/* 亿万品牌 · 共享样式 /assets/site.css */

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

:root {
  --ink: #0A1730;
  --panel: #132743;
  --cyan: #4CE0D2;
  --coral: #FF7B5C;
  --sand: #E9D8BC;
  --fog: #F5F8FC;
  --slate: #9DB3C6;
  --deep: #0B1523;
  --cyan-soft: #B7F5EF;
  --coral-soft: #FFD9CC;

  --shell: 1180px;
  --gutter: clamp(1.1rem, 4vw, 2.75rem);
  --measure: 40em;

  --r-sm: 8px;
  --r-md: 14px;
  --r-lg: 22px;

  --ease: cubic-bezier(.22, .61, .36, 1);

  --font-title: 'Inter Tight', 'HarmonyOS Sans SC', 'Noto Sans SC', 'PingFang SC', system-ui, sans-serif;
  --font-body: 'Noto Sans SC', 'Source Han Sans SC', 'PingFang SC', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'IBM Plex Mono', ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --line: rgba(157, 179, 198, .22);
  --line-strong: rgba(157, 179, 198, .38);
  --glass: rgba(19, 39, 67, .72);
}

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

@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--fog);
  background-color: var(--ink);
  background-image:
    radial-gradient(1100px 520px at 8% -8%, rgba(76, 224, 210, .16), transparent 62%),
    radial-gradient(900px 480px at 94% 2%, rgba(255, 123, 92, .13), transparent 58%),
    linear-gradient(180deg, rgba(19, 39, 67, .55) 0%, rgba(10, 23, 48, 0) 42%);
  background-repeat: no-repeat;
  font-family: var(--font-body);
  font-size: clamp(1rem, .45vw + .9rem, 1.0625rem);
  font-weight: 400;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  margin: 0;
  font-family: var(--font-title);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: -.012em;
  color: var(--fog);
}

p { margin: 0; }
ul, ol { margin: 0; padding: 0; }
li { list-style: none; }
img, svg, video { max-width: 100%; }

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

button { font: inherit; }

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 4px;
}

[hidden] { display: none !important; }

#main-content { display: block; }

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ---------- 布局骨架 ---------- */

.shell {
  width: 100%;
  max-width: calc(var(--shell) + var(--gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: clamp(2.75rem, 7vw, 5.5rem); }
.section--tight { padding-block: clamp(1.75rem, 4.5vw, 3rem); }

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(1rem, 2.4vw, 2rem);
}

.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-5 { grid-column: span 5; }
.col-6 { grid-column: span 6; }
.col-7 { grid-column: span 7; }
.col-8 { grid-column: span 8; }
.col-9 { grid-column: span 9; }
.col-10 { grid-column: span 10; }
.col-12 { grid-column: span 12; }

.stack > * + * { margin-top: clamp(.85rem, 2vw, 1.4rem); }

.hairline { border: 0; border-top: 1px solid var(--line); margin: 0; }

.prose { max-width: var(--measure); }
.prose p + p { margin-top: 1rem; }
.prose p { color: rgba(245, 248, 252, .82); }

@media (max-width: 899px) {
  .col-3, .col-4, .col-5, .col-6,
  .col-7, .col-8, .col-9, .col-10 { grid-column: 1 / -1; }
}

/* ---------- 文字语义 ---------- */

.eyebrow {
  font-family: var(--font-mono);
  font-size: .78rem;
  font-weight: 600;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--cyan);
}

.lead {
  font-size: clamp(1.05rem, 1.1vw + .8rem, 1.32rem);
  line-height: 1.7;
  color: var(--slate);
  max-width: var(--measure);
}

.mono { font-family: var(--font-mono); font-weight: 600; letter-spacing: .02em; }

.tag {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  padding: .22rem .7rem;
  border-radius: 6px;
  border: 1px solid rgba(157, 179, 198, .24);
  background: rgba(157, 179, 198, .14);
  color: var(--slate);
  font-size: .75rem;
  font-weight: 600;
  letter-spacing: .06em;
  line-height: 1.6;
}

.tag--cyan { border-color: rgba(76, 224, 210, .4); background: rgba(76, 224, 210, .14); color: var(--cyan-soft); }
.tag--coral { border-color: rgba(255, 123, 92, .42); background: rgba(255, 123, 92, .14); color: var(--coral-soft); }
.tag--sand { border-color: rgba(233, 216, 188, .4); background: rgba(233, 216, 188, .16); color: var(--sand); }

