:root {
  --bg: #f6fff9;
  --bg-soft: #e8fbef;
  --card: rgba(255, 255, 255, 0.84);
  --text: #14372b;
  --muted: #4f7d6f;
  --primary: #1fa57a;
  --primary-strong: #0f7a58;
  --accent: #f7d39a;
  --line: rgba(31, 165, 122, 0.18);
  --shadow: 0 18px 50px rgba(27, 103, 78, 0.13);
}

body.theme-red {
  --bg: #fff7f7;
  --bg-soft: #ffeaea;
  --card: rgba(255,255,255,0.92);
  --text: #4a2323;
  --muted: #a05a5a;
  --primary: #e14c4c;
  --primary-strong: #b92d2d;
  --accent: #ffd6c1;
  --line: rgba(225, 76, 76, 0.18);
  --shadow: 0 18px 50px rgba(225, 76, 76, 0.10);
}
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  min-height: 100vh;
  font-family: "Noto Sans SC", "PingFang SC", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 90% 6%, rgba(172, 233, 201, 0.4), transparent 38%),
    radial-gradient(circle at 5% 80%, rgba(249, 223, 185, 0.42), transparent 36%),
    linear-gradient(180deg, #f7fff9 0%, #effcf5 44%, #f8fff9 100%);
  overflow-x: hidden;
}

.container {
  width: min(1140px, calc(100vw - 2.4rem));
  margin: 0 auto;
}

.bg-orb {
  position: fixed;
  z-index: -1;
  border-radius: 999px;
  filter: blur(2px);
  opacity: 0.45;
  pointer-events: none;
  animation: floatOrb 12s ease-in-out infinite;
}

.orb-1 {
  width: 320px;
  height: 320px;
  top: -90px;
  left: -70px;
  background: radial-gradient(circle at 30% 30%, #cbf8dc 0%, #94dfb9 100%);
}

.orb-2 {
  width: 260px;
  height: 260px;
  top: 34%;
  right: -90px;
  background: radial-gradient(circle at 30% 30%, #ffe9c7 0%, #f7c88a 100%);
  animation-delay: 2s;
}

.orb-3 {
  width: 180px;
  height: 180px;
  bottom: 6%;
  left: 12%;
  background: radial-gradient(circle at 30% 30%, #c6ebff 0%, #93cae8 100%);
  animation-delay: 4s;
}

.site-header {
  position: sticky;
  top: 12px;
  z-index: 10;
  margin-top: 1rem;
  padding: 0.8rem 1rem;
  border-radius: 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  backdrop-filter: blur(10px);
  background: rgba(255, 255, 255, 0.74);
  border: 1px solid rgba(255, 255, 255, 0.64);
  box-shadow: 0 12px 24px rgba(17, 67, 50, 0.08);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
}

.brand-mark {
  width: 2.2rem;
  height: 2.2rem;
  border-radius: 12px;
  display: block;
  flex: 0 0 auto;
  object-fit: cover;
  box-shadow: 0 10px 24px rgba(22, 143, 103, 0.34);
}

.brand-text {
  font-family: "Ma Shan Zheng", cursive;
  font-size: 1.45rem;
  color: var(--primary-strong);
}

.top-nav {
  display: inline-flex;
  gap: 1rem;
}

.top-nav a {
  color: var(--primary-strong);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 0.36rem 0.72rem;
  border-radius: 999px;
  transition: all 0.22s ease;
}

.top-nav a:hover {
  color: #fff;
  background: var(--primary);
}

main {
  padding-bottom: 2rem;
}

.hero {
  margin-top: 1.8rem;
  padding: clamp(1.4rem, 2.8vw, 3rem);
  border-radius: 30px;
  background:
    linear-gradient(120deg, rgba(255, 255, 255, 0.84), rgba(233, 252, 242, 0.9)),
    repeating-linear-gradient(
      -45deg,
      rgba(171, 233, 202, 0.1) 0,
      rgba(171, 233, 202, 0.1) 10px,
      rgba(255, 255, 255, 0.1) 10px,
      rgba(255, 255, 255, 0.1) 20px
    );
  border: 1px solid rgba(255, 255, 255, 0.8);
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}

.hero::after {
  content: "";
  position: absolute;
  inset: auto -80px -120px auto;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(255, 231, 184, 0.6), transparent 70%);
  pointer-events: none;
}

.eyebrow {
  margin: 0;
  letter-spacing: 0.16em;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--primary);
}

.hero h1 {
  margin: 0.8rem 0 0;
  font-size: clamp(1.8rem, 3.8vw, 3.2rem);
  line-height: 1.14;
}

.hero h1 span {
  display: block;
  color: var(--primary-strong);
}

.hero-desc {
  max-width: 62ch;
  line-height: 1.85;
  color: var(--muted);
  margin: 1.1rem 0 0;
}

.hero-actions {
  margin-top: 1.2rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem;
}

