* {
  box-sizing: border-box;
}

:root {
  --ink: #12302c;
  --muted: #58716c;
  --line: #d7e5e1;
  --teal: #0f766e;
  --green: #159947;
  --coral: #e65f38;
  --paper: #f7fbfa;
  --white: #ffffff;
}

html {
  scroll-behavior: smooth;
}

body {
  background: var(--paper);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "Microsoft YaHei", Arial, sans-serif;
  margin: 0;
}

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

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

.site-header {
  align-items: center;
  background: rgba(247, 251, 250, 0.92);
  border-bottom: 1px solid rgba(215, 229, 225, 0.9);
  display: flex;
  gap: 18px;
  justify-content: space-between;
  left: 0;
  min-height: 68px;
  padding: 10px clamp(18px, 4vw, 48px);
  position: sticky;
  right: 0;
  top: 0;
  z-index: 10;
}

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

.brand img {
  border-radius: 8px;
  height: 38px;
  object-fit: contain;
  width: 58px;
}

.brand span {
  overflow-wrap: anywhere;
}

.site-nav {
  align-items: center;
  display: flex;
  gap: clamp(14px, 3vw, 30px);
}

.site-nav a {
  color: #274a45;
  font-size: 15px;
  font-weight: 700;
}

.header-phone,
.primary-action,
.secondary-action,
.contact-buttons a {
  align-items: center;
  border-radius: 8px;
  display: inline-flex;
  font-weight: 800;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
}

.header-phone,
.primary-action {
  background: var(--coral);
  color: #fff;
}

.hero {
  background:
    linear-gradient(135deg, rgba(15, 118, 110, 0.12), rgba(255, 255, 255, 0) 46%),
    var(--paper);
  border-bottom: 1px solid var(--line);
}

.hero-content {
  align-items: center;
  display: grid;
  gap: clamp(30px, 6vw, 76px);
  grid-template-columns: minmax(0, 0.9fr) minmax(320px, 0.82fr);
  margin: 0 auto;
  max-width: 1180px;
  min-height: 640px;
  padding: clamp(58px, 8vw, 96px) clamp(20px, 5vw, 64px);
}

.hero-copy-block {
  max-width: 680px;
}

.eyebrow,
.section-kicker {
  color: var(--teal);
  font-size: 13px;
  font-weight: 900;
  margin: 0 0 12px;
  text-transform: uppercase;
}

.hero h1 {
  color: var(--ink);
  font-size: 54px;
  line-height: 1.06;
  margin: 0;
}

.hero-copy {
  color: var(--muted);
  font-size: 19px;
  line-height: 1.8;
  margin: 20px 0 0;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.secondary-action {
  background: #fff;
  border: 1px solid var(--line);
  color: var(--ink);
}

.hero-visual {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 24px 60px rgba(18, 48, 44, 0.12);
  overflow: hidden;
}

.hero-visual-header {
  align-items: center;
  border-bottom: 1px solid var(--line);
  display: flex;
  gap: 12px;
  justify-content: space-between;
  padding: 16px 18px;
}

.hero-visual-header span {
  color: var(--muted);
  font-size: 14px;
  font-weight: 800;
}

.hero-visual-header strong {
  color: var(--coral);
  font-size: 15px;
}

.hero-visual img {
  aspect-ratio: 4 / 3;
  object-fit: contain;
  object-position: center;
  padding: 18px;
  width: 100%;
}

.signal-band {
  background: var(--white);
  border-bottom: 1px solid var(--line);
  display: grid;
  gap: 1px;
  grid-template-columns: repeat(3, 1fr);
}

.signal-band div {
  border-right: 1px solid var(--line);
  min-height: 112px;
  padding: 26px clamp(18px, 4vw, 46px);
}

.signal-band div:last-child {
  border-right: 0;
}

.signal-band strong,
.signal-band span {
  display: block;
}

.signal-band strong {
  font-size: 20px;
}

.signal-band span {
  color: var(--muted);
  line-height: 1.7;
  margin-top: 8px;
}

