:root {
  --bg: #f5f7fb;
  --paper: #ffffff;
  --ink: #152033;
  --muted: #5f6b7a;
  --soft: #8a95a5;
  --line: #dce4ee;
  --line-soft: #edf1f6;
  --brand: #1658a8;
  --teal: #0d766d;
  --amber: #b65f13;
  --red: #b42318;
  --green: #087f5b;
  --shadow: 0 14px 32px rgba(21, 32, 51, .08);
  --radius: 8px;
  --max: 1200px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  line-height: 1.6;
  max-width: 100%;
  overflow-x: hidden;
}

body.menu-open {
  overflow: hidden;
}

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

img {
  display: block;
  max-width: 100%;
}

button {
  font: inherit;
}

.progress {
  position: fixed;
  inset: 0 auto auto 0;
  width: 0;
  height: 3px;
  z-index: 90;
  background: var(--amber);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  min-height: 68px;
  padding: 10px max(24px, calc((100vw - var(--max)) / 2));
  background: rgba(255, 255, 255, .94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: 250px;
  color: #11284f;
  font-weight: 800;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 44px;
  height: 34px;
  color: #fff;
  background: #143b73;
  border-radius: var(--radius);
  font-size: 13px;
}

.brand-text {
  white-space: nowrap;
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 4px;
  flex-wrap: wrap;
}

.site-nav a {
  padding: 7px 9px;
  border-radius: var(--radius);
  color: #3d4a5c;
  font-size: 14px;
  font-weight: 700;
  border: 1px solid transparent;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--brand);
  background: #eef5ff;
  border-color: #d4e6ff;
}

.menu-button {
  display: none;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fff;
  color: var(--brand);
  padding: 8px 10px;
  font-weight: 800;
}

.hero {
  position: relative;
  min-height: 78vh;
  color: #fff;
  overflow: hidden;
  isolation: isolate;
  display: grid;
  align-items: end;
  padding: 112px max(22px, calc((100vw - var(--max)) / 2)) 36px;
}

.hero-media {
  position: absolute;
  inset: 0;
  z-index: -3;
  background-image: url("images/class-meeting.jpg");
  background-size: cover;
  background-position: center 42%;
}

.hero-shade {
  position: absolute;
  inset: 0;
  z-index: -2;
  background: rgba(7, 16, 31, .62);
}

.hero-content {
  width: 100%;
  min-width: 0;
  max-width: 820px;
}

.eyebrow,
.section-kicker {
  margin: 0 0 10px;
  color: var(--amber);
  font-size: 13px;
  font-weight: 900;
  text-transform: uppercase;
}

.hero .eyebrow {
  color: #ffd6a3;
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1 {
  margin: 0;
  font-size: 56px;
  line-height: 1.08;
  letter-spacing: 0;
}

.hero-subtitle {
  margin: 14px 0 0;
  color: #e9f2ff;
  font-size: 24px;
  font-weight: 800;
}

.hero-copy {
  max-width: 780px;
  margin: 16px 0 0;
  color: #dbe5f4;
  font-size: 17px;
}

.hero-actions,
.join-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.primary-action,
.secondary-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  border-radius: var(--radius);
  padding: 10px 14px;
  font-weight: 900;
  border: 1px solid transparent;
  box-shadow: 0 8px 18px rgba(0, 0, 0, .14);
}

.primary-action {
  background: #fff;
  color: #15305b;
}

.secondary-action {
  color: #fff;
  border-color: rgba(255, 255, 255, .55);
  background: rgba(255, 255, 255, .12);
}

.primary-action.light {
  background: #fff;
  color: #143b73;
}

.secondary-action.light {
  color: #fff;
  border-color: rgba(255, 255, 255, .56);
}

.hero-metrics {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  max-width: var(--max);
  width: 100%;
  margin-top: 48px;
}

.hero-metrics div {
  min-height: 94px;
  padding: 14px;
  background: rgba(255, 255, 255, .94);
  color: #152033;
  border: 1px solid rgba(255, 255, 255, .5);
  border-radius: var(--radius);
}

.hero-metrics strong {
  display: block;
  color: var(--brand);
  font-size: 28px;
  line-height: 1.1;
}

.hero-metrics span {
  display: block;
  margin-top: 6px;
  color: #526171;
  font-size: 14px;
  font-weight: 700;
}

.band {
  padding: 76px max(22px, calc((100vw - var(--max)) / 2));
  background: var(--bg);
  scroll-margin-top: 82px;
}

.band.white {
  background: var(--paper);
}

.section-head {
  max-width: 840px;
  margin-bottom: 28px;
}

.section-head h2 {
  margin: 0;
  font-size: 34px;
  line-height: 1.2;
  letter-spacing: 0;
  color: #101828;
}

.section-head p:last-child {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 16px;
}

.shift-grid,
.module-grid,
.semester-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.shift-grid article,
.module-grid article,
.semester-grid article,
.project-grid > article:not(.project-feature),
.evidence-files article {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: var(--shadow);
}

