:root { color-scheme: light; --ink:#17212b; --muted:#66717d; --line:#dfe5e8; --panel:#fff; --bg:#f3f6f5; --brand:#0f766e; --brand-dark:#0b5f59; --soft:#dff2ef; --danger:#b42318; --shadow:0 18px 50px rgba(24,42,40,.09); font-family:"Microsoft YaHei UI","PingFang SC",system-ui,sans-serif; }
* { box-sizing:border-box; }
body { margin:0; min-width:320px; color:var(--ink); background:var(--bg); }
a { color:var(--brand); text-decoration:none; }
button,input,select { font:inherit; }
.muted { color:var(--muted); }
.eyebrow { margin:0 0 8px; color:var(--brand); font-size:12px; font-weight:800; letter-spacing:.16em; text-transform:uppercase; }
.auth-shell { min-height:100vh; display:grid; place-items:center; padding:24px; background:radial-gradient(circle at 18% 12%,#d7eeea 0,transparent 34%),linear-gradient(135deg,#f8fbfa,#edf3f2); }
.auth-card { width:min(420px,100%); padding:44px; border:1px solid rgba(255,255,255,.9); border-radius:24px; background:rgba(255,255,255,.92); box-shadow:var(--shadow); backdrop-filter:blur(12px); }
.auth-card h1 { margin:0; font-size:30px; }
.auth-card>.muted { margin:8px 0 26px; }
.auth-form { display:grid; gap:18px; }
label { display:grid; gap:7px; color:#34404b; font-size:13px; font-weight:700; }
input,select { width:100%; min-height:42px; padding:9px 11px; color:var(--ink); border:1px solid #cdd6da; border-radius:10px; background:#fff; outline:none; transition:.15s border,.15s box-shadow; }
input:focus,select:focus { border-color:var(--brand); box-shadow:0 0 0 3px rgba(15,118,110,.12); }
input[readonly] { background:#f1f4f4; color:#58636d; }
.button { min-height:40px; padding:9px 16px; border:1px solid transparent; border-radius:10px; cursor:pointer; font-weight:750; transition:.15s transform,.15s background,.15s border; }
.button:hover { transform:translateY(-1px); }
.button:disabled { cursor:wait; opacity:.65; transform:none; }
.button.primary { color:#fff; background:var(--brand); }
.button.primary:hover { background:var(--brand-dark); }
.button.secondary { color:#2e3c43; border-color:#cad4d7; background:#fff; }
.button.secondary:hover { border-color:#9cafb2; background:#f8faf9; }
.wide { width:100%; margin-top:4px; }
.alert { margin:0 0 18px; padding:11px 13px; border-radius:10px; background:#fef3f2; color:var(--danger); font-size:14px; }
.topbar { height:66px; display:flex; align-items:center; justify-content:space-between; padding:0 clamp(18px,4vw,56px); border-bottom:1px solid var(--line); background:rgba(255,255,255,.94); position:sticky; top:0; z-index:20; backdrop-filter:blur(12px); }
.brand { display:flex; align-items:center; gap:10px; color:var(--ink); font-weight:800; }
.account { display:flex; align-items:center; gap:16px; color:var(--muted); font-size:14px; }
.account form { display:inline; }
.link-button { padding:0; color:var(--brand); border:0; background:transparent; cursor:pointer; }
.dashboard-shell { width:min(960px,calc(100% - 36px)); margin:70px auto; }
.welcome h1 { margin:0; font-size:clamp(28px,4vw,42px); }
.welcome .muted { margin:12px 0 38px; }
.feature-grid { display:grid; grid-template-columns:repeat(2,minmax(0,1fr)); gap:18px; }
.feature-card { display:grid; grid-template-columns:1fr auto; align-items:center; gap:22px; padding:28px; color:var(--ink); border:1px solid var(--line); border-radius:20px; background:var(--panel); box-shadow:0 8px 28px rgba(28,50,48,.06); transition:.2s transform,.2s box-shadow,.2s border; }
.feature-card:hover { transform:translateY(-3px); border-color:#a9ccc7; box-shadow:var(--shadow); }
.feature-card h2 { margin:0 0 7px; font-size:23px; }
.feature-card p { margin:0; color:var(--muted); }
.arrow { color:var(--brand); font-size:28px; }
.app-shell { width:min(1540px,calc(100% - 32px)); margin:28px auto 48px; }
.page-heading { display:flex; justify-content:space-between; align-items:flex-end; gap:24px; margin-bottom:18px; }
.page-heading h1 { margin:0; font-size:30px; }
.page-heading .muted { margin:6px 0 0; }
.toolbar { display:flex; align-items:end; justify-content:flex-end; flex-wrap:wrap; gap:9px; }