.signal-band a {
  color: var(--teal);
  font-weight: 900;
}

.section {
  padding: clamp(58px, 9vw, 104px) clamp(20px, 6vw, 80px);
}

.section-heading {
  margin: 0 auto 34px;
  max-width: 760px;
  text-align: center;
}

.section-kicker {
  color: var(--teal);
}

.section h2,
.contact-section h2 {
  font-size: 38px;
  line-height: 1.18;
  margin: 0;
}

.section-heading p:last-child,
.feature-copy p,
.contact-copy p,
.notice p {
  color: var(--muted);
  font-size: 17px;
  line-height: 1.85;
  margin: 16px 0 0;
}

.timeline,
.faculty-grid,
.resource-grid {
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(3, 1fr);
  margin: 0 auto;
  max-width: 1120px;
}

.timeline article,
.faculty-grid article,
.resource-grid article {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 24px;
}

.faculty-section {
  background: linear-gradient(180deg, #ffffff 0%, #f2faf7 100%);
}

.faculty-grid article {
  border-color: rgba(15, 118, 110, 0.18);
  box-shadow: 0 18px 42px rgba(18, 48, 44, 0.08);
}

.timeline span {
  color: var(--coral);
  display: block;
  font-size: 13px;
  font-weight: 900;
  margin-bottom: 16px;
}

.faculty-grid span {
  align-items: center;
  background: rgba(230, 95, 56, 0.12);
  border-radius: 999px;
  color: var(--coral);
  display: inline-flex;
  font-size: 13px;
  font-weight: 900;
  height: 34px;
  justify-content: center;
  margin-bottom: 18px;
  width: 44px;
}

.timeline h3,
.faculty-grid h3,
.resource-grid h3 {
  font-size: 22px;
  line-height: 1.25;
  margin: 0;
}

.timeline p,
.faculty-grid p,
.resource-grid p {
  color: var(--muted);
  line-height: 1.75;
  margin: 12px 0 0;
}

.feature-row {
  align-items: center;
  background: #eaf5f2;
  display: grid;
  gap: clamp(28px, 6vw, 72px);
  grid-template-columns: minmax(0, 0.86fr) minmax(300px, 1fr);
}

.feature-copy {
  max-width: 620px;
}

.check-list {
  display: grid;
  gap: 12px;
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
}

.check-list li {
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid rgba(15, 118, 110, 0.2);
  border-radius: 8px;
  line-height: 1.6;
  padding: 13px 15px;
}

.image-stack {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.image-stack img {
  aspect-ratio: 1 / 1;
  background: #fff;
  border-radius: 8px;
  box-shadow: 0 24px 54px rgba(18, 48, 44, 0.18);
  height: 100%;
  object-fit: contain;
  padding: 10px;
  width: 100%;
}

.article-video-panel {
  background: #12302c;
  border-radius: 8px;
  box-shadow: 0 24px 60px rgba(18, 48, 44, 0.18);
  margin: 0 0 28px;
  overflow: hidden;
}

.article-video-panel video {
  aspect-ratio: 16 / 9;
  background: #0b1e1b;
  display: block;
  width: 100%;
}

.article-body .lesson-key-points {
  background: #f7fbfa;
  border: 1px solid rgba(15, 118, 110, 0.18);
  border-radius: 8px;
  display: grid;
  gap: 10px;
  list-style: none;
  margin: 18px 0 4px;
  padding: 18px;
}

.article-body .lesson-key-points li {
  background: #fff;
  border: 1px solid rgba(215, 229, 225, 0.9);
  border-radius: 8px;
  color: #274a45;
  font-size: 16px;
  font-weight: 800;
  line-height: 1.65;
  padding: 12px 14px;
}

.resource-section {
  background: #fff;
}

.resource-grid {
  grid-template-columns: repeat(4, 1fr);
}

.knowledge-section {
  background: #f7fbfa;
}

.knowledge-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  margin: 0 auto 24px;
  max-width: 920px;
}

.knowledge-toolbar button {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--ink);
  cursor: pointer;
  font: inherit;
  font-size: 15px;
  font-weight: 800;
  min-height: 40px;
  padding: 0 14px;
}

