:root {
  --bg: #f5f3ee;
  --surface: #ffffff;
  --surface-2: #faf8f3;
  --ink: #141a22;
  --ink-2: #4a525c;
  --ink-3: #7b838d;
  --line: #e2ddd3;
  --line-strong: #c9c2b5;
  --accent: #f2b23a;
  --accent-ink: #5a3d00;
  --focus: #2b6cb0;
  --v-human: #2f855a;
  --v-some: #b7791f;
  --v-strong: #c05621;
  --v-ai: #c53030;
  --radius: 10px;
  --shadow: 0 1px 2px rgba(20, 26, 34, .05), 0 8px 24px -12px rgba(20, 26, 34, .18);
  --font: "Inter", "Helvetica Neue", Helvetica, Arial, system-ui, sans-serif;
  --mono: "SF Mono", "JetBrains Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font: 16px/1.55 var(--font);
  color: var(--ink);
  background: var(--bg);
  background-image: radial-gradient(circle at 1px 1px, rgba(20, 26, 34, .06) 1px, transparent 0);
  background-size: 22px 22px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
.wrap { width: min(880px, 100% - 2rem); margin-inline: auto; }
.mono { font-family: var(--mono); font-variant-numeric: tabular-nums; }
.muted { color: var(--ink-3); font-size: .9rem; margin: 0; }
.visually-hidden { position: absolute !important; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip { position: absolute; left: -999px; top: 0; background: var(--ink); color: #fff; padding: .5rem .75rem; z-index: 10; }
.skip:focus { left: .5rem; top: .5rem; }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }

/* Header */
.site-header { padding: 1.75rem 0 1.25rem; border-bottom: 1px solid var(--line); background: rgba(245, 243, 238, .85); backdrop-filter: blur(6px); }
.header-row { display: flex; flex-wrap: wrap; align-items: baseline; gap: .5rem 1.25rem; }
.brand { display: flex; align-items: center; gap: .6rem; }
.brand-mark { width: 18px; height: 18px; border-radius: 50%; border: 3px solid var(--accent); box-shadow: inset 0 0 0 3px var(--surface), inset 0 0 0 6px var(--ink); }
.brand-name { margin: 0; font-size: 1.6rem; letter-spacing: -.02em; font-weight: 700; }
.badge-beta { font-family: var(--mono); font-size: .72rem; font-weight: 700; letter-spacing: .12em; padding: .22em .55em; border-radius: 4px; background: var(--accent); color: var(--accent-ink); transform: translateY(-2px); }
.tagline { margin: 0; color: var(--ink-2); font-size: .95rem; }

/* Panel & tabs */
main { flex: 1; padding: 1.75rem 0 2.5rem; display: grid; gap: 1.25rem; align-content: start; }
.panel, .result, .disclaimer { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); }
.panel { padding: 0 1.25rem 1.25rem; }
.tabs { display: flex; gap: .25rem; border-bottom: 1px solid var(--line); margin: 0 -1.25rem 1.25rem; padding: 0 1rem; overflow-x: auto; }
.tab { appearance: none; background: none; border: 0; border-bottom: 2px solid transparent; margin-bottom: -1px; padding: .9rem .75rem .75rem; font: inherit; font-weight: 600; color: var(--ink-3); cursor: pointer; white-space: nowrap; transition: color .15s, border-color .15s; }
.tab:hover:not(:disabled) { color: var(--ink); }
.tab.is-active { color: var(--ink); border-bottom-color: var(--ink); }
.tab:disabled { cursor: not-allowed; color: var(--line-strong); }
.tab-note { font-weight: 400; font-size: .85em; }
.pane { display: grid; gap: .75rem; }
.field-label { font-weight: 600; font-size: .95rem; margin: 0; }
textarea {
  width: 100%; resize: vertical; min-height: 220px;
  font: 15px/1.6 var(--font); color: var(--ink);
  padding: .9rem 1rem; border: 1px solid var(--line-strong); border-radius: 8px; background: var(--surface-2);
  transition: border-color .15s, box-shadow .15s;
}
textarea:focus { border-color: var(--focus); box-shadow: 0 0 0 3px rgba(43, 108, 176, .15); outline: none; background: #fff; }
.field-foot { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: .75rem; }
.counter { color: var(--ink-3); font-size: .9rem; }
.counter.is-low { color: var(--v-strong); }
.counter.is-over { color: var(--v-ai); font-weight: 600; }
.actions { display: flex; gap: .5rem; margin-left: auto; }

.btn { font: inherit; font-weight: 600; padding: .6rem 1.1rem; border-radius: 8px; border: 1px solid transparent; cursor: pointer; transition: background .15s, transform .05s, opacity .15s; }
.btn:active:not(:disabled) { transform: translateY(1px); }
.btn:disabled { opacity: .45; cursor: not-allowed; }
.btn-primary { background: var(--ink); color: #fff; }
.btn-primary:hover:not(:disabled) { background: #232c38; }
.btn-ghost { background: transparent; color: var(--ink-2); border-color: var(--line-strong); }
.btn-ghost:hover:not(:disabled) { background: var(--surface-2); }

