:root {
  --ink: #17212b;
  --muted: #657181;
  --line: #dce4e8;
  --paper: #f7f8f4;
  --white: #ffffff;
  --teal: #0f766e;
  --teal-dark: #0b4f4a;
  --coral: #d85b42;
  --gold: #d59b2d;
  --blue: #315f8f;
  --shadow: 0 22px 50px rgba(23, 33, 43, 0.12);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  background: var(--paper);
  line-height: 1.6;
}

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 24px;
  justify-content: space-between;
  padding: 14px clamp(18px, 4vw, 56px);
  background: rgba(247, 248, 244, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: max-content;
  font-weight: 800;
  letter-spacing: 0;
}

.brand-mark {
  display: inline-grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: 8px;
  color: var(--white);
  background: var(--teal);
  font-size: 15px;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: clamp(8px, 2vw, 24px);
  flex: 1;
}

.nav a {
  padding: 8px 2px;
  color: var(--muted);
  font-size: 15px;
  border-bottom: 2px solid transparent;
  white-space: nowrap;
}

.nav a:hover,
.nav a.active {
  color: var(--ink);
  border-color: var(--coral);
}

.header-action,
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 18px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-weight: 700;
  cursor: pointer;
}

.header-action {
  color: var(--white);
  background: var(--ink);
  white-space: nowrap;
}

.button.primary {
  color: var(--white);
  background: var(--teal);
}

.button.secondary {
  color: var(--ink);
  background: var(--white);
  border-color: var(--line);
}

.hero {
  position: relative;
  min-height: 76vh;
  display: grid;
  align-items: end;
  padding: clamp(48px, 8vw, 92px) clamp(22px, 6vw, 86px);
  overflow: hidden;
}

.home-hero {
  color: var(--white);
}

.hero-media {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(12, 22, 28, 0.78), rgba(12, 22, 28, 0.34)),
    url("https://images.unsplash.com/photo-1519389950473-47ba0277781c?auto=format&fit=crop&w=1800&q=82") center / cover;
}

.hero-content {
  position: relative;
  max-width: 780px;
}

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

.home-hero .eyebrow {
  color: #ffc766;
}

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

h1 {
  margin-bottom: 18px;
  font-size: clamp(44px, 8vw, 92px);
  line-height: 1.02;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 12px;
  font-size: clamp(26px, 4vw, 44px);
  line-height: 1.18;
  letter-spacing: 0;
}

h3 {
  font-size: 22px;
  line-height: 1.25;
  letter-spacing: 0;
}

.hero-copy,
.page-hero p {
  max-width: 720px;
  font-size: clamp(17px, 2vw, 21px);
  color: rgba(255, 255, 255, 0.88);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.section {
  padding: clamp(48px, 7vw, 86px) clamp(20px, 6vw, 86px);
}

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

.section-heading {
  max-width: 780px;
  margin-bottom: 28px;
}

.feature-grid,
.course-grid,
.community-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.feature-card,
.event-card {
  min-height: 230px;
  padding: 26px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 10px 28px rgba(23, 33, 43, 0.06);
}

.band .feature-card {
  background: #fbfcf8;
}

.icon,
.date,
.tag {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 0 10px;
  border-radius: 999px;
  color: var(--teal-dark);
  background: #dcefeb;
  font-weight: 800;
  font-size: 13px;
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(320px, 1fr);
  gap: clamp(26px, 5vw, 70px);
  align-items: center;
}

.stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 28px;
}

.stats div {
  padding: 18px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.stats strong {
  display: block;
  color: var(--teal-dark);
  font-size: 30px;
  line-height: 1;
}

.stats span {
  color: var(--muted);
  font-size: 14px;
}

.image-panel {
  overflow: hidden;
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.image-panel img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.page-hero {
  min-height: 48vh;
  padding: clamp(70px, 10vw, 120px) clamp(22px, 6vw, 86px);
  color: var(--white);
  background:
    linear-gradient(90deg, rgba(19, 30, 34, 0.82), rgba(19, 30, 34, 0.42)),
    url("https://images.unsplash.com/photo-1522202176988-66273c2fd55f?auto=format&fit=crop&w=1800&q=80") center / cover;
}

.page-hero.compact {
  background:
    linear-gradient(90deg, rgba(19, 30, 34, 0.80), rgba(19, 30, 34, 0.32)),
    url("https://images.unsplash.com/photo-1517245386807-bb43f82c33c4?auto=format&fit=crop&w=1800&q=80") center / cover;
}

