/* 登录页 · 暖色 + 生物工程发展史短片（2026-10-26）
   规范取自 ~/.claude/skills/landing-page-design：字号只用 Tailwind 刻度、间距只用 2/4/8/12/16/24/32/40/48/64/80/96、
   背景纯色不渐变（渐变只用于大标题文字）、圆角按嵌套公式、动效统一 cubic-bezier(0.22,1,0.36,1)、不用斜体与 900 字重。
   字体：站点不走外链，中文用系统黑体；不使用 Inter/Roboto/Arial/Helvetica。 */
:root{
  --bg:#f7f1e8;--surface:#fffdf9;--paper:#fbf6ee;--line:#ecdfd0;--line-2:#dccbb8;
  --ink:#2a1e16;--ink-2:#5b4334;--muted:#8a7464;
  --terra:#b8482a;--terra-2:#9e3c22;--ring:rgba(196,83,45,.28);
  --ease:cubic-bezier(0.22,1,0.36,1);
  --font:"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans CJK SC","Source Han Sans SC",system-ui,sans-serif;
  --mono:ui-monospace,"SF Mono",Menlo,Consolas,monospace;
}
*{box-sizing:border-box}
html,body{height:100%}
body.login-body{margin:0;font-family:var(--font);color:var(--ink);background:var(--bg);overflow-x:hidden;-webkit-font-smoothing:antialiased}
.skip{position:absolute;left:16px;top:-48px;z-index:10;background:var(--ink);color:#fff;padding:8px 12px;border-radius:8px;font-size:.875rem;text-decoration:none}
.skip:focus{top:16px}

/* 顶部品牌条 */
.brand-bar{position:relative;z-index:2;display:flex;align-items:center;gap:16px;max-width:1240px;margin:0 auto;padding:32px 32px 0}
.brand-tust{height:40px;width:auto;display:block}
.brand-sep{width:1px;height:24px;background:var(--line-2)}
.brand-college{font-size:1.125rem;line-height:1.75rem;font-weight:600;color:var(--ink-2);letter-spacing:.08em}

.login-wrap{position:relative;z-index:1;display:grid;grid-template-columns:minmax(0,1fr) minmax(360px,420px);gap:48px;max-width:1240px;margin:0 auto;padding:40px 32px 24px;align-items:center}

/* 左侧文案 */
.hero{display:flex;flex-direction:column;min-width:0;animation:rise 800ms var(--ease) both}
.hero-title{display:inline-block;align-self:flex-start;margin:0;max-width:680px;font-size:3.75rem;line-height:1;font-weight:700;letter-spacing:.04em;text-wrap:balance;
  background:linear-gradient(90deg,#2a1e16,#5f4130);-webkit-background-clip:text;background-clip:text;color:transparent}
.hero-sub{margin:24px 0 0;max-width:680px;font-size:1.125rem;line-height:1.75rem;color:var(--ink-2);text-wrap:pretty}
.steps{list-style:none;margin:24px 0 0;padding:0;display:flex;flex-wrap:wrap;gap:8px}
.steps li{display:inline-flex;align-items:center;gap:8px;padding:8px 12px;border:1px solid var(--line);border-radius:12px;background:var(--surface);font-size:.875rem;line-height:1.25rem;font-weight:600;color:var(--ink-2)}
.steps .n{font-family:var(--mono);font-size:.75rem;line-height:1rem;color:var(--terra);font-weight:600}

