/* ─── tokens ─── */
:root {
  --bg: #f6f3eb;
  --bg-tint: #efeadd;
  --surface: #fdfbf6;
  --surface-2: #f0ece0;
  --ink: #1f2a26;          /* deep slate-green, not black */
  --ink-2: #4b5852;
  --ink-3: #7e887f;
  --line: #d9d3c1;
  --line-2: #c9c1ac;
  --accent: #2f6b4e;       /* forest green */
  --accent-ink: #2f6b4e;
  --accent-soft: #dfe9df;
  --gold: #b48538;         /* warm amber */
  --gold-soft: #f1e6cd;
  --ok: #2f6b4e;
  --ok-soft: #d8e7d9;
  --bad: #a83a2b;          /* warm clay red */
  --bad-soft: #f1d9d0;
  --pending: #7e887f;

  --r-sm: 6px;
  --r-md: 10px;
  --r-lg: 16px;

  --shadow-sm: 0 1px 0 rgba(31,42,38,.04), 0 1px 2px rgba(31,42,38,.04);
  --shadow-md: 0 1px 0 rgba(31,42,38,.04), 0 12px 32px -16px rgba(31,42,38,.18);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "IBM Plex Sans", ui-sans-serif, system-ui, sans-serif;
  font-size: 17px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  transition: background-color .25s ease, color .25s ease;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 24px;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

/* ─── dark theme ─── */
:root[data-theme="dark"] {
  --bg: #161b19;
  --bg-tint: #1d2421;
  --surface: #1f2624;
  --surface-2: #2a322f;
  --ink: #e6e4dc;
  --ink-2: #aab1a8;
  --ink-3: #6f7773;
  --line: #2f3835;
  --line-2: #3d4744;
  --accent: #4a9670;
  --accent-ink: #6db38a;
  --accent-soft: rgba(74,150,112,.18);
  --gold: #c69a4c;
  --gold-soft: rgba(198,154,76,.16);
  --ok: #5cad7d;
  --ok-soft: rgba(92,173,125,.16);
  --bad: #d97163;
  --bad-soft: rgba(217,113,99,.14);
  --pending: #7a8079;

  --shadow-sm: 0 1px 0 rgba(255,255,255,.02), 0 1px 2px rgba(0,0,0,.4);
  --shadow-md: 0 1px 0 rgba(255,255,255,.02), 0 12px 32px -16px rgba(0,0,0,.5);
}

:root[data-theme="dark"] .page {
  background:
    radial-gradient(1200px 600px at 50% -200px, #1b2421 0%, transparent 60%),
    var(--bg);
}

:root[data-theme="dark"] .result.ok .result-bar {
  background: rgba(92,173,125,.12);
  border-color: rgba(92,173,125,.32);
}
:root[data-theme="dark"] .result.bad .result-bar {
  background: rgba(217,113,99,.10);
  border-color: rgba(217,113,99,.32);
}
:root[data-theme="dark"] .chip {
  background: var(--surface-2);
  border-color: var(--line-2);
  color: var(--ink-2);
}
:root[data-theme="dark"] .chip.ok {
  background: rgba(92,173,125,.16);
  border-color: rgba(92,173,125,.4);
  color: var(--ok);
}
:root[data-theme="dark"] .chip.gold {
  background: rgba(198,154,76,.16);
  border-color: rgba(198,154,76,.4);
  color: var(--gold);
}
:root[data-theme="dark"] .proof-card {
  background: linear-gradient(180deg, var(--surface) 0%, var(--surface) 70%, #21281f 100%);
}
:root[data-theme="dark"] .input:focus,
:root[data-theme="dark"] .textarea:focus {
  background: var(--surface-2);
}

.mono { font-family: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, monospace; }

/* ─── page chrome ─── */
.page {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background:
    radial-gradient(1200px 600px at 50% -200px, #ece6d3 0%, transparent 60%),
    var(--bg);
}

.shell {
  width: min(1200px, 100% - 48px);
  margin: 0 auto;
  padding: 32px 0 72px;
}

