:root {
    --bg: #f4f6f8;
    --panel: #ffffff;
    --text: #182230;
    --muted: #667085;
    --line: #d9e0e8;
    --primary: #1769aa;
    --primary-dark: #0f4d7f;
    --success: #16794f;
    --danger: #b42318;
    --warning: #b54708;
}

* { box-sizing: border-box; }
body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font-family: Arial, "Microsoft YaHei", sans-serif;
    font-size: 14px;
}
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; }

.app-shell { display: flex; min-height: 100vh; }
.sidebar {
    width: 232px;
    background: #111827;
    color: #e5e7eb;
    padding: 20px 14px;
    display: flex;
    flex-direction: column;
    gap: 18px;
}
.brand { font-size: 20px; font-weight: 700; padding: 4px 8px; }
.user-chip {
    border: 1px solid rgba(255,255,255,.12);
    border-radius: 8px;
    padding: 10px;
    display: grid;
    gap: 4px;
}
.user-chip span { color: #9ca3af; font-size: 12px; }
.nav { display: grid; gap: 4px; }
.nav a {
    padding: 10px 12px;
    border-radius: 6px;
    color: #d1d5db;
}
.nav a:hover, .nav a.active { background: #1f2937; color: #fff; }
.logout-form { margin-top: auto; }
.logout-form button {
    width: 100%;
    border: 1px solid rgba(255,255,255,.15);
    background: transparent;
    color: #e5e7eb;
    border-radius: 6px;
    padding: 10px;
    cursor: pointer;
}
.main { flex: 1; padding: 24px; min-width: 0; }
.topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 18px;
}
.topbar h1 { margin: 0; font-size: 24px; }
.balance {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 9px 12px;
    font-weight: 700;
}
.grid { display: grid; gap: 14px; margin-bottom: 16px; }
.cards-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.cards-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.card, .panel {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: 8px;
}
.card { padding: 16px; }
.stat { display: grid; gap: 8px; }
.stat span { color: var(--muted); }
.stat strong { font-size: 28px; }
.panel { padding: 18px; margin-bottom: 16px; }
.panel-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 14px;
}
.panel-head h2 { margin: 0; font-size: 18px; }
.panel-subtitle { margin: 5px 0 0; color: var(--muted); }
.actions { display: flex; flex-wrap: wrap; gap: 10px; }
.button, button {
    border: 1px solid var(--line);
    background: #fff;
    color: var(--text);
    border-radius: 6px;
    padding: 9px 12px;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 38px;
}
.button.primary, button.primary {
    background: var(--primary);
    border-color: var(--primary);
    color: #fff;
}
.button.primary:hover, button.primary:hover { background: var(--primary-dark); }
.full { width: 100%; }
.alert {
    border-radius: 8px;
    padding: 11px 12px;
    margin-bottom: 14px;
    border: 1px solid var(--line);
    background: #fff;
}
.alert.error { border-color: #fecdca; color: var(--danger); background: #fffbfa; }
.alert.success { border-color: #abefc6; color: var(--success); background: #f6fef9; }
.alert.warning { border-color: #fedf89; color: var(--warning); background: #fffcf5; }
.floating { position: fixed; top: 16px; left: 50%; transform: translateX(-50%); z-index: 3; }

.login-page {
    min-height: 100vh;
    display: grid;
    place-items: center;
    padding: 24px;
    background: #eef2f6;
}
.login-card {
    width: min(420px, 100%);
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 28px;
    display: grid;
    gap: 16px;
    box-shadow: 0 16px 50px rgba(16, 24, 40, .08);
}
.login-title h1 { margin: 0 0 6px; font-size: 26px; }
.login-title p { margin: 0; color: var(--muted); }
label { display: grid; gap: 6px; color: var(--muted); }
input, select, textarea {
    width: 100%;
    border: 1px solid var(--line);
    border-radius: 6px;
    padding: 9px 10px;
    background: #fff;
    color: var(--text);
}
textarea { min-height: 90px; resize: vertical; }
.form-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
.upstream-form { display: grid; gap: 14px; }
.form-row { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.options-row { grid-template-columns: 1fr 1fr 1fr; }
.segmented,
.toggle-line {
    min-height: 38px;
    display: flex;
    align-items: center;
    gap: 10px;
    border: 1px solid var(--line);
    border-radius: 6px;
    background: #fff;
    padding: 7px 10px;
    color: var(--text);
}
.segmented label,
.toggle-line {
    display: flex;
    align-items: center;
    gap: 8px;
}
.segmented input,
.toggle-line input { width: auto; }
.order-actions { align-items: center; margin-top: 2px; }
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; background: #fff; }
th, td { border-bottom: 1px solid var(--line); padding: 10px; text-align: left; vertical-align: top; }
th { color: var(--muted); font-weight: 600; background: #f8fafc; }
.badge { display: inline-flex; border-radius: 999px; padding: 3px 8px; background: #eef2f6; color: var(--muted); font-size: 12px; }
.badge.ok { background: #dcfae6; color: var(--success); }
.badge.bad { background: #fee4e2; color: var(--danger); }
.course-list { display: grid; gap: 8px; max-height: 440px; overflow: auto; border: 1px solid var(--line); border-radius: 8px; padding: 10px; }
.course-list-collapsed { max-height: 260px; }
.course-item { display: flex; gap: 8px; align-items: flex-start; color: var(--text); }
.course-item input { width: auto; margin-top: 3px; }
.course-toolbar {
    display: grid;
    grid-template-columns: minmax(220px, 1fr) auto auto;
    gap: 10px;
    margin-bottom: 12px;
}
.muted { color: var(--muted); }
.row-actions { display: flex; gap: 8px; flex-wrap: wrap; }
.stack-form { display: grid; gap: 8px; min-width: 220px; }
.inline-edit {
    display: grid;
    grid-template-columns: minmax(140px, 1fr) auto;
    gap: 8px;
}
.inline-edit input { min-width: 0; }
.price-levels { display: grid; gap: 8px; margin-top: 4px; }
.price-level-row {
    display: grid;
    grid-template-columns: 1.2fr 1fr 1fr .8fr .9fr;
    gap: 8px;
    align-items: center;
}
.price-level-head {
    color: var(--muted);
    font-weight: 600;
    padding: 0 2px;
}
.price-preview {
    min-height: 38px;
    border: 1px solid var(--line);
    border-radius: 6px;
    background: #f8fafc;
    display: flex;
    align-items: center;
    padding: 9px 10px;
}

@media (max-width: 900px) {
    .app-shell { display: block; }
    .sidebar { width: 100%; min-height: auto; }
    .cards-3, .cards-4, .form-grid, .form-row, .options-row, .course-toolbar, .price-level-row { grid-template-columns: 1fr; }
    .price-level-head { display: none; }
    .main { padding: 16px; }
}