:root{
  --scu-red:#a8202a;      /* 川大朱红 */
  --scu-red-deep:#7d1219;
  --gold:#d8b46a;
  --paper:#f7f1e6;
  --ease:cubic-bezier(.65,0,.35,1);
  --ease-out:cubic-bezier(.16,1,.3,1);
}
*{box-sizing:border-box;margin:0;padding:0}
html,body{height:100%;overflow:hidden}
body{
  font-family:"Songti SC","STSong","Noto Serif SC","Source Han Serif SC","SimSun",serif;
  background:#111;color:#fff;
  -webkit-font-smoothing:antialiased;
}

/* 背景：从暗色渐变到宣纸色 */
.bg{position:fixed;inset:0;background:#111;transition:background 1.2s var(--ease)}
.bg::after{
  content:"";position:absolute;inset:0;opacity:0;transition:opacity 1.2s var(--ease);
  background:
    radial-gradient(circle at 50% 42%,rgba(168,32,42,.10),transparent 60%),
    var(--paper);
}
body.s-tint .bg::after{opacity:1}

/* 舞台：保持照片 3:4 比例，手机竖屏几乎全屏，电脑居中 */
.stage{
  position:fixed;left:50%;top:50%;
  height:min(92vh,92vw*4/3);height:min(92dvh,92vw*4/3);
  aspect-ratio:3/4;
  transform:translate(-50%,-50%);
}
.photo{
  position:absolute;inset:0;width:100%;height:100%;object-fit:cover;
  border-radius:clamp(10px,2vw,18px);
  box-shadow:0 30px 80px rgba(0,0,0,.5);
  opacity:0;transform:scale(1.06);filter:blur(6px);
  transition:opacity 1s var(--ease-out),transform 1.6s var(--ease-out),filter 1s var(--ease-out);
}
body.s-in .photo{opacity:1;transform:none;filter:none}
body.s-cut .photo{filter:brightness(.35) saturate(.4) blur(2px);transform:scale(.98)}
body.s-lift .photo{opacity:0;transform:scale(.92);filter:brightness(.2) blur(10px)}

/* 奶龙：位置为照片内百分比 */
.nl{
  position:absolute;
  left:42.26%;top:51.66%;width:19.81%;
  isolation:isolate;
  transform-origin:50% 50%;
  will-change:transform;
  opacity:0;
}
body.s-in .nl{opacity:1}
.nl-img{display:block;width:100%;height:auto;transition:filter 1.2s var(--ease)}
body.s-cut .nl-img{filter:drop-shadow(0 0 2px #fff) drop-shadow(0 0 14px rgba(255,236,150,.9))}
body.s-merge .nl-img{opacity:0;transition:opacity .35s var(--ease)}
body.s-merge .photo{opacity:0;filter:brightness(.15) blur(14px)}

/* 照片卡片：校园里其它几处的奶龙 */
.cards{
  position:fixed;left:50%;top:50%;transform:translate(-50%,-50%);
  width:min(100vw,108vh);height:100%;pointer-events:none;z-index:3;
}
.card{
  position:absolute;left:var(--x);top:var(--y);
  width:clamp(84px,22vw,140px);
  padding:5px 5px 15px;background:#fff;border-radius:7px;
  box-shadow:0 14px 34px rgba(0,0,0,.5);
  transform:translate(calc(-50% + var(--fx,0px)),calc(-50% + var(--fy,0px))) scale(.5);
  opacity:0;
  transition:transform .85s var(--ease-out) var(--d,0s),opacity .5s var(--ease) var(--d,0s);
}
.card img{display:block;width:100%;height:auto;border-radius:4px;background:#eee}
body.s-cards .card{opacity:1;transform:translate(-50%,-50%) scale(1)}
/* 剪影从卡片里脱出后，照片卡片随即隐去 */
body.s-merge .card{opacity:0;transition:opacity .45s var(--ease) .15s}

/* 汇聚层：四张照片里的剪影合拢成一个抽象轮廓 */
.morph{position:fixed;inset:0;width:100%;height:100%;pointer-events:none;z-index:4;overflow:visible}
.morph path{stroke-width:3;stroke-linejoin:round}