.knowledge-toolbar button.active {
  background: var(--teal);
  border-color: var(--teal);
  color: #fff;
}

.knowledge-grid {
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(3, 1fr);
  margin: 0 auto;
  max-width: 1120px;
}

.knowledge-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  display: flex;
  flex-direction: column;
  min-height: 230px;
  padding: 24px;
}

.knowledge-card span {
  color: var(--teal);
  font-size: 13px;
  font-weight: 900;
  margin-bottom: 14px;
}

.knowledge-card h3 {
  font-size: 22px;
  line-height: 1.28;
  margin: 0;
}

.knowledge-card p {
  color: var(--muted);
  line-height: 1.75;
  margin: 12px 0 0;
}

.knowledge-card a {
  color: var(--coral);
  font-weight: 900;
  margin-top: auto;
  padding-top: 18px;
}

.contact-section {
  align-items: center;
  background: #12302c;
  color: #fff;
  display: grid;
  gap: clamp(28px, 6vw, 72px);
  grid-template-columns: minmax(0, 1fr) 260px;
  padding: clamp(58px, 9vw, 104px) clamp(20px, 6vw, 80px);
}

.contact-copy {
  max-width: 780px;
}

.contact-copy p {
  color: rgba(255, 255, 255, 0.76);
}

.contact-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.contact-buttons a {
  background: #fff;
  color: #12302c;
}

.qr-panel {
  background: #fff;
  border-radius: 8px;
  color: var(--ink);
  margin: 0;
  padding: 16px;
  text-align: center;
}

.qr-panel img {
  aspect-ratio: 1;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  object-fit: contain;
  padding: 8px;
  width: 100%;
}

.qr-panel figcaption {
  font-weight: 800;
  margin-top: 12px;
}

.notice {
  background: #f2f7f5;
  border-top: 1px solid var(--line);
  padding: 24px clamp(20px, 6vw, 80px);
}

.notice p {
  font-size: 14px;
  margin: 0 auto;
  max-width: 1120px;
}

.site-footer {
  align-items: center;
  background: #fff;
  border-top: 1px solid var(--line);
  color: var(--muted);
  display: flex;
  gap: 14px;
  justify-content: space-between;
  padding: 22px clamp(20px, 6vw, 80px);
}

.site-footer a {
  color: var(--teal);
  font-weight: 800;
}

.topic-hero {
  background:
    linear-gradient(135deg, rgba(15, 118, 110, 0.14), rgba(255, 255, 255, 0) 48%),
    #ffffff;
  border-bottom: 1px solid var(--line);
}

.topic-hero-inner {
  align-items: center;
  display: grid;
  gap: clamp(30px, 6vw, 72px);
  grid-template-columns: minmax(0, 0.95fr) minmax(300px, 0.7fr);
  margin: 0 auto;
  max-width: 1180px;
  min-height: 560px;
  padding: clamp(56px, 8vw, 92px) clamp(20px, 5vw, 64px);
}

.topic-hero h1 {
  font-size: clamp(36px, 6vw, 58px);
  line-height: 1.12;
  margin: 0;
}

.topic-hero p {
  color: var(--muted);
  font-size: 18px;
  line-height: 1.85;
  margin: 20px 0 0;
}

.topic-hero-media {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 24px 60px rgba(18, 48, 44, 0.12);
  margin: 0;
  padding: 18px;
}

.topic-hero-media img {
  aspect-ratio: 4 / 3;
  object-fit: contain;
  width: 100%;
}

.topic-hero-media figcaption {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
  margin-top: 10px;
  text-align: center;
}

.faq-section {
  background: #f7fbfa;
}

.faq-list {
  display: grid;
  gap: 16px;
  margin: 0 auto;
  max-width: 980px;
}

.faq-list article {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 24px;
}

.faq-list h3 {
  font-size: 22px;
  line-height: 1.3;
  margin: 0;
}

.faq-list p {
  color: var(--muted);
  font-size: 17px;
  line-height: 1.85;
  margin: 12px 0 0;
}

.article-main {
  background: var(--paper);
}

.article-hero {
  background: #12302c;
  color: #fff;
  padding: clamp(58px, 9vw, 104px) clamp(20px, 6vw, 80px);
}