.path-hero {
  background:
    linear-gradient(90deg, rgba(19, 30, 34, 0.82), rgba(19, 30, 34, 0.34)),
    url("https://images.unsplash.com/photo-1509062522246-3755977927d7?auto=format&fit=crop&w=1800&q=80") center / cover;
}

.lab-hero {
  background:
    linear-gradient(90deg, rgba(19, 30, 34, 0.82), rgba(19, 30, 34, 0.32)),
    url("https://images.unsplash.com/photo-1518770660439-4636190af475?auto=format&fit=crop&w=1800&q=80") center / cover;
}

.community-hero {
  background:
    linear-gradient(90deg, rgba(19, 30, 34, 0.82), rgba(19, 30, 34, 0.32)),
    url("https://images.unsplash.com/photo-1521737604893-d14cc237f11d?auto=format&fit=crop&w=1800&q=80") center / cover;
}

.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 26px;
}

.chip {
  min-height: 38px;
  padding: 0 14px;
  color: var(--ink);
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 999px;
  cursor: pointer;
}

.chip.active {
  color: var(--white);
  background: var(--teal);
  border-color: var(--teal);
}

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

.course-card {
  overflow: hidden;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 12px 28px rgba(23, 33, 43, 0.07);
}

.course-card img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.course-card div {
  padding: 22px;
}

.timeline {
  display: grid;
  gap: 16px;
  max-width: 1040px;
  margin: 0 auto;
}

.path-step {
  display: grid;
  grid-template-columns: 64px minmax(0, 1fr);
  gap: 18px;
  align-items: start;
  padding: 24px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.path-step span {
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  color: var(--white);
  background: var(--blue);
  border-radius: 8px;
  font-weight: 900;
}

.lab-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(280px, 0.8fr);
  gap: 22px;
  align-items: stretch;
}

.prompt-console,
.feedback-panel {
  padding: 26px;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 12px 28px rgba(23, 33, 43, 0.07);
}

.console-top {
  display: flex;
  gap: 8px;
  margin-bottom: 18px;
}

.console-top span {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--coral);
}

.console-top span:nth-child(2) {
  background: var(--gold);
}

.console-top span:nth-child(3) {
  background: var(--teal);
}

label {
  display: block;
  margin-bottom: 10px;
  font-weight: 800;
}

textarea {
  width: 100%;
  min-height: 210px;
  margin-bottom: 16px;
  padding: 16px;
  resize: vertical;
  color: var(--ink);
  background: #f8faf9;
  border: 1px solid var(--line);
  border-radius: 8px;
  font: inherit;
}

.feedback-panel {
  background: #13232a;
  color: var(--white);
}

.feedback-panel p {
  color: rgba(255, 255, 255, 0.78);
}

.event-card:nth-child(2) .date {
  color: #67391f;
  background: #ffe4c7;
}

.event-card:nth-child(3) .date {
  color: #63363f;
  background: #ffdfe4;
}

.quote-band {
  padding-top: 20px;
}

blockquote {
  margin: 0;
  padding: clamp(30px, 6vw, 58px);
  color: var(--white);
  background: var(--teal-dark);
  border-radius: 8px;
  font-size: clamp(24px, 4vw, 46px);
  line-height: 1.25;
  font-weight: 800;
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
  padding: 24px clamp(20px, 6vw, 86px);
  color: var(--muted);
  background: var(--white);
  border-top: 1px solid var(--line);
}

.beian-link:hover {
  color: var(--teal-dark);
  text-decoration: underline;
}

@media (max-width: 860px) {
  .site-header {
    position: static;
    align-items: flex-start;
    flex-direction: column;
  }

  .nav {
    width: 100%;
    justify-content: flex-start;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .header-action {
    width: 100%;
  }

  .hero {
    min-height: 66vh;
  }

  .feature-grid,
  .course-grid,
  .community-grid,
  .split,
  .lab-layout {
    grid-template-columns: 1fr;
  }

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

  .path-step {
    grid-template-columns: 52px minmax(0, 1fr);
    padding: 18px;
  }
}

@media (max-width: 520px) {
  h1 {
    font-size: 42px;
  }

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

  .section,
  .page-hero {
    padding-left: 16px;
    padding-right: 16px;
  }
}