/* ═══════════════════════════════════════════════════════════
   深度探知 SD · 全平台导航
   进场动效复刻自 Google Gmail 进入页：标志展开 + 描边绘制 +
   高光扫过 + 红色进度条 + 品牌文字，随后揭示导航网格
   ═══════════════════════════════════════════════════════════ */

:root{
  --g-red:#EA4335; --g-yellow:#FBBC04; --g-green:#34A853; --g-blue:#4285F4;
  --ink:#111827; --ink-2:#4b5563; --ink-3:#8b93a1;
  --line:rgba(15,23,42,.08);
  --bg-top:#ffffff; --bg-bot:#eef1f7;
  --card:#ffffff;
  --radius:18px;
  --shadow-1:0 1px 2px rgba(16,24,40,.04), 0 10px 26px -14px rgba(16,24,40,.18);
  --shadow-2:0 2px 4px rgba(16,24,40,.05), 0 22px 46px -18px rgba(16,24,40,.30);
  --font:"PingFang SC","HarmonyOS Sans SC","Microsoft YaHei","Noto Sans SC","Source Han Sans SC",-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;
}

*{margin:0;padding:0;box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  font-family:var(--font);
  color:var(--ink);
  background:var(--bg-top);
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
  overflow-x:hidden;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.wrap{width:min(1240px,calc(100% - 44px));margin:0 auto}

/* ══════════════════ 1. 进场动画 ══════════════════ */
.splash{
  position:fixed;inset:0;z-index:100;
  background:#fff;
  display:flex;align-items:center;justify-content:center;
  cursor:pointer;
  transition:opacity .55s ease, visibility .55s ease;
}
.splash.is-gone{opacity:0;visibility:hidden;pointer-events:none}
.splash__inner{display:flex;flex-direction:column;align-items:center;justify-content:center}

.splash__mark{perspective:900px;margin-bottom:30px}
.splash__mark svg{
  display:block;
  transform-origin:50% 50%;
  animation:foldOpen 1.2s cubic-bezier(.22,.85,.28,1) both;
}
@keyframes foldOpen{
  0%   {transform:rotateX(-76deg) scale(.86);opacity:0}
  35%  {opacity:1}
  70%  {transform:rotateX(8deg)  scale(1.015)}
  100% {transform:rotateX(0deg)  scale(1);opacity:1}
}

/* 描边绘制 */
.ink{stroke-dasharray:1;stroke-dashoffset:1}
.ink--s{animation:draw 1.05s cubic-bezier(.62,0,.34,1) .30s forwards}
.ink--d{animation:draw 1.10s cubic-bezier(.62,0,.34,1) .62s forwards}
@keyframes draw{to{stroke-dashoffset:0}}

/* 高光扫过（字标线宽 10，高光取 4.5 保持同比例的细亮条） */
.ink--shine-s,.ink--shine-d{
  stroke-width:4.5;
  stroke-dasharray:.06 .94;
  stroke-dashoffset:0;
  opacity:0;
}
.ink--shine-s{animation:shine 3.2s cubic-bezier(.45,0,.35,1) 1.75s infinite}
.ink--shine-d{animation:shine 3.2s cubic-bezier(.45,0,.35,1) 2.05s infinite}
@keyframes shine{
  0%   {stroke-dashoffset:0;opacity:0}
  14%  {opacity:.55}
  58%  {opacity:.55}
  96%  {stroke-dashoffset:-1;opacity:0}
  100% {stroke-dashoffset:-1;opacity:0}
}

/* 进度条 */
.splash__bar{
  width:300px;max-width:64vw;height:3px;border-radius:99px;
  background:#e8eaed;overflow:hidden;
}
.splash__fill{
  display:block;height:100%;width:0;border-radius:99px;
  background:linear-gradient(90deg,#e9403a 0%,#f2614b 100%);
  transition:width .32s cubic-bezier(.22,.8,.3,1);
}

/* 品牌文字 */
.splash__brand{
  margin-top:23px;
  font-size:26px;line-height:1;font-weight:300;
  letter-spacing:.6px;color:#3c4043;
  opacity:0;transform:translateY(9px);
  animation:brandIn .75s cubic-bezier(.22,.8,.3,1) .95s forwards;
}
.splash__brand b{font-weight:600}
@keyframes brandIn{to{opacity:1;transform:none}}