/* ---------- 短片画框 ---------- */
.cinema{position:relative;margin-top:32px;aspect-ratio:2/1;min-height:300px;border:1px solid var(--line);border-radius:24px;overflow:hidden;background:var(--paper);
  box-shadow:0 32px 64px -40px rgba(91,67,52,.5),inset 0 0 96px rgba(120,80,50,.09);outline:0;isolation:isolate}
.cinema:focus-visible{box-shadow:0 0 0 4px var(--ring),inset 0 0 96px rgba(120,80,50,.09)}
.cinema::after{content:"";position:absolute;inset:0;z-index:1;pointer-events:none;opacity:.07;mix-blend-mode:multiply;
  background-image:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='160' height='160'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='2' stitchTiles='stitch'/></filter><rect width='160' height='160' filter='url(%23n)'/></svg>")}
.cinema canvas{position:absolute;inset:0;width:100%;height:100%;display:block;z-index:0;opacity:0;transition:opacity 1200ms var(--ease)}
.cinema.ready canvas{opacity:1}
.cine-top{position:absolute;z-index:2;left:24px;right:24px;top:16px;display:flex;justify-content:space-between;align-items:center;font-family:var(--mono);font-size:.75rem;line-height:1rem;color:var(--muted);letter-spacing:.08em}
.cine-brand{display:inline-flex;align-items:center;gap:8px}
.cine-brand i{width:8px;height:8px;border-radius:50%;background:var(--terra);animation:blink 2s var(--ease) infinite}
.cinema.paused .cine-brand i{animation:none;opacity:.4}

/* 字幕 */
.cine-text{position:absolute;z-index:2;left:32px;top:48px;bottom:64px;width:40%;display:flex;flex-direction:column;justify-content:center;pointer-events:none}
.cine-text>*{margin:0;opacity:0;transform:translateY(12px);filter:blur(4px);transition:opacity 700ms var(--ease),transform 700ms var(--ease),filter 700ms var(--ease)}
.cine-text.in>*{opacity:1;transform:none;filter:none}
.cine-text.in>:nth-child(2){transition-delay:80ms}.cine-text.in>:nth-child(3){transition-delay:160ms}.cine-text.in>:nth-child(4){transition-delay:260ms}
.cine-text.in>:nth-child(5){transition-delay:300ms}.cine-text.in>:nth-child(6){transition-delay:380ms}
.cine-text.out>*{opacity:0;transform:translateY(-8px);filter:blur(4px);transition-duration:350ms;transition-delay:0ms}
.cine-kicker{font-family:var(--mono);font-size:.75rem;line-height:1rem;font-weight:600;color:var(--terra);letter-spacing:.16em}
.cine-year{margin-top:4px!important;font-size:4.5rem;line-height:1;font-weight:700;font-variant-numeric:tabular-nums;letter-spacing:-.02em;
  background:linear-gradient(90deg,#2a1e16,#7a5238);-webkit-background-clip:text;background-clip:text;color:transparent}
.cine-title{margin-top:12px!important;font-size:1.5rem;line-height:2rem;font-weight:700;color:var(--ink);text-wrap:balance;white-space:pre-line}
.cine-people{margin-top:12px!important;display:flex;flex-wrap:wrap;gap:0 12px;font-size:.875rem;line-height:1.25rem;font-weight:600;color:var(--ink-2)}
.cine-people span{white-space:nowrap}
.cine-en{margin-top:2px!important;font-size:.75rem;line-height:1rem;color:var(--muted);letter-spacing:.02em}
.cine-desc{margin-top:12px!important;font-size:.875rem;line-height:1.25rem;color:var(--ink-2);text-wrap:pretty}
.cine-text.is-card .cine-year{display:none}
.cine-text.tight .cine-year{font-size:3rem}.cine-text.tight .cine-title{font-size:1.25rem;line-height:1.75rem;margin-top:8px!important}.cine-text.tight .cine-people,.cine-text.tight .cine-desc{margin-top:8px!important}
.cine-text.is-card .cine-title{font-size:1.5rem;line-height:2rem}

