:root {
  --ink: #122a24;
  --ink-soft: #466159;
  --forest: #0e4738;
  --forest-deep: #092f27;
  --mint: #b9dfc8;
  --lime: #ddec97;
  --paper: #f4f1e8;
  --paper-bright: #fbfaf5;
  --line: rgba(18, 42, 36, 0.14);
  --shadow: 0 22px 60px rgba(15, 52, 43, 0.12);
  --radius-md: 20px;
  --radius-sm: 12px;
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", "Noto Sans SC", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--font-sans);
  -webkit-font-smoothing: antialiased;
}

button,
input {
  font: inherit;
}

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

button,
a {
  -webkit-tap-highlight-color: transparent;
}

:focus-visible {
  outline: 3px solid #efb849;
  outline-offset: 4px;
}

.skip-link {
  position: fixed;
  z-index: 100;
  top: 12px;
  left: 12px;
  padding: 10px 16px;
  color: white;
  background: var(--forest-deep);
  transform: translateY(-150%);
}

.skip-link:focus {
  transform: translateY(0);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.site-header {
  position: relative;
  z-index: 10;
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  max-width: 1400px;
  margin: 0 auto;
  padding: 24px 4vw;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  justify-self: start;
}

.brand-mark {
  display: grid;
  width: 48px;
  height: 48px;
  place-items: center;
  color: var(--paper-bright);
  background: var(--forest);
  border-radius: 50% 50% 46% 54% / 57% 42% 58% 43%;
  font-family: var(--font-sans);
  font-size: 23px;
  font-style: normal;
  font-weight: 700;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.25);
}

.brand strong {
  display: block;
  font-family: var(--font-sans);
  font-size: 15px;
  letter-spacing: 0.02em;
}

nav {
  display: flex;
  gap: 34px;
  padding: 10px 24px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(251, 250, 245, 0.55);
  backdrop-filter: blur(12px);
  justify-self: end;
}

nav a {
  color: var(--ink-soft);
  font-size: 13px;
  font-weight: 600;
}

nav a:hover {
  color: var(--forest);
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 0 20px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 700;
  transition: transform 180ms ease, box-shadow 180ms ease, background 180ms ease;
}

.button:hover {
  transform: translateY(-2px);
}

.button-primary {
  color: var(--paper-bright);
  background: var(--forest);
  box-shadow: 0 12px 26px rgba(14, 71, 56, 0.22);
}

.button-primary:hover {
  background: var(--forest-deep);
}

.button-secondary {
  border-color: var(--line);
  background: rgba(251, 250, 245, 0.72);
}

.button-secondary:hover {
  background: var(--paper-bright);
}

.hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(380px, 0.92fr);
  gap: 7vw;
  align-items: center;
  min-height: 720px;
  max-width: 1400px;
  margin: 0 auto;
  padding: 68px 6vw 104px;
  overflow: hidden;
}

.contour {
  position: absolute;
  z-index: -1;
  border: 1px solid rgba(14, 71, 56, 0.12);
  border-radius: 47% 53% 61% 39% / 45% 38% 62% 55%;
  transform: rotate(-13deg);
}

.contour::before,
.contour::after {
  position: absolute;
  content: "";
  inset: 12%;
  border: inherit;
  border-radius: inherit;
}

.contour::after {
  inset: 25%;
}

.contour-one {
  top: -20px;
  left: -210px;
  width: 570px;
  height: 410px;
}

.contour-two {
  right: -120px;
  bottom: 10px;
  width: 430px;
  height: 340px;
  transform: rotate(24deg);
}

.hero h1,
.section-heading h2,
.about-section h2 {
  margin: 0;
  font-family: var(--font-sans);
  font-weight: 500;
  letter-spacing: -0.045em;
}

.hero h1 {
  max-width: 760px;
  font-size: clamp(48px, 5.8vw, 48px);
  line-height: 1.08;
}

.hero h1 em {
  color: var(--forest);
  font-weight: 500;
  text-decoration: underline;
  text-decoration-color: var(--lime);
  text-decoration-thickness: 12px;
  text-underline-offset: -5px;
  text-decoration-skip-ink: none;
}

.hero-intro {
  max-width: 650px;
  margin: 30px 0 0;
  color: var(--ink-soft);
  font-size: 16px;
  line-height: 1.9;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.traffic-note {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 22px 0 0;
  color: var(--ink-soft);
  font-size: 12px;
}

.traffic-note span {
  color: #3b9d6e;
  font-size: 10px;
  text-shadow: 0 0 8px rgba(59, 157, 110, 0.45);
}

