:root {
  color-scheme: light dark;
  --brand: #0066ff;
  --brand-hover: #0055dc;
  --brand-light: #2c82ff;
  --brand-soft: rgba(0, 102, 255, 0.10);
  --cyan: #20d8e8;
  --background: #f5f7fb;
  --surface: #ffffff;
  --surface-raised: rgba(255, 255, 255, 0.90);
  --surface-subtle: #f8faff;
  --text: #111827;
  --secondary: #5d6676;
  --tertiary: #8992a3;
  --border: rgba(17, 24, 39, 0.10);
  --success: #0a9c65;
  --warning: #e57500;
  --shadow: 0 18px 55px rgba(14, 37, 80, 0.09);
  --shadow-small: 0 8px 24px rgba(14, 37, 80, 0.07);
}

@media (prefers-color-scheme: dark) {
  :root {
    --brand: #3385ff;
    --brand-hover: #67a4ff;
    --brand-light: #63a2ff;
    --brand-soft: rgba(0, 102, 255, 0.18);
    --background: #070a10;
    --surface: #121721;
    --surface-raised: rgba(18, 23, 33, 0.90);
    --surface-subtle: #171d28;
    --text: #f5f7fb;
    --secondary: #a8b1c0;
    --tertiary: #7c8698;
    --border: rgba(255, 255, 255, 0.10);
    --success: #33d69a;
    --warning: #ff9d38;
    --shadow: none;
    --shadow-small: none;
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background:
    radial-gradient(circle at 72% -8%, rgba(0, 102, 255, 0.20), transparent 32rem),
    radial-gradient(circle at 13% 30%, rgba(32, 216, 232, 0.08), transparent 24rem),
    var(--background);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC", sans-serif;
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

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

.lang.en { display: none; }
body[data-language="en"] .lang.zh { display: none; }
body[data-language="en"] .lang.en { display: inline; }
body[data-language="zh-Hans"] .lang.zh { display: inline; }

.nav-wrap {
  position: sticky;
  top: 0;
  z-index: 30;
  padding: 12px 18px;
  border-bottom: 1px solid transparent;
  background: rgba(245, 247, 251, 0.82);
  backdrop-filter: saturate(160%) blur(18px);
  -webkit-backdrop-filter: saturate(160%) blur(18px);
}

@media (prefers-color-scheme: dark) {
  .nav-wrap { background: rgba(7, 10, 16, 0.82); }
}

.nav {
  width: min(100%, 1120px);
  min-height: 52px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 22px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  color: var(--text);
  text-decoration: none;
  font-weight: 780;
  letter-spacing: -0.02em;
}

.brand-mark {
  position: relative;
  width: 28px;
  height: 28px;
  border-radius: 9px;
  background: linear-gradient(145deg, var(--brand-light), var(--brand));
  box-shadow: 0 7px 18px rgba(0, 102, 255, 0.25);
}

.brand-mark::before,
.brand-mark::after {
  content: "";
  position: absolute;
  left: 5px;
  right: 5px;
  top: 13px;
  height: 2px;
  border-radius: 99px;
  background: #fff;
}

.brand-mark::after {
  left: 11px;
  right: 11px;
  top: 8px;
  height: 12px;
  background: transparent;
  border: 2px solid #fff;
  border-radius: 50%;
}

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

.nav-links a {
  padding: 8px 11px;
  border-radius: 9px;
  color: var(--secondary);
  text-decoration: none;
  font-size: 14px;
  font-weight: 620;
  white-space: nowrap;
}

.nav-links a:hover,
.nav-links a:focus-visible,
.nav-links a[aria-current="page"] {
  color: var(--text);
  background: var(--brand-soft);
  outline: none;
}

.language-switcher {
  display: inline-flex;
  flex: 0 0 auto;
  padding: 3px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface-raised);
}

.language-switcher button {
  min-width: 42px;
  border: 0;
  border-radius: 999px;
  padding: 6px 10px;
  background: transparent;
  color: var(--secondary);
  font: inherit;
  font-size: 13px;
  cursor: pointer;
}

