/* ============================================================
   学校群聊 · 抖音群介绍页
   Design system: 深空墨蓝底 + 极光渐变 + 毛玻璃 + 果冻动效
   ============================================================ */

/* ---------- 1. Tokens ---------- */
:root {
  /* 品牌色（抖音系） */
  --pink:   #fe2c55;
  --cyan:   #25f4ee;
  --violet: #7c5cff;
  --mint:   #3ee0b0;
  --amber:  #ffb86b;
  --blue:   #4d8cff;

  --grad-brand: linear-gradient(120deg, var(--cyan) 0%, var(--violet) 46%, var(--pink) 100%);
  --grad-soft:  linear-gradient(135deg, rgba(37,244,238,.18), rgba(124,92,255,.18) 50%, rgba(254,44,85,.18));

  /* 节奏 */
  --r-sm: 12px;
  --r-md: 18px;
  --r-lg: 26px;
  --r-xl: 34px;
  --r-full: 999px;

  --pad-sec: clamp(72px, 9vw, 132px);
  --wrap: 1200px;
  --nav-h: 70px;

  /* 缓动 */
  --ease-out: cubic-bezier(.22,.75,.24,1);
  --ease-spring: cubic-bezier(.2,1.42,.38,1);
  --ease-jelly: cubic-bezier(.34,1.56,.64,1);
}

/* 深色（默认） */
[data-theme="dark"] {
  --bg:        #07080f;
  --bg-2:      #0a0c17;
  --ink:       #edf0fa;
  --ink-2:     #a8b0c8;
  --ink-3:     #737b95;
  --line:      rgba(255,255,255,.10);
  --glass:     rgba(255,255,255,.055);
  --glass-2:   rgba(255,255,255,.10);
  --glass-brd: rgba(255,255,255,.14);
  --glass-hi:  rgba(255,255,255,.20);
  --shadow:    0 26px 70px -28px rgba(0,0,0,.85), 0 4px 18px -8px rgba(0,0,0,.6);
  --shadow-lg: 0 46px 110px -34px rgba(0,0,0,.9), 0 8px 28px -10px rgba(0,0,0,.65);
  --spot:      rgba(124,92,255,.16);
  --grain:     .045;
  --rise:      rgba(255,255,255,.06);
}
/* 浅色 */
[data-theme="light"] {
  --bg:        #eef1f8;
  --bg-2:      #e4e8f4;
  --ink:       #0e1120;
  --ink-2:     #4c5470;
  --ink-3:     #7b8399;
  --line:      rgba(16,20,44,.10);
  --glass:     rgba(255,255,255,.60);
  --glass-2:   rgba(255,255,255,.78);
  --glass-brd: rgba(255,255,255,.85);
  --glass-hi:  rgba(255,255,255,.95);
  --shadow:    0 26px 60px -30px rgba(28,36,80,.40), 0 4px 16px -8px rgba(28,36,80,.18);
  --shadow-lg: 0 46px 100px -36px rgba(28,36,80,.45), 0 8px 26px -12px rgba(28,36,80,.22);
  --spot:      rgba(124,92,255,.14);
  --grain:     .02;
  --rise:      rgba(255,255,255,.9);
}

/* ---------- 2. Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 26px);
  -webkit-text-size-adjust: 100%;
  /* 兜底：任何元素都不该把视口撑宽（否则手机端会整页缩放/横向滑动） */
  overflow-x: hidden;
  overflow-x: clip;
}

body {
  font-family: system-ui, -apple-system, "Segoe UI", "PingFang SC", "HarmonyOS Sans SC",
               "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans SC", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.7;
  font-size: 16px;
  overflow-x: hidden;
  overflow-x: clip;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  -webkit-tap-highlight-color: transparent;
  transition: background .5s var(--ease-out), color .5s var(--ease-out);
}
body.is-locked { overflow: hidden; touch-action: none; }

img, svg { display: block; max-width: 100%; }
img { height: auto; }
a { color: inherit; text-decoration: none; }
button, input { font: inherit; color: inherit; }
button { background: none; border: 0; cursor: pointer; }
ul, ol { list-style: none; }
code, .mono {
  font-family: ui-monospace, "SF Mono", "JetBrains Mono", "Cascadia Mono", Consolas, monospace;
  font-variant-numeric: tabular-nums;
  letter-spacing: .02em;
}
::selection { background: rgba(124,92,255,.35); color: #fff; }

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 6px;
}

.skip-link {
  position: fixed; top: 10px; left: 10px; z-index: 999;
  padding: 10px 16px; border-radius: var(--r-full);
  background: var(--violet); color: #fff; font-size: 14px;
  transform: translateY(-160%);
  transition: transform .3s var(--ease-spring);
}
.skip-link:focus { transform: none; }

/* 滚动条 */
::-webkit-scrollbar { width: 11px; height: 11px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, rgba(124,92,255,.6), rgba(254,44,85,.55));
  border: 3px solid transparent; border-radius: 99px; background-clip: content-box;
}
::-webkit-scrollbar-thumb:hover { background: linear-gradient(180deg, var(--cyan), var(--pink)); background-clip: content-box; }

/* ---------- 3. 背景层 ---------- */
.bg { position: fixed; inset: 0; z-index: -2; overflow: hidden; background:
  radial-gradient(120% 80% at 50% -10%, var(--bg-2), var(--bg) 60%); }

.bg__blob {
  position: absolute; border-radius: 50%;
  filter: blur(90px); opacity: .55;
  will-change: transform;
}
[data-theme="light"] .bg__blob { opacity: .5; filter: blur(80px); }

.bg__blob--1 { width: 46vw; height: 46vw; left: -8vw; top: -6vw;
  background: radial-gradient(circle at 30% 30%, rgba(37,244,238,.85), transparent 68%);
  animation: drift1 26s var(--ease-out) infinite alternate; }
.bg__blob--2 { width: 52vw; height: 52vw; right: -12vw; top: 2vw;
  background: radial-gradient(circle at 60% 40%, rgba(124,92,255,.9), transparent 68%);
  animation: drift2 32s var(--ease-out) infinite alternate; }
.bg__blob--3 { width: 44vw; height: 44vw; left: 14vw; bottom: -14vw;
  background: radial-gradient(circle at 50% 50%, rgba(254,44,85,.8), transparent 68%);
  animation: drift3 29s var(--ease-out) infinite alternate; }
.bg__blob--4 { width: 30vw; height: 30vw; right: 10vw; bottom: 4vw;
  background: radial-gradient(circle at 50% 50%, rgba(62,224,176,.7), transparent 68%);
  animation: drift1 35s var(--ease-out) infinite alternate-reverse; }

@keyframes drift1 { from { transform: translate3d(0,0,0) scale(1); } to { transform: translate3d(9vw,7vh,0) scale(1.22); } }
@keyframes drift2 { from { transform: translate3d(0,0,0) scale(1.1); } to { transform: translate3d(-11vw,9vh,0) scale(.92); } }
@keyframes drift3 { from { transform: translate3d(0,0,0) scale(.95); } to { transform: translate3d(8vw,-9vh,0) scale(1.25); } }

.bg__grid {
  position: absolute; inset: -1px;
  background-image:
    linear-gradient(to right, var(--line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--line) 1px, transparent 1px);
  background-size: 62px 62px;
  mask-image: radial-gradient(115% 85% at 50% 0%, #000 20%, transparent 78%);
  -webkit-mask-image: radial-gradient(115% 85% at 50% 0%, #000 20%, transparent 78%);
  opacity: .85;
}
.bg__grain {
  position: absolute; inset: 0; opacity: var(--grain); mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.82' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E");
}
.bg__vignette {
  position: absolute; inset: 0;
  background: radial-gradient(120% 70% at 50% 40%, transparent 40%, rgba(0,0,0,.35) 100%);
}
[data-theme="light"] .bg__vignette { background: radial-gradient(120% 70% at 50% 40%, transparent 45%, rgba(40,50,90,.14) 100%); }

/* 光标聚光 */
.spotlight {
  position: fixed; inset: 0; z-index: -1; pointer-events: none;
  opacity: 0; transition: opacity .6s ease;
  background: radial-gradient(560px circle at var(--mx, 50%) var(--my, 40%), var(--spot), transparent 62%);
}
body.has-pointer .spotlight { opacity: 1; }