/* 时间轴 */
.cine-bar{position:absolute;z-index:2;left:16px;right:24px;bottom:12px;display:flex;align-items:center;gap:4px}
.cine-btn{flex:none;width:32px;height:32px;display:flex;align-items:center;justify-content:center;padding:0;border:0;border-radius:999px;background:transparent;color:var(--ink-2);cursor:pointer;
  transition:background-color 300ms var(--ease),color 300ms var(--ease),transform 300ms var(--ease)}
.cine-btn svg{width:16px;height:16px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
.cine-play{background:var(--ink);color:#fff;margin-right:4px}
.cine-play svg{fill:currentColor}
.cine-play .i-play{display:none}.cinema.paused .cine-play .i-play{display:block}.cinema.paused .cine-play .i-pause{display:none}
.cine-btn:hover{background:#efe4d6;color:var(--ink)}
.cine-play:hover{background:var(--terra);color:#fff}
.cine-btn:active{transform:scale(.94)}
.cine-btn:focus-visible{outline:0;box-shadow:0 0 0 4px var(--ring)}
.cine-track{position:relative;flex:1;height:40px;margin-left:8px}
.cine-rail{position:absolute;left:0;right:0;top:12px;height:2px;border-radius:999px;background:var(--line-2);overflow:hidden}
.cine-fill{position:absolute;inset:0;background:var(--terra);transform:scaleX(0);transform-origin:left center}
.cine-ticks{position:absolute;inset:0}
.cine-tick{position:absolute;top:0;transform:translateX(-50%);display:flex;flex-direction:column;align-items:center;gap:4px;padding:6px 2px;border:0;background:none;cursor:pointer;color:var(--muted)}
.cine-tick i{width:8px;height:8px;border-radius:50%;background:var(--paper);border:2px solid var(--line-2);transition:border-color 300ms var(--ease),background-color 300ms var(--ease),transform 300ms var(--ease)}
.cine-tick span{font-family:var(--mono);font-size:.75rem;line-height:1rem;transition:color 300ms var(--ease)}
.cine-tick:hover i{border-color:var(--terra)}
.cine-tick:hover span{color:var(--ink)}
.cine-tick.on i{background:var(--terra);border-color:var(--terra);transform:scale(1.25)}
.cine-tick.on span{color:var(--terra);font-weight:600}
.cine-tick:focus-visible{outline:0}.cine-tick:focus-visible i{box-shadow:0 0 0 4px var(--ring)}
.cinema.no-webgl canvas{display:none}

/* 右侧登录卡 */
.panel{display:flex;align-items:center;justify-content:center;min-width:0;animation:rise 800ms 120ms var(--ease) both}
.card{width:100%;max-width:420px;background:var(--surface);border:1px solid var(--line);border-radius:24px;padding:40px;box-shadow:0 32px 64px -32px rgba(91,67,52,.35),0 2px 4px rgba(91,67,52,.04)}
.card-title{margin:0;font-size:1.5rem;line-height:2rem;font-weight:700;color:var(--ink)}
.card-sub{margin:4px 0 24px;font-size:.875rem;line-height:1.25rem;color:var(--muted)}
.alert{margin:0 0 16px;padding:12px;border:1px solid #f0c4b3;border-radius:12px;background:#fbeae4;color:#8f2f16;font-size:.875rem;line-height:1.25rem}
.login-form .f{display:block;margin-bottom:16px}
.f-label{display:block;margin-bottom:8px;font-size:.875rem;line-height:1.25rem;font-weight:600;color:var(--ink-2)}
.login-form input{width:100%;height:48px;padding:0 16px;border:1px solid var(--line-2);border-radius:12px;background:#fff;color:var(--ink);font:inherit;font-size:1rem;outline:0;
  transition:border-color 300ms var(--ease),box-shadow 300ms var(--ease)}
.login-form input::placeholder{color:#b3a090}
.login-form input:hover{border-color:#cdb39b}
.login-form input:focus{border-color:var(--terra);box-shadow:0 0 0 4px var(--ring)}
.pw{position:relative;display:block}
.pw input{padding-right:48px}
.eye{position:absolute;right:8px;top:8px;width:32px;height:32px;padding:0;display:flex;align-items:center;justify-content:center;border:0;border-radius:8px;background:transparent;color:var(--muted);cursor:pointer;
  transition:color 300ms var(--ease),background-color 300ms var(--ease)}
.eye:hover{color:var(--ink-2);background:#f3e9dd}
.eye.on{color:var(--terra);background:#f8e3d9}
.eye:focus-visible{outline:2px solid var(--terra);outline-offset:2px}
.submit{width:100%;height:48px;margin-top:8px;display:flex;align-items:center;justify-content:center;gap:8px;border:0;border-radius:12px;background:var(--terra);color:#fff;
  font:inherit;font-size:1rem;line-height:1.5rem;font-weight:600;letter-spacing:.2em;cursor:pointer;
  transition:background-color 300ms var(--ease),transform 300ms var(--ease)}
.submit svg{width:20px;height:20px;transition:transform 500ms var(--ease)}
.submit:hover{background:var(--terra-2)}
.submit:hover svg{transform:translateX(4px)}
.submit:active{transform:scale(.98)}
.submit:focus-visible{outline:0;box-shadow:0 0 0 4px var(--ring)}
.submit.loading{pointer-events:none;opacity:.8}
.submit.loading svg{animation:nudge 900ms var(--ease) infinite}
.tips{margin-top:24px;padding-top:16px;border-top:1px solid var(--line);font-size:.75rem;line-height:1rem;color:var(--muted)}
.tips p{margin:4px 0}
.tips .num{font-family:var(--mono)}
.login-foot{position:relative;z-index:1;padding:16px 32px 24px;text-align:center;font-size:.75rem;line-height:1rem;color:var(--muted)}