/* ══════════════════ 2. 导航主页 ══════════════════ */
.app{
  min-height:100vh;
  background:linear-gradient(180deg,var(--bg-top) 0%,#f6f8fb 46%,var(--bg-bot) 100%);
  display:flex;flex-direction:column;
}
.app[hidden]{display:none}

.topbar{
  position:sticky;top:0;z-index:20;
  background:rgba(255,255,255,.78);
  backdrop-filter:saturate(180%) blur(14px);
  -webkit-backdrop-filter:saturate(180%) blur(14px);
  border-bottom:1px solid var(--line);
  padding-left:env(safe-area-inset-left);padding-right:env(safe-area-inset-right);
}
.topbar__row{display:flex;align-items:center;justify-content:space-between;gap:16px;height:66px}
.brand{display:flex;align-items:center;gap:11px;flex:0 0 auto}
.brand__mark{
  display:flex;align-items:center;justify-content:center;
  width:54px;height:40px;background:transparent;flex:0 0 auto;
}
.brand__mark img{
  width:100%;height:100%;object-fit:contain;display:block;
}
.brand__text{display:flex;flex-direction:column;line-height:1.25;flex:0 0 auto}
.brand__text b{font-size:15.5px;font-weight:600;letter-spacing:.2px;white-space:nowrap}
.brand__text span{font-size:11.5px;color:var(--ink-3)}

.topbar__right{display:flex;align-items:center;gap:10px}
.search{
  display:flex;align-items:center;gap:8px;
  height:38px;padding:0 14px;border-radius:99px;
  background:#f1f3f7;border:1px solid transparent;color:var(--ink-3);
  transition:border-color .2s,background .2s,box-shadow .2s;
}
.search:focus-within{background:#fff;border-color:rgba(66,133,244,.45);box-shadow:0 0 0 4px rgba(66,133,244,.12)}
.search input{
  border:0;background:transparent;outline:0;color:var(--ink);
  font:inherit;font-size:13.5px;width:132px;
}
.search input::placeholder{color:#9aa3af}
.search input::-webkit-search-cancel-button{-webkit-appearance:none;height:14px;width:14px;background:var(--ink-3);cursor:pointer;
  -webkit-mask:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'><path d='M8 0a8 8 0 1 0 0 16A8 8 0 0 0 8 0zm2.8 10.1L9.4 8.7 7.3 10.8 5.9 9.4 8 7.3 5.9 5.2 7.3 3.8 9.4 5.9l1.4-1.4 1.4 1.4L10.8 7.3 12.2 8.7z'/></svg>") center/contain no-repeat}

.replay{
  display:inline-flex;align-items:center;gap:6px;
  height:38px;padding:0 14px;border:0;border-radius:99px;cursor:pointer;
  background:#0d1117;color:#fff;font:inherit;font-size:13px;
  transition:transform .2s cubic-bezier(.2,.8,.3,1),background .2s,box-shadow .2s;
}
@media (hover:hover){
  .replay:hover{transform:translateY(-1px);background:#171d26;box-shadow:0 8px 18px -10px rgba(13,17,23,.8)}
}
.replay:active{transform:translateY(0)}
.replay svg{opacity:.9}

.hero{padding:52px 0 30px;text-align:center}
.hero h1{
  font-size:clamp(26px,4vw,38px);font-weight:700;letter-spacing:-.4px;line-height:1.25;
  background:linear-gradient(92deg,#111827 8%,#4285F4 52%,#EA4335 96%);
  -webkit-background-clip:text;background-clip:text;color:transparent;
}
.hero p{margin-top:12px;color:var(--ink-2);font-size:14.5px}

