: 1.2;
  font-weight: 600;
}

.catalog-heading > p {
  margin: 0 0 4px;
  color: var(--ink-soft);
  font-size: 15px;
}

.learning-tabs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.learning-tabs button {
  position: relative;
  min-height: 64px;
  padding: 0 18px;
  border: 0;
  border-right: 1px solid var(--line);
  color: var(--ink-soft);
  background: transparent;
  cursor: pointer;
  font-size: 16px;
  font-weight: 650;
}

.learning-tabs button:last-child { border-right: 0; }

.learning-tabs button span {
  margin-left: 7px;
  color: #8d8b84;
  font-size: 11px;
}

.learning-tabs button::after {
  content: "";
  position: absolute;
  left: 20px;
  right: 20px;
  bottom: -1px;
  height: 3px;
  background: transparent;
}

.learning-tabs button:hover,
.learning-tabs button:focus-visible,
.learning-tabs button[aria-selected="true"] {
  color: var(--accent);
  outline: none;
}

.learning-tabs button[aria-selected="true"]::after { background: var(--accent); }

.learning-panels { padding-top: 36px; }
.learning-panel[hidden] { display: none; }

.camp-entry {
  display: grid;
  grid-template-columns: minmax(360px, .92fr) minmax(0, 1.08fr);
  min-height: 510px;
  overflow: hidden;
  border: 1px solid #244d60;
  border-radius: 6px;
  background: var(--surface);
  box-shadow: 0 24px 70px rgba(49, 46, 39, .12);
  transition: transform .2s ease, box-shadow .2s ease;
}

.camp-entry:hover,
.camp-entry:focus-visible {
  transform: translateY(-3px);
  box-shadow: 0 30px 80px rgba(49, 46, 39, .17);
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.camp-visual {
  position: relative;
  min-height: 510px;
  background: var(--night) url("/assets/learning/hero-mountains.webp") center / cover no-repeat;
}

.camp-visual::before {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(3, 17, 32, .63);
}

.camp-visual-copy {
  position: absolute;
  inset: 0;
  z-index: 1;
  padding: 46px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  color: #f5fbff;
}

.camp-visual-copy > span {
  margin-bottom: 16px;
  color: var(--cyan);
  font-size: 12px;
  font-weight: 800;
}

.camp-visual-copy strong {
  font-size: 58px;
  line-height: 1.12;
  font-weight: 850;
  letter-spacing: 0;
}

.camp-visual-copy strong small {
  margin-left: 9px;
  color: var(--gold);
  font-size: 19px;
  font-weight: 800;
  vertical-align: .25em;
}

.camp-detail {
  padding: 46px 50px;
  display: flex;
  flex-direction: column;
}

.camp-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 9px 18px;
  margin: 0 0 24px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 750;
}

.camp-meta span + span::before {
  content: "·";
  margin-right: 18px;
  color: #aaa49a;
}

.camp-detail h3 {
  margin: 0;
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: 34px;
  line-height: 1.45;
  font-weight: 600;
}

.camp-summary {
  margin: 20px 0 26px;
  color: var(--ink-soft);
  font-size: 16px;
  line-height: 1.85;
}

.camp-path {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.camp-path li {
  min-height: 43px;
  display: flex;
  align-items: center;
  gap: 16px;
  border-bottom: 1px solid var(--line);
  color: #353832;
  font-size: 14px;
}

.camp-path li span {
  width: 24px;
  color: var(--teal);
  font-size: 11px;
  font-weight: 800;
}

.camp-link {
  margin-top: auto;
  padding-top: 28px;
  color: var(--accent);
  font-size: 15px;
  font-weight: 800;
}

.camp-link > span { margin-left: 8px; }

.catalog-empty {
  min-height: 360px;
  padding: 72px 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  border-bottom: 1px solid var(--line);
}

.catalog-empty h3 {
  margin: 0;
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: 32px;
  font-weight: 600;
}

.catalog-empty > p:last-child {
  margin: 14px 0 0;
  color: var(--ink-soft);
  font-size: 16px;
}

.learning-footer {
  padding: 42px 0;
  color: #d6e2df;
  background: var(--teal);
}

.learning-footer .learning-shell {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 32px;
}

.learning-footer strong {
  display: block;
  color: #fff;
  font-family: Georgia, "Noto Serif SC", serif;
  font-size: 24px;
}

.learning-footer p {
  margin: 8px 0 0;
  font-size: 13px;
}

.learning-footer a {
  padding-bottom: 3px;
  border-bottom: 1px solid rgba(255, 255, 255, .5);
  color: #fff;
  font-size: 14px;
}

@media (max-width: 920px) {
  .learning-hero-grid { grid-template-columns: 1fr; gap: 34px; }
  .learning-hero h1 { font-size: 68px; }
  .learning-intro { max-width: 680px; }
  .camp-entry { grid-template-columns: 1fr; }
  .camp-visual { min-height: 360px; }
  .camp-detail { min-height: 480px; }
}

@media (max-width: 680px) {
  .learning-shell { width: min(100% - 28px, var(--max)); }
  .learning-nav {
    min-height: 60px;
    padding: 0 14px;
    gap: 12px;
  }
  .learning-brand { font-size: 15px; }
  .learning-nav nav a { min-width: auto; padding: 0 9px; font-size: 12px; }
  .learning-nav nav a:nth-child(3) { display: none; }
  .learning-hero { padding: 66px 0 58px; }
  .learning-hero h1 { font-size: 54px; }
  .learning-intro { font-size: 17px; line-height: 1.75; }
  .learning-catalog { padding: 56px 0 72px; }
  .catalog-heading { align-items: start; flex-direction: column; gap: 14px; margin-bottom: 30px; }
  .catalog-heading h2 { font-size: 32px; }
  .learning-tabs button { min-height: 58px; padding: 0 8px; font-size: 14px; }
  .learning-tabs button::after { left: 8px; right: 8px; }
  .learning-panels { padding-top: 22px; }
  .camp-entry { min-height: 0; }
  .camp-visual { min-height: 290px; }
  .camp-visual-copy { padding: 28px; }
  .camp-visual-copy strong { font-size: 45px; }
  .camp-visual-copy strong small { margin-left: 7px; font-size: 16px; }
  .camp-detail { min-height: 0; padding: 30px 24px 34px; }
  .camp-detail h3 { font-size: 27px; }
  .camp-summary { font-size: 15px; }
  .camp-link { margin-top: 0; }
  .learning-footer .learning-shell { align-items: start; flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .camp-entry { transition: none; }
}