/* ============================================================
   errlens — a calm diagnostic console.
   Deep slate console + one confident signal-cyan accent, with
   amber for "cause" and coral for the error line. Monospace for
   the pasted error and matched signatures; clean sans for prose.
   Signature motif: a lens/crosshair and a faint signal scanline.

   Light theme is the default block; a prefers-color-scheme: dark
   media query swaps in the console palette (this app leans dark,
   but honours the user's system setting either way).
   ============================================================ */

:root {
  /* surfaces */
  --bg:        #F4F6F8;
  --panel:     #FFFFFF;
  --panel2:    #EEF1F4;   /* inset / editor field */
  --rule:      #DBE1E7;
  --rule2:     #E8ECF0;

  /* ink */
  --ink:       #14202B;
  --ink-soft:  #465562;
  --ink-faint: #5C6B79;   /* AA on bg/panel/panel2 (>=4.8) */

  /* signal accent (teal/cyan) — NOT evensplit green */
  --signal:    #0E9E88;   /* large / decorative */
  --signal-dk: #0A7364;   /* body-text + buttons (AA on white AND signal-wash) */
  --signal-wash: #E1F3EF;

  /* semantic */
  --cause:     #9A6212;   /* amber for causes (AA on white) */
  --cause-wash:#FBEFD9;
  --fix:       #0A7364;   /* fixes reuse signal */
  --err:       #C6392B;   /* the error line / coral */
  --err-wash:  #FBE7E4;

  --code-ink:  #243542;   /* monospace text */

  --sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", "Roboto Mono", Menlo, Consolas, "Liberation Mono", monospace;

  --radius:    14px;
  --radius-sm: 10px;
  --radius-xs: 8px;
  --shadow:    0 1px 2px rgba(20,32,43,0.05), 0 12px 30px -20px rgba(20,32,43,0.25);
  --shadow-lift: 0 2px 6px rgba(20,32,43,0.08), 0 24px 50px -26px rgba(20,32,43,0.32);
  --wrap: 1160px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg:        #0F1720;
    --panel:     #151E28;
    --panel2:    #101922;   /* editor well, darker than panel */
    --rule:      #26313C;
    --rule2:     #1E2832;

    --ink:       #E9EEF2;
    --ink-soft:  #AEB9C4;
    --ink-faint: #8593A0;

    --signal:    #3BE0C6;
    --signal-dk: #5DE9D2;   /* brighter for text on dark */
    --signal-wash: rgba(59,224,198,0.12);

    --cause:     #F2B65A;
    --cause-wash:rgba(242,182,90,0.12);
    --fix:       #5DE9D2;
    --err:       #FF8575;
    --err-wash:  rgba(255,133,117,0.13);

    --code-ink:  #C7D3DE;

    --shadow:    0 1px 2px rgba(0,0,0,0.4), 0 14px 34px -20px rgba(0,0,0,0.6);
    --shadow-lift: 0 2px 6px rgba(0,0,0,0.45), 0 26px 54px -26px rgba(0,0,0,0.66);
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
  letter-spacing: -0.005em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* faint signal-scan backdrop — the lens motif, low-key */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(900px 520px at 92% -8%, var(--signal-wash), transparent 60%),
    radial-gradient(680px 420px at -6% 4%, var(--cause-wash), transparent 58%);
  opacity: 0.7;
  pointer-events: none;
}

h1, h2, h3, h4 { margin: 0; font-weight: 700; letter-spacing: -0.02em; line-height: 1.12; }
p { margin: 0; }

code, .mono { font-family: var(--mono); font-variant-ligatures: none; }

.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

.skip-link {
  position: absolute; left: 12px; top: -60px;
  background: var(--signal-dk); color: #fff;
  padding: 10px 16px; border-radius: 10px; font-weight: 700;
  z-index: 50; transition: top 0.18s var(--ease); text-decoration: none;
}
.skip-link:focus { top: 12px; }

/* shared focus ring */
a:focus-visible,
button:focus-visible,
textarea:focus-visible {
  outline: 3px solid var(--signal);
  outline-offset: 2px;
  border-radius: 8px;
}

.eyebrow {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--ink-faint);
  font-weight: 700;
  font-family: var(--mono);
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  border-bottom: 1px solid var(--rule);
  background: linear-gradient(180deg, var(--panel), var(--bg) 82%);
}
.hero__inner {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: clamp(24px, 4vw, 44px) clamp(20px, 5vw, 44px) clamp(28px, 4vw, 44px);
}

.brand { display: inline-flex; align-items: center; gap: 12px; text-decoration: none; color: inherit; }
.brand__mark { width: 36px; height: 36px; flex: none; }
.brand__bg { fill: var(--ink); }
.brand__lens { fill: none; stroke: var(--signal); stroke-width: 2.4; }
.brand__handle { stroke: var(--signal); stroke-width: 2.8; stroke-linecap: round; }
.brand__cross { stroke: var(--signal); stroke-width: 1.6; stroke-linecap: round; opacity: 0.85; }
.brand__word { font-size: 1.3rem; font-weight: 800; letter-spacing: -0.04em; font-family: var(--mono); }
.brand__word-accent { color: var(--signal-dk); }

