:root {
  --ink: #152238;
  --muted: #667085;
  --line: #d9e4e8;
  --paper: #ffffff;
  --soft: #f4faf9;
  --deep: #102a43;
  --teal: #177e78;
  --teal-dark: #0e5c57;
  --coral: #e76f51;
  --gold: #f2b84b;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

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

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px clamp(20px, 5vw, 72px);
  border-bottom: 1px solid rgba(217, 228, 232, 0.88);
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(12px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 900;
}
.logo-img{
    width:68px;
    height:68px;
    object-fit:contain;
  }
.name-img{
    width:100px;
    height:60px;
    object-fit:contain;
  }
.brand-mark {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  color: #fff;
  background: var(--teal);
}

.nav {
  display: flex;
  align-items: center;
  gap: clamp(16px, 3vw, 34px);
  color: var(--muted);
  font-size: 17px;
  font-weight: 700;
}

.nav a:hover {
  color: var(--teal-dark);
}

.menu-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.menu-toggle span {
  display: block;
  width: 19px;
  height: 2px;
  margin: 5px auto;
  background: var(--ink);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(320px, 1.08fr);
  gap: clamp(15px, 2.5vw, 34px);
  align-items: center;
  min-height: calc(50vh - 35px);
  padding: clamp(21px, 3.5vw, 45px) clamp(20px, 5vw, 72px) 24px;
  background:
    linear-gradient(120deg, rgba(23, 126, 120, 0.09), rgba(231, 111, 81, 0.08)),
    var(--soft);
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--coral);
  font-size: 15px;
  font-weight: 900;
}

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

h1 {
  max-width: 680px;
  margin-bottom: 22px;
  font-size: clamp(42px, 7vw, 76px);
  line-height: 1.05;
}

h2 {
  margin-bottom: 12px;
  font-size: clamp(30px, 4.5vw, 48px);
  line-height: 1.15;
}

h3 {
  margin-bottom: 10px;
  font-size: 20px;
  line-height: 1.3;
}

.hero-text {
  max-width: 620px;
  margin-bottom: 30px;
  color: var(--muted);
  font-size: 18px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.button,
.contact-form button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  border: 0;
  border-radius: 8px;
  padding: 0 22px;
  font: inherit;
  font-weight: 900;
  cursor: pointer;
}

.primary,
.contact-form button {
  color: #fff;
  background: var(--teal);
  box-shadow: 0 14px 28px rgba(23, 126, 120, 0.22);
}

.ghost {
  color: var(--teal-dark);
  background: #fff;
  border: 1px solid var(--line);
}

.hero-image img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: 8px;
  box-shadow: 0 26px 60px rgba(21, 34, 56, 0.18);
}

.metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  padding: 14px clamp(20px, 5vw, 72px);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.metrics strong {
  display: block;
  color: var(--teal-dark);
  font-size: clamp(30px, 5vw, 46px);
  line-height: 1;
}

.metrics span {
  color: var(--muted);
}

.section,
.about,
.contact {
  padding: clamp(29px, 4vw, 52px) clamp(20px, 5vw, 72px);
}

.section-head {
  max-width: 780px;
  margin-bottom: 32px;
}

.section-head p,
.course-card p,
.teacher-card p,
.about p,
.contact p,
.contact-info {
  color: var(--muted);
}

.alt {
  background: var(--soft);
}

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

.course-guide-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 27px;
}

.deck-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.deck-grid h3{
  white-space: nowrap;
  font-size:  18px;
}

.course-card,
.teacher-card {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.course-card img {
  width: 100%;
  height: auto;
  object-fit: cover;
}

.course-card div,
.teacher-card {
  padding: 24px;
}

.lecture-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(420px, 0.92fr);
  gap: 18px;
  align-items: stretch;
}

.lecture-main,
.lecture-item {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.lecture-main img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

.lecture-main div {
  padding: 24px;
}

.lecture-main p,
.lecture-item p {
  color: var(--muted);
}

/* 右边三张卡片 */
.lecture-list {
  display: grid;
  grid-template-rows: repeat(3, minmax(0, 1fr));
  gap: 18px;
  min-height: 0;
}

/* 图片在左，文字在右 */
.lecture-item {
  display: grid;
  grid-template-columns: 170px minmax(0, 1fr);
  min-width: 0;
  min-height: 0;
}

/* 图片缩小并完整显示 */
.lecture-item img {
  width: 170px;
  height: 100%;
  padding: 8px;
  object-fit: contain;
  background: #fff;
}

/* 右边文字 */
.lecture-item div {
  min-width: 0;
  padding: 10px 12px;
}

.lecture-item h3 {
  margin-bottom: 5px;
  font-size: 17px;
  line-height: 1.3;
}

.lecture-item p {
  margin-bottom: 0;
  font-size: 13px;
  line-height: 1.45;
}

.teacher-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.teacher-card img {
  width: 92px;
  height: 92px;
  margin-bottom: 18px;
  border-radius: 50%;
  object-fit: cover;
}

.about {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(320px, 1.05fr);
  gap: clamp(28px, 5vw, 64px);
  align-items: center;
}

.about img {
  width: 100%;
  aspect-ratio: 5 / 4;
  border-radius: 8px;
  object-fit: cover;
}

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

.check-list li {
  position: relative;
  padding-left: 30px;
  font-weight: 800;
}

.check-list li::before {
  position: absolute;
  left: 0;
  color: var(--teal);
  content: "✓";
}

.contact {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(320px, 0.78fr);
  gap: clamp(26px, 5vw, 58px);
  background: var(--deep);
  color: #fff;
}

.contact .eyebrow {
  color: #f7c66b;
}

.contact p,
.contact-info {
  color: #d8e6ec;
}

.contact-info {
  display: grid;
  gap: 8px;
  margin-top: 24px;
}

.contact-form {
  display: grid;
  gap: 14px;
  padding: 24px;
  border-radius: 8px;
  color: var(--ink);
  background: #fff;
  box-shadow: 0 18px 45px rgba(0, 0, 0, 0.2);
}

.contact-form label {
  display: grid;
  gap: 7px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 800;
}

.contact-form input,
.contact-form select,
.contact-form textarea {
  width: 100%;
  min-height: 46px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 12px;
  color: var(--ink);
  background: #fff;
  font: inherit;
}

.contact-form textarea {
  resize: vertical;
}

.form-note {
  min-height: 22px;
  margin: 0;
  color: var(--teal-dark);
  font-weight: 800;
}

.footer {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 24px clamp(20px, 5vw, 72px);
  color: var(--muted);
  border-top: 1px solid var(--line);
}

@media (max-width: 900px) {
  .menu-toggle {
    display: block;
  }

  .nav {
    position: absolute;
    top: 101px;
    right: 20px;
    left: 20px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 12px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: #fff;
    box-shadow: 0 18px 40px rgba(21, 34, 56, 0.14);
  }

  .nav.is-open {
    display: flex;
  }

  .nav a {
    padding: 12px;
  }

  .hero,
  .about,
  .contact {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .card-grid,
  .deck-grid,
  .teacher-grid,
  .lecture-layout,
  .lecture-item {
    grid-template-columns: 1fr;
  }

  .lecture-item img {
    aspect-ratio: 16 / 9;
    height: auto;
  }
}

@media (max-width: 560px) {
  .site-header {
    padding-inline: 16px;
  }

  h1 {
    font-size: 39px;
  }

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

  .footer {
    flex-direction: column;
  }

  .button,
  .contact-form button {
    width: 100%;
  }
}