/* Cloud Horizon — Set 2 */
:root {
  --cyan: #0E7490;
  --cyan-deep: #0C5F75;
  --cyan-soft: #0891B2;
  --sky: #E0F2FE;
  --sky-mid: #BAE6FD;
  --cloud: #F0F9FF;
  --white: #FFFFFF;
  --ink: #0F172A;
  --muted: #475569;
  --line: #7DD3FC;
  --rail: #38BDF8;
  --quote-border: #0E7490;
  --strip-bg: rgba(255, 255, 255, 0.72);
  --radius: 4px;
  --max: 960px;
  --font: "PingFang SC", "Microsoft YaHei", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: auto;
}

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: linear-gradient(180deg, var(--sky) 0%, var(--cloud) 40%, #F8FBFF 100%);
  line-height: 1.75;
  min-height: 100vh;
}

a {
  color: var(--cyan);
  text-decoration: none;
}

a:hover {
  color: var(--cyan-deep);
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
}

/* Nav — thin centered */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(240, 249, 255, 0.88);
  border-bottom: 1px solid rgba(14, 116, 144, 0.12);
  backdrop-filter: blur(8px);
}

.site-nav-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0.55rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 2rem;
}

.site-nav a {
  color: var(--muted);
  font-size: 0.95rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  text-decoration: none;
  padding: 0.2rem 0;
  border-bottom: 2px solid transparent;
}

.site-nav a:hover {
  color: var(--cyan);
  text-decoration: none;
}

.site-nav a.active {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
  font-weight: 600;
}

/* Hero — full-bleed */
.hero {
  position: relative;
  overflow: hidden;
  min-height: 72vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(165deg, #F0F9FF 0%, #E0F2FE 35%, #BAE6FD 70%, #67E8F9 100%);
  text-align: center;
  padding: 4.5rem 1.5rem 5rem;
}

.hero-clouds {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  opacity: 0.55;
}

.hero-inner {
  position: relative;
  z-index: 1;
  max-width: 720px;
}

.hero-brand {
  font-size: clamp(2.4rem, 6vw, 3.6rem);
  font-weight: 700;
  color: var(--cyan-deep);
  letter-spacing: 0.04em;
  margin: 0 0 1rem;
  line-height: 1.2;
}

.hero h1 {
  font-size: clamp(1.15rem, 2.8vw, 1.55rem);
  font-weight: 500;
  color: var(--ink);
  margin: 0 0 1rem;
  line-height: 1.45;
}

.hero-lead {
  font-size: 1.05rem;
  color: var(--muted);
  margin: 0 auto 1.75rem;
  max-width: 36em;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.7rem 1.4rem;
  font-family: var(--font);
  font-size: 0.95rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  text-decoration: none;
  transition: background 0.15s ease, color 0.15s ease;
}

.btn:hover {
  text-decoration: none;
}

.btn-primary {
  background: var(--cyan);
  color: var(--white);
}

.btn-primary:hover {
  background: var(--cyan-deep);
  color: var(--white);
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.65);
  color: var(--cyan-deep);
  border: 1px solid rgba(14, 116, 144, 0.35);
}

.btn-ghost:hover {
  background: var(--white);
  color: var(--cyan);
}

.btn:disabled {
  opacity: 0.75;
  cursor: wait;
}

/* Timeline shell */
.timeline {
  max-width: var(--max);
  margin: 0 auto;
  padding: 2.5rem 1.25rem 4rem;
  position: relative;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 1.85rem;
  top: 2.5rem;
  bottom: 4rem;
  width: 2px;
  background: linear-gradient(180deg, var(--rail), var(--line), transparent);
}

@media (min-width: 720px) {
  .timeline::before {
    left: 2.35rem;
  }
}

.tl-section {
  position: relative;
  padding: 0 0 2.75rem 3.25rem;
  margin: 0;
}

@media (min-width: 720px) {
  .tl-section {
    padding-left: 4rem;
  }
}

.tl-section::before {
  content: "";
  position: absolute;
  left: 1.35rem;
  top: 0.45rem;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--white);
  border: 3px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(14, 116, 144, 0.12);
}

@media (min-width: 720px) {
  .tl-section::before {
    left: 1.85rem;
  }
}

.tl-label {
  display: block;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--cyan-soft);
  text-transform: uppercase;
  margin-bottom: 0.35rem;
}

.tl-section h2 {
  font-size: 1.45rem;
  color: var(--cyan-deep);
  margin: 0 0 0.85rem;
  font-weight: 700;
}

.tl-section h3 {
  font-size: 1.1rem;
  color: var(--ink);
  margin: 1.25rem 0 0.5rem;
  font-weight: 600;
}

