:root{--brown:#76503c;--green:#285f58;--cream:#f6f1e8;--ink:#24211f;--line:#d8caba;--soft:#fbf8f3}
*{box-sizing:border-box}body{margin:0;background:#e9e1d6;color:var(--ink);font-family:Arial,"Microsoft YaHei",sans-serif;line-height:1.55}
.page{max-width:920px;margin:auto;background:var(--cream);min-height:100vh;box-shadow:0 0 32px #3b251a1a}
.teacher{padding:22px 26px;background:linear-gradient(135deg,#f7f1e7,#eee3d4);border-top:8px solid var(--brown);border-bottom:1px solid var(--line)}
.teacher-in{max-width:760px;margin:auto;display:flex;align-items:center;gap:24px}.teacher img{width:118px;height:118px;object-fit:contain;background:#fff;padding:6px;border-radius:8px}
.teacher .tag{display:inline-block;background:var(--green);color:#fff;border-radius:16px;padding:3px 11px;font-size:12px;font-weight:700}.teacher strong{display:block;color:var(--brown);font-size:22px;margin:9px 0 3px}.teacher p{margin:0;color:#615850}
header{background:var(--brown);color:#fff;padding:26px}header>div,main{max-width:850px;margin:auto}h1{font-size:25px;margin:0 0 4px}header p{margin:0;opacity:.88}
main{padding:26px 24px 58px}.full,.material,.list{background:#fff;border-radius:8px;box-shadow:0 3px 13px #4d30200f}.full{padding:18px;border-left:6px solid var(--green)}audio{width:100%;margin-top:10px}
h2{color:var(--brown);font-size:19px;margin:29px 0 15px}.material{margin:18px 0;padding:18px 20px;border-left:4px solid var(--green)}.mhead{display:flex;justify-content:space-between;align-items:center;gap:14px;margin-bottom:14px}.range{font-weight:700;color:var(--brown)}
.play{border:0;border-radius:18px;background:var(--green);color:#fff;padding:8px 15px;font-weight:700;cursor:pointer;white-space:nowrap}.play.playing{background:var(--brown)}
.qcard{padding:14px 0;border-top:1px solid #e8ded2}.qcard:first-child{border-top:0;padding-top:2px}.stem{font-size:16px;font-weight:600;margin-bottom:8px;overflow-wrap:anywhere}
.options{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));column-gap:24px;row-gap:7px}.option{display:grid;grid-template-columns:25px minmax(0,1fr);align-items:start;min-width:0}.olab{font-weight:700}.otext{overflow-wrap:anywhere}
.hint{color:#6f675f;font-size:13px;margin-top:22px}.list{overflow:hidden}.list a{display:block;padding:13px 17px;color:var(--ink);text-decoration:none;border-top:1px solid #e6dbcf}.list a:first-child{border-top:0}.list a:hover{background:#f2eadf}
footer{text-align:center;background:var(--brown);color:#fff;padding:18px;font-size:13px}.back{display:inline-block;margin-top:18px;color:var(--green);text-decoration:none;font-weight:700}
@media(max-width:600px){.page{box-shadow:none}.teacher{padding:17px 15px}.teacher-in{gap:14px}.teacher img{width:82px;height:82px}.teacher strong{font-size:18px}.teacher p{font-size:12px}header{padding:21px 17px}h1{font-size:21px}main{padding:20px 14px 44px}.material{padding:15px 14px}.mhead{align-items:flex-start}.options{grid-template-columns:1fr;row-gap:6px}.stem{font-size:15px}.option{grid-template-columns:25px minmax(0,1fr)}}