/* 滚动进度：用 scaleX 而不是 width，避免每帧触发布局（移动端尤其重要） */
.progress { position: fixed; top: 0; left: 0; right: 0; height: 3px; z-index: 120; pointer-events: none; }
.progress i {
  display: block; height: 100%; width: 100%;
  transform: scaleX(0); transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--cyan), var(--violet) 45%, var(--pink));
  box-shadow: 0 0 18px rgba(124,92,255,.85);
  will-change: transform;
}

/* ---------- 4. Utilities ---------- */
.wrap { width: 100%; max-width: var(--wrap); margin-inline: auto; padding-inline: clamp(18px, 4vw, 40px); }
.wrap--narrow { max-width: 860px; }

.glass {
  background: var(--glass);
  border: 1px solid var(--glass-brd);
  -webkit-backdrop-filter: blur(16px) saturate(170%);
  backdrop-filter: blur(16px) saturate(170%);
  box-shadow: var(--shadow), inset 0 1px 0 var(--glass-hi);
}

.grad {
  background: var(--grad-brand);
  background-size: 220% 220%;
  -webkit-background-clip: text; background-clip: text;
  color: transparent; -webkit-text-fill-color: transparent;
  animation: gradShift 9s ease infinite;
}
@keyframes gradShift { 0%,100% { background-position: 0% 50%; } 50% { background-position: 100% 50%; } }

.warn { color: var(--amber); }

/* ---------- 5. 按钮 ---------- */
.btn {
  position: relative;
  display: inline-flex; align-items: center; justify-content: center; gap: 9px;
  padding: 13px 24px;
  border-radius: var(--r-full);
  font-size: 15px; font-weight: 650; letter-spacing: .01em;
  white-space: nowrap; cursor: pointer; overflow: hidden;
  isolation: isolate;
  transition: transform .55s var(--ease-jelly), box-shadow .4s var(--ease-out),
              background .4s var(--ease-out), color .4s var(--ease-out), border-color .4s var(--ease-out);
}
.btn .ico { width: 18px; height: 18px; flex: none; }
.btn--sm { padding: 10px 18px; font-size: 14px; }
.btn--block { width: 100%; }

.btn--primary {
  color: #fff;
  background: var(--grad-brand);
  background-size: 190% 190%;
  box-shadow: 0 14px 34px -12px rgba(254,44,85,.6), 0 8px 26px -14px rgba(37,244,238,.55);
  animation: gradShift 7s ease infinite;
}
.btn--primary::after {
  content: ""; position: absolute; inset: 0; z-index: -1;
  background: linear-gradient(105deg, transparent 32%, rgba(255,255,255,.5) 50%, transparent 68%);
  transform: translateX(-130%);
  transition: transform .85s var(--ease-out);
}
.btn--primary:hover::after { transform: translateX(130%); }

.btn--ghost {
  color: var(--ink);
  background: var(--glass);
  border: 1px solid var(--glass-brd);
  -webkit-backdrop-filter: blur(14px); backdrop-filter: blur(14px);
}
.btn--ghost:hover { background: var(--glass-2); border-color: var(--glass-hi); }

.btn:hover  { transform: translateY(-3px) scale(1.035); }
.btn:active { transform: translateY(0) scale(.94); transition-duration: .1s; }
.btn--primary:hover { box-shadow: 0 22px 48px -14px rgba(254,44,85,.7), 0 12px 34px -14px rgba(37,244,238,.6); }
.ico--arrow { transition: transform .5s var(--ease-jelly); }
.btn:hover .ico--arrow { transform: translateX(4px); }

/* 图标按钮 */
.icon-btn {
  display: inline-grid; place-items: center;
  width: 40px; height: 40px; flex: none;
  border-radius: var(--r-full);
  color: var(--ink-2);
  background: var(--glass);
  border: 1px solid var(--glass-brd);
  -webkit-backdrop-filter: blur(12px); backdrop-filter: blur(12px);
  transition: transform .5s var(--ease-jelly), color .3s, background .3s, border-color .3s;
}
.icon-btn .ico { width: 19px; height: 19px; }
.icon-btn:hover { color: var(--ink); background: var(--glass-2); border-color: var(--glass-hi); transform: translateY(-2px) scale(1.08) rotate(-3deg); }
.icon-btn:active { transform: scale(.9); transition-duration: .09s; }

/* 小胶囊按钮 */
.mini {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 7px 14px; border-radius: var(--r-full);
  font-size: 13px; font-weight: 600; color: var(--ink-2);
  background: var(--glass); border: 1px solid var(--glass-brd);
  cursor: pointer;
  transition: transform .5s var(--ease-jelly), color .3s, background .3s, border-color .3s;
}
.mini .ico { width: 14px; height: 14px; }
.mini:hover { color: var(--ink); background: var(--glass-2); border-color: var(--glass-hi); transform: translateY(-2px) scale(1.06); }
.mini:active { transform: scale(.92); transition-duration: .09s; }
.mini--static { cursor: default; color: var(--mint); }
.mini--static:hover { transform: none; background: var(--glass); }

/* SVG 描边统一 */
.ico { fill: none; stroke: currentColor; stroke-width: 1.85; stroke-linecap: round; stroke-linejoin: round; }
.ico--sun g { stroke: currentColor; }

/* 主题图标切换 */
[data-theme="dark"] .ico--sun  { display: none; }
[data-theme="light"] .ico--moon { display: none; }

/* ============================================================
   6. 导航
   ============================================================ */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  padding: 14px clamp(14px, 3vw, 30px);
  transition: padding .45s var(--ease-out), transform .5s var(--ease-out);
}
.nav__inner {
  max-width: var(--wrap); margin-inline: auto;
  height: var(--nav-h);
  display: flex; align-items: center; gap: 18px;
  padding: 0 14px 0 16px;
  border-radius: var(--r-full);
  transition: box-shadow .5s var(--ease-out), background .5s var(--ease-out), height .45s var(--ease-out);
}
.nav.is-stuck { padding-top: 8px; }
.nav.is-stuck .nav__inner { height: 62px; box-shadow: var(--shadow-lg), inset 0 1px 0 var(--glass-hi); background: var(--glass-2); }

.brand { display: flex; align-items: center; gap: 11px; flex: none; }
.brand__mark {
  width: 40px; height: 40px; flex: none; border-radius: 13px;
  box-shadow: 0 10px 26px -10px rgba(124,92,255,.85);
  transition: transform .6s var(--ease-jelly);
}
.brand:hover .brand__mark { transform: rotate(-8deg) scale(1.1); }
.brand__text { display: flex; flex-direction: column; line-height: 1.2; }
.brand__text strong { font-size: 15.5px; font-weight: 750; letter-spacing: .01em; }
.brand__text small { font-size: 11px; color: var(--ink-3); }

.nav__links {
  position: relative;
  display: flex; align-items: center; gap: 2px;
  margin-inline: auto;
  padding: 5px;
  border-radius: var(--r-full);
  background: color-mix(in srgb, var(--glass) 70%, transparent);
  border: 1px solid var(--line);
}
.nav__links a {
  position: relative; z-index: 2;
  padding: 8px 15px; border-radius: var(--r-full);
  font-size: 14px; font-weight: 600; color: var(--ink-2);
  transition: color .3s var(--ease-out), transform .5s var(--ease-jelly);
}
.nav__links a:hover { color: var(--ink); transform: translateY(-1px); }
.nav__links a.active { color: #fff; }
[data-theme="light"] .nav__links a.active { color: #fff; }
.nav__pill {
  position: absolute; top: 5px; left: 0; z-index: 1;
  height: calc(100% - 10px); width: 0;
  border-radius: var(--r-full);
  background: linear-gradient(120deg, var(--violet), var(--pink));
  box-shadow: 0 8px 22px -8px rgba(124,92,255,.9);
  transform: translateX(0) scale(1);
  transition: transform .62s var(--ease-spring), width .55s var(--ease-spring), opacity .3s;
  opacity: 0;
  will-change: transform, width;
}
.nav__pill.show { opacity: 1; }

