/* ==========================================================================
   SyncBridge 展示页样式
   - 全部样式集中于本文件（CSP: style-src 'self'，禁止内联样式）
   - 无外部字体、无外部图片，仅系统字体 + 内联 SVG
   ========================================================================== */

:root {
  --ink: #0a0f1c;
  --ink-soft: #101a2d;
  --paper: #f7f8fa;
  --card: #ffffff;
  --line: #e3e7ee;
  --line-strong: #cfd5e0;
  --text: #0f1728;
  --muted: #5a6478;
  --muted-light: #9aa4b8;
  --accent: #0d9488;
  --accent-ink: #05645c;
  --accent-soft: #e6f6f3;
  --amber: #d97706;
  --radius-sm: 10px;
  --radius: 16px;
  --radius-lg: 22px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 40, .05);
  --shadow-md: 0 14px 34px -18px rgba(15, 23, 40, .28);
  --container: 1120px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC",
    Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
    "Liberation Mono", monospace;
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

h1, h2, h3 {
  margin: 0;
  font-weight: 650;
  letter-spacing: -.022em;
  line-height: 1.15;
  text-wrap: balance;
}

p { margin: 0; }

ul, ol, dl, dd { margin: 0; padding: 0; }

li { list-style: none; }

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

svg { display: block; }

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: clamp(20px, 5vw, 40px);
}

.sprite {
  position: absolute;
  width: 0;
  height: 0;
  overflow: hidden;
}

.icon {
  width: 20px;
  height: 20px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.6;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 12px;
  z-index: 100;
  padding: 10px 16px;
  border-radius: 999px;
  background: var(--ink);
  color: #fff;
  font-size: 14px;
}
.skip-link:focus-visible { left: 16px; }

/* ---------------------------------------------------------------- masthead */

.masthead {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(10, 15, 28, .82);
  border-bottom: 1px solid rgba(255, 255, 255, .07);
  backdrop-filter: saturate(140%) blur(14px);
  -webkit-backdrop-filter: saturate(140%) blur(14px);
}

.masthead__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 68px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  color: #fff;
}

.brand__logo {
  display: block;
  width: 44px;
  height: 44px;
  flex: none;
  border-radius: 12px;
  object-fit: cover;
  box-shadow: 0 8px 20px -12px rgba(0, 0, 0, .85);
}
.brand__logo--sm {
  width: 26px;
  height: 26px;
  border-radius: 8px;
  box-shadow: none;
}

.brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}
.brand__text strong {
  font-size: 15px;
  font-weight: 650;
  letter-spacing: .01em;
}
.brand__text small {
  font-size: 11px;
  color: rgba(255, 255, 255, .58);
  letter-spacing: .12em;
}

.nav {
  display: flex;
  align-items: center;
  gap: clamp(14px, 2.4vw, 30px);
}
.nav a {
  position: relative;
  font-size: 14px;
  color: rgba(255, 255, 255, .72);
  padding-block: 6px;
  transition: color .18s ease;
}
.nav a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 1px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .22s ease;
}
.nav a:hover { color: #fff; }
.nav a:hover::after { transform: scaleX(1); }

/* -------------------------------------------------------------------- hero */

.hero {
  position: relative;
  overflow: hidden;
  isolation: isolate;
  background:
    radial-gradient(120% 90% at 12% -10%, rgba(45, 212, 191, .18) 0%, rgba(45, 212, 191, 0) 55%),
    radial-gradient(90% 80% at 88% 0%, rgba(99, 102, 241, .22) 0%, rgba(99, 102, 241, 0) 60%),
    linear-gradient(180deg, #0a0f1c 0%, #0b1424 62%, #0a1320 100%);
  color: #fff;
}

.hero__grid {
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(to right, rgba(255, 255, 255, .055) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, .055) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse 85% 70% at 50% 30%, #000 20%, transparent 78%);
  -webkit-mask-image: radial-gradient(ellipse 85% 70% at 50% 30%, #000 20%, transparent 78%);
}

.hero__inner {
  position: relative;
  padding-block: clamp(88px, 13vw, 150px) clamp(80px, 11vw, 132px);
  max-width: 900px;
}

