:root {
  color-scheme: light dark;
  --bg: #f3f4f6; --card: #ffffff; --thead: #f2f2f2; --text: #1f2328; --muted: #646b76; --line: #dcdfe4;
  --accent: #1a66d6; --on-accent: #ffffff; --danger: #c62828; --ok: #1b7f3b; --warn: #b45f06; --now: #0b7285;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #111214; --card: #1a1c1f; --thead: #25282c; --text: #e7e9ec; --muted: #9aa1ab; --line: #2e3238;
    --accent: #7cacf8; --on-accent: #0b1220; --danger: #ff8a80; --ok: #6fdc8c; --warn: #f2b84b; --now: #5ccfe6; }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--text);
  font: 16px/1.55 Calibri, "Segoe UI", system-ui, -apple-system, Roboto, sans-serif; }
main { max-width: 1040px; margin: 0 auto; padding: 8px 16px 64px; }
h1 { margin: 20px 0 2px; font-size: 1.9rem; line-height: 1.2; }
h2 { margin: 24px 0 12px; font-size: 1.3rem; }
h3 { margin: 0; font-size: 1.05rem; }
p { margin: 6px 0; }
a { color: var(--accent); }
.muted { color: var(--muted); } .small { font-size: .82rem; }
.byline { margin: 0 0 16px; font-style: italic; color: var(--muted); }
.text { white-space: pre-wrap; overflow-wrap: anywhere; }
.empty { padding: 24px 0; text-align: center; color: var(--muted); }

.top { display: flex; justify-content: flex-end; align-items: center; gap: 12px; padding: 8px 16px;
  max-width: 1040px; margin: 0 auto; }
.right { display: flex; align-items: center; gap: 12px; }
.top .muted { margin-right: auto; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* Tabs: one per section of the doc */
.tabs { display: flex; gap: 4px; overflow-x: auto; border-bottom: 1px solid var(--line); scrollbar-width: none; }
.tabs::-webkit-scrollbar { display: none; }
.tab { flex: none; padding: 10px 16px; font: inherit; font-weight: 600; color: var(--muted); background: none;
  border: 0; border-bottom: 3px solid transparent; margin-bottom: -1px; cursor: pointer; }
.tab:hover { color: var(--text); }
.tab.active { color: var(--accent); border-bottom-color: var(--accent); }

/* The Classroom table, same look as the doc: grey header row, thin borders */
.table-wrap { overflow-x: auto; background: var(--card); border: 1px solid var(--line); border-radius: 10px; }
table.doc { width: 100%; border-collapse: collapse; font-size: .95rem; }
table.doc th, table.doc td { padding: 10px 12px; text-align: left; vertical-align: top; border: 1px solid var(--line); }
table.doc th { background: var(--thead); font-weight: 700; white-space: nowrap; }
table.doc tr > :first-child { border-left: 0; } table.doc tr > :last-child { border-right: 0; }
table.doc thead tr:first-child th { border-top: 0; } table.doc tbody tr:last-child td { border-bottom: 0; }

.card { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 14px 16px; }
.grid { display: grid; gap: 12px; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); }
.stack { display: flex; flex-direction: column; margin-top: 12px; }
.row { display: flex; justify-content: space-between; align-items: center; gap: 8px; }

form { display: flex; flex-direction: column; gap: 10px; }
input, textarea, select { width: 100%; padding: 10px 12px; font: inherit; color: var(--text); background: var(--bg);
  border: 1px solid var(--line); border-radius: 8px; }
input:focus, textarea:focus, select:focus { outline: 2px solid var(--accent); outline-offset: -1px; }
.field { display: flex; flex-direction: column; gap: 4px; }
.btn { display: inline-block; padding: 9px 16px; font: inherit; font-weight: 600; text-decoration: none; text-align: center;
  border: 1px solid var(--accent); border-radius: 8px; cursor: pointer; background: var(--accent); color: var(--on-accent); }
.btn:disabled { opacity: .6; cursor: wait; }
.btn.ghost { background: transparent; color: var(--text); border-color: var(--line); padding: 7px 12px; }
.btn.danger { background: transparent; color: var(--danger); border-color: var(--danger); padding: 6px 12px; }
.link { color: var(--accent); background: none; border: 0; font: inherit; cursor: pointer; text-decoration: none; }
.link:hover { text-decoration: underline; }
.actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
.error { color: var(--danger); font-size: .9rem; margin: 0; }
.error:empty { display: none; }
.ok { color: var(--ok); font-weight: 600; }
details.add { margin-bottom: 20px; }
details.add summary { cursor: pointer; font-weight: 600; }
details.add form { margin-top: 12px; }

