/* 登录页 · 深空蓝 + 青绿光晕，three.js DNA 背景 */
:root{--navy:#06122b;--navy-2:#0b1f3a;--cyan:#38d9c8;--blue:#4f8ff7;--ink:#0f2547;--muted:#7a869c;
  --font:"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans CJK SC","Source Han Sans SC","Segoe UI",Roboto,Helvetica,Arial,sans-serif}
*{box-sizing:border-box}
html,body{height:100%}
body.login-body{margin:0;font-family:var(--font);color:#fff;background:var(--navy);overflow-x:hidden}
#bg3d{position:fixed;inset:0;width:100%;height:100%;display:block;z-index:0}
.bg-fallback{position:fixed;inset:0;z-index:-1;background-image:url("../img/hero_dna.fcecbef32ff6.jpg");background-size:cover;background-position:center;background-color:var(--navy)}
.bg-fallback::after{content:"";position:absolute;inset:0;background:
  radial-gradient(900px 500px at 15% 10%,rgba(79,143,247,.35),transparent 60%),
  radial-gradient(700px 500px at 90% 90%,rgba(56,217,200,.28),transparent 60%),
  linear-gradient(160deg,rgba(6,18,43,.55),rgba(11,31,58,.6) 55%,rgba(6,42,62,.7))}
.login-wrap{position:relative;z-index:1;min-height:100%;display:grid;grid-template-columns:1.15fr .85fr;max-width:1240px;margin:0 auto;padding:40px 32px;gap:30px;align-items:center}

/* 左侧 hero */
.hero{padding:20px 10px;animation:rise .9s ease-out both}
.hero-banner{width:min(420px,90%);display:block;filter:drop-shadow(0 6px 18px rgba(0,0,0,.35))}
.hero-college{width:min(230px,55%);display:block;margin:14px 0 26px 2px;opacity:.95}
.hero-title{font-size:clamp(2rem,4.6vw,3.6rem);line-height:1.15;margin:0;font-weight:800;letter-spacing:2px;text-shadow:0 4px 24px rgba(0,0,0,.35)}
.hero-title{display:flex;align-items:center;gap:18px}
.hero-title>span span{display:block}
.hero-mark{width:clamp(64px,7vw,96px);height:auto;filter:drop-shadow(0 0 18px rgba(56,217,200,.55));animation:spin 40s linear infinite}
@keyframes spin{to{transform:rotate(360deg)}}
.hero-title .hl{background:linear-gradient(90deg,#8fe9dd,#5ab1ff 60%,#c7dbff);-webkit-background-clip:text;background-clip:text;color:transparent}
.hero-sub{margin:10px 0 24px;letter-spacing:3px;text-transform:uppercase;font-size:.8rem;opacity:.7}
.hero-points{list-style:none;padding:0;margin:0;display:grid;gap:10px;font-size:.95rem;opacity:.9}
.hero-points li{display:flex;align-items:flex-start;gap:10px}
.hero-points i{width:8px;height:8px;border-radius:50%;background:var(--cyan);box-shadow:0 0 12px var(--cyan);margin-top:8px;flex:none}

/* 右侧登录卡 */
.panel{display:flex;flex-direction:column;align-items:center;gap:16px;animation:rise 1s .15s ease-out both}
.panel-card{width:100%;max-width:420px;background:rgba(255,255,255,.96);color:var(--ink);border-radius:22px;padding:28px 28px 22px;
  box-shadow:0 30px 80px -20px rgba(0,0,0,.6),0 0 0 1px rgba(255,255,255,.35) inset;backdrop-filter:blur(14px);position:relative;overflow:hidden}
.panel-card::before{content:"";position:absolute;left:0;right:0;top:0;height:4px;background:linear-gradient(90deg,#1a4b9c,#0f9d8a,#38d9c8)}
.panel-head{display:flex;align-items:center;gap:12px;margin-bottom:18px}
.panel-emblem{width:48px;height:48px;object-fit:contain}
.panel-head b{display:block;font-size:1.25rem}
.panel-head small{color:var(--muted);font-size:.8rem}
.alert{background:#fdecec;color:#b91c1c;border:1px solid #f3b4b4;border-radius:10px;padding:9px 12px;font-size:.9rem;margin-bottom:12px}
.login-form .f{display:block;margin-bottom:14px}
.login-form .f>span:first-child{display:block;font-size:.82rem;font-weight:600;color:#34435c;margin-bottom:6px}
.login-form input{width:100%;height:46px;padding:0 14px;border:1px solid #cfd7e3;border-radius:12px;font-size:1rem;outline:0;background:#fff;transition:.15s;font-family:inherit}
.login-form input:focus{border-color:#1a4b9c;box-shadow:0 0 0 4px rgba(26,75,156,.15)}
.pw{position:relative;display:block}
.pw input{padding-right:44px}
.eye{position:absolute;right:6px;top:6px;height:34px;width:34px;border:0;background:none;cursor:pointer;opacity:.55;font-size:1rem}
.submit{width:100%;height:48px;border:0;border-radius:12px;margin-top:6px;cursor:pointer;font-size:1.05rem;font-weight:700;letter-spacing:4px;color:#fff;
  background:linear-gradient(90deg,#1a4b9c,#0f6a8f 60%,#0f9d8a);display:flex;align-items:center;justify-content:center;gap:8px;
  box-shadow:0 12px 24px -10px rgba(26,75,156,.7);transition:.2s;font-family:inherit}
.submit svg{width:20px;height:20px;transition:.2s}
.submit:hover{transform:translateY(-1px);box-shadow:0 16px 30px -10px rgba(15,157,138,.7)}
.submit:hover svg{transform:translateX(4px)}
.tips{margin-top:16px;font-size:.78rem;color:var(--muted);line-height:1.6;border-top:1px dashed #e2e7ef;padding-top:12px}
.tips p{margin:2px 0}
.tips b{color:#34435c}
.login-foot{font-size:.8rem;opacity:.7;text-align:center}

@keyframes rise{from{opacity:0;transform:translateY(18px)}to{opacity:1;transform:none}}

@media (max-width:900px){
  .login-wrap{grid-template-columns:1fr;padding:28px 18px 30px;gap:10px;align-content:start}
  .hero{padding:6px 4px 10px;text-align:center}
  .hero-banner,.hero-college{margin-left:auto;margin-right:auto}
  .hero-college{margin:10px auto 14px}
  .hero-title{font-size:clamp(1.7rem,7vw,2.4rem);justify-content:center;gap:12px}
  .hero-mark{width:56px}
  .hero-points{display:none}
  .panel-card{padding:22px 20px 18px;border-radius:18px}
}
@media (max-width:420px){
  .login-wrap{padding:18px 14px 24px}
  .hero-banner{width:80%}
  .hero-sub{margin-bottom:10px}
}
@media (prefers-reduced-motion:reduce){.hero,.panel{animation:none}}