/* ???? � ??????? app.css ???�???? */
.yt-shell{min-height:100vh;display:flex;flex-direction:column}
.yt-header{position:sticky;top:0;z-index:60;background:rgba(255,255,255,.96);backdrop-filter:blur(12px);border-bottom:1px solid var(--border);box-shadow:0 2px 10px rgba(28,18,36,.06)}
.yt-header-inner{max-width:1180px;margin:0 auto;padding:12px 24px;display:flex;align-items:center;gap:18px}
.yt-brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:inherit;flex-shrink:0}
.yt-brand img{width:48px;height:54px;object-fit:contain;background:#fff}
.yt-brand-title{font-weight:700;font-size:17px;color:var(--text);line-height:1.2;font-family:"Noto Serif SC","Songti SC",serif;letter-spacing:.06em}
.yt-brand-sub{font-size:12px;color:var(--text-muted);margin-top:2px}
.yt-nav{display:flex;align-items:center;gap:2px;flex:1;min-width:0;flex-wrap:wrap;justify-content:center}
.yt-nav a{font-size:13.5px;color:var(--text);font-weight:500;padding:8px 11px;border-radius:8px;text-decoration:none;white-space:nowrap;transition:color .15s,background .15s}
.yt-nav a:hover{color:var(--tsinghua);background:var(--tsinghua-50)}
.yt-nav a.is-active{color:var(--tsinghua);background:var(--brand-grad-soft);font-weight:600}
.yt-util{display:flex;align-items:center;gap:10px;flex-shrink:0;font-size:13px;margin-left:auto}
.yt-util .name{font-weight:600;color:var(--text);max-width:8em;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.yt-util a,.yt-util button.linkish{color:var(--text-muted);background:none;border:none;font:inherit;cursor:pointer;padding:0;text-decoration:none}
.yt-util a:hover,.yt-util button.linkish:hover{color:var(--tsinghua)}
.yt-main{flex:1}
.yt-footer{border-top:1px solid var(--border-soft);background:var(--bg-warm);padding:28px 24px 36px;margin-top:auto}
.yt-footer-inner{max-width:1180px;margin:0 auto;display:flex;flex-wrap:wrap;gap:16px 28px;justify-content:space-between;align-items:flex-start;font-size:13px;color:var(--text-muted)}
.yt-footer a{color:var(--green-700);text-decoration:none}
.yt-footer a:hover{color:var(--tsinghua)}

.yt-hero{position:relative;min-height:min(72vh,640px);display:flex;align-items:flex-end;color:#fff;overflow:hidden;background:#1c1224}
.yt-hero-bg{position:absolute;inset:0;background-position:center;background-size:cover;background-repeat:no-repeat;transform:scale(1.02);animation:ytHeroIn 1.1s ease both}
.yt-hero-bg::after{content:"";position:absolute;inset:0;background:linear-gradient(105deg,rgba(28,18,36,.88) 0%,rgba(28,18,36,.55) 42%,rgba(20,48,42,.28) 78%,rgba(20,48,42,.12) 100%)}
@keyframes ytHeroIn{from{opacity:.55;transform:scale(1.06)}to{opacity:1;transform:scale(1.02)}}
.yt-hero-inner{position:relative;z-index:2;max-width:1180px;width:100%;margin:0 auto;padding:88px 28px 72px}
.yt-hero-brand{margin:0;font-family:"Noto Serif SC","Songti SC",serif;font-size:clamp(40px,6vw,64px);font-weight:700;letter-spacing:.14em;line-height:1.15;text-shadow:0 2px 18px rgba(0,0,0,.28);animation:ytRise .7s ease .1s both}
.yt-hero-rule{width:64px;height:2px;margin:20px 0 22px;border-radius:2px;background:linear-gradient(90deg,rgba(255,255,255,.85),rgba(255,255,255,.15));animation:ytRise .7s ease .2s both}
.yt-hero-title{font-size:clamp(17px,2.2vw,24px);font-weight:500;margin:0 0 14px;max-width:540px;color:rgba(255,255,255,.92);letter-spacing:.04em;animation:ytRise .7s ease .28s both}
.yt-hero-lead{font-size:clamp(14px,1.5vw,16px);line-height:1.85;color:rgba(220,237,228,.9);max-width:480px;margin:0 0 28px;animation:ytRise .7s ease .36s both}
.yt-hero-actions{display:flex;flex-wrap:wrap;gap:12px;animation:ytRise .7s ease .44s both}
.yt-hero .btn-ghost{background:rgba(255,255,255,.1);border-color:rgba(255,255,255,.35);color:#fff}
.yt-hero .btn-ghost:hover{background:rgba(255,255,255,.18);color:#fff;border-color:rgba(255,255,255,.5)}
@keyframes ytRise{from{opacity:0;transform:translateY(14px)}to{opacity:1;transform:none}}

