/* ENGG4059 autograder — hand-written stylesheet, no build step. */

:root {
  --bg: #f5f6f8;
  --panel: #ffffff;
  --ink: #16181d;
  --muted: #6b7280;
  --line: #e3e6ea;
  --line-strong: #cfd4da;
  --accent: #1f5fd0;
  --accent-soft: #e8f0fd;
  --good: #147d52;
  --good-soft: #e4f4ec;
  --warn: #9a6206;
  --warn-soft: #fdf1dc;
  --bad: #b3261e;
  --bad-soft: #fbe9e8;
  --sidebar: #171a21;
  --sidebar-ink: #aeb6c2;
  --sidebar-active: #ffffff;
  --radius: 10px;
  --shadow: 0 1px 2px rgba(16, 24, 40, .06), 0 1px 3px rgba(16, 24, 40, .1);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font: 15px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

h1, h2, h3, h4 { margin: 0 0 .5rem; line-height: 1.25; font-weight: 650; letter-spacing: -.01em; }
h1 { font-size: 1.5rem; }
h2 { font-size: 1.15rem; }
h3 { font-size: 1rem; }
h4 { font-size: .92rem; }
p { margin: 0 0 .75rem; }
code, pre { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: .87em; }
code { background: #eef0f3; padding: .1em .35em; border-radius: 4px; }
pre { background: #12151b; color: #e6e9ef; padding: .9rem 1rem; border-radius: var(--radius); overflow: auto; }
pre code { background: none; padding: 0; color: inherit; }

/* ── layout ─────────────────────────────────────────────────────────────── */
.shell { display: flex; min-height: 100vh; }

.sidebar {
  width: 232px;
  flex: 0 0 232px;
  background: var(--sidebar);
  color: var(--sidebar-ink);
  display: flex;
  flex-direction: column;
  padding: 1.1rem .85rem;
  gap: .25rem;
}
.sidebar .brand {
  color: #fff; font-weight: 700; font-size: .98rem;
  padding: .35rem .55rem 1rem; letter-spacing: -.01em;
}
.sidebar .brand small { display: block; color: #7c8695; font-weight: 500; font-size: .74rem; letter-spacing: .02em; }
.sidebar a {
  display: block; color: var(--sidebar-ink); padding: .48rem .55rem;
  border-radius: 7px; font-size: .9rem; text-decoration: none;
}
.sidebar a:hover { background: #22262f; color: #fff; text-decoration: none; }
.sidebar a.active { background: #2b313c; color: var(--sidebar-active); font-weight: 600; }
.sidebar .sep { height: 1px; background: #262b34; margin: .7rem .3rem; }
.sidebar .spacer { flex: 1; }
.sidebar .who {
  border-top: 1px solid #262b34; padding: .7rem .55rem 0; font-size: .8rem; color: #7c8695;
}
.sidebar .who b { color: #dfe4ea; display: block; font-size: .85rem; }

.main { flex: 1; min-width: 0; display: flex; flex-direction: column; }
.topbar {
  background: var(--panel); border-bottom: 1px solid var(--line);
  padding: .85rem 1.4rem; display: flex; align-items: center; gap: 1rem;
  position: sticky; top: 0; z-index: 20;
}
.topbar h1 { margin: 0; font-size: 1.15rem; }
.topbar .spacer { flex: 1; }
.content { padding: 1.4rem; max-width: 1240px; width: 100%; }

/* ── cards & panels ─────────────────────────────────────────────────────── */
.card {
  background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius);
  box-shadow: var(--shadow); margin-bottom: 1.1rem; overflow: hidden;
}
.card > .card-head {
  padding: .85rem 1.05rem; border-bottom: 1px solid var(--line);
  display: flex; align-items: center; gap: .6rem; flex-wrap: wrap;
}
.card > .card-head h2, .card > .card-head h3 { margin: 0; }
.card > .card-head .spacer { flex: 1; }
.card > .card-body { padding: 1.05rem; }
.card > .card-body.tight { padding: .6rem 1.05rem; }

.grid { display: grid; gap: 1.1rem; }
.grid.cols-2 { grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }
.grid.cols-3 { grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); }
.grid.cols-4 { grid-template-columns: repeat(auto-fit, minmax(165px, 1fr)); }