/* ─── top bar ─── */
.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 0 28px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 42px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}
.brand-mark {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
}
.brand-name {
  font-family: "Fraunces", "IBM Plex Sans", serif;
  font-size: 20px;
  letter-spacing: -0.01em;
  font-weight: 500;
}
.brand-name .dim { color: var(--ink-3); font-weight: 400; }

.top-meta {
  display: flex;
  align-items: center;
  gap: 18px;
  font-size: 14px;
  color: var(--ink-2);
}

.theme-toggle {
  appearance: none;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--ink-2);
  width: 36px;
  height: 36px;
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background .15s ease, color .15s ease, border-color .15s ease, transform .15s ease;
  padding: 0;
  margin-left: 4px;
}
.theme-toggle:hover {
  background: var(--bg-tint);
  color: var(--ink);
  border-color: var(--line-2);
}
.theme-toggle:active { transform: scale(.94); }
.dot {
  display: inline-block;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent);
  margin-right: 7px;
  vertical-align: middle;
  box-shadow: 0 0 0 3px var(--accent-soft);
}

/* ─── hero ─── */
.hero {
  padding-bottom: 40px;
  margin-bottom: 36px;
  border-bottom: 1px solid var(--line);
}

.hero h1 {
  font-family: "Fraunces", "IBM Plex Sans", serif;
  font-weight: 400;
  font-size: 64px;
  letter-spacing: -0.025em;
  line-height: 1.0;
  margin: 0 0 16px;
  color: var(--ink);
  max-width: 18ch;
}
.hero h1 em {
  font-style: italic;
  font-weight: 400;
  color: var(--accent-ink);
}
.hero p {
  margin: 0;
  color: var(--ink-2);
  font-size: 17px;
  max-width: 52ch;
}

/* ─── stepper ─── */
.stepper {
  display: flex;
  gap: 8px;
  margin-bottom: 32px;
}
.stepper .step {
  flex: 1;
  padding: 13px 18px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 15px;
  color: var(--ink-2);
  transition: all .2s ease;
}
.stepper .step.active {
  background: var(--accent-soft);
  border-color: var(--accent);
  color: var(--accent-ink);
}
.stepper .step.done {
  background: var(--surface);
  border-color: var(--line);
  color: var(--ink-2);
}
.stepper .step .num {
  width: 26px; height: 26px;
  border-radius: 50%;
  background: var(--surface-2);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 600;
  color: var(--ink-2);
  flex-shrink: 0;
}
.stepper .step.active .num { background: var(--accent); color: #fff; }
.stepper .step.done .num { background: var(--ok); color: #fff; }

/* ─── cards ─── */
.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 36px;
  box-shadow: var(--shadow-sm);
}
.card + .card { margin-top: 24px; }
.card-h {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 6px;
}
.card-h h2 {
  margin: 0;
  font-size: 19px;
  font-weight: 600;
  letter-spacing: -0.005em;
}
.card-h .kbd {
  font-size: 12.5px;
  color: var(--ink-3);
  font-family: "IBM Plex Mono", monospace;
  letter-spacing: .04em;
}
.card-sub {
  color: var(--ink-2);
  font-size: 15.5px;
  margin: 0 0 26px;
}

/* ─── form ─── */
.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 16px;
}
.field label {
  font-size: 13.5px;
  font-weight: 500;
  color: var(--ink-2);
  letter-spacing: .02em;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
}
.field label .hint {
  color: var(--ink-3);
  font-weight: 400;
  font-size: 12.5px;
}
.input, .textarea {
  width: 100%;
  background: var(--bg-tint);
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  padding: 13px 15px;
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 14px;
  color: var(--ink);
  outline: none;
  transition: border-color .15s, box-shadow .15s, background .15s;
}
.input:focus, .textarea:focus {
  background: var(--surface);
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
.input::placeholder, .textarea::placeholder {
  color: var(--ink-3);
}
.textarea {
  resize: vertical;
  min-height: 80px;
  line-height: 1.5;
}