/* ---------- 按钮 ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  padding: .8rem 1.35rem;
  border: 1px solid transparent;
  border-radius: 999px;
  font-family: var(--font-title);
  font-size: .95rem;
  font-weight: 700;
  letter-spacing: .02em;
  text-decoration: none;
  cursor: pointer;
  transition: transform .26s var(--ease), background-color .26s var(--ease),
              color .26s var(--ease), border-color .26s var(--ease);
}

.btn:hover { transform: translateY(-2px); }

.btn--primary { background: var(--coral); color: var(--deep); }
.btn--primary:hover { background: #ff9077; color: var(--deep); }

.btn--ghost {
  border-color: rgba(76, 224, 210, .5);
  background: rgba(76, 224, 210, .07);
  color: var(--cyan);
}
.btn--ghost:hover { background: rgba(76, 224, 210, .16); color: var(--cyan-soft); }

.btn--quiet { border-color: var(--line-strong); color: var(--slate); }
.btn--quiet:hover { color: var(--fog); border-color: var(--fog); }

.btn--sm { padding: .55rem 1rem; font-size: .85rem; }

/* ---------- 面包屑 ---------- */

.breadcrumbs { font-size: .8rem; color: var(--slate); }

.breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .45rem;
}

.breadcrumbs__item + .breadcrumbs__item::before {
  content: "/";
  margin-right: .45rem;
  color: rgba(157, 179, 198, .6);
}

.breadcrumbs a { color: var(--slate); }
.breadcrumbs a:hover { color: var(--cyan); }
.breadcrumbs [aria-current="page"] { color: var(--fog); }

/* ---------- 图片容器 ---------- */

.media-frame {
  position: relative;
  overflow: hidden;
  border-radius: var(--r-lg);
  border: 1px solid rgba(157, 179, 198, .2);
  background:
    linear-gradient(150deg, rgba(76, 224, 210, .16), rgba(255, 123, 92, .12) 65%, rgba(19, 39, 67, .9)),
    var(--panel);
}

.media-frame__img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame__caption {
  padding: .6rem .95rem;
  font-size: .8rem;
  color: var(--slate);
  border-top: 1px solid rgba(157, 179, 198, .16);
}

.media-frame--wide { aspect-ratio: 16 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }

.media-frame--glass {
  background: linear-gradient(150deg, rgba(76, 224, 210, .2), rgba(10, 23, 48, .3));
  border-color: rgba(76, 224, 210, .28);
}

.media-frame--caption { aspect-ratio: auto; }

/* ---------- 时间轴 ---------- */

.timeline {
  position: relative;
  padding-left: 1.75rem;
  border-left: 1px solid var(--line);
}

.timeline__item {
  position: relative;
  padding-bottom: clamp(1.4rem, 3.4vw, 2.6rem);
}

.timeline__item::before {
  content: "";
  position: absolute;
  left: -1.75rem;
  top: .62rem;
  width: 10px;
  height: 10px;
  transform: translateX(-50%);
  border-radius: 50%;
  background: var(--slate);
  box-shadow: 0 0 0 4px rgba(157, 179, 198, .14);
  transition: background-color .3s var(--ease), box-shadow .3s var(--ease);
}

.timeline__item.is-current::before {
  background: var(--cyan);
  box-shadow: 0 0 0 5px rgba(76, 224, 210, .2);
}

.timeline__date {
  font-family: var(--font-mono);
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .06em;
  color: var(--cyan);
}

/* ---------- 标签页 / 分段切换 ---------- */

.tabs { display: block; }

.tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem;
  padding-bottom: .55rem;
  border-bottom: 1px solid var(--line);
}

.tabs__tab {
  appearance: none;
  padding: .55rem 1rem;
  border: 1px solid transparent;
  border-radius: 999px;
  background: transparent;
  color: var(--slate);
  font-weight: 600;
  font-size: .92rem;
  cursor: pointer;
  transition: color .24s var(--ease), background-color .24s var(--ease),
              border-color .24s var(--ease);
}

.tabs__tab:hover { color: var(--fog); }

.tabs__tab[aria-selected="true"] {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--deep);
}

.tabs__panel { padding-top: clamp(1.2rem, 3vw, 2rem); }

/* ---------- 手风琴 ---------- */

.accordion { border-top: 1px solid var(--line); }

.accordion__item { border-bottom: 1px solid var(--line); }

.accordion__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  width: 100%;
  padding: 1.05rem 0;
  border: 0;
  background: transparent;
  color: var(--fog);
  font-family: var(--font-title);
  font-weight: 700;
  font-size: 1.02rem;
  text-align: left;
  cursor: pointer;
}

.accordion__trigger::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 1.15rem;
  color: var(--cyan);
}

