/* ============================================================
   学生端（H5）样式
   桌面端以手机框展示，移动端全屏
   ============================================================ */

body.student-body{
  background:#dfe5f0;
  display:flex; align-items:center; justify-content:center;
  min-height:100vh; padding:24px 12px;
}

/* ---------- 手机外框 ---------- */
.phone{
  position:relative; width:390px; height:844px; flex:none;
  background:#0d1117; border-radius:46px; padding:9px;
  box-shadow:0 30px 70px rgba(16,26,50,.34), 0 0 0 1px rgba(255,255,255,.32) inset;
}
.phone-screen{
  position:relative; height:100%; border-radius:38px; overflow:hidden;
  background:#f4f6fa; display:flex; flex-direction:column;
}
.notch{
  position:absolute; top:9px; left:50%; transform:translateX(-50%);
  width:112px; height:26px; background:#0d1117; border-radius:0 0 16px 16px; z-index:60;
}
.statusbar{
  height:44px; flex:none; display:flex; align-items:center;
  padding:0 22px; font-size:12.5px; font-weight:600; color:#1c2333;
  position:relative; z-index:50;
}
.statusbar.on-blue{color:#fff}
.statusbar .right{margin-left:auto; display:flex; align-items:center; gap:5px}

/* ---------- 通用 ---------- */
.screen{flex:1; display:flex; flex-direction:column; min-height:0; position:relative}
.scroll{flex:1; overflow-y:auto; -webkit-overflow-scrolling:touch; overscroll-behavior:contain}
.s-pad{padding:0 16px}

.topbar-h5{
  flex:none; display:flex; align-items:center; gap:12px;
  padding:8px 16px 12px; background:#fff; position:relative; z-index:20;
}
.back-btn{
  width:34px; height:34px; border-radius:50%; background:#fff; flex:none;
  display:flex; align-items:center; justify-content:center; color:#1c2333;
  box-shadow:0 2px 8px rgba(20,30,60,.12);
}
.back-btn:active{background:#f2f4f8}
.topbar-h5 h1{font-size:17px; font-weight:600}
.topbar-h5 .right{margin-left:auto}

/* ---------- 登录 ---------- */
.s-login{
  flex:1; display:flex; flex-direction:column;
  background:
    radial-gradient(circle at 1px 1px, rgba(255,255,255,.2) 1px, transparent 0) 0 0/20px 20px,
    linear-gradient(160deg,#2b63ee 0%,#2f6dff 45%,#3f83ff 100%);
  padding:0 18px 22px;
}
.s-login-brand{margin:18px 0 20px}
.s-logo{
  width:46px; height:46px; border-radius:14px; background:rgba(255,255,255,.2);
  display:flex; align-items:center; justify-content:center; color:#fff;
  box-shadow:inset 0 0 0 1px rgba(255,255,255,.24); margin-bottom:14px;
}
.s-login-brand h1{color:#fff; font-size:25px; font-weight:700; letter-spacing:.02em}
.s-login-brand p{color:rgba(255,255,255,.8); font-size:11.5px; margin-top:4px}

.s-card{
  background:#fff; border-radius:18px; padding:22px 18px;
  box-shadow:0 18px 40px rgba(12,30,80,.22);
}
.s-card h2{font-size:19px; font-weight:700}
.s-card .hint{font-size:12px; color:var(--ink-3); margin-top:4px; margin-bottom:18px}
.s-field{margin-bottom:14px}
.s-field label{display:block; font-size:12px; color:var(--ink-2); margin-bottom:6px}
.s-input{position:relative}
.s-input .ico{position:absolute; left:12px; top:50%; transform:translateY(-50%); color:#b3bacb}
.s-input input{
  width:100%; height:46px; padding:0 42px 0 38px;
  border:1px solid #e3e7ef; border-radius:10px; background:#fff;
  font-size:14px; outline:none;
}
.s-input input:focus{border-color:var(--brand); box-shadow:0 0 0 3px rgba(47,107,255,.1)}
.s-input .eye{
  position:absolute; right:6px; top:50%; transform:translateY(-50%);
  width:32px; height:32px; display:flex; align-items:center; justify-content:center;
  color:#aab1c1;
}
.s-btn{
  width:100%; height:46px; border-radius:10px; font-size:15px; font-weight:600;
  display:flex; align-items:center; justify-content:center; gap:6px;
  transition:transform .12s, filter .15s;
}
.s-btn:active{transform:scale(.99)}
.s-btn-primary{background:var(--brand); color:#fff; box-shadow:0 6px 16px rgba(47,107,255,.28)}
.s-btn-outline{background:#f4f8ff; color:var(--brand); border:1px solid #cfe0ff; margin-top:10px}
.s-demo{
  margin-top:14px; padding:9px; border-radius:9px; background:#f7f9fc;
  font-size:11px; color:var(--ink-3); text-align:center; display:flex; align-items:center; justify-content:center; gap:5px;
}
.s-demo b{color:var(--ink-2); font-weight:600}

