/* КолледжОС — общий UI-кит. Подключается во всех модулях: <link rel="stylesheet" href="/_ui/cos.css"> */
:root {
  --cos-bg: #f4f6f9;
  --cos-surface: #ffffff;
  --cos-text: #1d2433;
  --cos-muted: #5f6b7d;
  --cos-border: #dde2ea;
  --cos-primary: #1f5fbf;
  --cos-primary-hover: #184d9c;
  --cos-primary-soft: #e8f0fc;
  --cos-success: #1e8a4c;
  --cos-success-soft: #e5f5ec;
  --cos-warning: #b26a00;
  --cos-warning-soft: #fff4e0;
  --cos-danger: #c62f2f;
  --cos-danger-soft: #fdeaea;
  --cos-radius: 10px;
  --cos-shadow: 0 1px 2px rgba(16, 24, 40, .06), 0 1px 3px rgba(16, 24, 40, .08);
  --cos-font: "Inter", "Segoe UI", Roboto, Arial, sans-serif;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body { font-family: var(--cos-font); font-size: 15px; line-height: 1.5; color: var(--cos-text); background: var(--cos-bg); }
a { color: var(--cos-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3 { line-height: 1.25; margin: 0 0 .6em; }
h1 { font-size: 1.6rem; } h2 { font-size: 1.3rem; } h3 { font-size: 1.1rem; }

/* Шапка */
.cos-header { background: var(--cos-surface); border-bottom: 1px solid var(--cos-border); position: sticky; top: 0; z-index: 50; }
.cos-header-inner { max-width: 1280px; margin: 0 auto; padding: 10px 20px; display: flex; align-items: center; gap: 16px; }
.cos-brand { font-weight: 700; font-size: 1.1rem; color: var(--cos-text); white-space: nowrap; }
.cos-brand span { color: var(--cos-primary); }
.cos-nav { display: flex; gap: 4px; flex-wrap: wrap; flex: 1; }
.cos-nav a { padding: 6px 10px; border-radius: 8px; color: var(--cos-muted); font-size: .9rem; }
.cos-nav a:hover, .cos-nav a.active { background: var(--cos-primary-soft); color: var(--cos-primary); text-decoration: none; }
.cos-user { display: flex; align-items: center; gap: 10px; font-size: .9rem; color: var(--cos-muted); white-space: nowrap; }
.cos-burger { display: none; background: none; border: 1px solid var(--cos-border); border-radius: 8px; padding: 6px 10px; cursor: pointer; }

/* Раскладка */
.cos-container { max-width: 1280px; margin: 0 auto; padding: 24px 20px; }
.cos-layout { display: grid; grid-template-columns: 240px 1fr; gap: 24px; }
.cos-sidebar { background: var(--cos-surface); border: 1px solid var(--cos-border); border-radius: var(--cos-radius); padding: 10px; align-self: start; position: sticky; top: 72px; }
.cos-sidebar a { display: block; padding: 8px 12px; border-radius: 8px; color: var(--cos-text); }
.cos-sidebar a:hover, .cos-sidebar a.active { background: var(--cos-primary-soft); color: var(--cos-primary); text-decoration: none; }
.cos-center { min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 20px; }
.cos-grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); }
.cos-row { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.cos-spacer { flex: 1; }

/* Карточки */
.cos-card { background: var(--cos-surface); border: 1px solid var(--cos-border); border-radius: var(--cos-radius); padding: 20px; box-shadow: var(--cos-shadow); }
.cos-card + .cos-card { margin-top: 16px; }
.cos-tile { display: block; background: var(--cos-surface); border: 1px solid var(--cos-border); border-radius: var(--cos-radius); padding: 18px; color: var(--cos-text); transition: border-color .15s, box-shadow .15s; }
.cos-tile:hover { border-color: var(--cos-primary); box-shadow: var(--cos-shadow); text-decoration: none; }
.cos-tile h3 { margin-bottom: 4px; }
.cos-tile p { margin: 0; color: var(--cos-muted); font-size: .9rem; }
.cos-stat { font-size: 1.8rem; font-weight: 700; }
.cos-muted { color: var(--cos-muted); }

