@import url('https://fonts.googleapis.com/css2?family=Be+Vietnam+Pro:wght@300;400;500;600;700&family=Noto+Sans:wght@300;400;500;600;700&display=swap');

:root {
  --paper: #ffffff;
  --stone: #f5f5f5;
  --ink: #1f1f1f;
  --ink-80: rgba(31, 31, 31, 0.82);
  --ink-60: rgba(31, 31, 31, 0.6);
  --ink-45: rgba(31, 31, 31, 0.45);
  --line: rgba(31, 31, 31, 0.1);
  --hair: rgba(255, 255, 255, 0.9);
  --glass: rgba(255, 255, 255, 0.7);
  --e1: 0 1px 2px rgba(31, 31, 31, 0.06), 0 3px 10px rgba(31, 31, 31, 0.05);
  --e2: 0 4px 10px rgba(31, 31, 31, 0.07), 0 12px 26px rgba(31, 31, 31, 0.07);
  --e3: 0 9px 20px rgba(31, 31, 31, 0.08), 0 22px 44px rgba(31, 31, 31, 0.09);
  --e4: 0 16px 32px rgba(31, 31, 31, 0.1), 0 38px 70px rgba(31, 31, 31, 0.11);
  --r: 28px;
  --maxw: 1160px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  overflow-x: hidden;
  font-family: "Be Vietnam Pro", "Noto Sans", -apple-system, BlinkMacSystemFont, "Segoe UI",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 17px;
  line-height: 1.62;
  color: var(--ink);
  background-color: var(--stone);
  background-image:
    radial-gradient(760px 520px at 88% -6%, rgba(31, 31, 31, 0.1), transparent 62%),
    radial-gradient(700px 480px at 4% 14%, rgba(31, 31, 31, 0.055), transparent 60%),
    linear-gradient(180deg, #ffffff 0%, #f5f5f5 48%, #ffffff 100%);
  background-attachment: fixed;
}

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

img {
  display: block;
  max-width: 100%;
}

h1,
h2,
h3 {
  margin: 0;
  line-height: 1.18;
  letter-spacing: -0.015em;
}

/* ---------- 顶部 ---------- */
.masthead {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(255, 255, 255, 0.74);
  backdrop-filter: blur(16px) saturate(1.15);
  -webkit-backdrop-filter: blur(16px) saturate(1.15);
  border-bottom: 1px solid var(--line);
  box-shadow: var(--e1);
  transition: box-shadow 0.25s ease;
}

.masthead.is-stuck {
  box-shadow: var(--e3);
}

.mast-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  align-items: center;
  gap: 10px;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 10px clamp(12px, 3vw, 28px);
}

.mast-inner > * {
  min-width: 0;
}

.nav-left,
.nav-right {
  display: flex;
  align-items: center;
  gap: 2px;
  flex-wrap: wrap;
  min-width: 0;
}

.nav-left {
  justify-self: start;
}

.nav-right {
  justify-self: end;
  justify-content: flex-end;
  position: relative;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 11px 12px;
  border-radius: 14px;
  font-size: 16px;
  font-weight: 500;
  color: var(--ink-60);
  transition: color 0.18s ease, background 0.18s ease, box-shadow 0.18s ease, transform 0.18s ease;
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--ink);
  background: var(--paper);
  box-shadow: var(--e2);
  transform: translateY(-2px);
}

.brand {
  justify-self: center;
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 7px 14px;
  border-radius: 18px;
  background: var(--paper);
  box-shadow: var(--e2);
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.brand:hover {
  box-shadow: var(--e3);
  transform: translateY(-2px);
}

.brand-mark {
  width: 34px;
  height: 34px;
  border-radius: 11px;
  object-fit: cover;
  box-shadow: var(--e1);
}

.brand-name {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.drop {
  position: relative;
}

.drop-btn {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 11px 14px;
  border-radius: 14px;
  font-size: 16px;
  font-weight: 500;
  color: var(--ink-60);
  cursor: pointer;
  list-style: none;
  transition: color 0.18s ease, background 0.18s ease, box-shadow 0.18s ease;
}

.drop-btn::-webkit-details-marker {
  display: none;
}

.drop-btn:hover {
  color: var(--ink);
  background: var(--paper);
  box-shadow: var(--e2);
}

.drop[open] .drop-btn {
  color: var(--ink);
  background: var(--paper);
  box-shadow: var(--e2);
}

.drop-panel {
  position: absolute;
  top: calc(100% + 10px);
  right: 0;
  z-index: 60;
  display: flex;
  flex-direction: column;
  min-width: 188px;
  max-width: calc(100vw - 28px);
  padding: 8px;
  border: 1px solid var(--hair);
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  box-shadow: var(--e4);
}

.drop-link {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 11px 12px;
  border-radius: 13px;
  font-size: 16px;
  color: var(--ink-80);
}