.stat { background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: .9rem 1rem; box-shadow: var(--shadow); }
.stat .n { font-size: 1.7rem; font-weight: 680; letter-spacing: -.02em; line-height: 1.1; }
.stat .l { color: var(--muted); font-size: .8rem; text-transform: uppercase; letter-spacing: .05em; }

/* ── tables ─────────────────────────────────────────────────────────────── */
table { width: 100%; border-collapse: collapse; font-size: .9rem; }
th, td { padding: .55rem .7rem; text-align: left; border-bottom: 1px solid var(--line); vertical-align: middle; }
th { font-size: .74rem; text-transform: uppercase; letter-spacing: .05em; color: var(--muted); font-weight: 600; background: #fafbfc; }
tbody tr:last-child td { border-bottom: 0; }
tbody tr:hover { background: #fafbfc; }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; }
.table-wrap { overflow-x: auto; }

/* ── buttons ────────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex; align-items: center; gap: .35rem;
  padding: .42rem .78rem; border-radius: 7px; border: 1px solid var(--line-strong);
  background: #fff; color: var(--ink); font: inherit; font-size: .87rem; font-weight: 550;
  cursor: pointer; text-decoration: none; white-space: nowrap;
}
.btn:hover { background: #f3f5f7; text-decoration: none; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.primary:hover { background: #1a51b4; }
.btn.danger { color: var(--bad); border-color: #e8c9c7; background: #fff; }
.btn.danger:hover { background: var(--bad-soft); }
.btn.ghost { border-color: transparent; background: transparent; color: var(--accent); }
.btn.ghost:hover { background: var(--accent-soft); }
.btn.small { padding: .24rem .5rem; font-size: .79rem; }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn-row { display: flex; gap: .4rem; flex-wrap: wrap; align-items: center; }

/* ── forms ──────────────────────────────────────────────────────────────── */
label { display: block; font-size: .8rem; font-weight: 600; color: #3d444e; margin-bottom: .25rem; }
input[type=text], input[type=password], input[type=email], input[type=number],
input[type=datetime-local], input[type=search], select, textarea {
  width: 100%; padding: .45rem .6rem; border: 1px solid var(--line-strong);
  border-radius: 7px; font: inherit; font-size: .9rem; background: #fff; color: var(--ink);
}
input:focus, select:focus, textarea:focus { outline: 2px solid var(--accent-soft); border-color: var(--accent); }
textarea { min-height: 90px; resize: vertical; line-height: 1.5; }
textarea.code { font-family: ui-monospace, Menlo, Consolas, monospace; font-size: .85rem; }
.field { margin-bottom: .75rem; }
.field .hint { font-size: .76rem; color: var(--muted); margin-top: .2rem; }
.form-row { display: flex; gap: .75rem; flex-wrap: wrap; }
.form-row > .field { flex: 1; min-width: 180px; margin-bottom: 0; }
.check { display: flex; align-items: center; gap: .45rem; margin-bottom: .35rem; font-weight: 500; font-size: .88rem; }
.check input { width: auto; }
.inline-form { display: inline; }

/* ── badges ─────────────────────────────────────────────────────────────── */
.badge {
  display: inline-block; padding: .12rem .45rem; border-radius: 999px;
  font-size: .73rem; font-weight: 650; letter-spacing: .01em; border: 1px solid transparent;
}
.badge.gray   { background: #eef0f3; color: #545b66; border-color: #e0e3e8; }
.badge.blue   { background: var(--accent-soft); color: var(--accent); border-color: #cfe0fb; }
.badge.green  { background: var(--good-soft); color: var(--good); border-color: #c9e7d9; }
.badge.amber  { background: var(--warn-soft); color: var(--warn); border-color: #f2ddb8; }
.badge.red    { background: var(--bad-soft); color: var(--bad); border-color: #f0cdca; }

/* ── messages ───────────────────────────────────────────────────────────── */
.flash {
  padding: .6rem .8rem; border-radius: 8px; margin-bottom: .9rem;
  font-size: .89rem; border: 1px solid;
}
.flash.success { background: var(--good-soft); color: var(--good); border-color: #c9e7d9; }
.flash.error   { background: var(--bad-soft); color: var(--bad); border-color: #f0cdca; }
.flash.info    { background: var(--accent-soft); color: var(--accent); border-color: #cfe0fb; }
.flash.warning { background: var(--warn-soft); color: var(--warn); border-color: #f2ddb8; }

