:root {
  --bg: #f7f8f5;
  --surface: #ffffff;
  --surface-soft: #f0f3ee;
  --text: #17201b;
  --muted: #6b756f;
  --line: #dde4dd;
  --primary: #246b55;
  --primary-dark: #184d3d;
  --accent: #e9a93a;
  --danger: #d8583a;
  --code: #111827;
  --shadow: 0 18px 50px rgba(18, 31, 25, 0.08);
  --radius: 18px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  font-family: "Microsoft YaHei", "Noto Sans SC", sans-serif;
  background: var(--bg);
}

body.modal-locked {
  overflow: hidden;
}

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

button {
  font: inherit;
}

img {
  max-width: 100%;
}

.site-header,
.section,
.footer {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

.nav {
  height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
}

.brand-mark {
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  color: #fff;
  border-radius: 10px;
  background: var(--primary);
  font-size: 0.9rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-links a {
  padding: 8px 12px;
  color: var(--muted);
  border-radius: 10px;
  font-size: 0.95rem;
}

.nav-links a:hover {
  color: var(--primary-dark);
  background: var(--surface-soft);
}

.hero {
  min-height: 520px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 360px;
  align-items: center;
  gap: 40px;
  padding: 72px 0 84px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--primary);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1,
h2,
h3,
h4,
p {
  margin-top: 0;
}

h1 {
  max-width: 720px;
  margin-bottom: 20px;
  font-size: clamp(2.4rem, 5.4vw, 4.6rem);
  line-height: 1.06;
  letter-spacing: -0.06em;
}

h2 {
  margin-bottom: 10px;
  font-size: clamp(1.9rem, 3.6vw, 3rem);
  line-height: 1.12;
  letter-spacing: -0.04em;
}

h3 {
  margin-bottom: 10px;
  font-size: 1.25rem;
}

h4 {
  margin-bottom: 10px;
  font-size: 0.98rem;
}

.hero-copy p:not(.eyebrow),
.section-heading p,
.showcase-content > p:not(.eyebrow),
.course-card p,
.step p,
.notice,
.faq p {
  color: var(--muted);
  line-height: 1.8;
}

.hero-copy p:not(.eyebrow) {
  max-width: 660px;
  font-size: 1.05rem;
}

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

.btn,
.small-btn,
.buy-btn,
.tab-button {
  cursor: pointer;
  border: 0;
  font-weight: 700;
  transition: transform 160ms ease, background 160ms ease, border-color 160ms ease;
}

.btn {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 18px;
  border-radius: 12px;
}

.btn.primary {
  color: #fff;
  background: var(--primary);
}

.btn.primary:hover {
  background: var(--primary-dark);
}

.btn.ghost {
  color: var(--text);
  border: 1px solid var(--line);
  background: var(--surface);
}

.btn.copy {
  width: 100%;
  margin-top: 8px;
  color: #fff;
  background: var(--danger);
}

.btn:hover,
.small-btn:hover,
.buy-btn:hover,
.tab-button:hover {
  transform: translateY(-1px);
}

.hero-card {
  display: grid;
  gap: 12px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.hero-card div {
  padding: 16px;
  border-radius: 14px;
  background: var(--surface-soft);
}

.hero-card span,
.hero-card strong {
  display: block;
}

.hero-card span {
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 0.9rem;
}

.hero-card strong {
  font-size: 1.1rem;
}

.section {
  padding: 66px 0;
}

.section-heading {
  max-width: 680px;
  margin-bottom: 26px;
}

.showcase-layout {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: 18px;
}

.showcase-tabs {
  display: grid;
  gap: 10px;
}

.tab-button {
  width: 100%;
  padding: 15px;
  text-align: left;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
}

.tab-button strong,
.tab-button span {
  display: block;
}

.tab-button strong {
  margin-bottom: 5px;
  font-size: 0.98rem;
}

.tab-button span {
  color: var(--muted);
  font-size: 0.88rem;
  line-height: 1.5;
}

.tab-button.is-active {
  color: #fff;
  border-color: var(--primary);
  background: var(--primary);
}

.tab-button.is-active span {
  color: rgba(255, 255, 255, 0.78);
}

.showcase-panel {
  overflow: hidden;
  min-height: 430px;
  display: grid;
  grid-template-columns: minmax(300px, 0.82fr) minmax(0, 1fr);
  border: 1px solid var(--line);
  border-radius: 24px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.showcase-visual {
  min-height: 430px;
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(circle at 70% 24%, rgba(233, 169, 58, 0.25), transparent 24%),
    linear-gradient(145deg, #17212f, #0c1118);
}