/* ---------- 首页 ---------- */
.s-home-head{
  flex:none; position:relative; overflow:hidden;
  background:
    radial-gradient(circle at 1px 1px, rgba(255,255,255,.13) 1px, transparent 0) 0 0/20px 20px,
    linear-gradient(160deg,#2b63ee,#3a7bff 70%,#4385ff);
  color:#fff; padding:0 16px 26px;
  border-radius:0 0 22px 22px;
}
.s-profile{display:flex; align-items:center; gap:11px; padding:6px 0 16px}
.s-avatar{
  width:42px; height:42px; border-radius:50%; flex:none;
  background:rgba(255,255,255,.24); color:#fff;
  display:flex; align-items:center; justify-content:center; font-size:16px; font-weight:600;
  box-shadow:inset 0 0 0 1px rgba(255,255,255,.3);
}
.s-profile .who{min-width:0}
.s-profile .nameline{display:flex; align-items:center; gap:7px}
.s-profile .nameline b{font-size:17px; font-weight:600}
.s-tier{
  height:19px; padding:0 7px; border-radius:5px; background:#c9f5d8; color:#15803d;
  font-size:10.5px; font-weight:600; display:inline-flex; align-items:center;
}
.s-profile .meta{font-size:11px; color:rgba(255,255,255,.78); margin-top:3px}
.s-profile .me{
  margin-left:auto; width:32px; height:32px; border-radius:50%; background:rgba(255,255,255,.2);
  display:flex; align-items:center; justify-content:center; color:#fff;
}
.s-stats{display:grid; grid-template-columns:repeat(3,1fr); gap:9px}
.s-stat{
  background:rgba(255,255,255,.17); border:1px solid rgba(255,255,255,.16);
  border-radius:11px; padding:10px 8px; text-align:center; color:#fff;
}
.s-stat b{font-size:19px; font-weight:700; display:block; line-height:1.2; letter-spacing:-.01em}
.s-stat span{font-size:10.5px; color:rgba(255,255,255,.8)}
.s-stat b i{font-size:11px; font-style:normal; font-weight:500}

.s-tabs-wrap{
  position:relative; margin:-14px 16px 0; background:#fff; border-radius:12px;
  padding:4px; box-shadow:0 4px 14px rgba(20,35,80,.09); display:flex; gap:4px;
}
.s-tab{
  flex:1; height:34px; border-radius:9px; font-size:13px; color:var(--ink-3);
  display:flex; align-items:center; justify-content:center; font-weight:500;
}
.s-tab.on{background:var(--brand); color:#fff; font-weight:600; box-shadow:0 3px 8px rgba(47,107,255,.24)}

.hw-card{
  background:#fff; border-radius:14px; padding:15px 15px 13px;
  margin:12px 16px 0; box-shadow:0 2px 10px rgba(20,35,80,.06);
  border:1px solid rgba(230,234,242,.9); cursor:pointer;
  transition:transform .15s, box-shadow .15s;
}
.hw-card:active{transform:scale(.995)}
.hw-card .top{display:flex; align-items:center; gap:8px; margin-bottom:9px}
.s-tag{
  height:20px; padding:0 8px; border-radius:5px; background:#eaf1ff; color:#2c6bf6;
  font-size:10.5px; font-weight:600; display:inline-flex; align-items:center;
}
.s-countdown{
  margin-left:auto; height:20px; padding:0 8px; border-radius:5px;
  background:#fdeeee; color:#e5484d; font-size:10.5px; font-weight:600;
  display:inline-flex; align-items:center; gap:4px;
}
.s-countdown.normal{background:#f4f6fa; color:#8b93a5}
.hw-card h3{font-size:15px; font-weight:600; line-height:1.4; letter-spacing:-.01em}
.hw-card .unit{font-size:11.5px; color:var(--ink-3); margin-top:6px; display:flex; align-items:center; gap:5px}
.hw-card .foot{display:flex; align-items:center; margin-top:11px; padding-top:11px; border-top:1px solid #f1f3f8}
.hw-card .prog{font-size:11.5px; color:var(--ink-3); display:flex; align-items:center; gap:5px}
.hw-card .go{margin-left:auto; font-size:13px; color:var(--brand); font-weight:600; display:flex; align-items:center; gap:3px}
.s-empty{display:flex; flex-direction:column; align-items:center; gap:8px; padding:60px 20px; color:var(--ink-3); font-size:12.5px}

