:root {
  color-scheme: dark;
  --bg: #071014;
  --bg-deep: #04090c;
  --surface: rgba(16, 29, 35, 0.78);
  --surface-strong: #13242b;
  --line: rgba(167, 229, 222, 0.16);
  --line-strong: rgba(167, 229, 222, 0.32);
  --text: #f5fbfa;
  --muted: #a7bab9;
  --lime: #d7ff58;
  --cyan: #5eead4;
  --cyan-soft: #9df5e8;
  --warning: #ffd78a;
  --shadow: 0 24px 70px rgba(0, 0, 0, 0.35);
  --radius-lg: 28px;
  --radius-md: 18px;
  --max-width: 1100px;
  font-family:
    Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "SF Pro Display",
    "SF Pro Text", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
    sans-serif;
  font-synthesis: none;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  background: var(--bg-deep);
}

body {
  min-width: 320px;
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(circle at 86% -8%, rgba(94, 234, 212, 0.2), transparent 29rem),
    radial-gradient(circle at 4% 12%, rgba(215, 255, 88, 0.1), transparent 25rem),
    linear-gradient(180deg, #091419 0%, var(--bg) 48%, var(--bg-deep) 100%);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--cyan-soft);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.2em;
}

a:hover {
  color: var(--lime);
}

a:focus-visible,
button:focus-visible {
  outline: 3px solid var(--lime);
  outline-offset: 4px;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

.site-header {
  position: sticky;
  z-index: 20;
  top: 0;
  border-bottom: 1px solid rgba(167, 229, 222, 0.1);
  background: rgba(4, 9, 12, 0.72);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}

.nav-wrap {
  display: flex;
  width: min(calc(100% - 36px), var(--max-width));
  min-height: 72px;
  margin: 0 auto;
  align-items: center;
  gap: 24px;
}

.brand {
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 11px;
  color: var(--text);
  font-size: 1rem;
  font-weight: 760;
  letter-spacing: -0.02em;
  text-decoration: none;
}

.brand-mark {
  position: relative;
  display: inline-grid;
  width: 34px;
  height: 34px;
  place-items: center;
  overflow: hidden;
  border: 1px solid rgba(94, 234, 212, 0.5);
  border-radius: 11px;
  background:
    linear-gradient(90deg, transparent 31%, rgba(94, 234, 212, 0.23) 32% 34%, transparent 35% 65%, rgba(94, 234, 212, 0.23) 66% 68%, transparent 69%),
    linear-gradient(transparent 31%, rgba(94, 234, 212, 0.23) 32% 34%, transparent 35% 65%, rgba(94, 234, 212, 0.23) 66% 68%, transparent 69%),
    #102228;
}

.brand-mark::before {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--lime);
  box-shadow: 0 0 18px rgba(215, 255, 88, 0.7);
  content: "";
}

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

.nav-links a {
  padding: 8px 11px;
  border-radius: 10px;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 620;
  text-decoration: none;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--text);
  background: rgba(167, 229, 222, 0.09);
}

.language-switch {
  display: inline-flex;
  flex: 0 0 auto;
  padding: 3px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.035);
}

.language-switch button {
  min-width: 48px;
  padding: 7px 9px;
  border: 0;
  border-radius: 9px;
  color: var(--muted);
  background: transparent;
  font: inherit;
  font-size: 0.78rem;
  font-weight: 720;
  cursor: pointer;
}

html[data-lang="en"] .language-switch [data-language="en"],
html[data-lang="zh"] .language-switch [data-language="zh"] {
  color: #081013;
  background: var(--lime);
  box-shadow: 0 3px 12px rgba(215, 255, 88, 0.18);
}

html[data-lang="en"] .lang-zh,
html[data-lang="zh"] .lang-en {
  display: none !important;
}

.page-shell {
  width: min(calc(100% - 36px), var(--max-width));
  min-height: calc(100vh - 220px);
  margin: 0 auto;
}

