:root {
  color-scheme: light dark;
  --bg: #fbfaf8;
  --surface: #ffffff;
  --ink: #16181d;
  --ink-soft: #545a66;
  --line: #e3e2de;
  --accent: #1f5f8b;
  --pos: #1a7f5a;
  --neg: #9a5b1c;
  --warn-bg: #fdf6e8;
  --warn-line: #e6cf9a;
  --banner-bg: #7d2230;
  --banner-ink: #fff2f3;
  --radius: 10px;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14161a;
    --surface: #1b1e24;
    --ink: #e8e9ec;
    --ink-soft: #a2a8b4;
    --line: #2c313a;
    --accent: #6fb3dd;
    --pos: #52c294;
    --neg: #d99a54;
    --warn-bg: #2a2418;
    --warn-line: #5c4c26;
    --banner-bg: #6d1f2b;
    --banner-ink: #ffeef0;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.65 ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto,
        Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.wrap { max-width: 820px; margin: 0 auto; padding: 0 20px; }

.banner {
  background: var(--banner-bg);
  color: var(--banner-ink);
  padding: 12px 20px;
  font-size: 14.5px;
  line-height: 1.55;
  text-align: center;
}
.banner strong { letter-spacing: .01em; }

header { padding: 40px 20px 8px; }
h1 {
  font-size: clamp(24px, 4.2vw, 34px);
  line-height: 1.2;
  margin: 0 0 12px;
  letter-spacing: -0.02em;
}
h2 { font-size: 20px; margin: 0 0 12px; letter-spacing: -0.01em; }
h3 { font-size: 16px; margin: 22px 0 6px; }
.sub { font-size: 17px; color: var(--ink-soft); margin: 0 0 10px; max-width: 62ch; }
.meta { font-family: var(--mono); font-size: 12.5px; color: var(--ink-soft); margin: 0; }

main { padding-bottom: 56px; }

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 24px;
  margin: 22px 0;
}
.card p { margin: 0 0 12px; max-width: 68ch; }
.card p:last-child { margin-bottom: 0; }

a { color: var(--accent); text-underline-offset: 2px; }

.hint { color: var(--ink-soft); font-size: 13.5px; }

/* ---- dropzone ---- */
.drop {
  border: 1.5px dashed var(--line);
  border-radius: var(--radius);
  padding: 30px 20px;
  text-align: center;
  cursor: pointer;
  transition: border-color .15s, background .15s;
  color: var(--ink-soft);
}
.drop:hover, .drop:focus-visible, .drop.over {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 6%, transparent);
  outline: none;
}
.drop-inner p { margin: 6px 0 0; }
.drop-inner p strong { color: var(--ink); }

.examples { margin-top: 16px; display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }
#example-buttons { display: flex; flex-wrap: wrap; gap: 8px; }
button.ex {
  font: inherit; font-size: 13px;
  padding: 5px 11px;
  border: 1px solid var(--line);
  background: var(--bg);
  color: var(--ink);
  border-radius: 999px;
  cursor: pointer;
}
button.ex:hover { border-color: var(--accent); color: var(--accent); }
button.ex:disabled { opacity: .5; cursor: default; }

/* ---- result ---- */
.result { margin-top: 22px; padding-top: 20px; border-top: 1px solid var(--line); }
.result-grid { display: flex; gap: 24px; flex-wrap: wrap; align-items: flex-start; }
.preview { margin: 0; }
.preview canvas {
  width: 224px; height: 224px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: #000;
  display: block;
}
.preview figcaption { font-size: 12px; color: var(--ink-soft); margin-top: 6px; text-align: center; }

.verdict { flex: 1 1 260px; min-width: 240px; }
.verdict-label { font-size: 21px; font-weight: 650; margin: 0 0 14px; letter-spacing: -0.01em; }
.verdict-label.pos { color: var(--pos); }
.verdict-label.neg { color: var(--neg); }