.grid{
  list-style:none;
  display:grid;gap:16px;
  grid-template-columns:repeat(auto-fill,minmax(252px,1fr));
  padding-bottom:56px;
}
.card{
  position:relative;
  background:var(--card);
  border:1px solid var(--line);
  border-radius:var(--radius);
  box-shadow:var(--shadow-1);
  opacity:0;transform:translateY(18px);
  transition:transform .3s cubic-bezier(.2,.8,.25,1),box-shadow .3s,border-color .3s;
}
.app.is-in .card{animation:cardIn .6s cubic-bezier(.2,.8,.25,1) forwards;animation-delay:calc(var(--i,0) * 42ms)}
@keyframes cardIn{to{opacity:1;transform:none}}
/* 仅在真正支持悬停的设备上抬升，避免触屏点完“粘住” */
@media (hover:hover){
  .card:hover{
    transform:translateY(-6px);
    box-shadow:var(--shadow-2);
    border-color:rgba(66,133,244,.24);
  }
}
.card:active{transform:translateY(-2px)}
.card:focus-within{outline:2px solid rgba(66,133,244,.55);outline-offset:3px}
.card a{
  display:flex;flex-direction:column;align-items:center;text-align:center;
  padding:28px 20px 22px;height:100%;
}
.card__icon{
  width:56px;height:56px;border-radius:15px;
  background:#f4f6f9;border:1px solid var(--line);
  display:flex;align-items:center;justify-content:center;
  overflow:hidden;flex:0 0 auto;
  transition:box-shadow .3s cubic-bezier(.2,.8,.25,1),transform .3s cubic-bezier(.2,.8,.25,1);
}
.card__icon img{width:100%;height:100%;object-fit:contain}
@media (hover:hover){
  .card:hover .card__icon{transform:scale(1.05)}
}
.card__title{margin-top:16px;font-size:15.5px;font-weight:600;line-height:1.35;color:var(--ink);text-wrap:balance}
/* 定位文案：最多两行，溢出截断。桌面端多为单行，窄屏自动折两行，不丢信息 */
.card__desc{
  margin-top:7px;font-size:12.5px;line-height:1.6;color:var(--ink-2);
  max-width:100%;
  display:-webkit-box;-webkit-box-orient:vertical;
  -webkit-line-clamp:2;line-clamp:2;overflow:hidden;
}
.card--main{
  background:linear-gradient(180deg,#ffffff 0%,#f6f9ff 100%);
  border-color:rgba(66,133,244,.24);
  box-shadow:0 1px 2px rgba(16,24,40,.04),0 20px 44px -20px rgba(66,133,244,.55);
}
.card--main .card__icon{
  box-shadow:0 0 0 4px rgba(66,133,244,.10);
}
.card--main .card__title{font-size:16px}

.empty{text-align:center;color:var(--ink-3);font-size:14px;padding:40px 0 70px}

.foot{border-top:1px solid var(--line);background:rgba(255,255,255,.6);margin-top:auto;padding-bottom:env(safe-area-inset-bottom)}
.foot__row{
  display:flex;align-items:center;justify-content:space-between;gap:14px;flex-wrap:wrap;
  padding:22px 0;font-size:12.5px;color:var(--ink-3);
}
.foot__links{display:flex;gap:18px}
.foot__links a{color:var(--ink-2);transition:color .2s}
.foot__links a:hover{color:var(--g-blue)}

/* 响应式 */
@media (max-width:640px){
  /* 触屏：去掉点击时的系统高亮块，保留 :active 反馈 */
  a,button,input{-webkit-tap-highlight-color:transparent}
  .wrap{width:calc(100% - 28px)}
  /* 顶栏压缩为单行：搜索框自适应填满，输入字号 16px 防止 iOS 聚焦自动放大 */
  .topbar__row{height:auto;padding:9px 0;gap:12px;flex-wrap:nowrap}
  .brand__text span{display:none}
  .topbar__right{flex:1 1 auto;min-width:0;gap:8px}
  /* 触控目标抬到 44px，符合移动端点按规范 */
  .search{flex:1 1 auto;min-width:0;height:44px;padding:0 12px}
  .search input{flex:1 1 auto;min-width:0;width:auto;font-size:16px;align-self:stretch;height:auto;padding:0;-webkit-appearance:none;appearance:none}
  .replay{height:44px;padding:0 14px;flex:0 0 auto}
  .replay span{display:none}
  .hero h1{font-size:clamp(21px,6.2vw,26px)}
  .grid{grid-template-columns:repeat(auto-fill,minmax(148px,1fr));gap:12px}
  .card a{padding:20px 10px 18px}
  .card__desc{font-size:11.5px;line-height:1.55}
  .splash__brand{font-size:22px}
  .splash__mark svg{width:172px;height:auto}
  /* 页脚快捷链接：扩大点按热区 */
  .foot__links{gap:4px}
  .foot__links a{display:inline-flex;align-items:center;min-height:40px;padding:0 10px}
}
/* 极窄屏：品牌文字也让位，保证搜索框可用宽度 */
@media (max-width:360px){
  .brand__text{display:none}
}

/* 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}
  .ink{stroke-dashoffset:0}
  .splash__brand{opacity:1;transform:none}
  .card{opacity:1;transform:none}
}