.hero__logo {
  margin: 0 0 clamp(22px, 3vw, 30px);
}
.hero__logo img {
  display: block;
  width: clamp(96px, 12vw, 132px);
  height: auto;
  border-radius: 26px;
  box-shadow:
    0 34px 70px -40px rgba(0, 0, 0, .95),
    0 0 0 1px rgba(255, 255, 255, .09);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin-bottom: 22px;
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, .66);
}
.eyebrow--dark { color: var(--muted); }

.dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #2dd4bf;
  box-shadow: 0 0 0 4px rgba(45, 212, 191, .16);
}

.hero__title {
  font-size: clamp(34px, 6.1vw, 64px);
  font-weight: 660;
  line-height: 1.12;
  letter-spacing: -.03em;
  background: linear-gradient(180deg, #ffffff 0%, #c8d6e2 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero__lede {
  margin-top: 26px;
  max-width: 46em;
  font-size: clamp(15.5px, 1.55vw, 18.5px);
  line-height: 1.8;
  color: rgba(226, 234, 244, .78);
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 34px;
}
.chips li {
  padding: 7px 14px;
  border: 1px solid rgba(255, 255, 255, .14);
  border-radius: 999px;
  background: rgba(255, 255, 255, .045);
  font-size: 13px;
  color: rgba(235, 242, 250, .82);
  transition: border-color .2s ease, background-color .2s ease;
}
.chips li:hover {
  border-color: rgba(45, 212, 191, .45);
  background: rgba(45, 212, 191, .1);
}

.hero__note {
  margin-top: 30px;
  font-size: 13px;
  color: rgba(255, 255, 255, .42);
}

/* ------------------------------------------------------------------- stats */

.stats,
.facts {
  position: relative;
  z-index: 2;
  margin-top: -46px;
}
.stats__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--line);
  box-shadow: var(--shadow-md);
}
.stat {
  background: var(--card);
  padding: clamp(20px, 3vw, 30px) clamp(16px, 2.4vw, 30px);
}
.stat dt {
  font-size: 12.5px;
  letter-spacing: .04em;
  color: var(--muted);
}
.stat dd {
  margin-top: 8px;
  font-size: clamp(26px, 3.4vw, 38px);
  font-weight: 640;
  letter-spacing: -.03em;
  font-variant-numeric: tabular-nums;
  color: var(--ink);
}
.stat .unit {
  margin-left: 2px;
  font-size: .5em;
  font-weight: 600;
  color: var(--accent);
}

/* 工商信息条：文字型指标，不用大字号数字 */
.stat dd.stat__text {
  font-size: 14px;
  font-weight: 560;
  line-height: 1.6;
  letter-spacing: 0;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}

/* ------------------------------------------------------------------ layout */

.section {
  padding-block: clamp(68px, 9vw, 112px);
}
.section--tint {
  background: #eef1f5;
  border-block: 1px solid var(--line);
}

.section__head {
  max-width: 640px;
  margin-bottom: clamp(34px, 4.6vw, 54px);
}
.section__title {
  font-size: clamp(25px, 3.5vw, 38px);
}
.section__lede {
  margin-top: 16px;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--muted);
}

/* ------------------------------------------------------------------- cards */

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(238px, 1fr));
  gap: 18px;
}

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 28px 26px 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--card);
  box-shadow: var(--shadow-sm);
  transition: transform .25s ease, box-shadow .25s ease, border-color .25s ease;
}
.card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 2px;
  border-radius: var(--radius) var(--radius) 0 0;
  background: linear-gradient(90deg, var(--accent), #6366f1);
  opacity: 0;
  transition: opacity .25s ease;
}
.card:hover {
  transform: translateY(-3px);
  border-color: var(--line-strong);
  box-shadow: var(--shadow-md);
}
.card:hover::before { opacity: 1; }

.card__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  margin-bottom: 20px;
  border-radius: 12px;
  background: var(--accent-soft);
  color: var(--accent-ink);
}