.scene-label {
  position: absolute;
  top: 18px;
  left: 18px;
  z-index: 2;
  padding: 7px 10px;
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.08);
  font-size: 0.85rem;
  font-family: Consolas, "Cascadia Code", monospace;
}

.scene {
  position: absolute;
  inset: 0;
}

.orbit-line,
.planet {
  position: absolute;
  border-radius: 50%;
}

.solar-scene .orbit-line {
  left: 50%;
  top: 50%;
  border: 1px solid rgba(255, 255, 255, 0.18);
  transform: translate(-50%, -50%);
}

.solar-scene .o1 {
  width: 50%;
  aspect-ratio: 1;
}

.solar-scene .o2 {
  width: 72%;
  aspect-ratio: 1;
}

.solar-scene::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  width: 70px;
  height: 70px;
  border-radius: 50%;
  transform: translate(-50%, -50%);
  background: radial-gradient(circle, #ffe49a, var(--accent));
  box-shadow: 0 0 60px rgba(233, 169, 58, 0.42);
}

.solar-scene .planet {
  animation: spin 10s linear infinite;
}

.solar-scene .p1 {
  width: 30px;
  height: 30px;
  left: 70%;
  top: 45%;
  background: #86d8a7;
}

.solar-scene .p2 {
  width: 22px;
  height: 22px;
  left: 30%;
  top: 64%;
  background: #5e8cff;
  animation-duration: 14s;
}

.solar-scene .p3 {
  width: 15px;
  height: 15px;
  left: 56%;
  top: 22%;
  background: #fff;
  animation-duration: 7s;
}

.maze-scene {
  background:
    linear-gradient(135deg, transparent 0 24%, rgba(134, 216, 167, 0.75) 24% 29%, transparent 29%),
    linear-gradient(45deg, transparent 0 34%, rgba(233, 169, 58, 0.75) 34% 39%, transparent 39%),
    linear-gradient(145deg, #17212f, #0c1118);
}

.maze-scene::before {
  content: "";
  position: absolute;
  left: 12%;
  right: 12%;
  bottom: 8%;
  height: 54%;
  transform: perspective(700px) rotateX(58deg);
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.14) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.14) 1px, transparent 1px);
  background-size: 46px 46px;
}

.particles-scene {
  background:
    radial-gradient(circle at 50% 82%, rgba(233, 169, 58, 0.55), transparent 14%),
    linear-gradient(145deg, #17212f, #0c1118);
}

.particles-scene span {
  position: absolute;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #86d8a7;
  animation: particle 3s ease-in-out infinite;
}

.particles-scene span:nth-child(1) { left: 30%; top: 62%; animation-delay: -0.2s; }
.particles-scene span:nth-child(2) { left: 45%; top: 42%; animation-delay: -0.8s; background: var(--accent); }
.particles-scene span:nth-child(3) { left: 58%; top: 55%; animation-delay: -1.4s; }
.particles-scene span:nth-child(4) { left: 68%; top: 34%; animation-delay: -2s; background: #fff; }
.particles-scene span:nth-child(5) { left: 38%; top: 25%; animation-delay: -2.4s; background: var(--danger); }

.lighting-scene {
  background:
    radial-gradient(circle at 70% 22%, rgba(233, 169, 58, 0.72), transparent 18%),
    linear-gradient(145deg, #17212f, #0c1118);
}

.lighting-scene::before {
  content: "";
  position: absolute;
  width: 150px;
  height: 150px;
  left: 31%;
  top: 35%;
  border-radius: 24px;
  transform: rotate(28deg);
  background: linear-gradient(135deg, #86d8a7, rgba(36, 107, 85, 0.45));
  box-shadow: 34px -30px 70px rgba(233, 169, 58, 0.24);
}

.showcase-content {
  padding: 28px;
}

.feature-columns {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
  margin-top: 18px;
}

.feature-columns ul,
.detail-block ul,
.course-card ul {
  margin: 0;
  padding-left: 18px;
}

.feature-columns li,
.detail-block li,
.course-card li {
  margin-bottom: 8px;
  color: var(--muted);
  line-height: 1.6;
}

.tech-row,
.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tech-row {
  margin-top: 20px;
}

.tech-row span,
.card-tags span {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 0 9px;
  color: var(--primary-dark);
  border-radius: 999px;
  background: #e8f1ec;
  font-size: 0.82rem;
  font-weight: 700;
}

.course-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.resource-tools {
  display: grid;
  grid-template-columns: minmax(220px, 1fr) 180px auto;
  align-items: center;
  gap: 12px;
  margin-bottom: 18px;
}

