:root{--ink:#202e35;--muted:#6d7b82;--line:#e2e8e8;--green:#187768;--pale:#edf5f2;--paper:#fff;--bg:#f5f7f7}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:15px/1.7 "Segoe UI","Microsoft YaHei",sans-serif}a{color:var(--green);text-decoration:none}a:hover{text-decoration:underline}.topbar{height:80px;background:#fff;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 max(5vw,24px)}.topbar nav{display:flex;gap:22px;align-items:center}.nav-link{font-size:14px}.container{max-width:1240px;margin:0 auto;padding:42px 28px 70px;min-height:calc(100vh - 152px)}h1,h2,h3,p{margin-top:0}h1{font-size:30px;line-height:1.4;letter-spacing:-.5px;margin-bottom:12px}h2{font-size:22px;margin-bottom:12px}h3{font-size:18px;margin-bottom:10px}.eyebrow{font-size:11px;letter-spacing:2px;color:var(--green);font-weight:700;margin-bottom:18px}.muted,.help{color:var(--muted);font-size:13px}.card{background:white;border:1px solid var(--line);border-radius:16px;padding:28px;margin-bottom:24px;box-shadow:0 4px 16px #223b3514}.narrow{max-width:520px;margin:40px auto}.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:22px}.grid .card{margin-bottom:0}.form-row{display:flex;flex-wrap:wrap;gap:18px;margin-bottom:12px;align-items:end}.form-row>*{flex:1;min-width:180px}.field{display:block;font-size:13px;font-weight:600;margin-bottom:18px}input[type=text],input[type=password],input[type=datetime-local],input[type=number],textarea,select{display:block;width:100%;border:1px solid #d6dfe0;border-radius:9px;padding:11px 13px;font:inherit;font-weight:400;color:var(--ink);background:white;margin-top:7px}textarea{min-height:110px;resize:vertical}input:focus,textarea:focus,select:focus{outline:2px solid #94cbbf;outline-offset:1px}input[type=checkbox]{accent-color:var(--green);margin-right:7px}input[type=file]{max-width:100%;padding:16px;border:1px dashed #aac6be;border-radius:10px;background:#f7faf8}button,.button,input[type=submit]{display:inline-block;cursor:pointer;background:var(--green);border:1px solid var(--green);color:#fff;border-radius:9px;padding:10px 19px;font:inherit;font-weight:600;text-decoration:none;line-height:1.5}button:hover,.button:hover,input[type=submit]:hover{background:#105f53;text-decoration:none}.button.secondary,.secondary{color:var(--green);background:#fff;border-color:#c8dcd5}.full{width:100%;margin-top:10px}.badge{display:inline-block;font-size:12px;padding:4px 11px;border-radius:6px;background:var(--pale);color:var(--green);font-weight:600}.badge.warning{background:#fff4dd;color:#8b631b}.badge.closed{background:#f0f2f3;color:#687880}.notice{background:var(--pale);border-left:3px solid var(--green);padding:12px 16px;border-radius:5px;margin:16px 0;color:#285f53;overflow-wrap:anywhere}.notice.error{background:#fff0ef;border-color:#bc524a;color:#a43b35}.table,table{width:100%;border-collapse:collapse;font-size:13px}th,td{text-align:left;border-bottom:1px solid var(--line);padding:13px 12px;vertical-align:top;overflow-wrap:anywhere}th{color:var(--muted);background:#f7f9f8;font-size:12px;font-weight:600}td a{font-weight:600}.table-wrap{overflow-x:auto}table{min-width:600px}table table{min-width:0}.page-head,.page-header{display:flex;justify-content:space-between;align-items:start;gap:20px;margin-bottom:24px}.stat,.stat-card{background:white;border:1px solid var(--line);border-radius:12px;padding:20px}.stat strong,.stat-card strong{display:block;font-size:30px;color:var(--green)}.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:16px;margin:22px 0}.actions{display:flex;gap:12px;flex-wrap:wrap;margin:15px 0}.empty{padding:36px;text-align:center;color:var(--muted)}pre{white-space:pre-wrap;overflow-wrap:anywhere}iframe{border:1px solid var(--line);border-radius:10px;max-width:100%}img{max-width:100%}details{margin:14px 0}summary{cursor:pointer;color:var(--green);font-weight:600}input:disabled{opacity:.5;cursor:not-allowed}@media(max-width:800px){.container{padding:25px 16px 45px}.card{padding:20px}.topbar{padding:0 18px;height:70px}.topbar nav{gap:12px}.page-head,.page-header{display:block}.form-row{display:block}}

#MainForm{display:flex;flex-direction:column;min-height:100vh}
.brand{color:var(--ink);font-size:22px;font-weight:650;text-decoration:none}
.brand:hover{text-decoration:none}
.topbar nav>div{display:flex;align-items:center;gap:20px}
.container{width:100%;flex:1;min-height:0}
.login-layout{display:flex;justify-content:center;align-items:center;min-height:calc(100vh - 257px)}
.login-card{width:100%;max-width:400px;padding:34px;margin:0}
.login-card h1{text-align:center;font-size:25px;margin-bottom:28px}
.login-links{display:flex;flex-wrap:wrap;justify-content:center;gap:8px 20px;margin-top:20px;font-size:13px}
footer{border-top:1px solid var(--line);padding:20px 16px;color:#81908e;font-size:12px;text-align:center}
@media(max-width:800px){.brand{font-size:20px}.login-layout{min-height:calc(100vh - 205px)}.login-card{padding:28px 24px}.topbar nav>div{gap:12px}}

/* 管理端布局 */
.admin-nav{display:flex;gap:12px;padding:14px max(5vw,24px);background:#fff;border-bottom:1px solid var(--line)}
.admin-nav a{padding:7px 16px;border-radius:7px;color:var(--muted);font-size:14px}
.admin-nav a.active,.admin-nav a:hover{background:var(--pale);color:var(--green);text-decoration:none}
.editor-layout{display:grid;grid-template-columns:1.05fr 1fr;gap:24px;align-items:start}
.editor-layout .card{margin:0}.settings-section{padding:14px 0;border-bottom:1px solid var(--line);margin-bottom:18px}.settings-section>.form-row{margin-top:18px}.settings-section>span{font-weight:600}
.setting-note{padding:18px;background:#f6f9f8;border-radius:10px;color:var(--muted);font-size:13px}.setting-note p{margin:8px 0 0}
.assignment-tabs{display:flex;gap:8px;border-bottom:1px solid var(--line);margin:0 0 24px;padding-bottom:14px;flex-wrap:wrap}.assignment-tabs a{padding:7px 15px;background:#fff;border:1px solid var(--line);border-radius:7px}
.section-header{display:flex;align-items:center;justify-content:space-between;gap:24px;margin-bottom:18px}.section-header h2{margin-bottom:4px}.section-header p{margin:0}.filter-field{width:160px;flex-shrink:0;margin-bottom:0}.search-box{display:flex;gap:10px;align-items:center}.search-box input[type=text]{margin:0;max-width:240px}.account-card{max-width:560px}.assignment-description{white-space:pre-wrap}th{white-space:nowrap}table{border:0}.admin-summary{margin-bottom:28px}
@media(max-width:900px){.editor-layout{grid-template-columns:1fr}.section-header{align-items:start;flex-direction:column}.admin-nav{padding:12px 16px;gap:6px}.admin-nav a{padding:6px 12px}.search-box{width:100%}.filter-field{width:100%}.editor-layout .card{margin-bottom:0}}
.assignment-tabs a.active{background:var(--pale);border-color:#a8cfc3;color:var(--green);font-weight:600}