.nav__actions { display: flex; align-items: center; gap: 9px; flex: none; }

/* 汉堡 */
.burger { display: none; flex-direction: column; gap: 4px; }
.burger span {
  display: block; width: 17px; height: 2px; border-radius: 2px; background: currentColor;
  transition: transform .45s var(--ease-jelly), opacity .3s;
}
.burger[aria-expanded="true"] span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.burger[aria-expanded="true"] span:nth-child(2) { opacity: 0; transform: scaleX(.3); }
.burger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* ============================================================
   7. 移动端抽屉
   ============================================================ */
.sheet { position: fixed; inset: 0; z-index: 110; }
.sheet[hidden] { display: none; }
.sheet::before {
  content: ""; position: absolute; inset: 0;
  background: rgba(4,5,12,.55);
  -webkit-backdrop-filter: blur(7px); backdrop-filter: blur(7px);
  opacity: 0; transition: opacity .4s ease;
}
.sheet.in::before { opacity: 1; }
.sheet__panel {
  position: absolute; top: 12px; right: 12px; left: 12px;
  padding: 16px;
  border-radius: var(--r-xl);
  display: flex; flex-direction: column; gap: 8px;
  transform: translateY(-18px) scale(.94);
  opacity: 0;
  transition: transform .55s var(--ease-spring), opacity .35s ease;
  max-height: calc(100vh - 24px); overflow-y: auto;
}
.sheet.in .sheet__panel { transform: none; opacity: 1; }
.sheet__head { display: flex; align-items: center; justify-content: space-between; padding: 2px 4px 8px; font-weight: 700; }
.sheet__link {
  padding: 14px 16px; border-radius: var(--r-md);
  font-weight: 600; color: var(--ink-2);
  background: var(--glass); border: 1px solid transparent;
  transform: translateY(10px); opacity: 0;
  transition: background .3s, color .3s, transform .55s var(--ease-jelly), opacity .4s ease, border-color .3s;
}
.sheet.in .sheet__link { transform: none; opacity: 1; }
.sheet.in .sheet__link:nth-child(2) { transition-delay: .05s; }
.sheet.in .sheet__link:nth-child(3) { transition-delay: .09s; }
.sheet.in .sheet__link:nth-child(4) { transition-delay: .13s; }
.sheet.in .sheet__link:nth-child(5) { transition-delay: .17s; }
.sheet.in .sheet__link:nth-child(6) { transition-delay: .21s; }
.sheet.in .sheet__link:nth-child(7) { transition-delay: .25s; }
.sheet__link:hover, .sheet__link:active { background: var(--glass-2); color: var(--ink); border-color: var(--glass-brd); }
.sheet__cta { margin-top: 8px; }

/* ============================================================
   8. 右侧章节指示器
   ============================================================ */
.dots {
  position: fixed; right: 18px; top: 50%; transform: translateY(-50%);
  z-index: 90; display: flex; flex-direction: column; gap: 6px;
}
.dots a {
  position: relative; display: flex; align-items: center; justify-content: flex-end; gap: 10px;
  padding: 5px 0 5px 10px; color: var(--ink-3); font-size: 12px; font-weight: 600;
}
.dots i {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--ink-3); opacity: .5;
  transition: transform .55s var(--ease-spring), background .35s, opacity .35s, box-shadow .35s;
}
.dots span {
  order: -1;
  opacity: 0; transform: translateX(8px);
  padding: 3px 10px; border-radius: var(--r-full);
  background: var(--glass); border: 1px solid var(--glass-brd);
  -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px);
  white-space: nowrap;
  transition: opacity .35s, transform .45s var(--ease-jelly);
}
.dots a:hover span, .dots a.active span { opacity: 1; transform: none; }
.dots a.active i {
  background: var(--grad-brand); opacity: 1;
  transform: scale(1.9);
  box-shadow: 0 0 0 4px rgba(124,92,255,.18), 0 0 16px rgba(124,92,255,.8);
}

/* ============================================================
   9. Hero
   ============================================================ */
.hero {
  position: relative;
  padding: calc(var(--nav-h) + clamp(48px, 8vw, 96px)) 0 clamp(60px, 8vw, 100px);
  min-height: 100svh;
  display: flex; align-items: center;
}
.hero__grid {
  display: grid; grid-template-columns: minmax(0, 1.08fr) minmax(0, .92fr);
  gap: clamp(30px, 5vw, 68px); align-items: center;
}

.chip {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 8px 16px; margin-bottom: 22px;
  border-radius: var(--r-full);
  font-size: 13px; font-weight: 600; color: var(--ink-2);
  background: var(--glass); border: 1px solid var(--glass-brd);
  -webkit-backdrop-filter: blur(14px); backdrop-filter: blur(14px);
  box-shadow: var(--shadow);
}
.chip b { color: var(--ink); font-weight: 700; }
.chip__dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--mint); box-shadow: 0 0 0 0 rgba(62,224,176,.7);
  animation: pulse 2.4s ease-out infinite;
}
@keyframes pulse {
  0%   { box-shadow: 0 0 0 0 rgba(62,224,176,.6); }
  70%  { box-shadow: 0 0 0 11px rgba(62,224,176,0); }
  100% { box-shadow: 0 0 0 0 rgba(62,224,176,0); }
}
.chip__sep { width: 1px; height: 14px; background: var(--line); }

.hero__title {
  font-size: clamp(3.1rem, 9.2vw, 6.4rem);
  font-weight: 900;
  line-height: .98;
  letter-spacing: -.035em;
  margin-bottom: 20px;
}
.hero__title span { display: inline-block; }
.hero__title span:last-child { margin-left: .1em; }

.hero__sub {
  font-size: clamp(15px, 1.55vw, 18px);
  color: var(--ink-2); max-width: 34em; margin-bottom: 30px;
}
.hero__sub br { display: none; }
@media (min-width: 760px) { .hero__sub br { display: block; } }

.hero__cta { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 34px; }

.stats {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(146px, 1fr));
  gap: 12px; max-width: 620px;
}
.stats__item {
  padding: 14px 16px; border-radius: var(--r-md);
  transition: transform .55s var(--ease-jelly), background .4s, border-color .4s;
}
.stats__item:hover { transform: translateY(-4px) scale(1.04); background: var(--glass-2); border-color: var(--glass-hi); }
.stats__item dt { font-size: 11.5px; color: var(--ink-3); letter-spacing: .04em; margin-bottom: 3px; }
.stats__item dd { font-size: 18px; font-weight: 750; display: flex; align-items: baseline; gap: 2px; }
.stats__item dd small { font-size: 12px; color: var(--ink-3); font-weight: 600; }
.stats__item dd.mono { font-size: 15.5px; letter-spacing: -.01em; }

/* 二维码卡片 */
.hero__card { display: flex; flex-direction: column; align-items: center; gap: 14px; }

.tilt {
  --rx: 0deg; --ry: 0deg; --ty: 0px; --sc: 1;
  transform: perspective(1000px) rotateX(var(--rx)) rotateY(var(--ry))
             translate3d(0, var(--ty), 0) scale(var(--sc));
  transform-style: preserve-3d;
  transition: transform .62s var(--ease-spring);
}
.tilt.is-tilting { transition: transform .12s linear; }

.qcard {
  position: relative;
  width: min(100%, 380px);
  padding: 16px;
  border-radius: var(--r-xl);
  overflow: hidden;
  box-shadow: var(--shadow-lg), inset 0 1px 0 var(--glass-hi);
}
.qcard__glow {
  position: absolute; inset: -40%;
  background: conic-gradient(from 0deg, transparent 0%, rgba(37,244,238,.5) 18%, transparent 34%,
                             transparent 52%, rgba(254,44,85,.5) 68%, transparent 84%);
  filter: blur(38px); opacity: .65;
  animation: spin 14s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.qcard__head {
  position: relative; z-index: 2;
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 12px;
}
.tag {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 5px 12px; border-radius: var(--r-full);
  font-size: 11.5px; font-weight: 700; color: var(--ink-2);
  background: var(--glass); border: 1px solid var(--glass-brd);
}
.tag--live { color: #06110d; background: linear-gradient(120deg, var(--mint), var(--cyan)); border-color: transparent; }
.tag--live i { width: 6px; height: 6px; border-radius: 50%; background: #06110d; animation: pulse 1.9s infinite; }

.qcard__frame {
  position: relative; z-index: 2;
  border-radius: var(--r-lg); overflow: hidden;
  background: #fff;
  box-shadow: 0 20px 44px -20px rgba(0,0,0,.7), inset 0 0 0 1px rgba(255,255,255,.4);
}
.qcard__frame img { width: 100%; display: block; transition: transform .8s var(--ease-out); }
.qcard:hover .qcard__frame img { transform: scale(1.035); }