.accordion__trigger[aria-expanded="true"]::after { content: "–"; }

.accordion__panel { padding-bottom: 1.25rem; }

/* ---------- 前端筛选 ---------- */

.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
}

.filter-chip {
  appearance: none;
  padding: .42rem .95rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(19, 39, 67, .5);
  color: var(--slate);
  font-size: .85rem;
  cursor: pointer;
  transition: color .24s var(--ease), border-color .24s var(--ease),
              background-color .24s var(--ease);
}

.filter-chip:hover { color: var(--fog); border-color: var(--line-strong); }

.filter-chip[aria-pressed="true"] {
  background: rgba(76, 224, 210, .16);
  border-color: var(--cyan);
  color: var(--cyan-soft);
}

[data-filter-item][hidden] { display: none; }

/* ---------- 显现 ---------- */

html[data-enhanced="true"] [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .38s var(--ease), transform .38s var(--ease);
}

html[data-enhanced="true"] [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 页头 ---------- */

.skip-link {
  position: absolute;
  top: .5rem;
  left: 50%;
  z-index: 200;
  padding: .6rem 1.1rem;
  border-radius: 999px;
  background: var(--cyan);
  color: var(--deep);
  font-family: var(--font-title);
  font-weight: 700;
  font-size: .9rem;
  text-decoration: none;
  transform: translate(-50%, -200%);
  transition: transform .24s var(--ease);
}

.skip-link:focus,
.skip-link:focus-visible { transform: translate(-50%, 0); color: var(--deep); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: linear-gradient(180deg, rgba(10, 23, 48, .94), rgba(10, 23, 48, .74));
  -webkit-backdrop-filter: blur(14px) saturate(130%);
  backdrop-filter: blur(14px) saturate(130%);
  border-bottom: 1px solid var(--line);
}

.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  overflow: hidden;
  background: rgba(157, 179, 198, .16);
}

.scroll-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: left center;
  background: linear-gradient(90deg, var(--cyan), var(--coral));
}

.site-header__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: .35rem;
  padding-block: clamp(.9rem, 2vw, 1.5rem);
  transition: padding-block .32s var(--ease);
}

.masthead {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: .25rem;
  max-height: 9rem;
  overflow: hidden;
  transition: max-height .34s var(--ease), opacity .34s var(--ease), transform .34s var(--ease);
}

.masthead__brand {
  display: inline-flex;
  align-items: baseline;
  gap: .4rem;
  font-family: var(--font-title);
  font-size: clamp(1.7rem, 3vw, 2.35rem);
  font-weight: 900;
  letter-spacing: .12em;
  color: var(--fog);
  text-decoration: none;
}

.masthead__brand:hover { color: var(--cyan); }

.masthead__brand-cn {
  font-family: var(--font-mono);
  font-size: .42em;
  font-weight: 700;
  letter-spacing: .18em;
  color: var(--cyan);
}

.masthead__motto {
  font-size: .78rem;
  letter-spacing: .3em;
  color: var(--sand);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: .55rem;
  padding: .45rem .9rem;
  border: 1px solid rgba(76, 224, 210, .42);
  border-radius: 999px;
  background: rgba(76, 224, 210, .1);
  color: var(--fog);
  font-size: .82rem;
  letter-spacing: .12em;
  cursor: pointer;
}

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 16px;
  height: 12px;
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform .28s var(--ease), top .28s var(--ease);
}

.nav-toggle__bars::before { top: 1px; }
.nav-toggle__bars::after { top: 9px; }

.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { top: 5px; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { top: 5px; transform: rotate(-45deg); }

.site-nav__list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
}

.site-nav__item + .site-nav__item { border-left: 1px solid var(--line); }

.site-nav__link {
  position: relative;
  display: block;
  padding: .5rem clamp(.75rem, 2vw, 1.4rem);
  color: var(--slate);
  font-size: .95rem;
  text-decoration: none;
  transition: color .24s var(--ease);
}

.site-nav__link:hover { color: var(--fog); }

.site-nav__link[aria-current="page"] { color: var(--cyan); }

.site-nav__link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: .05rem;
  width: clamp(14px, 55%, 44px);
  height: 2px;
  border-radius: 2px;
  background: var(--cyan);
  transform: translateX(-50%);
}

@media (min-width: 900px) {
  .site-header.is-condensed .masthead {
    max-height: 0;
    opacity: 0;
    transform: translateY(-.5rem);
  }

  .site-header.is-condensed .site-header__inner { padding-block: .35rem; }
}

@media (max-width: 899px) {
  .site-header {
    background: rgba(10, 23, 48, .97);
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
  }

  .site-header__inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding-block: .7rem;
  }

  .masthead { align-items: flex-start; max-height: none; }
  .masthead__brand { font-size: 1.35rem; letter-spacing: .1em; }
  .masthead__motto { font-size: .68rem; letter-spacing: .2em; }