.card h3 {
  font-size: 17.5px;
  font-weight: 640;
}
.card p {
  margin-top: 10px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--muted);
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: auto;
  padding-top: 20px;
}
.tags li {
  padding: 3px 9px;
  border-radius: 6px;
  background: #f1f3f7;
  font-size: 11.5px;
  color: var(--muted);
  letter-spacing: .02em;
}

/* -------------------------------------------------------------------- flow */

.flow {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
}

.flow__step {
  position: relative;
  padding: 30px 26px 30px 0;
}
.flow__step + .flow__step { padding-left: 30px; }
.flow__step::after {
  content: "";
  position: absolute;
  top: 36px;
  right: 14px;
  width: 10px;
  height: 10px;
  border-top: 1.5px solid var(--line-strong);
  border-right: 1.5px solid var(--line-strong);
  transform: rotate(45deg);
}
.flow__step:last-child::after { content: none; }

.flow__num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--accent-ink);
  background: var(--accent-soft);
  border-radius: 6px;
  padding: 3px 8px;
}
.flow__step h3 {
  margin-top: 16px;
  font-size: 17px;
}
.flow__step p {
  margin-top: 9px;
  font-size: 14px;
  line-height: 1.72;
  color: var(--muted);
  max-width: 26em;
}

/* ---------------------------------------------------------------- security */

.security {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
  gap: clamp(32px, 5vw, 64px);
  align-items: start;
}

.checks {
  display: grid;
  gap: 18px;
  margin-top: 34px;
}
.checks li {
  display: grid;
  grid-template-columns: 22px 1fr;
  gap: 13px;
}
.icon--check {
  width: 22px;
  height: 22px;
  margin-top: 2px;
  color: var(--accent);
  stroke-width: 1.9;
}
.checks strong {
  display: block;
  font-size: 15px;
  font-weight: 640;
}
.checks span {
  display: block;
  margin-top: 3px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

.codecard {
  position: sticky;
  top: 96px;
  overflow: hidden;
  border-radius: var(--radius);
  background: var(--ink);
  color: #dbe4ef;
  box-shadow: var(--shadow-md);
}
.codecard__head {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 14px 20px;
  border-bottom: 1px solid rgba(255, 255, 255, .08);
  font-size: 12.5px;
  letter-spacing: .06em;
  color: rgba(219, 228, 239, .72);
}
.icon--lock {
  width: 16px;
  height: 16px;
  color: #2dd4bf;
}
.codecard pre {
  margin: 0;
  padding: 22px 20px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.95;
  color: #a7f3d0;
  tab-size: 2;
}
.codecard code { font-family: inherit; }
.codecard__foot {
  padding: 0 20px 20px;
  font-size: 12px;
  color: rgba(219, 228, 239, .45);
}

/* ------------------------------------------------------------------- specs */

.specs {
  border-top: 1px solid var(--line-strong);
}
.specs__row {
  display: grid;
  grid-template-columns: minmax(120px, 190px) 1fr;
  gap: 20px;
  padding: 18px 4px;
  border-bottom: 1px solid var(--line);
}
.specs dt {
  font-size: 13.5px;
  color: var(--muted);
}
.specs dd {
  font-size: 14.5px;
  color: var(--text);
}

/* ------------------------------------------------------------------ footer */

.footer {
  background: var(--ink);
  color: rgba(226, 234, 244, .7);
  padding-block: 44px;
}
.footer__inner {
  display: grid;
  gap: 14px;
}
.footer__brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  color: #fff;
}
.footer__note {
  max-width: 56em;
  font-size: 13px;
  color: rgba(226, 234, 244, .5);
}
.footer__meta {
  font-size: 12px;
  letter-spacing: .04em;
  color: rgba(226, 234, 244, .35);
}

/* ------------------------------------------------------------------- about */

.about {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
  gap: clamp(32px, 5vw, 64px);
  align-items: start;
}

.about__p {
  margin-top: 18px;
  font-size: 15px;
  line-height: 1.9;
  color: var(--muted);
}

