:root {
  --bg: #fbfaf7; --fg: #1d1d1b; --muted: #5d5d58; --card: #ffffff; --line: #d7d4cb;
  --accent: #1c5d8a; --accent-fg: #ffffff; --warn: #8a3b00; --warn-bg: #fff1e0; --bad: #a11d1d; --ok: #1b6b3a;
  --fs: 1.0625rem;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #17181a; --fg: #ececea; --muted: #a8a8a2; --card: #202225; --line: #3a3d41; --accent: #6fb1e0; --accent-fg: #0b1a26;
          --warn: #ffc78a; --warn-bg: #3a2610; --bad: #ff9a9a; --ok: #8fd6a9; }
}
html.hc { --bg: #000; --fg: #fff; --muted: #fff; --card: #000; --line: #fff; --accent: #ffff00; --accent-fg: #000; --warn: #ffff00; --warn-bg: #000; --bad: #ff8080; --ok: #80ff80; }
html.fs-0 { --fs: 0.9375rem; } html.fs-1 { --fs: 1.0625rem; } html.fs-2 { --fs: 1.25rem; } html.fs-3 { --fs: 1.5rem; } html.fs-4 { --fs: 1.875rem; }

* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--fg); font: var(--fs)/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; }
main { max-width: 56rem; margin: 0 auto; padding: 1rem; }
h1 { font-size: 1.5em; margin: 0 0 .25rem; } h2 { font-size: 1.2em; }
.muted { color: var(--muted); margin: 0; }
.sr-only, .skip:not(:focus) { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip:focus { position: static; display: block; padding: .5rem; background: var(--accent); color: var(--accent-fg); }
[hidden] { display: none !important; }

button, input, textarea, select { font: inherit; color: inherit; }
button { border: 1px solid var(--line); background: var(--card); padding: .5rem .9rem; border-radius: .5rem; cursor: pointer; min-height: 2.5rem; }
button:hover:not(:disabled) { border-color: var(--accent); }
button:disabled { opacity: .5; cursor: not-allowed; }
button.primary { background: var(--accent); color: var(--accent-fg); border-color: var(--accent); }
button.danger { color: var(--bad); }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }
input[type=text], input[type=datetime-local], input[type=number], input[type=password], select, textarea { background: var(--card); border: 1px solid var(--line); border-radius: .5rem; padding: .5rem .7rem; width: 100%; }
label { display: block; font-weight: 600; margin: .75rem 0 .25rem; }
.code-input { font: 600 1.4em/1.3 ui-monospace, "SF Mono", Menlo, Consolas, monospace; letter-spacing: .08em; text-transform: uppercase; }
#join-form { max-width: 24rem; } #join-form button { margin-top: .75rem; width: 100%; }

.status { min-height: 1.5em; margin: .5rem 0 0; } .status.error { color: var(--bad); } .status.ok { color: var(--ok); }
.recorded { margin-top: 1.5rem; color: var(--muted); } .recorded summary { cursor: pointer; }

.doc-head { display: flex; justify-content: space-between; gap: 1rem; align-items: flex-start; flex-wrap: wrap; }
.tools { display: flex; gap: .4rem; }
.meter { display: flex; gap: .5rem; flex-wrap: wrap; margin: .75rem 0; }
.pill { border: 1px solid var(--line); border-radius: 999px; padding: .15rem .8rem; background: var(--card); font-variant-numeric: tabular-nums; }
.pill.warn { color: var(--warn); background: var(--warn-bg); border-color: var(--warn); }
.pill.bad { color: var(--bad); border-color: var(--bad); }
body.student main { max-width: 64rem; min-height: 100dvh; display: flex; flex-direction: column; }
body.student #screen-editor { flex: 1; display: flex; flex-direction: column; min-height: 0; }
.paper-wrap { position: relative; flex: 1; min-height: 50vh; display: flex; }
.paper { display: block; flex: 1; min-height: 50vh; resize: none; font-size: 1em; line-height: 1.6; padding: 1rem; scrollbar-gutter: stable; }
/* The styled layer sits behind a transparent text box, so everything below changes how text looks, never how wide it is. */
.paper-wrap .paper { position: absolute; inset: 0; width: 100%; height: 100%; margin: 0; border: 1px solid var(--line); border-radius: .5rem; font-family: inherit; letter-spacing: normal; word-spacing: normal; }
textarea.paper { background: transparent; color: transparent; caret-color: var(--fg); }
textarea.paper::placeholder { color: var(--muted); }
textarea.paper::selection { background: color-mix(in srgb, var(--accent) 35%, transparent); color: transparent; }
.styled { background: var(--card); color: var(--fg); white-space: pre-wrap; overflow-wrap: break-word; overflow: hidden; pointer-events: none; }
.styled .m { opacity: .4; }
.styled .b { -webkit-text-stroke: .045em currentColor; }
.styled .u { text-decoration: underline; text-underline-offset: .15em; }
.styled .w.i { display: inline-block; transform: skewX(-12deg); }
.format { display: flex; gap: .3rem; margin: .5rem 0 .25rem; }
button.fmt { min-width: 2.5rem; padding: .25rem .6rem; min-height: 2.25rem; }
.paper[readonly] { opacity: .75; }
.bar { display: flex; gap: 1rem; align-items: center; flex-wrap: wrap; margin-top: .75rem; }
.bar .status { margin: 0; flex: 1; }
#words { font-variant-numeric: tabular-nums; min-width: 9rem; }