.tl-section p {
  margin: 0 0 0.9rem;
  color: var(--muted);
}

.tl-section ul,
.tl-section ol {
  margin: 0 0 1rem;
  padding-left: 1.25rem;
  color: var(--muted);
}

.tl-section li {
  margin-bottom: 0.45rem;
}

/* Platform strips */
.strip-list {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  margin: 1.1rem 0;
}

.strip {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  width: 100%;
  padding: 1rem 1.15rem;
  background: var(--strip-bg);
  border: 1px solid rgba(14, 116, 144, 0.14);
  border-left: 4px solid var(--cyan);
}

.strip-icon {
  flex: 0 0 40px;
  width: 40px;
  height: 40px;
  color: var(--cyan);
}

.strip-body {
  flex: 1 1 200px;
  min-width: 0;
}

.strip-body strong {
  display: block;
  color: var(--ink);
  font-size: 1.05rem;
  margin-bottom: 0.15rem;
}

.strip-body span {
  display: block;
  font-size: 0.88rem;
  color: var(--muted);
}

.strip .btn {
  flex: 0 0 auto;
  margin-left: auto;
}

/* Capability grid inside timeline — not cards in hero sense; simple rows */
.ability-list {
  margin: 1rem 0 0;
  padding: 0;
  list-style: none;
}

.ability-list li {
  padding: 0.85rem 0;
  border-bottom: 1px solid rgba(56, 189, 248, 0.25);
  color: var(--muted);
}

.ability-list li:last-child {
  border-bottom: none;
}

.ability-list strong {
  display: block;
  color: var(--cyan-deep);
  margin-bottom: 0.25rem;
  font-size: 1.02rem;
}

/* Stats / data endorsement */
.stat-row {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem 2.5rem;
  margin: 1.25rem 0;
  padding: 1.25rem 0;
  border-top: 1px solid rgba(14, 116, 144, 0.15);
  border-bottom: 1px solid rgba(14, 116, 144, 0.15);
}

.stat-item {
  flex: 1 1 140px;
}

.stat-item .num {
  display: block;
  font-size: 1.85rem;
  font-weight: 700;
  color: var(--cyan);
  line-height: 1.2;
}

.stat-item .lbl {
  font-size: 0.88rem;
  color: var(--muted);
}

/* Pull quotes */
.pull-quotes {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  margin: 1.1rem 0;
}

.pull-quote {
  margin: 0;
  padding: 0.85rem 0 0.85rem 1.15rem;
  border-left: 5px solid var(--quote-border);
  background: transparent;
  color: var(--ink);
  font-size: 1.05rem;
  line-height: 1.7;
}

.pull-quote cite {
  display: block;
  margin-top: 0.55rem;
  font-size: 0.85rem;
  font-style: normal;
  color: var(--muted);
}

/* Compare table */
.compare-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: 0.92rem;
}

.compare-table th,
.compare-table td {
  padding: 0.65rem 0.75rem;
  text-align: left;
  border-bottom: 1px solid rgba(56, 189, 248, 0.3);
  color: var(--muted);
  vertical-align: top;
}

.compare-table th {
  color: var(--cyan-deep);
  font-weight: 600;
  background: rgba(224, 242, 254, 0.5);
}

.compare-table td:first-child {
  color: var(--ink);
  font-weight: 500;
  white-space: nowrap;
}

/* FAQ numbered list */
.faq-list {
  list-style: none;
  margin: 1rem 0 0;
  padding: 0;
  counter-reset: faq;
}

.faq-list > li {
  counter-increment: faq;
  margin-bottom: 1.5rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid rgba(56, 189, 248, 0.22);
}

.faq-list > li:last-child {
  border-bottom: none;
}

.faq-q {
  display: flex;
  gap: 0.65rem;
  align-items: flex-start;
  font-weight: 600;
  color: var(--cyan-deep);
  font-size: 1.05rem;
  margin-bottom: 0.5rem;
}

.faq-q::before {
  content: counter(faq, decimal-leading-zero);
  flex: 0 0 auto;
  color: var(--cyan-soft);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
}

.faq-a {
  margin: 0;
  padding-left: 2.4rem;
  color: var(--muted);
  font-size: 0.95rem;
}

/* Longform (zh-cn) */
.longform {
  max-width: 720px;
  margin: 0 auto;
  padding: 2.5rem 1.25rem 4rem;
}

.longform-hero {
  text-align: center;
  padding: 3rem 1.25rem 2rem;
  background: linear-gradient(180deg, #E0F2FE 0%, transparent 100%);
}

