/* Mobile-first. Works on phones, Chromebooks and desktops. */
:root {
  --navy: #1f2a44;
  --bg: #f3f5f9;
  --card: #ffffff;
  --line: #d5dae4;
  --text: #17202e;
  --muted: #5b6577;
  --accent: #2457d6;
  --ok: #17803a;
  --warn: #f2b01e;
  --bad: #c62828;
  --info: #1565c0;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.4 system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  padding-bottom: env(safe-area-inset-bottom);
}
h1 { font-size: 1.6rem; margin: 0 0 1rem; text-align: center; }
h3 { margin: 1.6rem 0 .4rem; font-size: 1.05rem; }
.hidden { display: none !important; }
.muted { color: var(--muted); font-size: .92rem; margin: .3rem 0; }
a { color: var(--accent); }

/* ---------- top bar & stats ---------- */
.topbar {
  display: flex; justify-content: space-between; align-items: center; gap: .5rem;
  background: var(--navy); color: #fff;
  padding: .6rem 1rem; padding-top: max(.6rem, env(safe-area-inset-top));
}
.topbar .who { font-weight: 600; }
.topbar nav { display: flex; align-items: center; gap: 1rem; }
.topbar a, .linkbtn { color: #fff; background: none; border: 0; font: inherit; text-decoration: underline; cursor: pointer; padding: .4rem 0; }
.topbar form { margin: 0; }
.tag { background: #ffffff33; border-radius: 4px; font-size: .75rem; padding: 1px 6px; margin-left: .3rem; font-weight: 500; }

.stats {
  display: flex; flex-wrap: wrap; justify-content: center; gap: .3rem 1.2rem;
  background: #e4e9f3; padding: .5rem 1rem; font-size: .95rem; border-bottom: 1px solid var(--line);
}
.stats b { font-size: 1.1rem; margin-left: .2rem; }

/* ---------- forms & buttons ---------- */
label { display: block; font-weight: 600; margin: 1rem 0 .3rem; }
input, select {
  width: 100%; font: inherit; padding: .75rem .8rem; min-height: 48px;
  border: 2px solid var(--line); border-radius: 10px; background: #fff; color: var(--text);
}
input:focus, select:focus, .btn:focus-visible, .tab:focus-visible {
  outline: 3px solid #8fb0ff; outline-offset: 1px; border-color: var(--accent);
}
.btn {
  display: inline-block; font: inherit; font-weight: 600; text-align: center; text-decoration: none;
  min-height: 48px; padding: .7rem 1.1rem; border-radius: 10px; cursor: pointer;
  border: 2px solid var(--navy); background: #fff; color: var(--navy);
}
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.secondary { background: #fff; }
.btn.danger { background: var(--bad); border-color: var(--bad); color: #fff; }
.btn.big { width: 100%; font-size: 1.3rem; min-height: 64px; margin-top: 1rem; }
.btn.small { min-height: 40px; padding: .4rem .8rem; font-size: .9rem; }
.btn:disabled { opacity: .55; cursor: not-allowed; }
.alert { background: #fdecea; color: #8a1c1c; border: 1px solid #f3b4b0; border-radius: 8px; padding: .6rem .8rem; margin: .8rem 0; }
.warn-box { background: #fff6dc; border: 1px solid #ecc96a; border-radius: 8px; padding: .7rem .9rem; }

/* ---------- login ---------- */
.card { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 1.4rem; }
.login { max-width: 420px; margin: 8vh auto 0; }
.login .btn { width: 100%; margin-top: 1.4rem; }
.login-page { padding: 0 1rem; }

/* ---------- check-in screen ---------- */
.scan { max-width: 520px; margin: 0 auto; padding: .5rem 1rem 2rem; }
.scan input { font-size: 2rem; letter-spacing: .12em; text-align: center; min-height: 68px; font-weight: 600; }
#ini { text-transform: uppercase; }
.scan .btn.secondary { width: 100%; margin-top: .8rem; }