.field-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

/* ─── buttons ─── */
.btn {
  appearance: none;
  border: 0;
  font-family: inherit;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: .005em;
  padding: 13px 22px;
  border-radius: var(--r-sm);
  cursor: pointer;
  transition: all .15s ease;
  display: inline-flex;
  align-items: center;
  gap: 9px;
}
.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover { background: var(--accent-ink); }
.btn-primary:disabled {
  background: var(--surface-2);
  color: var(--ink-3);
  cursor: not-allowed;
}
.btn-ghost {
  background: transparent;
  color: var(--ink-2);
  border: 1px solid var(--line);
}
.btn-ghost:hover { background: var(--bg-tint); color: var(--ink); }
.btn-link {
  background: transparent;
  color: var(--accent-ink);
  padding: 7px 0;
  font-size: 14px;
  text-decoration: underline;
  text-decoration-color: var(--line-2);
  text-underline-offset: 3px;
}
.btn-link:hover { text-decoration-color: var(--accent); }

.btn-row {
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
}

/* ─── result panel ─── */
.result {
  margin-top: 22px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
}
.result-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 22px;
  background: var(--bg-tint);
  border-bottom: 1px solid var(--line);
}
.result.ok .result-bar { background: var(--ok-soft); border-color: #b9d2bc; }
.result.bad .result-bar { background: var(--bad-soft); border-color: #e3bbab; }
.result.pending .result-bar { background: var(--bg-tint); }

.verdict {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 600;
  font-size: 16px;
  letter-spacing: -0.005em;
}
.verdict .badge {
  display: inline-flex;
  width: 26px; height: 26px;
  border-radius: 50%;
  align-items: center;
  justify-content: center;
  background: #fff;
}
.result.ok .verdict { color: var(--ok); }
.result.bad .verdict { color: var(--bad); }
.result.pending .verdict { color: var(--ink-2); }

.result-body {
  padding: 22px;
  background: var(--surface);
}
.kv {
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 10px 20px;
  font-size: 14px;
}
.kv dt {
  color: var(--ink-3);
  font-weight: 500;
  letter-spacing: .01em;
}
.kv dd {
  margin: 0;
  color: var(--ink);
  font-family: "IBM Plex Mono", monospace;
  word-break: break-all;
}
.kv dd.diff-hi {
  background: var(--bad-soft);
  padding: 1px 4px;
  border-radius: 3px;
}

/* ─── proof step ─── */
.proof-card {
  background: linear-gradient(180deg, var(--surface) 0%, var(--surface) 70%, #f7f2e3 100%);
  position: relative;
  overflow: hidden;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 11px;
  font-size: 13px;
  border-radius: 999px;
  background: var(--surface-2);
  color: var(--ink-2);
  border: 1px solid var(--line);
}
.chip.gold { background: var(--gold-soft); border-color: #e0c896; color: #6a4d1c; }
.chip.ok { background: var(--ok-soft); border-color: #b9d2bc; color: var(--ok); }

/* ─── empty/locked card ─── */
.locked {
  opacity: .55;
  pointer-events: none;
  filter: saturate(.4);
}

.foot {
  margin-top: 56px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  color: var(--ink-3);
  font-size: 13px;
}
.foot .mono { font-size: 12px; }

/* ─── animations ─── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}
.appear { animation: fadeUp .35s ease both; }

@keyframes pulse {
  0%   { box-shadow: 0 0 0 0 var(--accent-soft); }
  70%  { box-shadow: 0 0 0 10px transparent; }
  100% { box-shadow: 0 0 0 0 transparent; }
}
.pulse-dot { animation: pulse 1.8s ease-in-out infinite; }

/* spinner */
.spin {
  width: 14px; height: 14px;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: 50%;
  animation: rot .7s linear infinite;
  display: inline-block;
}
@keyframes rot { to { transform: rotate(360deg); } }

/* responsiveness */
@media (max-width: 860px) {
  .hero h1 { font-size: 48px; }
  .field-row { grid-template-columns: 1fr; }
  .kv { grid-template-columns: 1fr; gap: 4px 0; }
  .kv dt { margin-top: 6px; }
}