.course-dashboard {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  margin-top: 18px;
  padding: 12px 16px;
  color: var(--ink-soft);
  border: 1px solid var(--line);
  border-left: 3px solid var(--forest);
  border-radius: var(--radius-sm);
  background: rgba(251, 250, 245, 0.72);
  font-size: 11px;
}

.course-dashboard strong {
  color: var(--forest);
  font-family: var(--font-sans);
  font-size: 28px;
  font-weight: 500;
  line-height: 1;
}

.map-card {
  position: relative;
  min-height: 530px;
  padding: 20px;
  overflow: hidden;
  color: var(--paper-bright);
  background:
    linear-gradient(rgba(185, 223, 200, 0.09) 1px, transparent 1px),
    linear-gradient(90deg, rgba(185, 223, 200, 0.09) 1px, transparent 1px),
    var(--forest-deep);
  background-size: 38px 38px;
  border-radius: 52% 48% 45% 55% / 38% 42% 58% 62%;
  box-shadow: var(--shadow);
  transform: rotate(1.5deg);
}

.map-card::before {
  position: absolute;
  width: 270px;
  height: 270px;
  right: -60px;
  top: 80px;
  content: "";
  background: rgba(221, 236, 151, 0.12);
  border: 1px solid rgba(221, 236, 151, 0.3);
  border-radius: 48% 52% 63% 37% / 43% 36% 64% 57%;
}

.map-card-top {
  display: flex;
  justify-content: space-between;
  padding: 16px 22px;
  color: var(--mint);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.18em;
}

.map-stage {
  position: relative;
  height: 340px;
}

.map-orbit {
  position: absolute;
  border: 1px solid rgba(185, 223, 200, 0.26);
  border-radius: 50%;
  transform: rotate(-18deg);
}

.orbit-one {
  inset: 28px 46px 40px 20px;
}

.orbit-two {
  inset: 74px 14px 18px 72px;
  transform: rotate(25deg);
}

.map-pin {
  position: absolute;
  left: 48%;
  top: 45%;
  display: grid;
  width: 86px;
  height: 86px;
  place-items: center;
  border: 1px solid rgba(221, 236, 151, 0.42);
  border-radius: 50%;
  box-shadow: 0 0 0 18px rgba(221, 236, 151, 0.05);
}

.map-pin i {
  width: 16px;
  height: 16px;
  background: var(--lime);
  border: 4px solid var(--forest-deep);
  border-radius: 50%;
  box-shadow: 0 0 0 3px var(--lime);
}

.resource-section {
  max-width: none;
  padding: 86px 6vw;
  padding-right: max(6vw, calc((100vw - 1400px) / 2 + 6vw));
  padding-left: max(6vw, calc((100vw - 1400px) / 2 + 6vw));
  background: var(--paper-bright);
}

.section-heading {
  display: flex;
  justify-content: space-between;
  gap: 30px;
  align-items: end;
  margin-bottom: 38px;
}

.section-heading h2 {
  font-size: clamp(38px, 4vw, 58px);
}

.section-heading > p {
  max-width: 420px;
  margin: 0;
  color: var(--ink-soft);
  font-size: 13px;
  line-height: 1.8;
  text-align: right;
}

.search-panel {
  max-width: 760px;
  padding: 12px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: white;
}

.search-box {
  display: flex;
  flex: 1;
  align-items: center;
  gap: 12px;
  min-width: 260px;
  padding: 0 8px;
}

.search-box > span:first-child {
  color: var(--forest);
  font-family: var(--font-sans);
  font-size: 28px;
  transform: rotate(-18deg);
}

.search-box input {
  min-width: 0;
  width: 100%;
  height: 44px;
  color: var(--ink);
  border: 0;
  outline: 0;
  background: transparent;
  font-size: 14px;
}

.search-box input::placeholder {
  color: #82938d;
}

kbd {
  padding: 5px 8px;
  color: var(--ink-soft);
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--paper);
  font-size: 9px;
  font-family: inherit;
  white-space: nowrap;
}

.library-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin: 30px 0 14px;
  color: var(--ink-soft);
  font-size: 11px;
  letter-spacing: 0.06em;
}

.library-toolbar p {
  margin: 0;
}

.library-toolbar p strong {
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 18px;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 9px;
  min-width: 0;
}

.breadcrumb button {
  padding: 0;
  color: var(--forest);
  border: 0;
  border-bottom: 1px solid currentColor;
  background: transparent;
  cursor: pointer;
  font-size: 11px;
  font-weight: 700;
}

.breadcrumb strong {
  color: var(--ink);
  font-weight: 700;
  overflow-wrap: anywhere;
}

.directory-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--line);
}

.directory-card {
  position: relative;
  display: grid;
  grid-template-columns: 34px 48px minmax(0, 1fr) auto 20px;
  gap: 16px;
  align-items: center;
  min-height: 112px;
  padding: 22px 20px;
  color: var(--ink);
  text-align: left;
  border: 0;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: transparent;
  cursor: pointer;
  transition: background 160ms ease;
}