.notice { background: #fff; border: 1px solid var(--line); border-left: 3px solid var(--accent); padding: .7rem .9rem; border-radius: 6px; font-size: .88rem; }
.notice.warn { border-left-color: var(--warn); }
.notice.bad { border-left-color: var(--bad); }

/* ── login ──────────────────────────────────────────────────────────────── */
.auth-wrap { min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 1.5rem; }
.auth-card { width: 100%; max-width: 380px; background: var(--panel); border: 1px solid var(--line); border-radius: 14px; padding: 1.6rem; box-shadow: 0 10px 30px rgba(16, 24, 40, .09); }
.auth-card h1 { margin-bottom: .2rem; }
.auth-card .sub { color: var(--muted); font-size: .87rem; margin-bottom: 1.2rem; }

/* ── misc ───────────────────────────────────────────────────────────────── */
.muted { color: var(--muted); }
.small { font-size: .82rem; }
.mono { font-family: ui-monospace, Menlo, Consolas, monospace; }
.right { text-align: right; }
.nowrap { white-space: nowrap; }
.stack { display: flex; flex-direction: column; gap: .75rem; }
.row { display: flex; gap: .6rem; align-items: center; flex-wrap: wrap; }
.mt { margin-top: 1rem; }
.mb0 { margin-bottom: 0; }
.empty { color: var(--muted); font-size: .9rem; padding: 1.2rem; text-align: center; }

.tabs { display: flex; gap: .25rem; border-bottom: 1px solid var(--line); margin-bottom: 1rem; flex-wrap: wrap; }
.tabs a { padding: .5rem .8rem; font-size: .89rem; font-weight: 550; color: var(--muted); border-bottom: 2px solid transparent; }
.tabs a.active { color: var(--accent); border-bottom-color: var(--accent); }
.tabs a:hover { text-decoration: none; color: var(--ink); }

/* category weight meter */
.weight-bar { height: 7px; border-radius: 4px; background: #eceff3; overflow: hidden; }
.weight-bar i { display: block; height: 100%; background: var(--accent); }
.weight-bar.full i { background: var(--good); }
.weight-bar.over i { background: var(--bad); }

/* per-question option rows */
.opt-row { display: flex; gap: .5rem; align-items: center; margin-bottom: .35rem; }
.opt-row .lbl { flex: 0 0 26px; font-size: .74rem; color: var(--muted); font-weight: 700; }

/* chat */
.chat-box { display: flex; flex-direction: column; gap: .8rem; max-height: 60vh; overflow-y: auto; padding: .3rem; }
.msg { padding: .6rem .8rem; border-radius: 10px; font-size: .89rem; max-width: 82%; white-space: pre-wrap; word-wrap: break-word; }
.msg.user { background: var(--accent); color: #fff; align-self: flex-end; }
.msg.ai { background: #f1f3f6; align-self: flex-start; }
.msg .who { font-size: .68rem; text-transform: uppercase; letter-spacing: .06em; opacity: .65; margin-bottom: .2rem; }
.draft-box { border: 1px dashed var(--line-strong); border-radius: 8px; padding: .8rem; background: #fbfcfd; }
.draft-box pre { max-height: 260px; font-size: .78rem; }

/* gradebook grid */
.gradebook td.cell { text-align: center; font-variant-numeric: tabular-nums; }
.gradebook td.cell .score { font-weight: 650; }
.gradebook td.cell .pct { font-size: .72rem; color: var(--muted); }
.bar { height: 5px; border-radius: 3px; background: #eceff3; overflow: hidden; margin-top: 2px; }
.bar i { display: block; height: 100%; background: var(--accent); }
.bar.good i { background: var(--good); }
.bar.warn i { background: var(--warn); }
.bar.bad i { background: var(--bad); }

/* breakdown table */
.breakdown td.cat { font-weight: 600; }
.rationale { color: #3d444e; font-size: .87rem; margin-top: .15rem; }

@media (max-width: 820px) {
  .shell { flex-direction: column; }
  .sidebar { width: 100%; flex: none; flex-direction: row; flex-wrap: wrap; align-items: center; }
  .sidebar .sep, .sidebar .spacer, .sidebar .who { display: none; }
  .sidebar a { padding: .35rem .5rem; }
}