/* 剪切时的果冻形变 */
.nl.wobble{animation:wobble .9s var(--ease-out)}
@keyframes wobble{
  0%{scale:1 1}25%{scale:1.12 .9}50%{scale:.94 1.08}75%{scale:1.03 .98}100%{scale:1 1}
}

/* 校徽环 */
.emblem{
  position:fixed;left:50%;top:var(--emblem-y,38%);
  width:min(78vw,42vh);height:auto;
  transform:translate(-50%,-50%) scale(.85) rotate(-20deg);
  opacity:0;pointer-events:none;
  transition:opacity .8s var(--ease),transform 1.4s var(--ease-out);
}
body.s-ring .emblem{opacity:1;transform:translate(-50%,-50%) scale(1) rotate(0)}
.ring-outer,.ring-inner{fill:none;stroke:var(--scu-red);stroke-dasharray:1300;stroke-dashoffset:1300;transition:stroke-dashoffset 1.6s var(--ease)}
.ring-outer{stroke-width:5}
.ring-inner{stroke-width:2;stroke-dasharray:900;stroke-dashoffset:900;transition-delay:.15s}
body.s-ring .ring-outer,body.s-ring .ring-inner{stroke-dashoffset:0}
.ring-cn,.ring-en{fill:var(--scu-red);opacity:0;transition:opacity 1s var(--ease) .5s}
.ring-cn{font-size:34px;font-weight:700;letter-spacing:2px}
.ring-en{font-size:15px;letter-spacing:3px;font-family:Georgia,"Times New Roman",serif}
body.s-ring .ring-cn,body.s-ring .ring-en{opacity:1}

/* 文案 */
.caption{
  position:fixed;left:0;right:0;bottom:max(6vh,calc(env(safe-area-inset-bottom) + 24px));
  text-align:center;color:var(--scu-red);padding:0 20px;
  opacity:0;transform:translateY(16px);
  transition:opacity .9s var(--ease-out),transform .9s var(--ease-out);
}
body.s-ring .caption{opacity:1;transform:none}
.title{font-size:clamp(28px,6vw,44px);letter-spacing:.35em;text-indent:.35em;font-weight:900}
.motto{margin-top:6px;font-size:clamp(13px,2.6vw,16px);letter-spacing:.5em;text-indent:.5em;color:#8a5a3c}
.status{margin-top:18px;font-size:clamp(14px,3vw,17px);letter-spacing:.12em;color:#5b3a2c}
.dots i{font-style:normal;animation:dot 1.2s infinite}
.dots i:nth-child(2){animation-delay:.2s}.dots i:nth-child(3){animation-delay:.4s}
@keyframes dot{0%,80%,100%{opacity:.15}40%{opacity:1}}
.bar{margin:12px auto 0;width:min(280px,64vw);height:3px;border-radius:3px;background:rgba(168,32,42,.15);overflow:hidden}
.bar span{display:block;height:100%;width:100%;background:var(--scu-red);transform:scaleX(0);transform-origin:left}
.skip{display:inline-block;margin-top:14px;font-size:13px;color:#8a5a3c;text-decoration:none;letter-spacing:.1em;opacity:.75}
.skip:hover,.skip:focus-visible{opacity:1;text-decoration:underline}
.copyright{margin-top:10px;font-size:11px;letter-spacing:.14em;color:#a08a7a;opacity:.85}

/* 转场：朱红圆从奶龙处扩散铺满全屏 */
.wipe{
  position:fixed;inset:0;background:var(--scu-red);
  clip-path:circle(0% at var(--wx,50%) var(--wy,42%));
  transition:clip-path 1s var(--ease);
  pointer-events:none;z-index:10;
}
body.s-wipe .wipe{clip-path:circle(150% at var(--wx,50%) var(--wy,42%))}

@media (prefers-reduced-motion:reduce){
  *,*::before,*::after{animation-duration:.01ms!important;transition-duration:.3s!important}
}