.directory-card:nth-child(even) {
  border-right: 0;
}

.directory-card:hover {
  background: #f0f3e9;
}

.directory-index {
  color: #8b9a94;
  font-family: var(--font-sans);
  font-size: 11px;
}

.folder-mark {
  position: relative;
  display: block;
  width: 42px;
  height: 32px;
  border: 1px solid rgba(14, 71, 56, 0.32);
  border-radius: 4px 7px 7px 7px;
  background: #e3edda;
}

.folder-mark::before {
  position: absolute;
  top: -7px;
  left: -1px;
  width: 19px;
  height: 8px;
  content: "";
  border: 1px solid rgba(14, 71, 56, 0.32);
  border-bottom: 0;
  border-radius: 5px 5px 0 0;
  background: #e3edda;
}

.directory-copy strong {
  display: block;
}

.directory-copy strong {
  font-family: var(--font-sans);
  font-size: 17px;
  font-weight: 500;
}

.directory-count {
  color: var(--ink-soft);
  font-size: 10px;
}

.directory-arrow {
  color: var(--forest);
  font-size: 18px;
  font-style: normal;
}

.file-list {
  border-top: 1px solid var(--line);
}

.directory-heading {
  display: flex;
  justify-content: space-between;
  align-items: end;
  padding: 26px 20px;
  border-bottom: 1px solid var(--line);
  background: #f0f3e9;
}

.directory-heading span {
  color: var(--ink-soft);
  font-size: 9px;
  font-weight: 800;
  letter-spacing: 0.14em;
}

.directory-heading h3 {
  margin: 6px 0 0;
  font-family: var(--font-sans);
  font-size: 24px;
  font-weight: 500;
}

.directory-heading a {
  color: var(--forest);
  border-bottom: 1px solid currentColor;
  font-size: 11px;
  font-weight: 700;
}

.file-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 20px;
  align-items: center;
  min-height: 90px;
  padding: 20px;
  border-bottom: 1px solid var(--line);
}

.file-copy h3 {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 500;
  line-height: 1.5;
}

.file-actions {
  display: flex;
  gap: 7px;
}

.file-actions a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 36px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 10px;
  font-weight: 800;
}

.file-actions a:first-child {
  color: white;
  border-color: var(--forest);
  background: var(--forest);
}

.file-actions a:hover {
  border-color: var(--forest);
}

.empty-state {
  padding: 70px 20px;
  color: var(--ink-soft);
  text-align: center;
  border: 1px dashed var(--line);
  border-radius: var(--radius-md);
}

.empty-state span {
  color: var(--forest);
  font-family: var(--font-sans);
  font-size: 42px;
}

.empty-state h3 {
  margin: 12px 0 6px;
  color: var(--ink);
  font-family: var(--font-sans);
  font-weight: 500;
}

.empty-state p {
  margin: 0;
  font-size: 12px;
}

.about-section {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 8vw;
  padding: 110px max(6vw, calc((100vw - 1400px) / 2 + 6vw));
  color: var(--paper-bright);
  background:
    radial-gradient(circle at 12% 18%, rgba(221, 236, 151, 0.12), transparent 22%),
    var(--forest-deep);
}

.about-section h2 {
  font-size: clamp(38px, 4vw, 58px);
  line-height: 1.2;
}

.about-copy {
  align-self: end;
}

.about-copy > p {
  margin: 0;
  color: var(--mint);
  font-size: 14px;
  line-height: 2;
}

.about-actions {
  display: flex;
  align-items: center;
  gap: 24px;
  margin-top: 28px;
}

.button-light {
  color: var(--forest-deep);
  background: var(--lime);
}

.about-actions > a:not(.button) {
  color: var(--mint);
  border-bottom: 1px solid currentColor;
  font-size: 12px;
}

@media (max-width: 1080px) {
  .site-header {
    grid-template-columns: 1fr auto;
  }

  nav {
    display: none;
  }

  .hero {
    grid-template-columns: 1fr 0.78fr;
    gap: 4vw;
    padding-right: 4vw;
    padding-left: 4vw;
  }

  .map-card {
    min-height: 480px;
  }

  .directory-count {
    display: none;
  }

}

@media (max-width: 760px) {
  .site-header {
    padding: 18px 20px;
  }

  .hero {
    display: block;
    min-height: 0;
    padding: 74px 22px 70px;
  }

  .hero h1 {
    font-size: clamp(43px, 13vw, 64px);
  }

  .hero-intro {
    font-size: 14px;
  }

  .hero-actions .button {
    width: 100%;
  }

  .map-card {
    min-height: 430px;
    margin-top: 54px;
    border-radius: 34px;
    transform: none;
  }

