:root {
  color-scheme: light;
  --bg: #f8f4eb;
  --paper: #fffdf7;
  --paper-soft: #f2eadc;
  --ink: #23201b;
  --muted: #70685d;
  --faint: #9b9183;
  --line: #ded1bb;
  --line-strong: #c7b594;
  --folder: #e7b75c;
  --folder-deep: #c48732;
  --green: #365f4c;
  --red: #9b4d3e;
  --shadow: 0 20px 52px rgba(69, 48, 24, 0.11);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    linear-gradient(180deg, rgba(255, 253, 247, 0.86), rgba(248, 244, 235, 0.2) 44%, var(--bg)),
    var(--bg);
  color: var(--ink);
  font-family:
    ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.72;
  text-rendering: optimizeLegibility;
}

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

.site-header,
.site-footer,
main {
  width: min(1080px, calc(100% - 40px));
  margin: 0 auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 30px 0 22px;
}

.brand,
.site-nav,
.site-footer {
  display: flex;
  align-items: center;
}

.brand {
  gap: 12px;
}

.brand-seal {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  border: 1px solid var(--line-strong);
  border-radius: 50%;
  background: var(--paper);
  color: var(--green);
  font-family: Georgia, "Times New Roman", serif;
  font-weight: 700;
}

.brand strong,
.brand small {
  display: block;
}

.brand small {
  color: var(--muted);
  font-size: 13px;
}

.site-nav {
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 18px;
  color: var(--muted);
  font-size: 15px;
}

.site-nav a {
  border-bottom: 1px solid transparent;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  border-color: currentColor;
  color: var(--ink);
}

.hero,
.page-hero {
  border-top: 1px solid var(--line);
  padding: 62px 0 34px;
}

.kicker {
  margin: 0 0 12px;
  color: var(--red);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1,
h2,
h3 {
  letter-spacing: 0;
}

h1 {
  max-width: 820px;
  margin-bottom: 20px;
  font-family: "Songti SC", "STSong", "Noto Serif CJK SC", Georgia, serif;
  font-size: clamp(40px, 7vw, 72px);
  line-height: 1.08;
}

h2 {
  margin-bottom: 10px;
  font-family: "Songti SC", "STSong", "Noto Serif CJK SC", Georgia, serif;
  font-size: clamp(26px, 4vw, 38px);
  line-height: 1.22;
}

h3 {
  margin-bottom: 6px;
  font-size: 20px;
}

.hero-lead,
.page-lead,
.simple-note p,
.course-card p,
.guide-card p {
  color: var(--muted);
}

.hero-lead,
.page-lead {
  max-width: 760px;
  font-size: 18px;
}

.term-board {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  padding: 24px 0 54px;
}

.term-folder {
  position: relative;
  min-height: 178px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--paper);
  padding: 26px;
  box-shadow: 0 12px 34px rgba(69, 48, 24, 0.06);
}

.term-folder::before {
  position: absolute;
  top: 0;
  left: 24px;
  width: 116px;
  height: 28px;
  border-radius: 0 0 8px 8px;
  background: var(--folder);
  content: "";
}

.term-folder::after {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 8px;
  background: linear-gradient(90deg, var(--folder), var(--folder-deep));
  content: "";
  opacity: 0.72;
}

.term-folder span,
.term-folder strong,
.term-folder small {
  display: block;
}

.term-folder span {
  margin-top: 22px;
  color: var(--folder-deep);
  font-size: 14px;
  font-weight: 800;
}

.term-folder strong {
  margin-top: 6px;
  font-family: "Songti SC", "STSong", "Noto Serif CJK SC", Georgia, serif;
  font-size: 27px;
}

.term-folder small {
  margin-top: 12px;
  color: var(--muted);
  font-size: 14px;
}

.term-folder:hover,
.term-folder.is-ready {
  border-color: var(--line-strong);
  box-shadow: var(--shadow);
}

.simple-note,
.guide-card {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(255, 253, 247, 0.74);
  padding: 26px;
}

.simple-note {
  margin-bottom: 74px;
}

.page-shell {
  border-top: 1px solid var(--line);
  padding: 54px 0 86px;
}

.breadcrumb {
  margin-bottom: 18px;
  color: var(--muted);
  font-size: 14px;
}

.breadcrumb a {
  border-bottom: 1px solid var(--line-strong);
}

.course-list {
  display: grid;
  gap: 12px;
  margin-top: 30px;
}

.course-card {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr) auto;
  gap: 18px;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(255, 253, 247, 0.78);
  padding: 18px 20px;
}

.course-icon {
  display: grid;
  width: 42px;
  height: 34px;
  place-items: center;
  border-radius: 7px;
  background: linear-gradient(180deg, #f3c76d, #dfa647);
  color: #6c431c;
  font-weight: 900;
}

.course-card h2 {
  margin-bottom: 2px;
  font-family: inherit;
  font-size: 20px;
}

.course-card p {
  margin-bottom: 0;
  font-size: 14px;
}

.course-status {
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  padding: 5px 10px;
  color: var(--muted);
  font-size: 13px;
  white-space: nowrap;
}

.guide-list {
  display: grid;
  gap: 16px;
  max-width: 820px;
  margin-top: 30px;
}

.site-footer {
  justify-content: space-between;
  gap: 18px;
  border-top: 1px solid var(--line);
  padding: 26px 0 34px;
  color: var(--muted);
  font-size: 14px;
}

.hidden-mark {
  color: var(--line-strong);
}

.secret-body {
  display: grid;
  min-height: 100vh;
  place-items: center;
}

.secret-shell {
  width: min(560px, calc(100% - 40px));
  margin: 0 auto;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--paper);
  padding: 36px;
  box-shadow: var(--shadow);
}

.button-link {
  display: inline-flex;
  min-height: 42px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: var(--green);
  padding: 0 16px;
  color: #fffdf7;
  font-weight: 800;
}

.muted-link {
  display: inline-block;
  margin-left: 14px;
  color: var(--muted);
}

@media (max-width: 860px) {
  .site-header,
  .site-footer,
  main {
    width: min(100% - 28px, 1080px);
  }

  .site-header,
  .site-footer {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-nav {
    justify-content: flex-start;
  }

  .hero,
  .page-shell {
    padding-top: 42px;
  }

  .term-board {
    grid-template-columns: 1fr;
  }

  .course-card {
    grid-template-columns: 42px minmax(0, 1fr);
  }

  .course-status {
    grid-column: 2;
    width: max-content;
  }
}