.qcard__scan {
  position: absolute; left: 0; right: 0; top: 0; height: 24%;
  background: linear-gradient(180deg, transparent, rgba(37,244,238,.42), transparent);
  mix-blend-mode: screen;
  animation: scan 3.6s var(--ease-out) infinite;
  pointer-events: none;
  will-change: transform, opacity;
}
/* 只动 transform，避免动画 top 造成整块重排 */
@keyframes scan {
  0%   { transform: translateY(-120%); opacity: 0; }
  12%  { opacity: 1; }
  88%  { opacity: 1; }
  100% { transform: translateY(430%); opacity: 0; }
}

.qcard__foot {
  position: relative; z-index: 2;
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  margin-top: 14px; padding: 0 2px;
}
.qcard__meta { display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.qcard__meta strong { font-size: 15.5px; font-weight: 750; }
.qcard__meta span { font-size: 12.5px; color: var(--ink-3); }
.qcard__acts { display: flex; gap: 8px; }

.qcard__shine {
  position: absolute; inset: 0; z-index: 3; pointer-events: none;
  background: linear-gradient(105deg, transparent 38%, rgba(255,255,255,.30) 47%, transparent 56%);
  transform: translateX(-120%);
  transition: transform 1s var(--ease-out);
}
.qcard:hover .qcard__shine { transform: translateX(120%); }

.hero__hint { font-size: 12.5px; color: var(--ink-3); text-align: center; }

.scroller {
  position: absolute; left: 50%; bottom: 22px; transform: translateX(-50%);
  display: flex; flex-direction: column; align-items: center; gap: 8px;
  color: var(--ink-3); font-size: 11.5px; letter-spacing: .14em;
  animation: bob 2.6s var(--ease-out) infinite;
}
.scroller__mouse {
  width: 22px; height: 34px; border-radius: 12px;
  border: 1.6px solid currentColor; display: grid; justify-items: center; padding-top: 6px;
}
.scroller__mouse i { width: 3px; height: 7px; border-radius: 2px; background: currentColor; animation: wheel 1.9s var(--ease-out) infinite; }
@keyframes wheel { 0%,100% { transform: translateY(0); opacity: 1; } 55% { transform: translateY(9px); opacity: .2; } }
@keyframes bob { 0%,100% { transform: translateX(-50%) translateY(0); } 50% { transform: translateX(-50%) translateY(7px); } }

/* ============================================================
   10. 跑马灯
   ============================================================ */
.marquee {
  position: relative;
  padding: 18px 0;
  border-block: 1px solid var(--line);
  background: color-mix(in srgb, var(--glass) 60%, transparent);
  -webkit-backdrop-filter: blur(10px); backdrop-filter: blur(10px);
  overflow: hidden;
  mask-image: linear-gradient(90deg, transparent, #000 7%, #000 93%, transparent);
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 7%, #000 93%, transparent);
}
.marquee__track { display: flex; gap: 44px; width: max-content; animation: slide 38s linear infinite; }
.marquee:hover .marquee__track { animation-play-state: paused; }
.marquee__item {
  display: inline-flex; align-items: center; gap: 10px;
  font-size: clamp(15px, 2vw, 21px); font-weight: 750;
  color: var(--ink-2); white-space: nowrap;
  opacity: .82; transition: opacity .3s, color .3s, transform .5s var(--ease-jelly);
}
.marquee__item:hover { opacity: 1; color: var(--ink); transform: scale(1.06); }
.marquee__item i { width: 7px; height: 7px; border-radius: 50%; background: var(--grad-brand); }
@keyframes slide { to { transform: translateX(-50%); } }

/* ============================================================
   11. 章节与卡片
   ============================================================ */
.sec { position: relative; padding: var(--pad-sec) 0; }
.sec__head { max-width: 720px; margin-bottom: clamp(34px, 5vw, 58px); }
.eyebrow {
  display: inline-block; margin-bottom: 12px;
  font-size: 12px; font-weight: 800; letter-spacing: .24em; text-transform: uppercase;
  background: var(--grad-brand); -webkit-background-clip: text; background-clip: text;
  color: transparent; -webkit-text-fill-color: transparent;
}
.sec__title {
  font-size: clamp(1.9rem, 4.4vw, 3.15rem);
  font-weight: 850; line-height: 1.16; letter-spacing: -.028em;
  margin-bottom: 14px;
}
.sec__desc { color: var(--ink-2); font-size: clamp(14.5px, 1.4vw, 16.5px); max-width: 46em; }
.sec__desc b { color: var(--ink); }

.bento {
  display: grid; gap: 16px;
  grid-template-columns: repeat(6, 1fr);
}
.card {
  position: relative;
  grid-column: span 2;
  padding: 26px 24px 24px;
  border-radius: var(--r-lg);
  overflow: hidden;
  isolation: isolate;
}
.card--wide { grid-column: span 4; }
.card > * { position: relative; z-index: 2; }
.card::before {
  content: ""; position: absolute; inset: 0; z-index: 1;
  background: radial-gradient(340px circle at var(--cx, 50%) var(--cy, 0%), rgba(124,92,255,.20), transparent 70%);
  opacity: 0; transition: opacity .45s var(--ease-out);
  pointer-events: none;
}
.card:hover::before { opacity: 1; }

.card__ico {
  display: grid; place-items: center;
  width: 48px; height: 48px; margin-bottom: 16px;
  border-radius: 15px; font-size: 22px;
  background: var(--glass-2); border: 1px solid var(--glass-brd);
  box-shadow: inset 0 1px 0 var(--glass-hi);
  transition: transform .6s var(--ease-jelly);
}
.card:hover .card__ico { transform: translateY(-3px) rotate(-7deg) scale(1.09); }
.card__ico.g1 { background: linear-gradient(140deg, rgba(37,244,238,.30), rgba(77,140,255,.24)); }
.card__ico.g2 { background: linear-gradient(140deg, rgba(124,92,255,.32), rgba(254,44,85,.22)); }
.card__ico.g3 { background: linear-gradient(140deg, rgba(254,44,85,.30), rgba(255,184,107,.26)); }
.card__ico.g4 { background: linear-gradient(140deg, rgba(62,224,176,.30), rgba(37,244,238,.24)); }
.card__ico.g5 { background: linear-gradient(140deg, rgba(255,184,107,.30), rgba(124,92,255,.24)); }

.card h3 { font-size: 18.5px; font-weight: 750; letter-spacing: -.012em; margin-bottom: 9px; }
.card p { color: var(--ink-2); font-size: 14.5px; }

.chips { display: flex; flex-wrap: wrap; gap: 7px; margin-top: 16px; }
.chips li {
  padding: 5px 12px; border-radius: var(--r-full);
  font-size: 12px; font-weight: 600; color: var(--ink-2);
  background: var(--glass); border: 1px solid var(--line);
  transition: transform .5s var(--ease-jelly), color .3s, border-color .3s;
}
.card:hover .chips li { border-color: var(--glass-brd); }
.chips li:hover { transform: translateY(-2px) scale(1.07); color: var(--ink); }

/* 轨道小球 */
.orbit { position: relative; height: 46px; margin-top: 18px; display: flex; flex-wrap: wrap; gap: 8px; }
.orbit span {
  padding: 6px 14px; border-radius: var(--r-full);
  font-size: 12.5px; font-weight: 650;
  background: var(--glass-2); border: 1px solid var(--glass-brd);
  animation: float 4.4s var(--ease-out) infinite;
}
.orbit span:nth-child(2n) { animation-delay: .6s; }
.orbit span:nth-child(3n) { animation-delay: 1.2s; }
.orbit span:nth-child(4n) { animation-delay: 1.8s; }
@keyframes float { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-6px); } }