.strategy-options { display:flex; align-items:center; gap:12px; min-height:40px; margin:0 4px 0 0; padding:7px 12px; border:1px solid #cad4d7; border-radius:10px; background:#fff; }
.strategy-options legend { padding:0 4px; color:#66717d; font-size:11px; font-weight:750; }
.strategy-check { display:flex; grid-template-columns:none; align-items:center; gap:6px; cursor:pointer; white-space:nowrap; }
.strategy-check input { width:16px; min-height:16px; height:16px; margin:0; accent-color:var(--brand); box-shadow:none; }
.strategy-check span { color:#34404b; font-size:13px; font-weight:750; }
.threshold { display:grid; grid-template-columns:96px 74px 20px; align-items:center; gap:6px; }
.threshold input { min-height:40px; }
.status-message { max-height:0; overflow:hidden; opacity:0; padding:0 14px; border-radius:10px; transition:.2s; }
.status-message.visible { max-height:100px; opacity:1; padding:11px 14px; margin-bottom:14px; color:#176052; background:#e4f4f0; }
.status-message.visible.error { color:var(--danger); background:#fef0ef; }
.workspace-grid { display:grid; grid-template-columns:minmax(620px,1.4fr) minmax(430px,1fr); gap:16px; align-items:start; }
.first-grade-grid { grid-template-columns:minmax(720px,1.55fr) minmax(470px,1fr); }
.right-column { display:grid; gap:16px; }
.panel { border:1px solid var(--line); border-radius:16px; background:var(--panel); box-shadow:0 5px 20px rgba(25,46,43,.04); overflow:hidden; }
.panel-title { min-height:60px; display:flex; align-items:center; justify-content:space-between; gap:14px; padding:13px 16px; border-bottom:1px solid var(--line); }
.panel-title>div { display:flex; align-items:center; gap:9px; }
.panel-title h2 { margin:0; font-size:17px; }
.badge { min-width:28px; padding:3px 7px; color:var(--brand); border-radius:999px; background:var(--soft); font-size:12px; text-align:center; }
.search { grid-template-columns:auto minmax(150px,220px); align-items:center; }
.search input { min-height:36px; }
.table-wrap { overflow:auto; }
.student-table-wrap { height:708px; }
table { width:100%; border-collapse:collapse; font-size:13px; white-space:nowrap; }
th { position:sticky; top:0; z-index:2; padding:10px 11px; color:#5b6871; border-bottom:1px solid var(--line); background:#f7f9f9; text-align:left; font-size:12px; }
td { padding:10px 11px; border-bottom:1px solid #edf0f1; }
tbody tr { transition:.12s background; }
#studentRows tr:not(:has(.empty)) { cursor:pointer; }
tbody tr:hover { background:#f2f8f7; }
tbody tr.selected { background:#e2f2ef; box-shadow:inset 3px 0 var(--brand); }
.empty { padding:40px; color:var(--muted); text-align:center; }
.student-form { padding:15px; }
.student-form fieldset { display:grid; grid-template-columns:repeat(3,1fr); gap:12px; margin:0; padding:0; border:0; }
.student-form fieldset:disabled { opacity:.55; }
.student-form .wide-field { grid-column:span 2; }
.sync-status { flex:0 0 auto; padding:4px 8px; border-radius:999px; color:#49615d; background:#edf3f2; font-size:12px; font-weight:700; }
.sync-status.pending,.sync-status.saving { color:#806000; background:#fff4cc; }
.sync-status.saved { color:#176052; background:#e1f3ef; }
.sync-status.error { color:var(--danger); background:#fef0ef; }
.metrics-panel table { text-align:center; }
.metrics-panel th { text-align:center; }
.spread-summary { margin:0; padding:12px 15px; color:#47545d; border-top:1px solid var(--line); background:#fbfcfc; font-size:13px; }
@media (max-width:1120px) { .page-heading { align-items:flex-start; flex-direction:column; } .toolbar { justify-content:flex-start; } .workspace-grid { grid-template-columns:1fr; } .student-table-wrap { height:460px; } }
@media (max-width:680px) { .topbar { padding:0 14px; } .account>span { display:none; } .app-shell { width:min(100% - 18px,1540px); margin-top:18px; } .toolbar { width:100%; } .toolbar .button { flex:1 1 44%; } .threshold { width:100%; grid-template-columns:1fr 90px 20px; } .student-form fieldset { grid-template-columns:1fr 1fr; } .student-form .wide-field { grid-column:span 2; } .auth-card { padding:32px 25px; } .feature-grid { grid-template-columns:1fr; } .feature-card { grid-template-columns:1fr; } .feature-card .arrow { display:none; } }