.resource-tools input,
.resource-tools select {
  width: 100%;
  min-height: 44px;
  padding: 0 13px;
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface);
  outline: none;
}

.resource-tools input:focus,
.resource-tools select:focus {
  border-color: var(--primary);
}

.resource-tools span {
  color: var(--muted);
  font-size: 0.92rem;
  white-space: nowrap;
}

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

.requirement-box {
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.requirement-box h3 {
  margin-top: 22px;
}

.requirement-box h3:first-child {
  margin-top: 0;
}

.requirement-box p,
.requirement-box li,
.detail-pdf li {
  color: var(--muted);
  line-height: 1.75;
}

.requirement-box ol,
.detail-pdf ol {
  margin: 0;
  padding-left: 20px;
}

.detail-pdf {
  margin-top: 12px;
}

.stat-card {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.stat-card span,
.stat-card strong {
  display: block;
}

.stat-card span {
  margin-bottom: 10px;
  color: var(--muted);
  font-size: 0.92rem;
}

.stat-card strong {
  font-size: 1.35rem;
}

.stat-note {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.7;
}

.empty-state {
  grid-column: 1 / -1;
  padding: 34px;
  text-align: center;
  color: var(--muted);
  border: 1px dashed var(--line);
  border-radius: 18px;
  background: var(--surface);
}

.load-more {
  width: 100%;
  margin-top: 18px;
}

.load-more[hidden] {
  display: none;
}

.course-card {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.course-visual {
  min-height: 150px;
  position: relative;
  color: #fff;
  background: #17212f;
}

.course-visual::before {
  content: attr(data-label);
  position: absolute;
  left: 18px;
  bottom: 16px;
  z-index: 2;
  font-size: 1.1rem;
  font-weight: 700;
}

.course-visual.solar {
  background:
    radial-gradient(circle at 72% 36%, #f0c15a 0 9%, transparent 9.5%),
    radial-gradient(circle at 34% 58%, #86d8a7 0 5%, transparent 5.5%),
    #17212f;
}

.course-visual.maze {
  background:
    linear-gradient(135deg, transparent 0 23%, rgba(134, 216, 167, 0.8) 23% 29%, transparent 29%),
    repeating-linear-gradient(90deg, #17212f 0 34px, #202b3a 34px 68px);
}

.course-visual.particles {
  background:
    radial-gradient(circle at 52% 78%, rgba(233, 169, 58, 0.76), transparent 16%),
    radial-gradient(circle at 30% 46%, rgba(216, 88, 58, 0.78), transparent 7%),
    radial-gradient(circle at 62% 34%, rgba(134, 216, 167, 0.9), transparent 6%),
    #17212f;
}

.course-visual.lighting {
  background:
    radial-gradient(circle at 70% 28%, rgba(240, 193, 90, 0.92), transparent 18%),
    linear-gradient(135deg, rgba(36, 107, 85, 0.82), transparent 55%),
    #17212f;
}

.course-body {
  padding: 20px;
}

.course-top {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
}

.course-code,
.course-price {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 0 10px;
  border-radius: 999px;
  font-size: 0.86rem;
  font-weight: 700;
}

.course-code {
  color: var(--primary-dark);
  background: #e8f1ec;
}

.course-price {
  color: #fff;
  background: var(--text);
}

.course-card p {
  margin-bottom: 14px;
}

.course-card ul {
  margin-bottom: 16px;
}

.card-tags {
  margin-bottom: 18px;
}

.card-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.small-btn,
.buy-btn {
  min-height: 42px;
  border-radius: 12px;
}

.small-btn {
  color: var(--text);
  border: 1px solid var(--line);
  background: var(--surface);
}

.buy-btn {
  color: #fff;
  background: var(--primary);
}

.buy-btn:hover {
  background: var(--primary-dark);
}

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

.step {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: var(--surface);
}

.step span {
  display: inline-grid;
  width: 34px;
  height: 34px;
  margin-bottom: 16px;
  place-items: center;
  color: #fff;
  border-radius: 50%;
  background: var(--primary);
  font-size: 0.86rem;
  font-weight: 700;
}

.step p {
  margin-bottom: 0;
}

.notice {
  margin: 14px 0 0;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--surface-soft);
}

.faq details {
  margin-bottom: 10px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--surface);
}

.faq summary {
  cursor: pointer;
  padding: 16px 18px;
  font-weight: 700;
}

.faq details p {
  margin: 0;
  padding: 0 18px 16px;
}

.faq code {
  padding: 2px 6px;
  border-radius: 6px;
  background: var(--surface-soft);
}