  .nav-toggle { display: inline-flex; }

  .site-nav {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 70;
    padding: .9rem max(1rem, env(safe-area-inset-left)) calc(1rem + env(safe-area-inset-bottom));
    background: rgba(19, 39, 67, .97);
    border-top: 1px solid rgba(76, 224, 210, .3);
    box-shadow: 0 -18px 40px rgba(4, 10, 22, .55);
    transform: translateY(115%);
    visibility: hidden;
    transition: transform .34s var(--ease), visibility .34s var(--ease);
  }

  .site-nav[data-open] { transform: translateY(0); visibility: visible; }

  .site-nav__list {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: .4rem;
  }

  .site-nav__item + .site-nav__item { border-left: 0; }

  .site-nav__link {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: .4rem;
    padding: .7rem .3rem;
    border-radius: var(--r-sm);
    font-size: .74rem;
    letter-spacing: .06em;
    text-align: center;
  }

  .site-nav__link::before {
    content: "";
    width: 16px;
    height: 16px;
    border: 1.5px solid currentColor;
    border-radius: 5px;
    opacity: .8;
  }

  .site-nav__item:nth-child(3n + 2) .site-nav__link::before { border-radius: 50%; }

  .site-nav__item:nth-child(3n) .site-nav__link::before {
    border-radius: 2px;
    transform: rotate(45deg) scale(.82);
  }

  .site-nav__link[aria-current="page"] {
    background: rgba(76, 224, 210, .12);
    color: var(--cyan);
  }

  .site-nav__link[aria-current="page"]::after { display: none; }
}

/* ---------- 页脚 ---------- */

.site-footer {
  position: relative;
  margin-top: clamp(3rem, 8vw, 6rem);
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(10, 23, 48, 0) 0%, rgba(19, 39, 67, .82) 32%, #0b1626 100%);
  color: var(--fog);
}

.footer__inner {
  display: grid;
  grid-template-columns: 1.1fr 1.6fr 1fr;
  gap: clamp(1.6rem, 4vw, 3.5rem);
  padding-block: clamp(2.5rem, 5vw, 4rem);
}

.footer__brand {
  display: flex;
  align-items: baseline;
  gap: .35rem;
  font-family: var(--font-title);
  font-size: 1.55rem;
  font-weight: 900;
  letter-spacing: .12em;
}

.footer__brand-cn {
  font-family: var(--font-mono);
  font-size: .44em;
  letter-spacing: .18em;
  color: var(--cyan);
}

.footer__motto {
  margin-top: .6rem;
  font-size: .9rem;
  letter-spacing: .14em;
  color: var(--sand);
}

.footer__note {
  margin-top: .7rem;
  font-size: .85rem;
  line-height: 1.7;
  color: var(--slate);
  max-width: 26em;
}

.footer__col--links {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.25rem;
}

.footer__group-title {
  font-family: var(--font-mono);
  font-size: .74rem;
  font-weight: 600;
  letter-spacing: .2em;
  color: var(--cyan);
}

.footer__list { margin-top: .8rem; }
.footer__list li + li { margin-top: .5rem; }

.footer__link {
  color: var(--slate);
  font-size: .92rem;
  text-decoration: none;
  transition: color .24s var(--ease);
}

.footer__link:hover { color: var(--fog); }

.footer__region {
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .16em;
  color: var(--slate);
}

.footer__contact { margin-top: .9rem; }
.footer__contact li { margin-top: .55rem; font-size: .88rem; color: var(--fog); }

.footer__label {
  display: block;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .16em;
  color: var(--slate);
}

.footer__icp {
  margin-top: 1rem;
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .04em;
  color: var(--slate);
}

.footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .75rem 1.5rem;
  padding-block: 1.1rem 1.7rem;
  border-top: 1px solid var(--line);
  font-size: .8rem;
  color: var(--slate);
}

.footer__fineprint-list {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem 1.25rem;
}

.footer__fineprint-list a { color: var(--slate); }
.footer__fineprint-list a:hover { color: var(--cyan); }

@media (max-width: 1023px) {
  .footer__inner { grid-template-columns: 1fr 1fr; }
  .footer__col--brand { grid-column: 1 / -1; }
}

@media (max-width: 639px) {
  .footer__inner { grid-template-columns: 1fr; }
  .footer__col--links { grid-template-columns: 1fr 1fr; }
  .footer__bottom { flex-direction: column; align-items: flex-start; }
}

/* ---------- 降低动效偏好 ---------- */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }

  html[data-enhanced="true"] [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .site-nav { transition: none; }
}