/* Формы */
.cos-field { display: flex; flex-direction: column; gap: 4px; margin-bottom: 14px; }
.cos-field label { font-size: .85rem; font-weight: 600; color: var(--cos-muted); }
input, select, textarea { font: inherit; color: inherit; padding: 9px 12px; border: 1px solid var(--cos-border); border-radius: 8px; background: #fff; width: 100%; }
input:focus, select:focus, textarea:focus { outline: 2px solid var(--cos-primary-soft); border-color: var(--cos-primary); }
input[type=checkbox], input[type=radio] { width: auto; }
textarea { min-height: 90px; resize: vertical; }

/* Кнопки */
.cos-btn { display: inline-flex; align-items: center; justify-content: center; gap: 6px; font: inherit; font-weight: 600; padding: 9px 16px; border-radius: 8px; border: 1px solid var(--cos-primary); background: var(--cos-primary); color: #fff; cursor: pointer; white-space: nowrap; }
.cos-btn:hover { background: var(--cos-primary-hover); text-decoration: none; }
.cos-btn:disabled { opacity: .55; cursor: not-allowed; }
.cos-btn-secondary { background: #fff; color: var(--cos-primary); }
.cos-btn-secondary:hover { background: var(--cos-primary-soft); }
.cos-btn-danger { background: var(--cos-danger); border-color: var(--cos-danger); }
.cos-btn-sm { padding: 5px 10px; font-size: .85rem; }

/* Таблицы */
.cos-table-wrap { overflow-x: auto; }
table.cos-table { width: 100%; border-collapse: collapse; background: var(--cos-surface); }
.cos-table th, .cos-table td { text-align: left; padding: 9px 12px; border-bottom: 1px solid var(--cos-border); vertical-align: top; }
.cos-table th { font-size: .8rem; text-transform: uppercase; letter-spacing: .02em; color: var(--cos-muted); background: #fafbfc; }
.cos-table tr:hover td { background: #fafcff; }

/* Метки и сообщения */
.cos-badge { display: inline-block; padding: 2px 8px; border-radius: 999px; font-size: .78rem; font-weight: 600; background: var(--cos-primary-soft); color: var(--cos-primary); }
.cos-badge.success { background: var(--cos-success-soft); color: var(--cos-success); }
.cos-badge.warning { background: var(--cos-warning-soft); color: var(--cos-warning); }
.cos-badge.danger { background: var(--cos-danger-soft); color: var(--cos-danger); }
.cos-badge.muted { background: #eef0f3; color: var(--cos-muted); }
.cos-alert { padding: 12px 14px; border-radius: 8px; margin-bottom: 14px; background: var(--cos-primary-soft); color: var(--cos-primary); }
.cos-alert.error { background: var(--cos-danger-soft); color: var(--cos-danger); }
.cos-alert.success { background: var(--cos-success-soft); color: var(--cos-success); }
.cos-alert.warning { background: var(--cos-warning-soft); color: var(--cos-warning); }

/* Модальное окно */
.cos-modal-back { position: fixed; inset: 0; background: rgba(16, 24, 40, .45); display: flex; align-items: center; justify-content: center; z-index: 100; padding: 16px; }
.cos-modal { background: #fff; border-radius: 12px; max-width: 640px; width: 100%; max-height: 90vh; overflow: auto; padding: 22px; }
.cos-toast { position: fixed; right: 20px; bottom: 20px; background: var(--cos-text); color: #fff; padding: 12px 16px; border-radius: 8px; z-index: 200; box-shadow: var(--cos-shadow); }
.cos-pager { display: flex; gap: 6px; align-items: center; margin-top: 12px; }

@media (max-width: 860px) {
  .cos-layout { grid-template-columns: 1fr; }
  .cos-sidebar { position: static; }
  .cos-burger { display: inline-block; }
  .cos-nav { display: none; position: absolute; top: 56px; left: 0; right: 0; background: #fff; flex-direction: column; padding: 10px; border-bottom: 1px solid var(--cos-border); }
  .cos-nav.open { display: flex; }
  .cos-user .cos-user-name { display: none; }
  .cos-brand { min-width: 0; flex: 1; overflow: hidden; text-overflow: ellipsis; }
  .cos-container { padding: 16px 12px; }
}