.gauge {
  position: relative;
  height: 10px;
  background: var(--line);
  border-radius: 999px;
  overflow: visible;
  margin-bottom: 10px;
}
.gauge-fill {
  height: 100%; width: 0%;
  border-radius: 999px;
  background: var(--accent);
  transition: width .35s cubic-bezier(.2,.7,.3,1);
}
.gauge-thr {
  position: absolute; top: -4px; width: 2px; height: 18px;
  background: var(--ink-soft); opacity: .8; border-radius: 1px;
}
.prob { margin: 0 0 6px; }
#prob { font-family: var(--mono); font-size: 26px; font-weight: 600; }
.prob .hint { display: block; }
.truth { margin-top: 10px; font-style: italic; }

.status { margin: 14px 0 0; font-size: 13.5px; color: var(--ink-soft); min-height: 1.2em; }
.status.err { color: var(--banner-bg); }

/* ---- callouts & lists ---- */
.warn {
  background: var(--warn-bg);
  border: 1px solid var(--warn-line);
  border-radius: 8px;
  padding: 14px 16px;
  margin-top: 16px;
}
.warn p { margin: 0; font-size: 14.5px; }

.findings { padding-left: 20px; margin: 12px 0 0; }
.findings li { margin-bottom: 10px; max-width: 68ch; }

code {
  font-family: var(--mono);
  font-size: .9em;
  background: color-mix(in srgb, var(--ink) 8%, transparent);
  padding: 1px 5px;
  border-radius: 4px;
}

/* ---- table ---- */
.tablewrap { overflow-x: auto; }
table { border-collapse: collapse; width: 100%; font-size: 14px; margin-top: 8px; }
th, td { text-align: right; padding: 6px 10px; border-bottom: 1px solid var(--line); white-space: nowrap; }
th:first-child, td:first-child { text-align: left; font-family: var(--mono); font-size: 13px; }
thead th { color: var(--ink-soft); font-weight: 600; font-size: 12.5px; text-transform: uppercase; letter-spacing: .04em; }
tr.spacer td { border: 0; height: 6px; padding: 0; }
td.bar-cell { width: 40%; }
.bar { height: 7px; border-radius: 999px; background: var(--accent); opacity: .75; }

footer { margin-top: 34px; padding-top: 20px; border-top: 1px solid var(--line); }
footer p { margin: 0 0 8px; }

@media (max-width: 560px) {
  /* the id selector on #segcanvas outranks .preview canvas, so it has to be
     named here too or stage two stays pinned at 224px on a phone */
  .preview canvas, #segcanvas { width: 100%; height: auto; aspect-ratio: 1; }
  .card { padding: 18px 16px; }
}

/* ---- Grad-CAM overlay ---- */
#cam-toggle { margin-top: 8px; width: 100%; font-size: 12.5px; }
.cam-note { margin-top: 12px; max-width: 42ch; }
.preview figcaption { max-width: 224px; margin-left: auto; margin-right: auto; }

/* ---- stage two: segmentation ---- */
.stage-head {
  margin: 0 0 14px;
  font-size: 13px;
  font-weight: 650;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--ink-soft);
}
.stage2 { margin-top: 26px; padding-top: 20px; border-top: 1px solid var(--line); }
.stage2 .hint { max-width: 62ch; }
#seg-intro { margin: 0 0 14px; }
button.ex.wide { padding: 8px 16px; font-size: 14px; }
#seg-toggle { margin-top: 8px; width: 100%; font-size: 12.5px; }

.legend { list-style: none; margin: 0 0 14px; padding: 0; font-size: 14px; }
.legend li { display: flex; align-items: center; gap: 8px; margin-bottom: 5px; }
.legend b { font-family: var(--mono); font-size: 13px; font-weight: 500;
            color: var(--ink-soft); margin-left: auto; }
.chip { width: 13px; height: 13px; border-radius: 3px; flex: 0 0 auto;
        border: 1px solid rgba(0, 0, 0, .25); }
.chip-ps { background: rgb(255, 196, 46); }
.chip-fh { background: rgb(64, 174, 255); }

.verdict-label.sm { font-size: 17px; margin-bottom: 10px; }
#segcanvas { width: 224px; height: 224px; }