button.icon { display: inline-flex; align-items: center; gap: .4rem; padding: .4rem .6rem; }
.clock-text { display: none; font-variant-numeric: tabular-nums; }
button.icon:hover .clock-text, button.icon:focus-visible .clock-text, button.icon[aria-pressed=true] .clock-text, button.icon.urgent .clock-text { display: inline; }
button.icon.urgent { color: var(--warn); border-color: var(--warn); }
#fullscreen:not([aria-pressed=true]) { border-color: var(--accent); }

.assignment { border: 1px solid var(--line); border-radius: .5rem; background: var(--card); margin: .5rem 0; padding: .25rem .9rem; }
.assignment summary { cursor: pointer; font-weight: 600; padding: .35rem 0; }
.assignment-text { white-space: pre-wrap; max-height: 35vh; overflow: auto; padding: .25rem 0 .6rem; }

.sync { display: inline-flex; align-items: center; gap: .4rem; color: var(--muted); font-size: .9em; }
.sync-icon { width: 1.1rem; height: 1.1rem; display: inline-block; }
.sync[data-state=saved] .sync-icon::after { content: ""; display: block; width: .35rem; height: .7rem; margin: .05rem auto 0; border: solid currentColor; border-width: 0 2px 2px 0; transform: rotate(45deg); }
.sync[data-state=saving] .sync-icon { border: 2px solid var(--line); border-top-color: var(--muted); border-radius: 50%; }
.sync:not([data-state=saved]):not([data-state=saving]) { color: var(--warn); }
.sync:not([data-state=saved]):not([data-state=saving]) .sync-icon { background: currentColor; border-radius: 50%; transform: scale(.55); }
.sync[data-state=saved] .sync-text, .sync[data-state=saving] .sync-text { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
@media (prefers-reduced-motion: no-preference) { .sync[data-state=saving] .sync-icon { animation: spin .8s linear infinite; } }
@keyframes spin { to { transform: rotate(360deg); } }

.overlay { position: fixed; inset: 0; background: color-mix(in srgb, var(--bg) 88%, transparent); display: grid; place-items: center; padding: 1rem; z-index: 10; }
.card { background: var(--card); border: 2px solid var(--line); border-radius: .75rem; padding: 1.25rem 1.5rem; max-width: 30rem; }
dialog { background: var(--card); color: var(--fg); border: 2px solid var(--line); border-radius: .75rem; max-width: 28rem; }
dialog::backdrop { background: rgb(0 0 0 / .5); }
.row { display: flex; gap: .5rem; justify-content: flex-end; flex-wrap: wrap; }
dl.receipt { margin: 1rem 0; } dl.receipt dt { color: var(--muted); } dl.receipt dd { margin: 0; }

@media (prefers-reduced-motion: no-preference) { button { transition: border-color .15s; } }

a.btn { display: inline-block; padding: .7rem 1.2rem; border-radius: .5rem; text-decoration: none; background: var(--accent); color: var(--accent-fg); font-weight: 600; }

