:root {
  --navy: #16314d;
  --navy-dark: #0f2136;
  --paper: #f7f5ef;
  --paper-panel: #ffffff;
  --ink: #1c2b3a;
  --ink-dim: #6b7c8c;
  --rule: #dfe3e8;
  --amber: #d98c2b;
  --teal: #2f8f83;
  --green: #4c9a52;
  --orange: #cf7e21;
  --yellow: #c9ab1f;
  --blue: #3a86c8;
  --red: #c24b45;
  --font: "Segoe UI", "PT Sans", Arial, sans-serif;
}
* { box-sizing: border-box; }
body { margin: 0; font-family: var(--font); background: var(--paper); color: var(--ink); }
.hidden { display: none !important; }
button { font-family: inherit; cursor: pointer; }
input, select { font-family: inherit; }

/* ---------- login ---------- */
.login-screen { min-height: 100vh; display: flex; align-items: center; justify-content: center; background: var(--navy-dark); }
.login-card { background: var(--paper-panel); padding: 32px 36px; border-radius: 10px; width: 320px; display: flex; flex-direction: column; gap: 12px; box-shadow: 0 10px 30px rgba(0,0,0,0.3); }
.login-card h1 { font-size: 18px; margin: 0 0 8px; color: var(--navy); }
.login-card label { display: flex; flex-direction: column; gap: 4px; font-size: 13px; color: var(--ink-dim); }
.login-card input { padding: 8px 10px; border: 1px solid var(--rule); border-radius: 6px; font-size: 14px; }
.login-card button { margin-top: 8px; padding: 10px; border: none; border-radius: 6px; background: var(--navy); color: #fff; font-weight: 600; }
.error-text { color: var(--red); font-size: 13px; min-height: 1.2em; }

/* ---------- layout ---------- */
.topbar { display: flex; align-items: center; gap: 24px; background: var(--navy); color: #fff; padding: 10px 20px; }
.topbar__title { font-weight: 700; letter-spacing: 0.02em; }
.tabs { display: flex; gap: 4px; flex: 1; }
.tab { background: transparent; border: none; color: rgba(255,255,255,0.7); padding: 8px 14px; border-radius: 6px; font-size: 14px; }
.tab.active { background: rgba(255,255,255,0.15); color: #fff; font-weight: 600; }
.topbar__user { display: flex; align-items: center; gap: 10px; font-size: 13px; color: rgba(255,255,255,0.85); }

.tab-panel { padding: 20px; }

.toolbar { display: flex; align-items: center; gap: 14px; margin-bottom: 14px; flex-wrap: wrap; }
.toolbar label { font-size: 14px; color: var(--ink-dim); display: flex; align-items: center; gap: 6px; }
.toolbar input[type=date], .toolbar select { padding: 7px 10px; border: 1px solid var(--rule); border-radius: 6px; }
.hint { font-size: 12px; color: var(--ink-dim); }
.badge-text { font-size: 13px; color: var(--teal); font-weight: 600; }

.btn { padding: 8px 14px; border-radius: 6px; border: 1px solid var(--navy); background: var(--paper-panel); color: var(--navy); font-size: 13px; font-weight: 600; }
.btn:hover { background: var(--navy); color: #fff; }
.btn--primary { background: var(--navy); color: #fff; }
.btn--primary:hover { opacity: 0.85; }
.btn--ghost { border-color: transparent; color: var(--ink-dim); }
.btn--ghost:hover { background: rgba(0,0,0,0.06); color: var(--ink); }
.btn--danger { border-color: var(--red); color: var(--red); }
.btn--danger:hover { background: var(--red); color: #fff; }

/* ---------- conflicts ---------- */
.conflicts-box { background: #fdecea; border: 1px solid var(--red); color: #7a2b26; padding: 10px 14px; border-radius: 6px; margin-bottom: 12px; font-size: 13px; }
.conflicts-box b { display: block; margin-bottom: 4px; }