.hero {
  display: grid;
  min-height: 520px;
  padding: 96px 0 72px;
  align-items: center;
  grid-template-columns: minmax(0, 1.15fr) minmax(300px, 0.85fr);
  gap: 72px;
}

.eyebrow {
  display: inline-flex;
  margin: 0 0 20px;
  align-items: center;
  gap: 9px;
  color: var(--lime);
  font-size: 0.78rem;
  font-weight: 780;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.eyebrow::before {
  width: 22px;
  height: 1px;
  background: currentColor;
  content: "";
}

h1,
h2,
h3 {
  margin-top: 0;
  line-height: 1.12;
  letter-spacing: -0.035em;
}

h1 {
  max-width: 800px;
  margin-bottom: 22px;
  font-size: clamp(2.8rem, 7vw, 5.9rem);
  font-weight: 820;
}

.document-hero h1 {
  font-size: clamp(2.5rem, 6vw, 4.7rem);
}

.gradient-text {
  color: transparent;
  background: linear-gradient(105deg, var(--text) 12%, var(--cyan) 68%, var(--lime));
  background-clip: text;
  -webkit-background-clip: text;
}

.hero-copy {
  max-width: 660px;
  margin: 0 0 30px;
  color: var(--muted);
  font-size: clamp(1.05rem, 1.8vw, 1.25rem);
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.button {
  display: inline-flex;
  min-height: 48px;
  padding: 0 19px;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  border-radius: 14px;
  color: var(--text);
  background: rgba(255, 255, 255, 0.035);
  font-size: 0.93rem;
  font-weight: 720;
  text-decoration: none;
  transition: transform 160ms ease, border-color 160ms ease, background 160ms ease;
}

.button.primary {
  border-color: transparent;
  color: #081013;
  background: var(--lime);
}

.button:hover {
  color: var(--text);
  border-color: var(--line-strong);
  background: rgba(255, 255, 255, 0.075);
  transform: translateY(-2px);
}

.button.primary:hover {
  color: #081013;
  background: #e2ff81;
}

.coach-card {
  position: relative;
  padding: 28px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background:
    linear-gradient(150deg, rgba(94, 234, 212, 0.12), transparent 48%),
    var(--surface);
  box-shadow: var(--shadow);
}

.coach-card::after {
  position: absolute;
  z-index: -1;
  right: -70px;
  bottom: -80px;
  width: 210px;
  height: 210px;
  border-radius: 50%;
  background: rgba(215, 255, 88, 0.12);
  filter: blur(10px);
  content: "";
}

.camera-frame {
  position: relative;
  display: grid;
  aspect-ratio: 4 / 5;
  place-items: center;
  overflow: hidden;
  border: 1px solid rgba(167, 229, 222, 0.24);
  border-radius: 21px;
  background:
    linear-gradient(90deg, transparent 32.8%, rgba(215, 255, 88, 0.27) 33%, rgba(215, 255, 88, 0.27) 33.4%, transparent 33.6% 66.1%, rgba(215, 255, 88, 0.27) 66.3%, rgba(215, 255, 88, 0.27) 66.7%, transparent 66.9%),
    linear-gradient(transparent 32.8%, rgba(215, 255, 88, 0.27) 33%, rgba(215, 255, 88, 0.27) 33.4%, transparent 33.6% 66.1%, rgba(215, 255, 88, 0.27) 66.3%, rgba(215, 255, 88, 0.27) 66.7%, transparent 66.9%),
    radial-gradient(circle at 67% 34%, rgba(215, 255, 88, 0.32), transparent 12%),
    linear-gradient(145deg, #193039, #0b171c 64%);
}

.focus-ring {
  display: grid;
  width: 94px;
  height: 94px;
  place-items: center;
  border: 1px solid var(--cyan);
  border-radius: 50%;
  box-shadow: inset 0 0 0 9px rgba(94, 234, 212, 0.04), 0 0 38px rgba(94, 234, 212, 0.12);
}

.focus-ring::before {
  width: 28px;
  height: 28px;
  border: 6px solid var(--cyan);
  border-right-color: var(--lime);
  border-radius: 50%;
  content: "";
  transform: rotate(35deg);
}