.tabbar{
  flex:none; height:58px; background:#fff; border-top:1px solid #eef1f6;
  display:flex; padding-bottom:env(safe-area-inset-bottom);
}
.tabbar button{
  flex:1; display:flex; flex-direction:column; align-items:center; justify-content:center; gap:3px;
  font-size:10.5px; color:#98a1b3;
}
.tabbar button.on{color:var(--brand)}

/* ---------- 作业详情 ---------- */
.s-detail-head{background:#fff; padding:0 16px 16px; border-radius:0 0 18px 18px}
.s-detail-title{display:flex; align-items:flex-start; gap:9px; margin-top:4px}
.s-detail-title .nm{font-size:17px; font-weight:700; line-height:1.35; letter-spacing:-.01em}
.s-detail-sub{font-size:11.5px; color:var(--ink-3); margin-top:8px; display:flex; align-items:center; gap:5px}
.s-metrics{display:grid; grid-template-columns:repeat(3,1fr); gap:8px; margin-top:14px}
.s-metric{background:#f6f8fc; border-radius:11px; padding:11px 6px; text-align:center}
.s-metric b{font-size:16px; font-weight:700; display:block; color:#1c2333}
.s-metric span{font-size:10.5px; color:var(--ink-3)}

.q-preview{margin:12px 16px 0; background:#fff; border-radius:14px; padding:4px 15px; box-shadow:0 2px 10px rgba(20,35,80,.05)}
.q-preview .head{
  display:flex; align-items:center; gap:7px; padding:13px 0; font-size:13.5px; font-weight:600;
  border-bottom:1px solid #f1f3f8;
}
.q-row{display:flex; gap:10px; padding:13px 0; border-bottom:1px solid #f5f7fa}
.q-row:last-child{border-bottom:0}
.q-idx{
  width:22px; height:22px; border-radius:6px; background:#eef4ff; color:var(--brand);
  font-size:11.5px; font-weight:600; display:flex; align-items:center; justify-content:center; flex:none;
}
.q-row .stem{font-size:13px; line-height:1.55; color:#1c2333}
.q-row .meta{display:flex; align-items:center; gap:7px; margin-top:6px}
.q-type{
  height:19px; padding:0 7px; border-radius:5px; background:#f2f4f9; color:#6b7488;
  font-size:10.5px; display:inline-flex; align-items:center;
}
.q-min{font-size:10.5px; color:#a6aebe}

.bottom-action{
  flex:none; padding:10px 16px calc(10px + env(safe-area-inset-bottom));
  background:#fff; border-top:1px solid #eef1f6;
}

/* ---------- 作答 ---------- */
.answer-wrap{padding:12px 16px 20px; display:flex; flex-direction:column; gap:12px}
.ans-card{background:#fff; border-radius:14px; padding:15px; box-shadow:0 2px 10px rgba(20,35,80,.05)}
.ans-card .stem{font-size:13.5px; line-height:1.6; margin:9px 0 11px}
.opt-list{display:flex; flex-direction:column; gap:8px}
.opt{
  display:flex; align-items:center; gap:9px; padding:11px 12px;
  border:1px solid #e7ebf3; border-radius:10px; font-size:13px; color:#394152;
  cursor:pointer; transition:all .15s; background:#fff;
}
.opt .key{
  width:20px; height:20px; border-radius:50%; border:1.4px solid #d6dce8; flex:none;
  display:flex; align-items:center; justify-content:center; font-size:10.5px; color:#98a1b3;
}
.opt.on{border-color:var(--brand); background:#f5f9ff; color:#1c4fd0}
.opt.on .key{border-color:var(--brand); background:var(--brand); color:#fff}
.blank-input, .write-input{
  width:100%; border:1px solid #e7ebf3; border-radius:10px; padding:11px 12px;
  font-size:13.5px; outline:none; background:#fcfdff;
}
.blank-input:focus, .write-input:focus{border-color:var(--brand); background:#fff; box-shadow:0 0 0 3px rgba(47,107,255,.1)}
.write-input{min-height:96px; resize:vertical; line-height:1.6}
.ans-tip{
  margin-top:9px; font-size:11px; color:#8b93a5; background:#f7f9fc; border-radius:8px; padding:8px 10px;
  display:none;
}
.ans-tip.show{display:block}
.ans-top{display:flex; align-items:center; gap:7px; margin-bottom:4px}
.ans-top .n{font-size:11.5px; color:var(--ink-3)}