  .map-stage {
    height: 275px;
  }

  .resource-section {
    padding: 68px 20px;
  }

  .section-heading {
    display: block;
  }

  .section-heading > p {
    margin-top: 16px;
    text-align: left;
  }

  .directory-grid {
    grid-template-columns: 1fr;
  }

  .directory-card,
  .directory-card:nth-child(even) {
    grid-template-columns: 28px 42px minmax(0, 1fr) 18px;
    border-right: 0;
  }

  .directory-card .directory-count {
    display: none;
  }

  .search-box {
    min-width: 0;
  }

  kbd {
    display: none;
  }

  .library-toolbar {
    align-items: flex-start;
    gap: 12px;
  }

  .directory-heading {
    align-items: flex-start;
    gap: 18px;
    flex-direction: column;
  }

  .file-row {
    grid-template-columns: 1fr;
    gap: 14px;
    padding: 20px 14px;
  }

  .file-actions {
    grid-column: 1;
  }

  .file-actions a {
    flex: 1;
  }

  .about-section {
    grid-template-columns: 1fr;
    padding: 78px 22px;
  }

  .about-copy {
    margin-top: 24px;
  }

}

@media (max-width: 450px) {
  .site-header {
    padding: 16px;
  }

  .brand {
    min-width: 0;
    gap: 10px;
  }

  .brand-mark {
    flex: 0 0 auto;
    width: 42px;
    height: 42px;
    font-size: 20px;
  }

  .brand > span {
    min-width: 0;
  }

  .brand strong {
    font-size: 13px;
    line-height: 1.45;
    overflow-wrap: anywhere;
  }

  .hero {
    padding: 54px 18px 60px;
  }

  .hero h1 {
    font-size: clamp(30px, 9vw, 40px);
    letter-spacing: -0.035em;
  }

  .hero h1 em {
    text-decoration-thickness: 8px;
    text-underline-offset: -3px;
  }

  .hero-intro {
    margin-top: 22px;
    line-height: 1.7;
  }

  .hero-actions {
    gap: 10px;
    margin-top: 28px;
  }

  .traffic-note {
    align-items: flex-start;
    line-height: 1.6;
  }

  .traffic-note span {
    flex: 0 0 auto;
    margin-top: 0.3em;
  }

  .course-dashboard {
    max-width: 100%;
    flex-wrap: wrap;
  }

  .map-card {
    min-height: 350px;
    margin-top: 40px;
    padding: 14px;
    border-radius: 28px;
  }

  .map-card-top {
    padding: 12px 14px;
  }

  .map-stage {
    height: 240px;
  }

  .map-pin {
    width: 72px;
    height: 72px;
  }

  .resource-section {
    padding: 56px 16px;
  }

  .section-heading {
    margin-bottom: 28px;
  }

  .section-heading h2 {
    font-size: 34px;
  }

  .search-panel {
    padding: 8px 10px;
  }

  .search-box {
    gap: 8px;
    padding: 0 4px;
  }

  .search-box > span:first-child {
    font-size: 24px;
  }

  .library-toolbar {
    flex-direction: column;
    margin-top: 24px;
  }

  .breadcrumb {
    gap: 6px;
  }

  .breadcrumb button,
  .breadcrumb strong,
  .directory-copy strong,
  .directory-heading h3,
  .file-copy h3 {
    overflow-wrap: anywhere;
  }

  .directory-card,
  .directory-card:nth-child(even) {
    grid-template-columns: 22px 36px minmax(0, 1fr) 16px;
    gap: 10px;
    min-height: 92px;
    padding: 18px 10px;
  }

  .folder-mark {
    width: 34px;
    height: 27px;
  }

  .folder-mark::before {
    width: 16px;
  }

  .directory-copy strong {
    font-size: 15px;
    line-height: 1.45;
  }

  .directory-heading {
    gap: 14px;
    padding: 20px 14px;
  }

  .directory-heading h3 {
    font-size: 21px;
    line-height: 1.4;
  }

  .directory-heading a {
    line-height: 1.5;
  }

  .file-row {
    padding: 18px 10px;
  }

  .file-copy h3 {
    font-size: 15px;
  }

  .file-actions {
    width: 100%;
    gap: 6px;
  }

  .file-actions a {
    padding: 0 10px;
  }

  .empty-state {
    padding: 54px 14px;
  }

  .about-section {
    padding: 60px 18px;
  }

  .about-section h2 {
    font-size: clamp(28px, 8.5vw, 36px);
  }

  .about-actions {
    flex-wrap: wrap;
    gap: 16px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
  }
}