.score-chip {
  position: absolute;
  top: 17px;
  right: 17px;
  padding: 7px 11px;
  border: 1px solid rgba(215, 255, 88, 0.4);
  border-radius: 999px;
  color: var(--lime);
  background: rgba(4, 9, 12, 0.68);
  font-size: 0.76rem;
  font-weight: 760;
  letter-spacing: 0.04em;
}

.level-line {
  position: absolute;
  right: 14%;
  bottom: 19%;
  left: 14%;
  height: 2px;
  border-radius: 999px;
  background: var(--lime);
  box-shadow: 0 0 15px rgba(215, 255, 88, 0.4);
}

.card-caption {
  display: flex;
  margin-top: 18px;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.card-caption strong {
  font-size: 0.94rem;
}

.card-caption span {
  color: var(--muted);
  font-size: 0.78rem;
}

.trust-strip {
  display: grid;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.025);
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.trust-item {
  padding: 9px 14px;
  border-right: 1px solid var(--line);
}

.trust-item:last-child {
  border-right: 0;
}

.trust-item strong,
.trust-item span {
  display: block;
}

.trust-item strong {
  margin-bottom: 4px;
  color: var(--text);
  font-size: 0.95rem;
}

.trust-item span {
  color: var(--muted);
  font-size: 0.8rem;
}

.section {
  padding: 88px 0;
}

.section-heading {
  max-width: 680px;
  margin-bottom: 36px;
}

.section-heading h2 {
  margin-bottom: 14px;
  font-size: clamp(2rem, 4vw, 3.4rem);
}

.section-heading p {
  margin: 0;
  color: var(--muted);
}

.link-card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.link-card {
  position: relative;
  min-height: 240px;
  padding: 26px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  color: var(--text);
  background: var(--surface);
  text-decoration: none;
  transition: transform 180ms ease, border-color 180ms ease;
}

.link-card::after {
  position: absolute;
  top: 24px;
  right: 24px;
  color: var(--cyan);
  font-size: 1.25rem;
  content: "↗";
}

.link-card:hover {
  color: var(--text);
  border-color: rgba(94, 234, 212, 0.44);
  transform: translateY(-4px);
}

.card-index {
  display: block;
  margin-bottom: 52px;
  color: var(--lime);
  font-family: ui-monospace, "SFMono-Regular", Menlo, monospace;
  font-size: 0.75rem;
  letter-spacing: 0.08em;
}

.link-card h3 {
  margin-bottom: 10px;
  font-size: 1.35rem;
}

.link-card p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.document-hero {
  max-width: 850px;
  padding: 100px 0 50px;
}

.document-hero .hero-copy {
  max-width: 760px;
}

.document-meta {
  display: flex;
  flex-wrap: wrap;
  margin-top: 26px;
  gap: 10px;
}

.meta-pill {
  padding: 7px 11px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  background: rgba(255, 255, 255, 0.025);
  font-size: 0.78rem;
}

.document-layout {
  display: grid;
  padding: 20px 0 100px;
  grid-template-columns: 220px minmax(0, 760px);
  gap: 54px;
}

.toc {
  position: sticky;
  top: 104px;
  align-self: start;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: rgba(11, 23, 28, 0.62);
}

.toc-label {
  margin: 0 0 10px;
  color: var(--lime);
  font-size: 0.7rem;
  font-weight: 780;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.toc a {
  display: block;
  padding: 6px 0;
  color: var(--muted);
  font-size: 0.82rem;
  text-decoration: none;
}

.toc a:hover {
  color: var(--text);
}

.document {
  min-width: 0;
}

.document section {
  padding: 30px 0;
  border-top: 1px solid var(--line);
  scroll-margin-top: 100px;
}

.document section:first-child {
  padding-top: 0;
  border-top: 0;
}

.document h2 {
  margin-bottom: 14px;
  font-size: clamp(1.45rem, 2.7vw, 2rem);
}

.document h3 {
  margin: 25px 0 10px;
  font-size: 1.06rem;
  letter-spacing: -0.015em;
}