.shift-grid span,
.gate-timeline span,
.evidence-files span,
.semester-grid span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 38px;
  height: 30px;
  margin-bottom: 14px;
  padding: 0 8px;
  color: var(--brand);
  background: #eef5ff;
  border: 1px solid #d4e6ff;
  border-radius: var(--radius);
  font-size: 13px;
  font-weight: 900;
}

.shift-grid h3,
.module-grid h3,
.semester-grid h3,
.project-grid h3,
.evidence-files h3,
.teacher-layout h3,
.join-panel h3,
.investment-copy h3,
.repo-structure h3 {
  margin: 0 0 8px;
  color: #102a63;
  font-size: 19px;
  line-height: 1.25;
  letter-spacing: 0;
}

.shift-grid p,
.module-grid p,
.semester-grid p,
.project-grid p,
.evidence-files p,
.investment-copy p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.org-layout {
  display: grid;
  grid-template-columns: minmax(260px, .8fr) minmax(0, 1.5fr);
  gap: 16px;
  align-items: stretch;
}

.org-core {
  display: flex;
  min-height: 420px;
  flex-direction: column;
  justify-content: center;
  padding: 30px;
  color: #fff;
  background: #143b73;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.org-core span {
  color: #ffd6a3;
  font-size: 13px;
  font-weight: 900;
}

.org-core h3 {
  margin: 10px 0;
  font-size: 30px;
  line-height: 1.2;
  letter-spacing: 0;
}

.org-core p {
  margin: 0;
  color: #dbe7ff;
}

.org-pillars {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.org-pillars article {
  min-height: 200px;
  padding: 20px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.org-pillars h3 {
  margin: 0 0 8px;
  color: var(--teal);
}

.org-pillars p {
  margin: 0;
  color: var(--muted);
}

.gate-timeline {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 10px;
}

.gate-timeline article {
  position: relative;
  min-height: 210px;
  padding: 18px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.gate-timeline h3 {
  margin: 0 0 8px;
  color: #102a63;
  font-size: 17px;
  line-height: 1.25;
}

.gate-timeline p {
  margin: 0;
  color: var(--muted);
  font-size: 13px;
}

.investment-grid {
  display: grid;
  grid-template-columns: minmax(260px, .8fr) minmax(0, 1.4fr);
  gap: 16px;
  margin-top: 18px;
}

.investment-copy,
.teacher-principle,
.rubric,
.join-panel,
.repo-structure {
  padding: 22px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.investment-levels {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 10px;
  margin: 0;
}

.investment-levels div {
  padding: 14px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.investment-levels dt {
  color: var(--amber);
  font-weight: 900;
}

.investment-levels dd {
  margin: 7px 0 0;
  color: var(--muted);
  font-size: 13px;
}

.photo-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) repeat(2, minmax(0, .8fr));
  gap: 14px;
}

.photo-grid figure {
  position: relative;
  min-height: 330px;
  margin: 0;
  overflow: hidden;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background: #e9eef5;
  box-shadow: var(--shadow);
}

.photo-grid .large-photo {
  min-height: 450px;
}

.photo-grid img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.photo-grid figcaption {
  position: absolute;
  left: 12px;
  bottom: 12px;
  max-width: calc(100% - 24px);
  padding: 7px 10px;
  color: #fff;
  background: rgba(10, 18, 32, .76);
  border-radius: var(--radius);
  font-size: 13px;
  font-weight: 800;
}

.project-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.project-feature {
  grid-column: span 2;
  grid-row: span 2;
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.project-image {
  height: 300px;
  background: #e9eef5;
}

.project-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 42%;
}

.project-body {
  padding: 22px;
}

.project-body ul {
  margin: 14px 0 0;
  padding-left: 18px;
  color: var(--muted);
}

.tag {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  margin-bottom: 12px;
  padding: 4px 8px;
  color: var(--teal);
  background: #e8f8f6;
  border: 1px solid #bde7e1;
  border-radius: var(--radius);
  font-size: 12px;
  font-weight: 900;
}

.tag.orange {
  color: var(--amber);
  background: #fff3e8;
  border-color: #ffd6b0;
}

.maturity-strip {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 10px;
  margin-top: 18px;
}

.maturity-strip div {
  padding: 14px;
  color: #fff;
  background: #143b73;
  border-radius: var(--radius);
}

.maturity-strip strong {
  display: block;
  font-size: 22px;
}

.maturity-strip span {
  color: #dbe7ff;
  font-size: 13px;
}

.evidence-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(320px, .85fr);
  gap: 16px;
}

.evidence-files {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.repo-structure pre {
  margin: 14px 0 0;
  padding: 16px;
  overflow: auto;
  color: #dce9ff;
  background: #101828;
  border-radius: var(--radius);
  font-size: 13px;
  line-height: 1.55;
}

.teaching-band {
  background: #f3f7fb;
}

.teacher-layout {
  display: grid;
  grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr);
  gap: 16px;
}

.principle-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.principle-columns ul,
.join-panel ul {
  margin: 0;
  padding-left: 18px;
  color: var(--muted);
}