.drop-link:hover {
  background: var(--stone);
  color: var(--ink);
}

.cta {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  margin-left: 4px;
  padding: 12px 18px;
  border-radius: 15px;
  font-size: 16px;
  font-weight: 600;
  color: #ffffff;
  background: linear-gradient(160deg, #333333, #1f1f1f);
  box-shadow: var(--e3);
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

.cta:hover {
  transform: translateY(-2px);
  box-shadow: var(--e4);
}

/* ---------- 首屏 ---------- */
.hero {
  position: relative;
  isolation: isolate;
  display: flex;
  align-items: flex-end;
  justify-content: flex-end;
  min-height: 70vh;
  overflow: hidden;
  padding: clamp(28px, 6vw, 72px) clamp(18px, 5vw, 64px) clamp(64px, 9vw, 112px);
  background: linear-gradient(135deg, #1f1f1f 0%, #3c3c3c 52%, #1a1a1a 100%);
  clip-path: polygon(0 0, 100% 0, 100% 92%, 0 100%);
}

.hero-media {
  position: absolute;
  inset: -12% 0 -8%;
  z-index: 0;
  opacity: 0.6;
}

.hero-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transform: scale(1.04);
  will-change: transform;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(212deg, rgba(31, 31, 31, 0.12), rgba(31, 31, 31, 0.86));
}

.hero-band {
  position: absolute;
  left: -8%;
  right: -8%;
  bottom: 17%;
  z-index: 2;
  height: 52px;
  transform: skewY(-3.2deg);
  background: linear-gradient(90deg, rgba(255, 255, 255, 0.92), rgba(255, 255, 255, 0.24) 62%, rgba(255, 255, 255, 0));
  box-shadow: 0 20px 48px rgba(0, 0, 0, 0.34);
}

.hero-text {
  position: relative;
  z-index: 3;
  max-width: 16ch;
  min-width: 0;
  text-align: right;
}

.hero h1 {
  color: #ffffff;
  font-size: clamp(30px, 5.6vw, 60px);
  font-weight: 700;
  text-shadow: 0 8px 30px rgba(0, 0, 0, 0.45);
  overflow-wrap: break-word;
}

/* ---------- 主体 ---------- */
.deck {
  position: relative;
  z-index: 6;
  display: grid;
  grid-template-columns: 236px minmax(0, 1fr);
  align-items: start;
  gap: clamp(16px, 2.4vw, 30px);
  max-width: var(--maxw);
  margin: -64px auto 0;
  padding: 0 clamp(14px, 4vw, 40px) clamp(48px, 7vw, 96px);
}

.rail {
  position: sticky;
  top: 96px;
  min-width: 0;
  padding: 20px 16px;
  border: 1px solid var(--hair);
  border-radius: 24px;
  background: var(--glass);
  backdrop-filter: blur(18px) saturate(1.1);
  -webkit-backdrop-filter: blur(18px) saturate(1.1);
  box-shadow: var(--e3);
}

.rail-title {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.1em;
}

.rail hr {
  height: 1px;
  margin: 12px 0 14px;
  border: 0;
  background: var(--line);
}

.rail-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
  margin: 0;
  padding: 0;
  list-style: none;
}

.rail-list a {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 10px 10px;
  border-radius: 13px;
  font-size: 16px;
  color: var(--ink-60);
  transition: color 0.18s ease, background 0.18s ease, box-shadow 0.18s ease, transform 0.18s ease;
}

.rail-list a:hover {
  color: var(--ink);
  background: var(--paper);
  box-shadow: var(--e2);
  transform: translateX(3px);
}

.rail-num {
  font-size: 16px;
  font-variant-numeric: tabular-nums;
  color: var(--ink-45);
}

.stream {
  min-width: 0;
  overflow-wrap: break-word;
  word-break: break-word;
}

.stream > section {
  position: relative;
  min-width: 0;
  margin-bottom: clamp(18px, 2.6vw, 32px);
  padding: clamp(22px, 3.2vw, 44px);
  border: 1px solid var(--hair);
  border-radius: var(--r);
  background: rgba(255, 255, 255, 0.74);
  backdrop-filter: blur(14px) saturate(1.05);
  -webkit-backdrop-filter: blur(14px) saturate(1.05);
  box-shadow: var(--e3);
  transition: box-shadow 0.25s ease, transform 0.25s ease;
}

.stream > section:nth-child(1) {
  box-shadow: var(--e4);
}

.stream > section:nth-child(odd) {
  margin-right: clamp(0px, 2.5vw, 26px);
}

.stream > section:nth-child(even) {
  margin-left: clamp(0px, 2.5vw, 26px);
}

.stream > section:hover {
  box-shadow: var(--e4);
  transform: translateY(-2px);
}

.stream h2 {
  margin-bottom: 2px;
  font-size: clamp(22px, 2.9vw, 30px);
  font-weight: 700;
  overflow-wrap: break-word;
}