.article-hero-inner,
.article-body,
.article-cta {
  margin: 0 auto;
  max-width: 880px;
}

.article-back {
  color: rgba(255, 255, 255, 0.82);
  display: inline-flex;
  font-weight: 800;
  margin-bottom: 26px;
}

.article-meta {
  color: #9ee0d7;
  font-size: 14px;
  font-weight: 900;
  margin: 0 0 14px;
}

.article-hero h1 {
  font-size: clamp(34px, 6vw, 52px);
  line-height: 1.14;
  margin: 0;
}

.article-intro {
  color: rgba(255, 255, 255, 0.78);
  font-size: 18px;
  line-height: 1.85;
  margin: 20px 0 0;
}

.article-body {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  margin-top: -36px;
  padding: clamp(28px, 5vw, 48px);
}

.article-body h2 {
  font-size: 28px;
  line-height: 1.25;
  margin: 34px 0 12px;
}

.article-body h2:first-child {
  margin-top: 0;
}

.article-body p,
.article-body li {
  color: var(--muted);
  font-size: 17px;
  line-height: 1.9;
}

.article-body p {
  margin: 0 0 16px;
}

.article-body ul {
  display: grid;
  gap: 10px;
  margin: 14px 0 0;
  padding-left: 20px;
}

.article-body figure {
  margin: 18px 0 24px;
}

.article-body figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.article-body figcaption {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
  margin-top: 8px;
  text-align: center;
}

.article-cta {
  align-items: center;
  background: #eaf5f2;
  border: 1px solid var(--line);
  border-radius: 8px;
  display: flex;
  gap: 18px;
  justify-content: space-between;
  margin-bottom: clamp(50px, 7vw, 82px);
  margin-top: 24px;
  padding: 22px;
}

.article-cta p {
  color: var(--muted);
  line-height: 1.75;
  margin: 0;
}

.article-cta a {
  align-items: center;
  background: var(--coral);
  border-radius: 8px;
  color: #fff;
  display: inline-flex;
  font-weight: 900;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  white-space: nowrap;
}

@media (max-width: 900px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
    min-height: 0;
  }

  .site-nav {
    flex-wrap: wrap;
  }

  .header-phone {
    position: absolute;
    right: 16px;
    top: 10px;
  }

  .hero h1 {
    font-size: 40px;
  }

  .hero-copy {
    font-size: 17px;
  }

  .signal-band,
  .timeline,
  .faculty-grid,
  .resource-grid,
  .knowledge-grid,
  .hero-content,
  .topic-hero-inner,
  .feature-row,
  .contact-section {
    grid-template-columns: 1fr;
  }

  .signal-band div {
    border-bottom: 1px solid var(--line);
    border-right: 0;
  }

  .contact-section {
    justify-items: start;
  }

  .qr-panel {
    max-width: 260px;
  }
}

@media (max-width: 560px) {
  .site-header {
    padding: 10px 14px;
  }

  .brand span {
    max-width: 180px;
  }

  .site-nav a {
    font-size: 14px;
  }

  .header-phone {
    min-height: 38px;
    padding: 0 12px;
  }

  .hero-content {
    gap: 28px;
    min-height: 0;
    padding: 42px 18px 46px;
  }

  .hero h1 {
    font-size: 34px;
  }

  .topic-hero-inner {
    min-height: 0;
    padding: 42px 18px 46px;
  }

  .hero-actions,
  .contact-buttons {
    align-items: stretch;
    flex-direction: column;
  }

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

  .section h2,
  .contact-section h2 {
    font-size: 30px;
  }

  .section {
    padding: 48px 18px;
  }

  .feature-row,
  .contact-section {
    padding: 48px 18px;
  }

  .image-stack {
    gap: 12px;
  }

  .timeline article,
  .resource-grid article,
  .knowledge-card {
    padding: 20px;
  }

  .site-footer {
    align-items: flex-start;
    flex-direction: column;
    padding: 22px 18px;
  }

  .article-cta {
    align-items: stretch;
    flex-direction: column;
  }
}