.auth { max-width: 400px; padding-top: 12vh; text-align: center; }
.auth .card { text-align: left; margin: 16px 0; }
.seg { display: grid; grid-template-columns: 1fr 1fr; gap: 4px; padding: 4px; margin-bottom: 14px;
  background: var(--bg); border-radius: 10px; }
.seg-btn { padding: 8px; font: inherit; font-weight: 600; color: var(--muted); background: none; border: 0;
  border-radius: 8px; cursor: pointer; }
.seg-btn.active { background: var(--card); color: var(--text); box-shadow: 0 0 0 1px var(--line); }

.comment { padding: 12px 2px; border-bottom: 1px solid var(--line); }

/* Task status colours. The class changes by itself when the time passes. */
.task { border-left: 5px solid var(--accent); }
.badge { padding: 2px 10px; border-radius: 99px; font-size: .75rem; font-weight: 700; white-space: nowrap; }
.badge.upcoming { background: color-mix(in srgb, var(--accent) 15%, transparent); color: var(--accent); }
.task.soon { border-left-color: var(--warn); }
.badge.soon { background: color-mix(in srgb, var(--warn) 18%, transparent); color: var(--warn); }
.task.now { border-left-color: var(--now); }
.badge.now { background: color-mix(in srgb, var(--now) 18%, transparent); color: var(--now); }
.task.done { border-left-color: var(--ok); background: color-mix(in srgb, var(--ok) 7%, var(--card)); }
.task.done h3 { opacity: .65; }
.badge.done { background: color-mix(in srgb, var(--ok) 18%, transparent); color: var(--ok); }

/* Phones: each table row becomes a labelled block */
@media (max-width: 760px) {
  main { padding: 4px 12px 48px; }
  .table-wrap { background: none; border: 0; overflow: visible; }
  table.doc, table.doc tbody, table.doc tr, table.doc td { display: block; width: 100%; }
  table.doc thead { display: none; }
  table.doc tr { margin-bottom: 12px; padding: 6px 14px; background: var(--card); border: 1px solid var(--line); border-radius: 10px; }
  table.doc td { display: flex; justify-content: space-between; gap: 16px; padding: 7px 0; border: 0; text-align: right;
    overflow-wrap: anywhere; }
  table.doc td + td { border-top: 1px solid var(--line); }
  table.doc td::before { content: attr(data-label); flex: none; color: var(--muted); font-size: .8rem; text-align: left; }
  table.doc td:first-child { font-weight: 700; }
}

/* Google sign-in and password reset */
.wide { width: 100%; padding: 10px 16px; }
.or { display: flex; align-items: center; gap: 10px; margin: 14px 0; color: var(--muted); font-size: .85rem; }
.or::before, .or::after { content: ""; flex: 1; height: 1px; background: var(--line); }
.forgot { align-self: flex-start; padding: 0; }
.ok:empty { display: none; }

/* Checkbox rows, JSON import */
.check { display: flex; align-items: flex-start; gap: 10px; cursor: pointer; }
.check input { width: auto; flex: none; margin-top: 4px; accent-color: var(--accent); }
.json-import { display: flex; flex-direction: column; gap: 12px; }
.json-import > p, .json-import > h3 { margin: 0; }
.drop { padding: 18px 16px; text-align: center; border: 2px dashed var(--line); border-radius: 10px; background: var(--bg); }
.drop.over { border-color: var(--accent); background: color-mix(in srgb, var(--accent) 8%, var(--bg)); }
.drop p { margin: 0 0 10px; color: var(--muted); }
.drop input { background: var(--card); }
.files { margin: 0; }
.file-row { display: flex; justify-content: space-between; align-items: center; gap: 12px; padding: 10px 2px; border-bottom: 1px solid var(--line); }
.file-row .fname { overflow-wrap: anywhere; }
.problems summary { cursor: pointer; font-weight: 600; }
.problems ul { margin: 8px 0 0; padding-left: 20px; }
.problems pre { margin: 10px 0; padding: 12px; overflow-x: auto; font-size: .8rem; line-height: 1.45; background: var(--bg);
  border: 1px solid var(--line); border-radius: 8px; }
.sum table.doc td:not(:first-child), .sum table.doc th:not(:first-child) { text-align: right; }

/* Rescheduled (set by hand) and the admin status picker */
:root { --resched: #7b4fd6; }
@media (prefers-color-scheme: dark) { :root { --resched: #b79bff; } }
.task.rescheduled { border-left-color: var(--resched); }
.badge.rescheduled { background: color-mix(in srgb, var(--resched) 18%, transparent); color: var(--resched); }
.status-select { width: auto; padding: 7px 10px; }
.field > .muted { font-weight: 600; }