.principle-columns li,
.join-panel li {
  margin: 8px 0;
}

.rubric dl {
  display: grid;
  gap: 8px;
  margin: 0;
}

.rubric dl div {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 9px 0;
  border-bottom: 1px solid var(--line-soft);
}

.rubric dl div:last-child {
  border-bottom: 0;
}

.rubric dt {
  color: var(--muted);
  font-weight: 700;
}

.rubric dd {
  margin: 0;
  color: var(--brand);
  font-weight: 900;
}

.news-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.news-grid article {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 16px;
  align-items: stretch;
  overflow: hidden;
  padding: 12px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.news-grid img {
  width: 100%;
  height: 180px;
  object-fit: cover;
  border-radius: var(--radius);
}

.news-grid span {
  color: var(--amber);
  font-size: 12px;
  font-weight: 900;
}

.news-grid h3 {
  margin: 8px 0;
  color: #102a63;
  font-size: 18px;
  line-height: 1.25;
}

.news-grid p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.join-section {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(280px, .48fr);
  gap: 18px;
  padding: 72px max(22px, calc((100vw - var(--max)) / 2));
  color: #fff;
  background: #143b73;
}

.join-content h2 {
  margin: 0;
  font-size: 34px;
  line-height: 1.2;
  letter-spacing: 0;
}

.join-content p:not(.section-kicker) {
  max-width: 780px;
  margin: 12px 0 0;
  color: #dbe7ff;
}

.join-panel {
  color: var(--ink);
  background: #fff;
}

.site-footer {
  padding: 24px max(22px, calc((100vw - var(--max)) / 2));
  color: var(--muted);
  background: #fff;
  border-top: 1px solid var(--line);
  font-size: 13px;
}

.site-footer p {
  margin: 4px 0;
}

[data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity .45s ease, transform .45s ease;
}

[data-reveal].visible {
  opacity: 1;
  transform: none;
}

@media (max-width: 1100px) {
  .shift-grid,
  .module-grid,
  .semester-grid,
  .gate-timeline,
  .investment-levels,
  .maturity-strip {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .org-layout,
  .investment-grid,
  .evidence-layout,
  .teacher-layout,
  .join-section,
  .photo-grid {
    grid-template-columns: 1fr;
  }

  .org-core {
    min-height: 260px;
  }

  .photo-grid .large-photo,
  .photo-grid figure {
    min-height: 300px;
  }

  .project-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .news-grid article {
    grid-template-columns: 1fr;
  }

  .news-grid img {
    height: 240px;
  }
}

@media (max-width: 760px) {
  .site-header {
    min-height: 62px;
    padding: 10px 14px;
    width: 100vw;
    max-width: 100vw;
    overflow: hidden;
  }

  .brand {
    flex: 1 1 0;
    min-width: 0;
    max-width: min(300px, calc(100vw - 92px));
  }

  .brand-text {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    font-size: 15px;
  }

  .menu-button {
    display: inline-flex;
    flex: 0 0 auto;
    position: absolute;
    top: 13px;
    right: auto;
    left: min(320px, calc(100vw - 72px));
  }

  .site-nav {
    position: fixed;
    top: 62px;
    right: 12px;
    left: 12px;
    display: none;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 8px;
    padding: 12px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
  }

  .site-nav.open {
    display: grid;
  }

  .site-nav a {
    text-align: center;
    font-size: 13px;
  }

  .hero {
    width: 100vw;
    max-width: 100vw;
    min-height: 82vh;
    padding: 96px 18px 24px;
  }

  .hero-content {
    max-width: min(354px, calc(100vw - 36px));
  }

  h1 {
    font-size: 34px;
    max-width: min(354px, calc(100vw - 36px));
    word-break: break-all;
    line-break: anywhere;
  }

  .hero-subtitle {
    font-size: 18px;
    max-width: min(354px, calc(100vw - 36px));
    word-break: break-all;
    line-break: anywhere;
  }

  .hero-copy {
    max-width: min(354px, calc(100vw - 36px));
    font-size: 15px;
  }

  .hero-metrics,
  .section-head {
    max-width: min(354px, calc(100vw - 36px));
  }

  .hero-metrics,
  .shift-grid,
  .module-grid,
  .semester-grid,
  .gate-timeline,
  .investment-levels,
  .maturity-strip,
  .org-pillars,
  .project-grid,
  .evidence-files,
  .principle-columns,
  .news-grid {
    grid-template-columns: 1fr;
  }

  .project-feature {
    grid-column: span 1;
    grid-row: span 1;
  }

  .project-image {
    height: 220px;
  }

  .band,
  .join-section {
    padding: 54px 18px;
  }

  .section-head h2,
  .join-content h2 {
    font-size: 27px;
  }

  .hero-metrics div {
    min-height: 74px;
  }

  .photo-grid .large-photo,
  .photo-grid figure {
    min-height: 240px;
  }

  .news-grid img {
    height: 210px;
  }
}

@media (max-width: 420px) {
  .hero-actions,
  .join-actions {
    flex-direction: column;
  }

  .primary-action,
  .secondary-action {
    width: 100%;
  }

  h1 {
    font-size: 30px;
  }
}