.footer {
  padding: 34px 0 46px;
  display: flex;
  justify-content: space-between;
  gap: 18px;
  color: var(--muted);
}

.footer a {
  color: var(--primary);
  font-weight: 700;
}

.modal {
  position: fixed;
  inset: 0;
  z-index: 20;
  display: none;
}

.modal.is-open {
  display: block;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(17, 24, 39, 0.56);
}

.modal-panel {
  width: min(680px, calc(100% - 32px));
  max-height: calc(100vh - 32px);
  overflow: auto;
  position: relative;
  margin: 16px auto;
  padding: 24px;
  border-radius: 22px;
  background: var(--surface);
  box-shadow: 0 22px 80px rgba(0, 0, 0, 0.22);
}

.detail-panel {
  width: min(820px, calc(100% - 32px));
}

.modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 36px;
  height: 36px;
  cursor: pointer;
  border: 0;
  border-radius: 50%;
  color: #fff;
  font-size: 1.45rem;
  line-height: 1;
  background: var(--text);
}

.modal-head {
  padding-right: 46px;
}

.modal-head p:not(.eyebrow) {
  color: var(--muted);
  line-height: 1.7;
}

.pay-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin: 20px 0;
}

.qr-card {
  margin: 0;
  padding: 16px;
  text-align: center;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--surface);
}

.qr-card img {
  display: block;
  width: 100%;
  max-width: 210px;
  margin: 0 auto 10px;
  border-radius: 12px;
}

.qr-card figcaption {
  font-weight: 700;
}

.order-box,
.detail-meta {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.detail-meta {
  grid-template-columns: repeat(3, 1fr);
  margin-top: 12px;
}

.order-box > div,
.contact-box,
.detail-meta > div,
.detail-block {
  padding: 16px;
  border-radius: 14px;
  background: var(--surface-soft);
}

.order-box span,
.detail-meta span {
  display: block;
  color: var(--muted);
  font-size: 0.86rem;
}

.order-box strong,
.detail-meta strong {
  display: block;
  margin-top: 5px;
  font-size: 1.15rem;
}

.contact-box {
  margin-top: 12px;
}

.contact-box p {
  margin-bottom: 8px;
  color: var(--muted);
  line-height: 1.7;
}

.contact-box strong {
  color: var(--text);
}

.detail-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-top: 16px;
}

.modal-actions {
  display: flex;
  justify-content: flex-end;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 16px;
}

.toast {
  position: fixed;
  left: 50%;
  bottom: 24px;
  z-index: 30;
  transform: translate(-50%, 12px);
  opacity: 0;
  pointer-events: none;
  padding: 10px 14px;
  color: #fff;
  border-radius: 999px;
  background: var(--text);
  transition: opacity 160ms ease, transform 160ms ease;
}

.toast.is-visible {
  opacity: 1;
  transform: translate(-50%, 0);
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

@keyframes particle {
  0%, 100% {
    transform: translateY(34px) scale(0.75);
    opacity: 0.35;
  }
  50% {
    transform: translateY(-34px) scale(1.15);
    opacity: 1;
  }
}

@media (max-width: 920px) {
  .hero,
  .showcase-layout,
  .showcase-panel {
    grid-template-columns: 1fr;
  }

  .hero-card {
    grid-template-columns: repeat(3, 1fr);
  }

  .showcase-tabs {
    grid-template-columns: repeat(2, 1fr);
  }

  .showcase-visual {
    min-height: 330px;
  }
}

@media (max-width: 720px) {
  .site-header,
  .section,
  .footer {
    width: min(100% - 28px, 1120px);
  }

  .nav {
    height: auto;
    padding: 18px 0;
    align-items: flex-start;
    flex-direction: column;
  }

  .nav-links {
    width: 100%;
    overflow-x: auto;
  }

  .hero {
    min-height: auto;
    padding: 42px 0 56px;
  }

  .hero-card,
  .showcase-tabs,
  .feature-columns,
  .resource-tools,
  .stats-grid,
  .course-grid,
  .steps,
  .detail-grid,
  .detail-meta {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 48px 0;
  }
}

@media (max-width: 520px) {
  .hero-actions,
  .footer,
  .modal-actions {
    flex-direction: column;
  }

  .btn,
  .modal-actions .btn {
    width: 100%;
  }

  .pay-grid,
  .order-box,
  .card-actions {
    grid-template-columns: 1fr;
  }

  .modal-panel {
    padding: 20px;
  }
}