/* ---- teacher console and verifier ---- */
body.staff main { max-width: 74rem; }
nav.top { display: flex; gap: .5rem; flex-wrap: wrap; align-items: center; padding: .75rem 1rem; border-bottom: 1px solid var(--line); background: var(--card); }
nav.top .brand { font-weight: 700; margin-right: auto; }
nav.top a { color: inherit; padding: .5rem .9rem; border: 1px solid var(--line); border-radius: .5rem; text-decoration: none; background: var(--card); }
nav.top a:hover { border-color: var(--accent); }
.panel { background: var(--card); border: 1px solid var(--line); border-radius: .75rem; padding: 1rem 1.25rem; margin: 1rem 0; }
.grid2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(16rem, 1fr)); gap: 0 1rem; }
table { border-collapse: collapse; width: 100%; } th, td { text-align: left; padding: .45rem .6rem; border-bottom: 1px solid var(--line); vertical-align: middle; }
th { color: var(--muted); font-weight: 600; font-size: .9em; } td.num { text-align: right; font-variant-numeric: tabular-nums; }
.badge { display: inline-block; padding: .05rem .6rem; border-radius: 999px; border: 1px solid var(--line); font-size: .9em; }
.badge.writing { color: var(--ok); border-color: var(--ok); } .badge.submitted { background: var(--ok); color: var(--bg); border-color: var(--ok); }
.badge.frozen, .badge.expired { color: var(--warn); border-color: var(--warn); } .badge.not_started { color: var(--muted); }
.actions { display: flex; gap: .3rem; flex-wrap: wrap; align-items: center; margin-top: .5rem; }
.actions input[type=number] { width: 7rem; } .actions button { padding: .2rem .6rem; min-height: 2rem; font-size: .9em; }
.errors { background: var(--warn-bg); color: var(--warn); border: 1px solid var(--warn); border-radius: .5rem; padding: .5rem 1rem; } .errors ul { margin: .25rem 0; padding-left: 1.2rem; }
textarea.mono, pre.mono { font: .95em/1.4 ui-monospace, "SF Mono", Menlo, Consolas, monospace; }
textarea.mono { min-height: 14rem; }
.result { font-size: 1.3em; font-weight: 700; } .result.valid { color: var(--ok); } .result.invalid { color: var(--bad); }

.slips { display: grid; grid-template-columns: repeat(auto-fill, minmax(17rem, 1fr)); gap: .75rem; }
.slip { border: 2px dashed var(--line); border-radius: .5rem; padding: .9rem 1rem; break-inside: avoid; background: var(--card); }
.slip .who { font-weight: 700; } .slip .where { color: var(--muted); font-size: .9em; } .slip .code { margin: .5rem 0; }

@media print {
  body.printing nav.top, body.printing .no-print, body.printing header { display: none !important; }
  body.printing { background: #fff; color: #000; font-size: 11pt; }
  body.printing .panel { border: 0; padding: 0; margin: 0; }
  body.printing .slips { grid-template-columns: repeat(2, 1fr); gap: 6mm; }
  body.printing .slip { border: 1px dashed #000; background: #fff; color: #000; }
  body.printing .slip .where { color: #000; }
}

/* ---- the writing record (teacher) ---- */
.badge.review { color: var(--bad); border-color: var(--bad); font-weight: 600; }
.badge.notice { color: var(--warn); border-color: var(--warn); }
dialog.record { width: min(60rem, 96vw); max-height: 92vh; overflow: auto; padding: 1rem 1.5rem; }
.record-head { display: flex; justify-content: space-between; align-items: center; gap: 1rem; }
.attention { font-size: 1.15em; font-weight: 700; margin: .25rem 0; }
.attention.review { color: var(--bad); } .attention.notice { color: var(--warn); } .attention.none { color: var(--ok); }
.flag { border: 1px solid var(--line); border-left-width: 6px; border-radius: .5rem; padding: .5rem .9rem; margin: .6rem 0; background: var(--card); }
.flag.sev-review { border-left-color: var(--bad); } .flag.sev-notice { border-left-color: var(--warn); } .flag.sev-info { border-left-color: var(--line); }
.flag p { margin: .3rem 0; } .flag-head { display: flex; gap: .6rem; align-items: center; flex-wrap: wrap; }
.small { font-size: .88em; } .inline { display: inline-flex; gap: .3rem; align-items: center; font-weight: 400; margin: 0; }
.badge.sev.info { color: var(--muted); }
.replay { margin: .5rem 0 1rem; } .replay input[type=range] { width: 100%; margin: .6rem 0 .2rem; } .replay canvas { width: 100%; height: 3.5rem; display: block; background: var(--card); border: 1px solid var(--line); border-radius: .4rem; }
.paper-view { white-space: pre-wrap; word-break: break-word; max-height: 22rem; overflow: auto; background: var(--card); border: 1px solid var(--line); border-radius: .5rem; padding: .8rem 1rem; font: inherit; margin: .5rem 0; }
.src-internal_paste { background: color-mix(in srgb, #3b82f6 22%, transparent); }
.src-external_paste { background: color-mix(in srgb, #f59e0b 38%, transparent); }
.src-ime { background: color-mix(in srgb, #10b981 18%, transparent); }
.src-dictation { background: color-mix(in srgb, #8b5cf6 25%, transparent); }
.big { background: color-mix(in srgb, #ef4444 30%, transparent); outline: 1px solid #ef4444; }
.swatch { display: inline-block; padding: 0 .5rem; margin-right: .5rem; border-radius: .25rem; border: 1px solid var(--line); }
.k { padding: 0 .4rem; border-radius: .2rem; color: #fff; } .k.gray { background: #777; } .k.orange { background: #e08a00; } .k.red { background: #d22; }
table.profile th { width: 55%; font-weight: 400; color: var(--muted); }
details.notes { margin-top: 1rem; } details.notes h4 { margin: .6rem 0 .2rem; }