.btn {
  text-decoration: none;
  border-radius: 999px;
  padding: 0.72rem 1.25rem;
  font-weight: 700;
  transition: transform 0.2s ease;
}

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

.btn-primary {
  color: #fff;
  background: linear-gradient(120deg, var(--primary), var(--primary-strong));
  box-shadow: 0 14px 28px rgba(225, 76, 76, 0.16);
}

.btn-ghost {
  color: var(--primary-strong);
  background: rgba(255, 220, 220, 0.62);
  border: 1px solid rgba(225, 76, 76, 0.18);
}

.hero-metrics {
  list-style: none;
  padding: 0;
  margin: 1.5rem 0 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.75rem;
}

.hero-metrics li {
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid var(--line);
  padding: 0.9rem;
}

.hero-metrics strong {
  display: block;
  font-size: 1.2rem;
}

.hero-metrics span {
  color: var(--muted);
  font-size: 0.9rem;
}

.section {
  margin-top: 1.6rem;
  padding: 1rem 0;
}

.section-head h2 {
  margin: 0;
  font-size: clamp(1.3rem, 2.4vw, 2rem);
}

.section-head p {
  margin-top: 0.42rem;
  color: #588471;
}

.channel-grid {
  margin-top: 0.9rem;
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: 1rem;
}

.channel-card {
  grid-column: span 6;
  position: relative;
  overflow: hidden;
  border-radius: 24px;
  text-decoration: none;
  color: inherit;
  background: var(--card);
  border: 1px solid rgba(255, 255, 255, 0.86);
  box-shadow: var(--shadow);
  padding: 1rem;
  transition: transform 0.2s ease;
}

.channel-card:hover {
  transform: translateY(-4px);
}

.channel-card::before {
  content: "";
  position: absolute;
  top: -40px;
  right: -30px;
  width: 130px;
  height: 130px;
  border-radius: 999px;
  background: radial-gradient(circle, rgba(171, 233, 203, 0.62), transparent 70%);
}

.channel-card h3 {
  margin: 0;
  font-size: 1.15rem;
}

.channel-card p {
  margin: 0.4rem 0 0;
  color: var(--muted);
  line-height: 1.6;
}

.channel-foot {
  margin-top: 0.7rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.badge {
  font-size: 0.76rem;
  color: var(--primary-strong);
  padding: 0.24rem 0.58rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--accent);
}

.chev {
  font-size: 1.15rem;
  color: var(--primary-strong);
}

.featured-grid {
  margin-top: 1rem;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}

.feature-card {
  background: rgba(255, 255, 255, 0.82);
  border-radius: 20px;
  border: 1px solid rgba(255, 255, 255, 0.88);
  box-shadow: 0 12px 30px rgba(28, 109, 84, 0.12);
  text-decoration: none;
  color: inherit;
  padding: 1rem;
  transition: transform 0.2s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
}

.feature-tag {
  display: inline-flex;
  font-size: 0.75rem;
  border-radius: 999px;
  color: var(--primary-strong);
  border: 1px solid var(--line);
  background: var(--accent);
  padding: 0.22rem 0.56rem;
}

.feature-card h3 {
  margin: 0.6rem 0 0;
  line-height: 1.35;
  font-size: 1.06rem;
}

.feature-card p {
  margin-top: 0.42rem;
  color: #5a8474;
  line-height: 1.6;
}

.learning-path {
  position: relative;
}

.path-list {
  margin: 1rem 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.8rem;
}

.path-list li {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 0.8rem;
  align-items: start;
  border-radius: 18px;
  padding: 0.85rem;
  background: rgba(255, 255, 255, 0.74);
  border: 1px dashed var(--line);
}

.path-step {
  width: 54px;
  height: 54px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  font-weight: 800;
  color: #fff;
  background: linear-gradient(145deg, var(--primary), var(--primary-strong));
}

.path-list h3 {
  margin: 0.2rem 0 0;
  font-size: 1.02rem;
}

.path-list p {
  margin: 0.3rem 0 0;
  color: #5c8978;
}

.site-footer {
  padding: 1.2rem 0 2.2rem;
  color: #4f7b6d;
  text-align: center;
}

.tip {
  margin-top: 0.4rem;
  font-size: 0.9rem;
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.show {
  opacity: 1;
  transform: translateY(0);
}

@keyframes floatOrb {
  0%,
  100% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(-16px);
  }
}

@media (max-width: 980px) {
  .channel-card {
    grid-column: span 12;
  }

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

@media (max-width: 720px) {
  .site-header {
    flex-wrap: wrap;
    gap: 0.7rem;
  }

  .top-nav {
    width: 100%;
    justify-content: space-between;
  }

  .top-nav a {
    font-size: 0.88rem;
    padding: 0.32rem 0.55rem;
  }

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

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

  .path-list li {
    grid-template-columns: 1fr;
  }
}