/* ============================================================
   12. 圈子网格
   ============================================================ */
.circles {
  display: grid; gap: 16px;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
}
.ccard {
  position: relative;
  padding: 22px 20px 52px;
  border-radius: var(--r-lg);
  overflow: hidden; isolation: isolate;
  color: inherit;
}
.ccard > * { position: relative; z-index: 2; }
.ccard::before {
  content: ""; position: absolute; inset: 0; z-index: 1;
  background: radial-gradient(300px circle at var(--cx, 50%) var(--cy, 0%), var(--c, rgba(124,92,255,.4)), transparent 68%);
  opacity: 0; transition: opacity .45s var(--ease-out);
}
.ccard:hover::before { opacity: .5; }
.ccard__ico {
  display: grid; place-items: center;
  width: 50px; height: 50px; margin-bottom: 15px;
  border-radius: 16px; font-size: 24px;
  background: var(--glass-2); border: 1px solid var(--glass-brd);
  box-shadow: inset 0 1px 0 var(--glass-hi);
  transition: transform .62s var(--ease-jelly), box-shadow .4s;
}
.ccard:hover .ccard__ico { transform: translateY(-4px) rotate(-8deg) scale(1.12); box-shadow: 0 14px 30px -12px var(--c, rgba(124,92,255,.8)); }
.ccard h3 { font-size: 17.5px; font-weight: 750; margin-bottom: 6px; display: flex; align-items: center; gap: 8px; }
.ccard h3 em {
  font-style: normal; font-size: 11px; font-weight: 700; color: var(--ink-3);
  padding: 2px 8px; border-radius: var(--r-full); background: var(--glass); border: 1px solid var(--line);
}
.ccard p { font-size: 13.5px; color: var(--ink-2); min-height: 2.9em; }

/* 覆盖整张卡片的原生按钮：键盘 / 读屏都可用 */
.ccard .ccard__hit {
  position: absolute; inset: 0; z-index: 3;
  display: block; width: 100%;
  border-radius: inherit; cursor: pointer;
  text-align: left; color: inherit;
}
.ccard .ccard__hit:focus-visible { outline: 2px solid var(--cyan); outline-offset: -3px; border-radius: var(--r-lg); }
.ccard__more {
  position: absolute; left: 20px; bottom: 17px;
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 12.5px; font-weight: 700; color: var(--ink-3);
  transition: color .3s, gap .4s var(--ease-jelly);
}
.ccard__more svg { width: 14px; height: 14px; }
.ccard:hover .ccard__more { color: var(--ink); gap: 10px; }
.ccard__ring {
  position: absolute; right: -46px; bottom: -46px; z-index: 1;
  width: 130px; height: 130px; border-radius: 50%;
  border: 1.5px dashed var(--line);
  transition: transform 1.1s var(--ease-jelly), border-color .5s;
}
.ccard:hover .ccard__ring { transform: rotate(70deg) scale(1.14); border-color: var(--glass-brd); }

.hint { margin-top: 22px; font-size: 13px; color: var(--ink-3); }
.hint b { color: var(--ink); }

/* ============================================================
   13. 群聊氛围
   ============================================================ */
.live {
  display: grid; grid-template-columns: minmax(0, 1fr) minmax(320px, 420px);
  gap: clamp(30px, 5vw, 70px); align-items: center;
}
.live__acts { display: flex; flex-wrap: wrap; gap: 12px; margin: 26px 0 22px; }
.live__facts { display: flex; flex-direction: column; gap: 10px; }
.live__facts li { display: flex; align-items: center; gap: 10px; font-size: 14px; color: var(--ink-2); }
.dot { width: 8px; height: 8px; border-radius: 50%; flex: none; }
.dot.d1 { background: var(--cyan); box-shadow: 0 0 12px var(--cyan); }
.dot.d2 { background: var(--violet); box-shadow: 0 0 12px var(--violet); }
.dot.d3 { background: var(--pink); box-shadow: 0 0 12px var(--pink); }

.phone { position: relative; display: flex; justify-content: center; }
.phone__body {
  position: relative;
  width: min(100%, 380px);
  border-radius: 40px;
  padding: 14px 12px 12px;
  display: flex; flex-direction: column;
  height: min(620px, 76vh);
  box-shadow: var(--shadow-lg), inset 0 1px 0 var(--glass-hi);
  overflow: hidden;
}
.phone__aura {
  position: absolute; inset: 12% -18%; z-index: -1; border-radius: 50%;
  background: radial-gradient(circle, rgba(124,92,255,.4), transparent 66%);
  filter: blur(58px); animation: float 7s var(--ease-out) infinite;
}
.phone__notch {
  position: absolute; top: 8px; left: 50%; transform: translateX(-50%);
  width: 82px; height: 5px; border-radius: 4px; background: var(--line);
}
.phone__bar {
  display: flex; align-items: center; gap: 10px;
  padding: 10px 8px 12px;
  border-bottom: 1px solid var(--line);
}
.phone__ava {
  display: grid; place-items: center;
  width: 38px; height: 38px; flex: none; border-radius: 12px;
  font-weight: 800; font-size: 16px; color: #fff;
  background: var(--grad-brand); background-size: 200% 200%;
  animation: gradShift 7s ease infinite;
}
.phone__meta { display: flex; flex-direction: column; line-height: 1.25; min-width: 0; }
.phone__meta strong { font-size: 14.5px; font-weight: 700; }
.phone__meta small { font-size: 10.5px; color: var(--ink-3); display: flex; align-items: center; gap: 5px; }
.online { width: 6px; height: 6px; border-radius: 50%; background: var(--mint); box-shadow: 0 0 8px var(--mint); }
.phone__num { margin-left: auto; font-size: 10.5px; color: var(--ink-3); }

.phone__stream {
  flex: 1; min-height: 0;
  overflow-y: auto; overscroll-behavior: contain;
  padding: 14px 6px 8px;
  display: flex; flex-direction: column; gap: 12px;
  scrollbar-width: thin;
  mask-image: linear-gradient(180deg, transparent 0, #000 26px);
  -webkit-mask-image: linear-gradient(180deg, transparent 0, #000 26px);
}
.phone__stream::-webkit-scrollbar { width: 5px; }
.phone__stream::-webkit-scrollbar-thumb { background: var(--line); border: 0; border-radius: 6px; }

.msg { display: flex; gap: 9px; max-width: 92%; animation: msgIn .62s var(--ease-jelly) both; }
@keyframes msgIn {
  0%   { opacity: 0; transform: translateY(14px) scale(.86); }
  62%  { opacity: 1; transform: translateY(0) scale(1.035); }
  100% { opacity: 1; transform: translateY(0) scale(1); }
}
.msg__ava {
  display: grid; place-items: center;
  width: 30px; height: 30px; flex: none; border-radius: 10px;
  font-size: 13px; font-weight: 750; color: #fff;
  box-shadow: inset 0 1px 0 rgba(255,255,255,.3);
  transform: scale(.9); opacity: 0;
  animation: msgIn .5s var(--ease-jelly) .06s both;
}
.msg__col { display: flex; flex-direction: column; gap: 4px; min-width: 0; }
.msg__name { font-size: 10.5px; color: var(--ink-3); padding-left: 3px; }
.msg__bubble {
  padding: 10px 14px; border-radius: 4px 16px 16px 16px;
  font-size: 13.5px; line-height: 1.55;
  background: var(--glass-2); border: 1px solid var(--glass-brd);
  -webkit-backdrop-filter: blur(8px); backdrop-filter: blur(8px);
  word-break: break-word;
}
.msg__tag {
  display: inline-block; margin-top: 6px; padding: 2px 9px;
  font-size: 10.5px; font-weight: 700; border-radius: var(--r-full);
  background: var(--glass); border: 1px solid var(--line); color: var(--ink-2);
}
.msg--me { flex-direction: row-reverse; margin-left: auto; }
.msg--me .msg__col { align-items: flex-end; }
.msg--me .msg__bubble {
  border-radius: 16px 4px 16px 16px;
  color: #fff; border-color: transparent;
  background: linear-gradient(125deg, var(--violet), var(--pink));
  box-shadow: 0 12px 26px -14px rgba(254,44,85,.9);
}
.msg--me .msg__name { padding-right: 3px; padding-left: 0; }

.typing { display: flex; gap: 4px; padding: 12px 15px; border-radius: 4px 16px 16px 16px;
  background: var(--glass-2); border: 1px solid var(--glass-brd); width: fit-content; }
.typing i { width: 6px; height: 6px; border-radius: 50%; background: var(--ink-3); animation: bounceDot 1.3s var(--ease-out) infinite; }
.typing i:nth-child(2) { animation-delay: .16s; }
.typing i:nth-child(3) { animation-delay: .32s; }
@keyframes bounceDot { 0%,60%,100% { transform: translateY(0); opacity: .45; } 30% { transform: translateY(-5px); opacity: 1; } }