.document p,
.document li {
  color: #c1d0cf;
}

.document p {
  margin: 0 0 14px;
}

.document ul,
.document ol {
  margin: 12px 0 18px;
  padding-left: 1.3rem;
}

.document li {
  margin: 8px 0;
  padding-left: 4px;
}

.callout {
  margin: 20px 0;
  padding: 18px 20px;
  border: 1px solid rgba(215, 255, 88, 0.22);
  border-left: 3px solid var(--lime);
  border-radius: 12px;
  color: #dce8e7;
  background: rgba(215, 255, 88, 0.045);
}

.callout strong {
  color: var(--lime);
}

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

.info-card {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 15px;
  background: rgba(255, 255, 255, 0.025);
}

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

.info-card strong {
  margin-bottom: 5px;
  color: var(--text);
}

.info-card span {
  color: var(--muted);
  font-size: 0.86rem;
}

.support-card {
  padding: 30px;
  border: 1px solid rgba(94, 234, 212, 0.26);
  border-radius: var(--radius-md);
  background:
    radial-gradient(circle at 90% 0, rgba(94, 234, 212, 0.13), transparent 16rem),
    var(--surface);
}

.support-email {
  display: inline-block;
  margin: 8px 0 18px;
  color: var(--lime);
  font-size: clamp(1.2rem, 4vw, 2rem);
  font-weight: 760;
  letter-spacing: -0.025em;
}

.site-footer {
  border-top: 1px solid var(--line);
  background: rgba(4, 9, 12, 0.65);
}

.footer-wrap {
  display: grid;
  width: min(calc(100% - 36px), var(--max-width));
  padding: 34px 0 40px;
  margin: 0 auto;
  grid-template-columns: 1fr auto;
  gap: 24px;
}

.footer-note,
.footer-links {
  color: var(--muted);
  font-size: 0.8rem;
}

.footer-note {
  margin: 0;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-links a {
  color: var(--muted);
  text-decoration: none;
}

.footer-links a:hover {
  color: var(--text);
}

@media (max-width: 820px) {
  .nav-wrap {
    min-height: 64px;
    gap: 10px;
  }

  .nav-links {
    display: none;
  }

  .language-switch {
    margin-left: auto;
  }

  .hero {
    padding-top: 62px;
    grid-template-columns: 1fr;
    gap: 44px;
  }

  .hero-copy {
    font-size: 1.03rem;
  }

  .coach-card {
    max-width: 480px;
  }

  .trust-strip,
  .link-card-grid {
    grid-template-columns: 1fr;
  }

  .trust-item {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .trust-item:last-child {
    border-bottom: 0;
  }

  .link-card {
    min-height: 200px;
  }

  .card-index {
    margin-bottom: 34px;
  }

  .document-hero {
    padding-top: 72px;
  }

  .document-layout {
    display: block;
  }

  .toc {
    position: static;
    margin-bottom: 38px;
  }
}

@media (max-width: 540px) {
  .page-shell,
  .nav-wrap,
  .footer-wrap {
    width: min(calc(100% - 24px), var(--max-width));
  }

  .brand-label {
    display: none;
  }

  h1 {
    font-size: 2.65rem;
  }

  .hero {
    min-height: auto;
  }

  .coach-card,
  .support-card {
    padding: 18px;
  }

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

  .footer-wrap {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
  }
}

@media print {
  :root {
    color-scheme: light;
    --text: #101516;
    --muted: #465254;
    --line: #d7dede;
  }

  body {
    color: #101516;
    background: white;
  }

  .site-header,
  .toc,
  .site-footer,
  .button-row {
    display: none;
  }

  .page-shell {
    width: 100%;
  }

  .document-hero {
    padding: 20px 0;
  }

  .document-layout {
    display: block;
    padding: 0;
  }

  .document p,
  .document li {
    color: #222b2c;
  }

  html[data-lang="en"] .lang-zh,
  html[data-lang="zh"] .lang-en {
    display: block !important;
  }
}