.language-switcher button[aria-pressed="true"] {
  background: var(--brand);
  color: #fff;
  font-weight: 700;
}

.page {
  width: min(100% - 36px, 1120px);
  margin: 0 auto;
  padding: 56px 0 72px;
}

.hero {
  position: relative;
  overflow: hidden;
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(280px, 0.7fr);
  gap: 48px;
  align-items: center;
  padding: 56px;
  border: 1px solid var(--border);
  border-radius: 30px;
  background:
    radial-gradient(circle at 88% 14%, rgba(32, 216, 232, 0.16), transparent 16rem),
    linear-gradient(145deg, var(--brand-soft), transparent 62%),
    var(--surface);
  box-shadow: var(--shadow);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 14px;
  color: var(--brand);
  font-size: 14px;
  font-weight: 760;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.eyebrow::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: currentColor;
  box-shadow: 0 0 0 6px var(--brand-soft);
}

h1 {
  max-width: 720px;
  margin: 0;
  font-size: clamp(2.65rem, 7vw, 5.4rem);
  line-height: 0.98;
  letter-spacing: -0.06em;
}

.hero-copy {
  max-width: 680px;
  margin: 24px 0 0;
  color: var(--secondary);
  font-size: clamp(1.04rem, 2vw, 1.25rem);
  line-height: 1.65;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.button {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 11px 18px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--surface-raised);
  color: var(--text);
  text-decoration: none;
  font-weight: 700;
  box-shadow: var(--shadow-small);
  transition: transform 160ms ease, background 160ms ease;
}

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

.button:hover,
.button:focus-visible {
  transform: translateY(-1px);
  outline: 3px solid var(--brand-soft);
}

.button-icon {
  display: inline-grid;
  width: 22px;
  height: 22px;
  place-items: center;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.18);
  font-size: 14px;
  font-weight: 800;
}

.status-card {
  position: relative;
  min-height: 270px;
  padding: 28px;
  border: 1px solid var(--border);
  border-radius: 24px;
  background: var(--surface-raised);
  box-shadow: var(--shadow-small);
}

.status-graph {
  height: 114px;
  margin-bottom: 22px;
  border-bottom: 1px solid var(--border);
  background:
    linear-gradient(90deg, transparent 0 13%, var(--border) 13% 13.3%, transparent 13.3% 42%, var(--border) 42% 42.3%, transparent 42.3% 72%, var(--border) 72% 72.3%, transparent 72.3%),
    linear-gradient(0deg, transparent 0 30%, var(--border) 30% 30.5%, transparent 30.5% 65%, var(--border) 65% 65.5%, transparent 65.5%);
  clip-path: inset(0 round 14px);
}

.pulse-line {
  position: relative;
  top: 58px;
  width: 100%;
  height: 4px;
  border-radius: 99px;
  background: var(--brand);
  box-shadow: 0 0 18px rgba(0, 102, 255, 0.32);
}

.pulse-line::before {
  content: "";
  position: absolute;
  left: 40%;
  top: -25px;
  width: 44px;
  height: 48px;
  border-left: 4px solid var(--cyan);
  border-bottom: 4px solid var(--cyan);
  transform: skewX(-26deg) rotate(-45deg);
  background: transparent;
}

.metric-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.metric {
  padding: 12px 14px;
  border-radius: 14px;
  background: var(--surface-subtle);
}

.metric small {
  display: block;
  color: var(--secondary);
  font-size: 12px;
}

.metric strong {
  display: block;
  margin-top: 3px;
  font-size: 18px;
  letter-spacing: -0.02em;
}

.section {
  padding-top: 80px;
  scroll-margin-top: 86px;
}

.section-heading {
  max-width: 760px;
  margin-bottom: 28px;
}

h2 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 3.25rem);
  line-height: 1.08;
  letter-spacing: -0.045em;
}

.section-heading p {
  margin: 14px 0 0;
  color: var(--secondary);
  font-size: 1.05rem;
}

.quick-grid,
.topic-grid {
  display: grid;
  gap: 16px;
}

.quick-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.topic-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }

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

.step-card {
  padding: 26px;
}

.step-number {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  margin-bottom: 20px;
  border-radius: 12px;
  background: var(--brand);
  color: #fff;
  font-weight: 800;
  box-shadow: 0 8px 20px rgba(0, 102, 255, 0.22);
}

h3 {
  margin: 0;
  font-size: 1.15rem;
  line-height: 1.35;
}

.card p {
  margin: 9px 0 0;
  color: var(--secondary);
}

.topic-card {
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
  padding: 24px;
}

.topic-icon {
  display: grid;
  width: 48px;
  height: 48px;
  place-items: center;
  border-radius: 15px;
  background: var(--brand-soft);
  color: var(--brand);
  font-size: 20px;
  font-weight: 800;
}

.faq-list {
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: 22px;
  background: var(--surface);
  box-shadow: var(--shadow-small);
}

details + details { border-top: 1px solid var(--border); }

summary {
  position: relative;
  padding: 22px 64px 22px 24px;
  cursor: pointer;
  list-style: none;
  font-weight: 720;
}

summary::-webkit-details-marker { display: none; }

summary::after {
  content: "+";
  position: absolute;
  top: 50%;
  right: 24px;
  width: 28px;
  height: 28px;
  transform: translateY(-50%);
  border-radius: 50%;
  background: var(--brand-soft);
  color: var(--brand);
  text-align: center;
  font-size: 19px;
  line-height: 27px;
}

details[open] summary::after { content: "−"; }

.answer {
  padding: 0 64px 22px 24px;
  color: var(--secondary);
}

.answer p { margin: 0; }
.answer p + p { margin-top: 10px; }
.answer ol, .answer ul { margin: 10px 0 0; padding-left: 1.35rem; }
.answer li + li { margin-top: 7px; }

.note {
  margin-top: 18px;
  padding: 16px 18px;
  border-left: 4px solid var(--warning);
  border-radius: 12px;
  background: rgba(229, 117, 0, 0.09);
  color: var(--secondary);
}

.contact {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 32px;
  align-items: center;
  padding: 38px;
  border: 1px solid rgba(0, 102, 255, 0.22);
  border-radius: 26px;
  background:
    radial-gradient(circle at 100% 0, rgba(32, 216, 232, 0.14), transparent 18rem),
    linear-gradient(145deg, var(--brand-soft), transparent 70%),
    var(--surface);
  box-shadow: var(--shadow);
}

.contact h2 { font-size: clamp(1.8rem, 4vw, 2.7rem); }
.contact p { max-width: 700px; margin: 12px 0 0; color: var(--secondary); }

.contact-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  margin-top: 16px;
  color: var(--secondary);
  font-size: 14px;
}

.contact-meta a { color: var(--brand); text-decoration: none; }
.contact-meta a:hover { text-decoration: underline; }

footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 18px;
  padding: 34px 2px 0;
  color: var(--secondary);
  font-size: 13px;
}

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

footer a { text-decoration: none; }
footer a:hover { color: var(--brand); }

@media (max-width: 860px) {
  .hero { grid-template-columns: 1fr; padding: 42px; }
  .status-card { min-height: 0; }
  .quick-grid { grid-template-columns: 1fr; }
  .topic-grid { grid-template-columns: 1fr; }
  .contact { grid-template-columns: 1fr; }
}

@media (max-width: 700px) {
  .nav { gap: 12px; }
  .nav-links a:not([aria-current="page"]) { display: none; }
  .nav-links { margin-left: auto; }
  .page { width: min(100% - 20px, 1120px); padding-top: 24px; }
  .hero { padding: 30px 22px; border-radius: 22px; gap: 32px; }
  h1 { font-size: clamp(2.65rem, 16vw, 4.3rem); }
  .section { padding-top: 58px; }
  .topic-card { grid-template-columns: 42px minmax(0, 1fr); padding: 20px; }
  .topic-icon { width: 42px; height: 42px; }
  summary { padding: 19px 56px 19px 19px; }
  summary::after { right: 18px; }
  .answer { padding: 0 20px 20px; }
  .contact { padding: 28px 22px; }
  footer { flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .button { transition: none; }
}