/* Dropzone */
.dropzone { border: 1.5px dashed var(--line-strong); border-radius: 8px; background: var(--surface-2); padding: 1.75rem 1rem; text-align: center; cursor: pointer; transition: border-color .15s, background .15s; color: var(--ink-2); }
.dropzone:hover, .dropzone.is-over { border-color: var(--ink); background: #fff; }
.dropzone.is-over { border-style: solid; }
.drop-idle p { margin: .35rem 0 0; }
.drop-idle svg { color: var(--ink-3); }
.link { color: var(--focus); text-decoration: underline; }
.drop-preview { display: flex; align-items: center; gap: 1rem; text-align: left; }
.drop-preview img { width: 96px; height: 96px; object-fit: cover; border-radius: 6px; border: 1px solid var(--line); background: #fff; }
.preview-meta { display: grid; gap: .15rem; font-size: .9rem; word-break: break-all; }

/* Status */
.status { margin-top: 1rem; padding: .75rem 1rem; border-radius: 8px; font-size: .95rem; border: 1px solid var(--line); background: var(--surface-2); }
.status.is-error { border-color: #f3b7b7; background: #fff5f5; color: #822727; }
.status.is-loading { display: flex; align-items: center; gap: .6rem; }
.spinner { width: 16px; height: 16px; border: 2px solid var(--line-strong); border-top-color: var(--ink); border-radius: 50%; animation: spin .8s linear infinite; flex: none; }
@keyframes spin { to { transform: rotate(360deg); } }

/* Result */
.result { overflow: hidden; animation: rise .3s ease-out; }
@keyframes rise { from { opacity: 0; transform: translateY(6px); } }
.result-head { display: grid; grid-template-columns: auto 1fr; gap: 1.5rem; align-items: center; padding: 1.5rem 1.25rem; border-bottom: 1px solid var(--line); background: var(--surface-2); }
.score-block { display: grid; }
.score-label { font-family: var(--mono); font-size: .72rem; letter-spacing: .12em; text-transform: uppercase; color: var(--ink-3); }
.score { font-family: var(--mono); font-size: clamp(3rem, 9vw, 4.5rem); font-weight: 700; line-height: 1; letter-spacing: -.04em; color: var(--verdict-color, var(--ink)); }
.score small { font-size: .45em; font-weight: 500; }
.verdict-block { display: grid; gap: .5rem; }
.verdict { font-size: 1.25rem; font-weight: 700; color: var(--verdict-color, var(--ink)); }
.meter { height: 10px; border-radius: 999px; background: linear-gradient(90deg, var(--v-human) 0 25%, var(--v-some) 25% 50%, var(--v-strong) 50% 75%, var(--v-ai) 75% 100%); opacity: .25; position: relative; }
.meter-fill { position: absolute; inset: 0; width: 0; border-radius: 999px; background: var(--verdict-color, var(--ink)); opacity: 1; transition: width .5s cubic-bezier(.2, .7, .2, 1); }
.verdict-block .meter { opacity: 1; background: var(--line); }
.meter-scale { display: flex; justify-content: space-between; font-size: .7rem; color: var(--ink-3); }
.result-body { padding: 1.25rem; }
.result-title { margin: 0 0 .75rem; font-size: 1rem; }
.reasons { margin: 0; padding-left: 1.25rem; display: grid; gap: .5rem; }
.reasons li { padding-left: .25rem; }
.reasons li::marker { color: var(--verdict-color, var(--ink-3)); }
.result-note { margin: .5rem 0 0; color: var(--ink-2); }
.details { margin-top: 1rem; border-top: 1px solid var(--line); padding-top: .75rem; }
.details summary { cursor: pointer; color: var(--ink-2); font-size: .9rem; }
.stats { display: grid; grid-template-columns: max-content 1fr; gap: .3rem 1rem; margin: .75rem 0 0; font-size: .875rem; }
.stats dt { color: var(--ink-3); font-family: var(--mono); }
.stats dd { margin: 0; }

/* Verdict themes */
.result[data-band="human"] { --verdict-color: var(--v-human); }
.result[data-band="some"] { --verdict-color: var(--v-some); }
.result[data-band="strong"] { --verdict-color: var(--v-strong); }
.result[data-band="ai"] { --verdict-color: var(--v-ai); }

/* Disclaimer & footer */
.disclaimer { padding: 1rem 1.25rem; border-left: 4px solid var(--accent); font-size: .92rem; color: var(--ink-2); }
.disclaimer p { margin: 0; }
.disclaimer .privacy { margin-top: .5rem; color: var(--ink-3); }
.site-footer { border-top: 1px solid var(--line); padding: 1rem 0; font-size: .85rem; color: var(--ink-3); }
.site-footer a { color: inherit; }

@media (max-width: 600px) {
  .result-head { grid-template-columns: 1fr; gap: 1rem; }
  .panel { padding-inline: 1rem; }
  .tabs { margin-inline: -1rem; }
  .actions { width: 100%; }
  .actions .btn { flex: 1; }
}
@media (prefers-reduced-motion: reduce) {
  .result, .meter-fill, .spinner { animation: none; transition: none; }
}