.phone__input {
  display: flex; align-items: center; gap: 8px;
  margin-top: 10px; padding: 7px 7px 7px 16px;
  border-radius: var(--r-full);
  background: var(--glass); border: 1px solid var(--glass-brd);
  transition: border-color .3s, background .3s, box-shadow .3s;
}
.phone__input:focus-within {
  border-color: var(--glass-hi); background: var(--glass-2);
  box-shadow: 0 0 0 4px rgba(124,92,255,.14);
}
.phone__input input { flex: 1; min-width: 0; background: none; border: 0; outline: none; font-size: 13.5px; }
.phone__input input::placeholder { color: var(--ink-3); }
.send {
  display: grid; place-items: center;
  width: 34px; height: 34px; flex: none; border-radius: 50%;
  color: #fff; background: linear-gradient(125deg, var(--violet), var(--pink));
  transition: transform .5s var(--ease-jelly), box-shadow .4s;
}
.send .ico { width: 16px; height: 16px; }
.send:hover { transform: scale(1.12) rotate(-8deg); box-shadow: 0 10px 22px -8px rgba(254,44,85,.9); }
.send:active { transform: scale(.88); }

/* ============================================================
   14. 加入
   ============================================================ */
.steps {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 16px; margin-bottom: 26px; counter-reset: s;
}
.step {
  position: relative;
  padding: 26px 24px;
  border-radius: var(--r-lg);
  overflow: hidden;
}
.step__no {
  position: absolute; right: 20px; top: 14px;
  font-size: 52px; font-weight: 900; line-height: 1;
  color: transparent; -webkit-text-stroke: 1.4px var(--line);
  transition: -webkit-text-stroke-color .5s, transform .7s var(--ease-jelly);
}
.step:hover .step__no { transform: scale(1.08) translateY(-2px); -webkit-text-stroke-color: var(--glass-hi); }
.step__ico {
  display: grid; place-items: center;
  width: 46px; height: 46px; margin-bottom: 14px;
  border-radius: 14px; font-size: 22px;
  background: var(--glass-2); border: 1px solid var(--glass-brd);
  transition: transform .6s var(--ease-jelly);
}
.step:hover .step__ico { transform: translateY(-3px) rotate(-7deg) scale(1.1); }
.step h3 { font-size: 17px; font-weight: 750; margin-bottom: 7px; }
.step p { font-size: 14px; color: var(--ink-2); }
.step b { color: var(--ink); }

.joinbox {
  display: grid; grid-template-columns: minmax(0, 250px) minmax(0, 1fr);
  gap: clamp(20px, 3vw, 40px); align-items: center;
  padding: clamp(20px, 3vw, 32px);
  border-radius: var(--r-xl);
}
.joinbox__qr {
  border-radius: var(--r-lg); overflow: hidden; background: #fff;
  box-shadow: 0 22px 50px -22px rgba(0,0,0,.75);
  transition: transform .7s var(--ease-jelly);
}
.joinbox__qr:hover { transform: scale(1.03) rotate(-1.2deg); }
.joinbox__info h3 { font-size: clamp(1.2rem, 2.6vw, 1.6rem); font-weight: 800; margin-bottom: 16px; letter-spacing: -.02em; }
.copyrow {
  display: flex; align-items: center; gap: 12px; flex-wrap: wrap;
  padding: 11px 14px; margin-bottom: 9px;
  border-radius: var(--r-md);
  background: var(--glass); border: 1px solid var(--line);
  transition: border-color .3s, background .3s, transform .5s var(--ease-jelly);
}
.copyrow:hover { border-color: var(--glass-brd); background: var(--glass-2); transform: translateX(3px); }
.copyrow__label { font-size: 12.5px; color: var(--ink-3); min-width: 74px; }
.copyrow code { font-size: 15.5px; font-weight: 700; letter-spacing: .01em; margin-right: auto; }
.joinbox__acts { display: flex; flex-wrap: wrap; gap: 12px; margin: 18px 0 14px; }
.joinbox__note { font-size: 12.5px; color: var(--ink-3); line-height: 1.75; }
.joinbox__note b { color: var(--ink-2); }

/* ============================================================
   15. 手风琴
   ============================================================ */
.acc { display: flex; flex-direction: column; gap: 11px; }
.acc__item {
  border-radius: var(--r-md);
  overflow: hidden;
  transition: background .4s, border-color .4s, transform .5s var(--ease-jelly);
}
.acc__item:hover { border-color: var(--glass-brd); }
.acc__item.open { background: var(--glass-2); border-color: var(--glass-hi); }
.acc__btn {
  display: flex; align-items: center; gap: 14px; width: 100%;
  padding: 17px 18px; text-align: left;
  font-size: 15.5px; font-weight: 700; color: var(--ink);
}
.acc__idx {
  display: grid; place-items: center;
  width: 26px; height: 26px; flex: none; border-radius: 9px;
  font-size: 11.5px; font-weight: 800; color: var(--ink-3);
  background: var(--glass-2); border: 1px solid var(--line);
  transition: color .35s, background .35s, transform .55s var(--ease-jelly);
}
.acc__item.open .acc__idx { color: #fff; background: var(--grad-brand); border-color: transparent; transform: rotate(-6deg) scale(1.06); }
.acc__ico {
  margin-left: auto; flex: none; width: 26px; height: 26px;
  display: grid; place-items: center; border-radius: 50%;
  background: var(--glass); border: 1px solid var(--line);
  transition: transform .6s var(--ease-jelly), background .35s, border-color .35s, color .35s;
}
.acc__ico .ico { width: 14px; height: 14px; }
.acc__item.open .acc__ico { transform: rotate(135deg); background: var(--glass-2); border-color: var(--glass-hi); }
.acc__body {
  display: grid; grid-template-rows: 0fr;
  transition: grid-template-rows .5s var(--ease-out);
}
.acc__item.open .acc__body { grid-template-rows: 1fr; }
.acc__inner { overflow: hidden; min-height: 0; }
.acc__inner > div {
  padding: 0 18px 18px 58px;
  font-size: 14px; color: var(--ink-2);
  opacity: 0; transform: translateY(-6px);
  transition: opacity .4s ease .06s, transform .5s var(--ease-jelly) .06s;
}
.acc__item.open .acc__inner > div { opacity: 1; transform: none; }

/* 群主卡 */
.owner {
  display: flex; align-items: center; gap: 16px; flex-wrap: wrap;
  margin-top: 40px; padding: 20px 22px;
  border-radius: var(--r-lg);
}
.owner__ava {
  display: grid; place-items: center;
  width: 62px; height: 62px; flex: none; border-radius: 20px;
  font-size: 20px; font-weight: 800; color: #fff;
  background: var(--grad-brand); background-size: 200% 200%;
  animation: gradShift 8s ease infinite;
  box-shadow: 0 14px 30px -14px rgba(124,92,255,.95);
  transition: transform .6s var(--ease-jelly);
}
/* 群主头像是真实照片时：铺满裁切 + 内描边 */
img.owner__ava {
  object-fit: cover;
  border: 1px solid var(--glass-brd);
  box-shadow: 0 14px 30px -14px rgba(124,92,255,.95), inset 0 1px 0 var(--glass-hi);
}
.owner:hover .owner__ava { transform: rotate(-8deg) scale(1.08); }
.owner__meta { display: flex; flex-direction: column; gap: 3px; margin-right: auto; min-width: 0; }
.owner__meta strong { font-size: 13px; color: var(--ink-3); font-weight: 650; }
.owner__meta > span { font-size: 21px; font-weight: 800; letter-spacing: .01em; }
.owner__meta small { font-size: 12.5px; color: var(--ink-3); }