@keyframes rise{from{opacity:0;transform:translateY(24px)}to{opacity:1;transform:none}}
@keyframes nudge{50%{transform:translateX(4px)}}
@keyframes blink{50%{opacity:.25}}

/* 矮屏桌面：压缩标题区，让短片完整落在首屏 */
@media (min-width:901px) and (max-height:820px){
  .login-wrap{padding-top:24px}
  .hero-title{font-size:3rem}
  .hero-sub{margin-top:16px;font-size:1rem;line-height:1.5rem}
  .steps{margin-top:16px}
  .cinema{margin-top:24px;aspect-ratio:2.2/1}
  .cine-year{font-size:3.75rem}
}
/* 平板 / 手机：上下排布，短片为竖幅，字幕在画面下方 */
@media (max-width:900px){
  .brand-bar{justify-content:center;padding:24px 16px 0}
  .brand-tust{height:32px}
  .brand-college{font-size:1rem;line-height:1.5rem}
  .login-wrap{grid-template-columns:1fr;gap:24px;padding:24px 16px 16px}
  .hero{align-items:center;text-align:center}
  .hero-title{align-self:center;font-size:2.25rem;line-height:2.5rem}
  .hero-sub{margin-top:12px;font-size:1rem;line-height:1.5rem}
  .br-wide{display:none}
  .steps{justify-content:center;margin-top:16px}
  .cinema{width:100%;aspect-ratio:3/4;min-height:0;margin-top:24px;text-align:left}
  .cine-en{display:none}
  .cine-text{left:20px;right:20px;width:auto;top:auto;bottom:64px;justify-content:flex-end}
  .cine-year{font-size:3rem}
  .cine-title{font-size:1.25rem;line-height:1.75rem}
  .cine-bar{left:12px;right:16px}
  .cine-tick span{display:none}
  .cine-tick.on span{display:block;position:absolute;top:24px}
  .card{padding:32px 24px;border-radius:24px}
}
@media (max-width:420px){
  .steps li{padding:4px 8px;font-size:.75rem;line-height:1rem}
  .cine-desc{font-size:.75rem;line-height:1rem}
}
@media (prefers-reduced-motion:reduce){
  .hero,.panel{animation:fadein 400ms var(--ease) both}
  @keyframes fadein{from{opacity:0}to{opacity:1}}
  .cine-text>*{transition:opacity 200ms var(--ease);transform:none!important;filter:none!important}
  .cine-brand i{animation:none}
}