/* ---------- editable grid ---------- */
.editor-layout { display: flex; gap: 16px; align-items: flex-start; }
.grid-scroll { flex: 1; overflow: auto; max-height: 60vh; border: 1px solid var(--rule); border-radius: 8px; background: var(--paper-panel); }
.edit-grid { border-collapse: collapse; width: 100%; font-size: 13px; }
.edit-grid th, .edit-grid td { border: 1px solid var(--rule); padding: 6px 8px; text-align: center; }
.edit-grid thead th { background: var(--navy); color: #fff; position: sticky; top: 0; z-index: 1; }
.edit-grid tbody th { background: #eef1f4; }
.edit-grid td { cursor: pointer; min-width: 90px; }
.edit-grid td:hover { outline: 2px solid var(--navy); outline-offset: -2px; }
.edit-grid .cell-subject { font-weight: 600; display: block; }
.edit-grid .cell-meta { color: var(--ink-dim); font-size: 11px; }
.edit-grid td.c-teacher { background: rgba(76,154,82,0.18); }
.edit-grid td.c-room { background: rgba(207,126,33,0.18); }
.edit-grid td.c-split { background: rgba(201,171,31,0.18); }
.edit-grid td.c-attention { background: rgba(58,134,200,0.18); }
.edit-grid td.c-cancelled .cell-subject { text-decoration: line-through; color: var(--red); }

.edit-panel { width: 300px; background: var(--paper-panel); border: 1px solid var(--rule); border-radius: 8px; padding: 16px; position: sticky; top: 12px; }
.edit-panel h3 { margin: 0 0 10px; font-size: 15px; }
.edit-panel label { display: block; font-size: 12px; color: var(--ink-dim); margin-top: 10px; }
.edit-panel input, .edit-panel select { width: 100%; padding: 7px 8px; border: 1px solid var(--rule); border-radius: 6px; margin-top: 3px; font-size: 13px; }
.edit-panel .checkbox-row { display: flex; align-items: center; gap: 6px; margin-top: 10px; }
.edit-panel .checkbox-row input { width: auto; margin: 0; }
.edit-panel .actions { display: flex; gap: 8px; margin-top: 16px; }
.edit-panel fieldset { border: 1px dashed var(--rule); border-radius: 6px; margin-top: 12px; padding: 8px; }
.edit-panel legend { font-size: 11px; color: var(--ink-dim); padding: 0 4px; }

/* ---------- data tables (subs, zameny files, refs) ---------- */
.subs-section { margin-top: 24px; }
.subs-section__head { display: flex; align-items: center; justify-content: space-between; }
.data-table { width: 100%; border-collapse: collapse; margin-top: 10px; font-size: 13px; background: var(--paper-panel); }
.data-table th, .data-table td { border: 1px solid var(--rule); padding: 6px 8px; text-align: left; }
.data-table th { background: #eef1f4; }
.data-table tr.row-yellow td { background: #fff2a6; }
.data-table tr.row-red td { background: #f4a6a6; }
.data-table td input[type=date] { padding: 4px 6px; border: 1px solid var(--rule); border-radius: 4px; }

/* ---------- reference lists ---------- */
.refs-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.ref-col { background: var(--paper-panel); border: 1px solid var(--rule); border-radius: 8px; padding: 14px; }
.ref-col h2 { font-size: 14px; margin: 0 0 10px; }
.ref-list { max-height: 40vh; overflow: auto; display: flex; flex-direction: column; gap: 4px; margin-bottom: 10px; }
.ref-item { display: flex; align-items: center; justify-content: space-between; gap: 6px; padding: 4px 6px; border-radius: 4px; font-size: 13px; }
.ref-item:hover { background: #f0f2f4; }
.ref-item button { background: none; border: none; color: var(--ink-dim); font-size: 15px; }
.ref-item button:hover { color: var(--red); }
.ref-add { display: flex; gap: 6px; }
.ref-add input { flex: 1; padding: 6px 8px; border: 1px solid var(--rule); border-radius: 6px; }
.ref-add button { padding: 6px 10px; border-radius: 6px; border: 1px solid var(--navy); background: var(--paper-panel); color: var(--navy); font-size: 12px; }

.settings-form { display: flex; align-items: center; gap: 12px; }
.settings-form input { padding: 8px 10px; border: 1px solid var(--rule); border-radius: 6px; }

@media (max-width: 1000px) {
  .editor-layout { flex-direction: column; }
  .edit-panel { width: 100%; position: static; }
  .refs-grid { grid-template-columns: 1fr 1fr; }
}