.stream h3 {
  margin: 1.1em 0 0.4em;
  font-size: clamp(19px, 2.2vw, 22px);
  font-weight: 600;
  overflow-wrap: break-word;
}

.stream p {
  margin: 0 0 1em;
  color: var(--ink-80);
}

.stream p:last-child {
  margin-bottom: 0;
}

.stream ul,
.stream ol {
  margin: 0 0 1em;
  padding-left: 1.3em;
  color: var(--ink-80);
}

.stream li {
  margin-bottom: 0.4em;
}

.stream li::marker {
  color: var(--ink-45);
}

.stream hr {
  height: 1px;
  margin: 12px 0 20px;
  border: 0;
  background: var(--line);
}

.stream img {
  margin: 1em 0;
  max-width: 100%;
  height: auto;
  border-radius: 20px;
  box-shadow: var(--e2);
}

.stream a {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.stream blockquote {
  margin: 1em 0;
  padding: 12px 18px;
  border-left: 3px solid var(--ink);
  border-radius: 0 16px 16px 0;
  background: rgba(255, 255, 255, 0.8);
  box-shadow: var(--e1);
}

.stream blockquote p {
  margin: 0;
}

.stream table {
  display: block;
  width: 100%;
  max-width: 100%;
  overflow-x: auto;
  margin: 1em 0;
  border-collapse: collapse;
  font-size: 16px;
}

.stream th,
.stream td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--line);
  text-align: left;
}

main section[id] {
  scroll-margin-top: 100px;
}

/* ---------- 页脚 ---------- */
.foot {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr) minmax(0, 1fr);
  align-items: start;
  gap: clamp(18px, 3vw, 40px);
  margin-top: clamp(36px, 5vw, 72px);
  padding: clamp(28px, 4vw, 46px) clamp(16px, 6vw, 80px);
  border-top: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: 0 -16px 44px rgba(31, 31, 31, 0.05);
}

.foot-brand,
.foot-nav,
.foot-legal {
  min-width: 0;
}

.foot-logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 4px 0;
  font-size: 17px;
  font-weight: 700;
}

.sub {
  display: flex;
  gap: 8px;
  max-width: 320px;
  margin-top: 12px;
}

.sub-field {
  flex: 1 1 auto;
  min-width: 0;
  min-height: 44px;
  padding: 11px 14px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--paper);
  box-shadow: var(--e1);
  font-family: inherit;
  font-size: 16px;
  color: var(--ink);
}

.sub-field:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 1px;
}

.sub-btn {
  flex: 0 0 auto;
  min-height: 44px;
  padding: 11px 16px;
  border: 0;
  border-radius: 14px;
  background: var(--ink);
  color: #ffffff;
  font-family: inherit;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  box-shadow: var(--e2);
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

.sub-btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--e3);
}

.foot-nav dl {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 2px 12px;
  margin: 0;
}

.foot-nav dt,
.foot-nav dd {
  margin: 0;
  min-width: 0;
}

.foot-nav dd {
  min-height: 44px;
}

.foot-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  max-width: 100%;
  padding: 9px 8px;
  border-radius: 13px;
  font-size: 16px;
  color: var(--ink-60);
  transition: color 0.18s ease, background 0.18s ease, box-shadow 0.18s ease;
}

.foot-link:hover {
  color: var(--ink);
  background: var(--paper);
  box-shadow: var(--e2);
}

.foot-legal {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.copy {
  margin: 0;
  font-size: 16px;
  color: var(--ink-45);
}

.foot-links {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin: 0;
}

/* ---------- 响应式 ---------- */
@media (max-width: 900px) {
  .mast-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 4px;
    padding-bottom: 8px;
  }

  .brand {
    order: -1;
    justify-self: center;
  }

  .nav-left,
  .nav-right {
    justify-self: center;
    justify-content: center;
    max-width: 100%;
  }

  .hero {
    min-height: 58vh;
    clip-path: polygon(0 0, 100% 0, 100% 94%, 0 100%);
  }

  .deck {
    grid-template-columns: minmax(0, 1fr);
    margin-top: -44px;
  }

  .rail {
    position: static;
    padding: 14px 12px;
  }

  .rail-list {
    flex-direction: row;
    flex-wrap: nowrap;
    gap: 8px;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    padding-bottom: 6px;
  }

  .rail-list li {
    flex: 0 0 auto;
  }

  .rail-list a {
    white-space: nowrap;
  }

  .foot {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (max-width: 560px) {
  .stream > section:nth-child(odd),
  .stream > section:nth-child(even) {
    margin-left: 0;
    margin-right: 0;
  }

  .stream > section {
    padding: 20px 18px;
    border-radius: 24px;
  }

  .hero-text {
    max-width: 100%;
  }

  .foot-nav dl {
    gap: 2px 8px;
  }

  .sub {
    max-width: 100%;
  }
}

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

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

button[aria-expanded]{min-width:44px;min-height:44px}