.yt-wrap{max-width:1180px;margin:0 auto;padding:40px 28px 64px}
.yt-page-head{margin-bottom:28px}
.yt-page-head h1{margin:0 0 8px;font-size:clamp(24px,3vw,32px);font-weight:700;color:var(--text);font-family:"Noto Serif SC","Songti SC",serif;letter-spacing:.04em}
.yt-page-head p{margin:0;color:var(--text-muted);font-size:15px;line-height:1.7;max-width:720px}
.yt-sec{margin-top:36px}
.yt-sec-title{display:flex;align-items:baseline;justify-content:space-between;gap:12px;margin-bottom:14px}
.yt-sec-title h2,.yt-sec-title h3{margin:0;font-size:18px;font-weight:700;color:var(--text)}
.yt-sec-title a{font-size:13px;color:var(--green-700);text-decoration:none}
.yt-sec-title a:hover{color:var(--tsinghua)}

.yt-grid{display:grid;gap:16px}
.yt-grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}
.yt-grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.yt-grid-4{grid-template-columns:repeat(4,minmax(0,1fr))}
@media(max-width:900px){.yt-grid-3,.yt-grid-4{grid-template-columns:repeat(2,minmax(0,1fr))}.yt-header-inner{flex-wrap:wrap}.yt-nav{order:3;width:100%;justify-content:flex-start;overflow-x:auto}}
@media(max-width:640px){.yt-grid-2,.yt-grid-3,.yt-grid-4{grid-template-columns:1fr}.yt-wrap{padding:28px 16px 48px}.yt-hero-inner{padding:72px 16px 56px}}

.yt-tile{display:block;padding:20px 18px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);text-decoration:none;color:inherit;transition:var(--tr);box-shadow:var(--shadow-sm)}
.yt-tile:hover{border-color:var(--tsinghua-100);box-shadow:var(--shadow-md);transform:translateY(-2px)}
.yt-tile .t{font-weight:650;color:var(--text);font-size:15px}
.yt-tile .d{margin-top:6px;font-size:13px;color:var(--text-muted);line-height:1.55}
.yt-panel{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow-sm)}
.yt-panel + .yt-panel{margin-top:12px}
.yt-list-item{display:block;padding:16px 18px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);margin-bottom:10px;text-decoration:none;color:inherit;transition:var(--tr)}
.yt-list-item:hover{border-color:var(--tsinghua-100);background:var(--tsinghua-50)}
.yt-list-item .row{display:flex;justify-content:space-between;align-items:flex-start;gap:12px}
.yt-form input,.yt-form textarea,.yt-form select{width:100%;margin-bottom:10px;padding:10px 12px;border:1px solid var(--border);border-radius:10px;font:inherit;font-size:14px;color:var(--text);background:#fff}
.yt-form input:focus,.yt-form textarea:focus,.yt-form select:focus{outline:none;border-color:var(--tsinghua-100);box-shadow:0 0 0 3px rgba(102,8,116,.08)}
.yt-form label.check{display:inline-flex;align-items:center;gap:6px;font-size:13px;margin:0 12px 8px 0;color:var(--text-body)}
.yt-muted{color:var(--text-muted)}
.yt-back{display:inline-block;font-size:13px;color:var(--green-700);text-decoration:none;margin-bottom:10px}
.yt-back:hover{color:var(--tsinghua)}
.yt-tabs{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:16px}
.yt-empty{padding:28px;text-align:center;color:var(--text-muted);font-size:14px;border:1px dashed var(--border);border-radius:var(--radius);background:rgba(255,255,255,.5)}
.yt-status{display:inline-flex;align-items:center;padding:2px 10px;border-radius:999px;font-size:12px;font-weight:500;background:var(--green-50);color:var(--green-700);white-space:nowrap}
.yt-mine-hero{border-radius:var(--radius);padding:28px;background:var(--hero-grad);color:#fff;margin-bottom:24px}
.yt-mine-hero .sub{color:#CFEEDF;font-size:13.5px;margin-top:6px}
.yt-entry-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}
@media(max-width:720px){.yt-entry-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
.yt-entry-grid a{text-align:center;padding:16px 10px;background:var(--surface);border:1px solid var(--border);border-radius:10px;font-size:13.5px;font-weight:600;color:var(--text-body);text-decoration:none;transition:var(--tr)}
.yt-entry-grid a:hover{border-color:var(--tsinghua-100);color:var(--tsinghua);background:var(--tsinghua-50)}