/* ============================================================
   16. 页脚 / 回到顶部 / toast / modal
   ============================================================ */
.footer { padding: 0 0 clamp(28px, 5vw, 52px); }
.footer__inner {
  display: grid; gap: 26px;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
  padding: clamp(26px, 4vw, 40px);
  border-radius: var(--r-xl);
}
.footer__brand { display: flex; gap: 14px; align-items: flex-start; }
.footer__brand .brand__mark { width: 46px; height: 46px; border-radius: 15px; }
.footer__brand strong { font-size: 17px; font-weight: 780; display: block; margin-bottom: 4px; }
.footer__brand p { font-size: 13.5px; color: var(--ink-2); max-width: 30em; }
.footer__facts { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 14px; align-content: start; }
.footer__facts dt { font-size: 11.5px; color: var(--ink-3); margin-bottom: 3px; }
.footer__facts dd { font-size: 15px; font-weight: 700; }
.footer__links { display: flex; flex-wrap: wrap; gap: 8px; grid-column: 1 / -1; }
.footer__links a {
  padding: 8px 15px; border-radius: var(--r-full);
  font-size: 13.5px; font-weight: 600; color: var(--ink-2);
  background: var(--glass); border: 1px solid var(--line);
  transition: transform .5s var(--ease-jelly), color .3s, border-color .3s, background .3s;
}
.footer__links a:hover { color: var(--ink); background: var(--glass-2); border-color: var(--glass-brd); transform: translateY(-2px) scale(1.05); }
.footer__legal {
  grid-column: 1 / -1; padding-top: 20px; border-top: 1px solid var(--line);
  font-size: 12px; color: var(--ink-3); line-height: 1.85;
}

.to-top {
  position: fixed; right: 20px; bottom: 22px; z-index: 95;
  width: 48px; height: 48px; border-radius: 50%;
  display: grid; place-items: center;
  color: #fff;
  background: linear-gradient(130deg, var(--violet), var(--pink));
  box-shadow: 0 16px 34px -14px rgba(124,92,255,.95);
  opacity: 0; transform: translateY(18px) scale(.7); pointer-events: none;
  transition: opacity .4s, transform .6s var(--ease-jelly), box-shadow .4s;
}
.to-top.show { opacity: 1; transform: none; pointer-events: auto; }
.to-top:hover { transform: translateY(-4px) scale(1.09) rotate(-6deg); }
.to-top:active { transform: scale(.9); }
.to-top .ico { width: 21px; height: 21px; }

.toast-host {
  position: fixed; left: 50%; bottom: 26px; z-index: 200;
  transform: translateX(-50%);
  display: flex; flex-direction: column-reverse; align-items: center; gap: 9px;
  pointer-events: none; width: max-content; max-width: 92vw;
}
.toast {
  display: flex; align-items: center; gap: 9px;
  padding: 11px 20px; border-radius: var(--r-full);
  font-size: 14px; font-weight: 650; color: var(--ink);
  background: var(--glass-2); border: 1px solid var(--glass-brd);
  -webkit-backdrop-filter: blur(18px) saturate(180%); backdrop-filter: blur(18px) saturate(180%);
  box-shadow: var(--shadow-lg);
  animation: toastIn .6s var(--ease-jelly) both;
}
.toast.out { animation: toastOut .35s var(--ease-out) both; }
.toast .ico { width: 17px; height: 17px; color: var(--mint); }
@keyframes toastIn {
  0%   { opacity: 0; transform: translateY(22px) scale(.8); }
  60%  { opacity: 1; transform: translateY(0) scale(1.05); }
  100% { opacity: 1; transform: translateY(0) scale(1); }
}
@keyframes toastOut { to { opacity: 0; transform: translateY(12px) scale(.9); } }

.modal { position: fixed; inset: 0; z-index: 210; display: grid; place-items: center; padding: 18px; }
.modal[hidden] { display: none; }
.modal__backdrop {
  position: absolute; inset: 0;
  background: rgba(3,4,10,.6);
  -webkit-backdrop-filter: blur(9px); backdrop-filter: blur(9px);
  opacity: 0; transition: opacity .38s ease;
}
.modal.in .modal__backdrop { opacity: 1; }
.modal__panel {
  position: relative;
  width: min(100%, 640px); max-height: min(86vh, 780px);
  border-radius: var(--r-xl);
  padding: clamp(22px, 3.4vw, 34px);
  overflow-y: auto; overscroll-behavior: contain;
  opacity: 0; transform: translateY(22px) scale(.9);
  transition: opacity .35s ease, transform .58s var(--ease-spring);
  box-shadow: var(--shadow-lg), inset 0 1px 0 var(--glass-hi);
}
.modal.in .modal__panel { opacity: 1; transform: none; }
.modal__close { position: absolute; top: 14px; right: 14px; z-index: 3; }

.mhead { display: flex; align-items: center; gap: 14px; margin-bottom: 18px; padding-right: 46px; }
.mhead__ico {
  display: grid; place-items: center;
  width: 56px; height: 56px; flex: none; border-radius: 18px; font-size: 26px;
  background: var(--glass-2); border: 1px solid var(--glass-brd);
  box-shadow: inset 0 1px 0 var(--glass-hi);
}
.mhead h3 { font-size: clamp(1.2rem, 2.8vw, 1.55rem); font-weight: 800; letter-spacing: -.02em; }
.mhead p { font-size: 13px; color: var(--ink-3); }
.msec { margin-bottom: 18px; }
.msec h4 {
  font-size: 12px; font-weight: 800; letter-spacing: .16em; text-transform: uppercase;
  color: var(--ink-3); margin-bottom: 9px;
}
.msec p { font-size: 14.5px; color: var(--ink-2); }
.msec ul { display: flex; flex-direction: column; gap: 8px; }
.msec ul li {
  position: relative; padding-left: 20px;
  font-size: 14.5px; color: var(--ink-2);
}
.msec ul li::before {
  content: ""; position: absolute; left: 4px; top: .62em;
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--grad-brand);
}
.mquote {
  display: flex; flex-direction: column; gap: 8px;
  padding: 16px 18px; border-radius: var(--r-md);
  background: var(--glass); border: 1px solid var(--line);
}
.mquote span { font-size: 13.5px; color: var(--ink-2); }
.mquote span b { color: var(--ink); }
.modal__qr { border-radius: var(--r-lg); overflow: hidden; background: #fff; margin-bottom: 18px; }
.modal__qr img { width: 100%; max-width: 420px; margin-inline: auto; }

/* ============================================================
   17. Reveal + 果冻
   ============================================================ */
.reveal {
  --ty: 28px; --sc: .975;
  opacity: 0;
  filter: blur(9px);
  transform: translate3d(0, var(--ty), 0) scale(var(--sc));
  transition:
    opacity .82s var(--ease-out),
    transform .96s var(--ease-spring),
    filter .82s var(--ease-out);
  will-change: transform, opacity;
}
.reveal.in { --ty: 0px; --sc: 1; opacity: 1; filter: blur(0); }
.reveal.in { will-change: auto; }

/* 果冻点击（由 JS 挂到按钮/卡片上） */
@keyframes jellyWobble {
  0%   { transform: scale(.9); }
  28%  { transform: scale(1.07) scaleY(.95); }
  50%  { transform: scale(.97) scaleY(1.03); }
  72%  { transform: scale(1.025) scaleY(.99); }
  100% { transform: scale(1); }
}
.jelly.wobble { animation: jellyWobble .62s var(--ease-out) both; }

/* 非倾斜卡片的按压反馈（倾斜卡片由 --sc 变量处理） */
.step, .joinbox, .owner { transition: transform .5s var(--ease-jelly); }
.step.is-press, .joinbox.is-press, .owner.is-press { transform: scale(.988); }

/* ============================================================
   18. 响应式（移动优先打磨）
   ============================================================ */

/* --- 平板 / 窄桌面 --- */
@media (max-width: 1180px) {
  .dots { display: none; }
}
@media (max-width: 1024px) {
  .hero { min-height: auto; }
  .hero__grid { grid-template-columns: 1fr; gap: 44px; }
  .hero__copy { order: -1; }            /* 手机上先看标题与按钮，再看二维码 */
  .hero__card { order: 1; }
  .qcard { width: min(100%, 400px); margin-inline: auto; }
  .live { grid-template-columns: 1fr; }
  .live__copy { order: -1; }
  .phone { order: 1; }
  .footer__inner { grid-template-columns: 1fr; }
  .card { grid-column: span 3; }
  .card--wide { grid-column: span 6; }
}
@media (max-width: 900px) {
  .nav__links { display: none; }
  .burger { display: flex; }
  .brand__text small { display: none; }
  /* 链接隐藏后，居中用的 auto 外边距没了，这里把操作区推到右侧 */
  .nav__actions { margin-left: auto; }
}

/* --- 手机 --- */
@media (max-width: 760px) {
  :root { --nav-h: 60px; --pad-sec: 68px; }