.result {
  position: fixed; inset: 0; z-index: 50; display: flex; align-items: center; justify-content: center;
  padding: 1.5rem; text-align: center; overflow-y: auto;
}
.result.ok   { background: var(--ok);   color: #fff; }
.result.bad  { background: var(--bad);  color: #fff; }
.result.info { background: var(--info); color: #fff; }
.result.warn { background: var(--warn); color: #231a00; }
.result-inner { max-width: 520px; width: 100%; }
.res-icon { font-size: 5rem; line-height: 1; margin-bottom: .5rem; }
.result h2 { font-size: 2.1rem; line-height: 1.1; margin: 0 0 .8rem; letter-spacing: .02em; }
.res-detail { font-size: 1.25rem; margin: 0 0 .8rem; }
.res-student { font-size: 1.1rem; opacity: .9; margin: 0 0 1.5rem; font-variant-numeric: tabular-nums; }
.res-actions { display: flex; flex-direction: column; gap: .8rem; }
.res-actions .btn { width: 100%; min-height: 60px; font-size: 1.15rem; background: #fff; color: #111; border-color: #fff; }

/* ---------- admin ---------- */
.tabs { display: flex; gap: .3rem; overflow-x: auto; padding: .6rem 1rem 0; background: var(--bg); }
.tab {
  font: inherit; font-weight: 600; border: 0; background: #e4e9f3; color: var(--navy);
  padding: .7rem 1rem; border-radius: 10px 10px 0 0; cursor: pointer; white-space: nowrap; min-height: 44px;
}
.tab.active { background: var(--card); box-shadow: 0 2px 0 var(--card); }
.admin { max-width: 900px; margin: 0 auto; padding: 0 1rem 3rem; }
.panel { background: var(--card); border: 1px solid var(--line); border-radius: 0 12px 12px 12px; padding: 1rem; }
.row { display: flex; gap: .5rem; flex-wrap: wrap; }
.row > input[type=search], .row > input { flex: 1 1 160px; }
.row > select { flex: 0 1 200px; }
.stack { display: flex; flex-direction: column; gap: .6rem; max-width: 420px; }
.list { display: flex; flex-direction: column; gap: .6rem; margin-top: .6rem; }
.item { border: 1px solid var(--line); border-radius: 10px; padding: .7rem .8rem; }
.item .head { display: flex; align-items: center; flex-wrap: wrap; gap: .5rem; margin-bottom: .5rem; }
.item .sid { font-size: 1.2rem; font-weight: 700; font-variant-numeric: tabular-nums; letter-spacing: .04em; }
.item .ini { font-size: 1.1rem; }
.item .actions { display: flex; flex-wrap: wrap; gap: .4rem; }
.badge { font-size: .75rem; font-weight: 700; padding: 2px 8px; border-radius: 999px; background: #e4e9f3; color: var(--navy); }
.badge.bad { background: #fbd5d2; color: #8a1c1c; }
.badge.ok { background: #cdeed6; color: #0f5426; }
.badge.warn { background: #fde7a8; color: #5c4200; }
.addbox { margin-top: 1.2rem; }
.addbox summary { cursor: pointer; font-weight: 600; padding: .5rem 0; }
.log { font-size: .9rem; border-bottom: 1px solid var(--line); padding: .4rem 0; display: grid; grid-template-columns: 8.5rem 1fr; gap: .1rem .6rem; }
.log .t { color: var(--muted); }
.result-box { margin-top: 1rem; padding: .8rem 1rem; border-radius: 10px; background: #eef6ff; border: 1px solid #b9d4f5; }
.result-box ul { margin: .4rem 0 0 1.2rem; padding: 0; }

@media (min-width: 700px) {
  .scan { padding-top: 1.5rem; }
  .log { grid-template-columns: 10rem 1fr; }
}

@media (prefers-reduced-motion: no-preference) {
  .result { animation: pop .12s ease-out; }
  @keyframes pop { from { opacity: 0; transform: scale(.98); } to { opacity: 1; transform: none; } }
}