.profile {
  padding: 26px 24px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--card);
  box-shadow: var(--shadow-sm);
}
.profile__title {
  font-size: 15px;
  letter-spacing: .02em;
}
.profile__list {
  display: grid;
  gap: 13px;
  margin-top: 18px;
}
.profile__list > div {
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}
.profile__list > div:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}
.profile dt {
  font-size: 12px;
  color: var(--muted-light);
  letter-spacing: .04em;
}
.profile dd {
  margin-top: 3px;
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--text);
}
.profile__foot {
  margin-top: 14px;
  font-size: 12px;
  color: var(--muted);
}

/* ----------------------------------------------------------------- service */

.split {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(34px, 5vw, 72px);
  align-items: start;
}

.clients {
  display: grid;
  gap: 10px;
  margin-top: 26px;
}
.clients li {
  display: flex;
  align-items: center;
  gap: 11px;
  padding: 12px 15px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--card);
  font-size: 14.5px;
  transition: border-color .2s ease, transform .2s ease;
}
.clients li:hover {
  border-color: var(--line-strong);
  transform: translateX(2px);
}
.clients .icon {
  width: 18px;
  height: 18px;
  color: var(--accent);
  flex: none;
}

.steps {
  display: grid;
  gap: 20px;
  margin-top: 26px;
}
.steps li {
  display: grid;
  grid-template-columns: 36px 1fr;
  gap: 14px;
  align-items: start;
}
.steps__num {
  display: block;
  padding: 5px 0;
  border-radius: 8px;
  background: var(--accent-soft);
  color: var(--accent-ink);
  font-family: var(--font-mono);
  font-size: 12px;
  text-align: center;
}
.steps strong {
  display: block;
  font-size: 15px;
  font-weight: 640;
}
.steps strong + span {
  display: block;
  margin-top: 3px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

/* -------------------------------------------------------------- compliance */

.checks--wide {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px 44px;
  margin-top: 0;
}

.legalbar {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 38px;
  padding: 15px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--card);
  font-size: 13px;
  color: var(--muted);
}
.legalbar .icon {
  width: 18px;
  height: 18px;
  color: var(--accent);
  flex: none;
}
.legalbar strong {
  color: var(--text);
  font-weight: 600;
  letter-spacing: .02em;
}

/* ---------------------------------------------------------------- reveals */

.js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .6s cubic-bezier(.22, .61, .36, 1),
    transform .6s cubic-bezier(.22, .61, .36, 1);
}
.js [data-reveal].is-in {
  opacity: 1;
  transform: none;
}

/* ---------------------------------------------------------------- responsive */

@media (max-width: 900px) {
  .security { grid-template-columns: 1fr; }
  .codecard { position: static; }
  .about { grid-template-columns: 1fr; }
  .split { grid-template-columns: 1fr; }
  .checks--wide { grid-template-columns: 1fr; }
  .flow { grid-template-columns: repeat(2, 1fr); }
  .flow__step { padding-right: 22px; }
  .flow__step + .flow__step { padding-left: 0; }
  .flow__step:nth-child(2n)::after { content: none; }
  .stats__grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
  .nav { gap: 14px; }
  .nav a { font-size: 13px; }
  .brand__text small { display: none; }
  .brand__logo { width: 36px; height: 36px; border-radius: 9px; }
  .hero__title { letter-spacing: -.02em; }
  .flow { grid-template-columns: 1fr; }
  .flow__step { padding: 22px 0; }
  .flow__step + .flow__step { padding-left: 0; }
  .flow__step::after { content: none; }
  .specs__row { grid-template-columns: 1fr; gap: 4px; }
  .stat dd { font-size: 28px; }
}

@media (max-width: 420px) {
  .stats__grid { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    transition-duration: .001ms !important;
  }
  .js [data-reveal] { opacity: 1; transform: none; }
}

@media (prefers-contrast: more) {
  :root { --muted: #3c4658; --line: #b9c1cf; }
  .hero__lede { color: #f2f6fb; }
}

@media print {
  .masthead, .skip-link { display: none; }
  .hero { background: #fff; color: #000; }
  .hero__title, .hero__lede, .eyebrow { color: #000; background: none; -webkit-text-fill-color: #000; }
  .js [data-reveal] { opacity: 1; transform: none; }
}