  /* iOS 刘海 / 底部横条安全区 */
  .nav { padding-top: max(10px, env(safe-area-inset-top)); }
  body { padding-bottom: calc(78px + env(safe-area-inset-bottom, 0px)); }
  .sheet__panel { top: calc(10px + env(safe-area-inset-top, 0px)); }

  /* 移动端 GPU 更吃力：降低毛玻璃成本，去掉噪点与聚光 */
  .glass { -webkit-backdrop-filter: blur(11px) saturate(150%); backdrop-filter: blur(11px) saturate(150%); }
  .btn--ghost, .icon-btn, .mini { -webkit-backdrop-filter: blur(9px); backdrop-filter: blur(9px); }
  .bg__blob { filter: blur(56px); }
  .bg__grain, .spotlight { display: none; }
  .msg__bubble { -webkit-backdrop-filter: none; backdrop-filter: none; }

  /* 触控目标尽量 ≥ 44px */
  .icon-btn { width: 44px; height: 44px; }
  .mini { padding: 11px 16px; font-size: 13.5px; }
  .send { width: 40px; height: 40px; }

  .hero { padding: calc(var(--nav-h) + 22px) 0 56px; }
  .hero__title { font-size: clamp(2.55rem, 13vw, 3.5rem); letter-spacing: -.03em; }
  .hero__sub { font-size: 15px; }
  .hero__sub br { display: none; }
  .chip { font-size: 12px; padding: 7px 13px; gap: 8px; }
  .hero__cta { gap: 10px; margin-bottom: 26px; }
  .hero__cta .btn { flex: 1 1 auto; }
  .hero__hint { display: none; }
  .scroller { display: none; }

  /* 统计卡固定 2×2，避免 3+1 的尴尬换行 */
  .stats { grid-template-columns: 1fr 1fr; max-width: none; gap: 10px; }
  .stats__item { padding: 12px 13px; }
  .stats__item dd { font-size: 16px; }
  .stats__item dd.mono { font-size: 13.5px; letter-spacing: -.02em; }

  .qcard { width: min(100%, 360px); padding: 13px; border-radius: var(--r-lg); }
  .qcard__foot { flex-direction: column; align-items: stretch; gap: 10px; }
  .qcard__acts { justify-content: flex-end; }

  .bento { grid-template-columns: 1fr; }
  .card, .card--wide { grid-column: span 1; }
  .card { padding: 22px 20px; }
  .circles { grid-template-columns: 1fr; }
  .ccard p { min-height: 0; }
  .sec__head { margin-bottom: 26px; }

  .joinbox { grid-template-columns: 1fr; }
  .joinbox__qr { max-width: 250px; margin-inline: auto; width: 100%; }
  .copyrow { padding: 12px 13px; }
  .copyrow__label { min-width: 100%; font-size: 12px; }
  .copyrow code { font-size: 15px; }
  .joinbox__acts { flex-direction: column; }
  .joinbox__acts .btn { width: 100%; }

  .acc__btn { padding: 16px 15px; font-size: 15px; gap: 11px; }
  .acc__inner > div { padding: 0 15px 16px 15px; font-size: 13.5px; }
  /* 群主卡：头像与文字同行，按钮独占一行（比 flex 换行后的堆叠更紧凑） */
  .owner {
    padding: 18px;
    display: grid;
    grid-template-columns: auto minmax(0, 1fr);
    grid-template-areas: "ava meta" "btn btn";
    align-items: center;
    gap: 14px 16px;
  }
  .owner__ava { grid-area: ava; }
  .owner__meta { grid-area: meta; margin-right: 0; }
  .owner__meta > span { font-size: 19px; }
  .owner > .btn { grid-area: btn; width: 100%; }

  .phone__body { height: min(540px, 68vh); border-radius: 30px; }
  .footer__inner { padding: 22px 18px; }
  .modal { padding: 12px; }
  .modal__panel { padding: 22px 18px; max-height: 88vh; border-radius: var(--r-lg); }
  .mhead__ico { width: 48px; height: 48px; font-size: 22px; }
  .modal__qr img { max-width: 100%; }
  .toast-host { bottom: calc(88px + env(safe-area-inset-bottom, 0px)); width: calc(100vw - 28px); }
  .toast { width: 100%; justify-content: center; font-size: 13.5px; }
  .to-top { right: 14px; bottom: calc(84px + env(safe-area-inset-bottom, 0px)); width: 44px; height: 44px; }
}

/* --- 小屏手机 --- */
@media (max-width: 560px) {
  .nav__actions #shareBtn,
  .nav__actions > .btn--primary { display: none; }   /* 底部常驻条已承担主 CTA */
  .brand__text strong { font-size: 14.5px; }
  .hero__title { font-size: clamp(2.4rem, 14vw, 3.1rem); }
  .stats__item dd.mono { font-size: 12.5px; }
  .circles { grid-template-columns: 1fr; }
  .phone__body { height: min(500px, 64vh); }
  /* inset 为负的光晕在窄屏会把视口撑宽 → 改用 box-shadow 实现同样的辉光 */
  .phone__aura { display: none; }
  .phone__body { box-shadow: 0 34px 80px -34px rgba(124,92,255,.8), 0 14px 40px -20px rgba(254,44,85,.45),
                              var(--shadow-lg), inset 0 1px 0 var(--glass-hi); }
}
@media (max-width: 400px) {
  .brand__text strong { font-size: 14px; }
  .btn { padding: 12px 16px; font-size: 14px; }
  .hero__title { font-size: clamp(2.25rem, 13.5vw, 2.9rem); }
  .stats__item dd.mono { font-size: 11.5px; }
  .qcard { width: 100%; }
}

/* --- 触屏：关掉依赖 hover 的效果 --- */
@media (hover: none) {
  .card:hover::before, .ccard:hover::before { opacity: 0; }
  .spotlight { display: none; }
  .btn:hover { transform: none; box-shadow: none; }
  .btn--primary:hover { box-shadow: 0 14px 34px -12px rgba(254,44,85,.6), 0 8px 26px -14px rgba(37,244,238,.55); }
  .card:hover .card__ico, .ccard:hover .ccard__ico, .step:hover .step__ico, .owner:hover .owner__ava { transform: none; }
  .card:hover .card__ico { transform: none; }
  .qcard:hover .qcard__frame img { transform: none; }
  .qcard:hover .qcard__shine { transform: translateX(-120%); }
  .joinbox__qr:hover { transform: none; }
  .ccard:hover .ccard__ring { transform: none; }
  .acc__item:hover { border-color: var(--glass-brd); }
  .marquee:hover .marquee__track { animation-play-state: running; }
}

/* ============================================================
   19. 移动端底部常驻操作条
   ============================================================ */
.mobilebar { display: none; }
@media (max-width: 760px) {
  .mobilebar {
    display: block;
    position: fixed; left: 0; right: 0; bottom: 0; z-index: 96;
    padding: 8px 12px calc(8px + env(safe-area-inset-bottom, 0px));
    pointer-events: none;
    transition: transform .55s var(--ease-spring), opacity .35s var(--ease-out);
  }
  .mobilebar.is-hidden { transform: translateY(135%); opacity: 0; }
  .mobilebar__inner {
    display: grid; grid-template-columns: 1fr 1fr; gap: 8px;
    padding: 7px; border-radius: var(--r-full);
    pointer-events: auto;
    /* 常驻在内容之上，底色要足够实，压在白色二维码卡上也能看清 */
    background: color-mix(in srgb, var(--bg) 84%, transparent);
    -webkit-backdrop-filter: blur(20px) saturate(170%);
    backdrop-filter: blur(20px) saturate(170%);
  }
  .mobilebar .btn--ghost { background: var(--glass-2); }
  .mobilebar .btn { width: 100%; padding: 13px 10px; font-size: 14px; }
}

/* ---------- 20. 无障碍 / 降低动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  .reveal { opacity: 1; filter: none; transform: none; }
  .bg__blob, .qcard__glow, .qcard__scan, .marquee__track { animation: none !important; }
  .marquee__track { transform: none !important; }
}
@media print {
  .nav, .dots, .to-top, .bg, .spotlight, .progress, .phone { display: none !important; }
  body { background: #fff; color: #000; }
  .reveal { opacity: 1 !important; filter: none !important; transform: none !important; }
}