/* ---------- 结果 ---------- */
.result-wrap{padding:26px 16px; text-align:center}
.result-ico{
  width:70px; height:70px; border-radius:24px; margin:0 auto 14px;
  background:linear-gradient(150deg,#e9f8ef,#d3f2e1); color:#16a34a;
  display:flex; align-items:center; justify-content:center;
}
.result-wrap h2{font-size:20px; font-weight:700}
.result-wrap .score{font-size:40px; font-weight:700; color:var(--brand); margin:10px 0 4px; letter-spacing:-.02em}
.result-wrap p{font-size:12.5px; color:var(--ink-3)}
.result-stats{display:grid; grid-template-columns:repeat(3,1fr); gap:8px; margin:20px 0}
.result-stats div{background:#fff; border-radius:11px; padding:12px 6px}
.result-stats b{display:block; font-size:16px; font-weight:700}
.result-stats span{font-size:10.5px; color:var(--ink-3)}
.result-advice{
  display:flex; gap:9px; align-items:flex-start;
  text-align:left; background:#fff; border:1px solid var(--line);
  border-radius:12px; padding:13px 14px; font-size:11.5px;
  color:var(--ink-2); line-height:1.7;
}
.result-advice .ai{flex:none; color:var(--brand); margin-top:2px}

/* ---------- 加入班级 ---------- */
.join-wrap{padding:18px 16px}
.join-card{background:#fff; border-radius:18px; padding:22px 18px; box-shadow:0 6px 22px rgba(20,35,80,.08)}
.join-ico{
  width:52px; height:52px; border-radius:15px; background:#eef3ff; color:var(--brand);
  margin:0 auto 14px; display:flex; align-items:center; justify-content:center;
}
.join-card h2{font-size:16px; font-weight:700; text-align:center}
.join-card .hint{font-size:11.5px; color:var(--ink-3); text-align:center; margin:6px 0 20px}
.code-input{
  width:100%; height:52px; border:1px solid #e3e7ef; border-radius:11px;
  text-align:center; font-size:20px; letter-spacing:.42em; font-weight:600;
  outline:none; text-transform:uppercase; padding-left:.42em;
}
.code-input:focus{border-color:var(--brand); box-shadow:0 0 0 3px rgba(47,107,255,.1)}
.two-col{display:grid; grid-template-columns:1fr 1fr; gap:10px}

/* ---------- 我的 / 错题本 ---------- */
.mine-head{background:linear-gradient(160deg,#2b63ee,#3a7bff); color:#fff; padding:24px 16px 30px; border-radius:0 0 20px 20px}
.mine-head .row{display:flex; align-items:center; gap:12px}
.mine-head .big{width:54px; height:54px; border-radius:50%; background:rgba(255,255,255,.24); display:flex; align-items:center; justify-content:center; font-size:20px; font-weight:600}
.mine-list{margin:14px 16px 0; background:#fff; border-radius:14px; overflow:hidden}
.mine-item{display:flex; align-items:center; gap:10px; padding:14px 15px; border-bottom:1px solid #f3f5f9; font-size:13px}
.mine-item:last-child{border-bottom:0}
.mine-item .v{margin-left:auto; color:var(--ink-3); font-size:12px}
.wrong-card{background:#fff; border-radius:14px; margin:12px 16px 0; padding:14px; box-shadow:0 2px 10px rgba(20,35,80,.05)}
.wrong-card .kp{font-size:10.5px; color:var(--ink-3); margin-top:6px}

/* ---------- 移动端全屏 ---------- */
@media (max-width:480px){
  body.student-body{padding:0; background:#f4f6fa; display:block}
  .phone{width:100%; height:100vh; height:100dvh; border-radius:0; padding:0; box-shadow:none; background:transparent}
  .phone-screen{border-radius:0; height:100%}
  .notch{display:none}
  .statusbar{display:none}
}
@media (min-width:481px) and (max-height:900px){
  body.student-body{padding:10px}
  .phone{height:calc(100vh - 20px); max-height:844px; width:auto; aspect-ratio:390/844}
}