.longform-hero .brand {
  font-size: clamp(2rem, 5vw, 2.8rem);
  font-weight: 700;
  color: var(--cyan-deep);
  margin: 0 0 0.75rem;
}

.longform-hero h1 {
  font-size: 1.25rem;
  font-weight: 500;
  margin: 0 0 0.75rem;
  color: var(--ink);
}

.longform-hero p {
  color: var(--muted);
  max-width: 36em;
  margin: 0 auto;
}

.longform article h2 {
  font-size: 1.35rem;
  color: var(--cyan-deep);
  margin: 2.25rem 0 0.85rem;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid rgba(14, 116, 144, 0.2);
}

.longform article h3 {
  font-size: 1.1rem;
  color: var(--ink);
  margin: 1.5rem 0 0.55rem;
}

.longform article p {
  color: var(--muted);
  margin: 0 0 1rem;
}

.longform article ul {
  color: var(--muted);
  padding-left: 1.25rem;
  margin: 0 0 1rem;
}

.cta-band {
  margin: 2.5rem 0 1rem;
  padding: 1.75rem 1.25rem;
  text-align: center;
  background: linear-gradient(90deg, rgba(224, 242, 254, 0.9), rgba(186, 230, 253, 0.85));
  border-left: 5px solid var(--cyan);
}

.cta-band p {
  margin: 0 0 1rem;
  color: var(--ink);
}

/* Steps */
.steps {
  margin: 1rem 0;
  padding: 0;
  list-style: none;
  counter-reset: step;
}

.steps li {
  counter-increment: step;
  position: relative;
  padding: 0.75rem 0 0.75rem 2.75rem;
  border-bottom: 1px dashed rgba(56, 189, 248, 0.35);
  color: var(--muted);
}

.steps li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0.75rem;
  width: 1.75rem;
  height: 1.75rem;
  border-radius: 50%;
  background: var(--cyan);
  color: var(--white);
  font-size: 0.85rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1.75rem;
  text-align: center;
}

.steps li strong {
  display: block;
  color: var(--ink);
  margin-bottom: 0.2rem;
}

/* Version list */
.version-list {
  margin: 1rem 0;
  padding: 0;
  list-style: none;
}

.version-list li {
  padding: 0.85rem 0;
  border-bottom: 1px solid rgba(56, 189, 248, 0.25);
  color: var(--muted);
}

.version-list .ver {
  color: var(--cyan);
  font-weight: 700;
  margin-right: 0.5rem;
}

/* Feature deep dive blocks */
.feature-block {
  margin: 1.25rem 0;
  padding-left: 0.85rem;
  border-left: 3px solid var(--line);
}

.feature-block h3 {
  margin-top: 0;
}

/* Page title bar for download */
.page-head {
  background: linear-gradient(165deg, #F0F9FF, #BAE6FD);
  padding: 3rem 1.25rem 2.25rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.page-head .hero-clouds {
  opacity: 0.4;
}

.page-head-inner {
  position: relative;
  z-index: 1;
  max-width: 640px;
  margin: 0 auto;
}

.page-head .brand {
  font-size: 2rem;
  font-weight: 700;
  color: var(--cyan-deep);
  margin: 0 0 0.5rem;
}

.page-head h1 {
  font-size: 1.2rem;
  font-weight: 500;
  margin: 0 0 0.65rem;
  color: var(--ink);
}

.page-head p {
  margin: 0;
  color: var(--muted);
  font-size: 0.98rem;
}

/* Footer */
.site-footer {
  background: linear-gradient(180deg, transparent, rgba(224, 242, 254, 0.9));
  border-top: 1px solid rgba(14, 116, 144, 0.15);
  padding: 2rem 1.25rem 2.5rem;
  text-align: center;
}

.site-footer p {
  max-width: 720px;
  margin: 0 auto 0.65rem;
  font-size: 0.85rem;
  color: var(--muted);
  line-height: 1.65;
}

.site-footer .secure {
  color: var(--cyan-deep);
  font-weight: 500;
}

@keyframes spin {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

@media (max-width: 560px) {
  .site-nav-inner {
    gap: 1rem;
  }

  .site-nav a {
    font-size: 0.85rem;
  }

  .strip {
    flex-direction: column;
    align-items: flex-start;
  }

  .strip .btn {
    margin-left: 0;
    width: 100%;
  }

  .faq-a {
    padding-left: 0;
  }

  .timeline::before {
    left: 1.1rem;
  }

  .tl-section {
    padding-left: 2.5rem;
  }

  .tl-section::before {
    left: 0.7rem;
  }
}