.hero__title {
  font-size: clamp(2rem, 5vw, 3.2rem);
  margin: 18px 0 0;
  max-width: 20ch;
}
.hero__accent { color: var(--signal-dk); }
.hero__lede {
  margin-top: 15px;
  max-width: 62ch;
  color: var(--ink-soft);
  font-size: clamp(0.98rem, 1.2vw, 1.08rem);
}

.hero__langs {
  margin-top: 22px;
  display: flex; flex-wrap: wrap; gap: 7px;
}
.hero__langs span {
  font-family: var(--mono);
  font-size: 0.76rem; font-weight: 600;
  color: var(--ink-soft);
  background: var(--panel);
  border: 1px solid var(--rule);
  border-radius: 999px;
  padding: 3px 11px;
}

/* ============================================================
   BUTTONS
   ============================================================ */
.btn {
  font-family: var(--sans);
  font-weight: 700;
  font-size: 0.95rem;
  letter-spacing: -0.01em;
  border-radius: 11px;
  cursor: pointer;
  border: 1px solid transparent;
  padding: 11px 20px;
  text-decoration: none;
  display: inline-flex; align-items: center; justify-content: center;
  transition: transform 0.12s var(--ease), background 0.16s var(--ease),
              box-shadow 0.16s var(--ease), border-color 0.16s var(--ease), color 0.16s var(--ease);
}
.btn:active { transform: translateY(1px); }
.btn--sm { padding: 7px 13px; font-size: 0.84rem; border-radius: 9px; }

.btn--quiet {
  background: transparent;
  color: var(--ink);
  border-color: var(--rule);
}
.btn--quiet:hover { border-color: var(--signal); color: var(--signal-dk); background: var(--signal-wash); }

/* ============================================================
   LAYOUT
   ============================================================ */
.grid {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: clamp(20px, 3vw, 30px) clamp(20px, 5vw, 44px) 24px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(16px, 2vw, 22px);
  align-items: start;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 18px 20px 20px;
  min-width: 0;
}
.panel--output { align-self: stretch; }
.panel--input { position: sticky; top: 16px; }

.panel__head {
  display: flex; align-items: center; gap: 12px;
  margin-bottom: 14px;
}
.panel__title {
  font-size: 0.82rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.13em;
  color: var(--ink-faint); font-family: var(--mono);
}
.panel__tools { margin-left: auto; display: flex; gap: 8px; }
.panel__count {
  margin-left: auto;
  font-family: var(--mono);
  font-size: 0.76rem; font-weight: 600;
  color: var(--signal-dk);
  background: var(--signal-wash);
  border: 1px solid var(--signal);
  padding: 2px 10px; border-radius: 999px;
}
.panel__count:empty { display: none; }

/* ============================================================
   EDITOR (paste area)
   ============================================================ */
.editor {
  position: relative;
  display: flex;
  background: var(--panel2);
  border: 1px solid var(--rule);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: border-color 0.15s var(--ease), box-shadow 0.15s var(--ease);
}
.editor:focus-within { border-color: var(--signal); box-shadow: 0 0 0 3px var(--signal-wash); }
.editor__gutter {
  flex: none;
  width: 40px;
  padding: 14px 0;
  text-align: center;
  font-family: var(--mono);
  font-size: 0.85rem; font-weight: 700;
  color: var(--signal-dk);
  background: color-mix(in srgb, var(--signal) 8%, transparent);
  border-right: 1px solid var(--rule);
  user-select: none;
}
.editor__area {
  flex: 1;
  min-height: 260px;
  resize: vertical;
  border: none; outline: none;
  background: transparent;
  color: var(--code-ink);
  font-family: var(--mono);
  font-size: 0.92rem;
  line-height: 1.6;
  padding: 13px 15px;
  width: 100%;
  tab-size: 2;
}
.editor__area::placeholder { color: var(--ink-faint); }

.editor__hint {
  margin-top: 11px;
  font-size: 0.8rem;
  color: var(--ink-faint);
  line-height: 1.5;
}
.editor__kbd {
  font-family: var(--mono);
  font-size: 0.74rem; font-weight: 600;
  color: var(--ink-soft);
  background: var(--panel2);
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: 1px 6px;
}

/* ============================================================
   META STRIP (parsed error class + top frame)
   ============================================================ */
.meta {
  display: flex; flex-wrap: wrap; gap: 8px 20px;
  margin-bottom: 16px;
  padding: 11px 14px;
  background: var(--panel2);
  border: 1px solid var(--rule);
  border-radius: var(--radius-sm);
}
.meta__item { display: inline-flex; align-items: baseline; gap: 8px; min-width: 0; }
.meta__key {
  font-size: 0.66rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.09em;
  color: var(--ink-faint); font-family: var(--mono);
  flex: none;
}
.meta__val {
  font-family: var(--mono);
  font-size: 0.86rem; font-weight: 600;
  color: var(--code-ink);
  overflow-wrap: anywhere;
}

/* ============================================================
   EMPTY STATE
   ============================================================ */
.empty {
  text-align: center;
  padding: 40px 20px 46px;
  color: var(--ink-faint);
}
.empty__mark { width: 56px; height: 56px; color: var(--signal); opacity: 0.55; }
.empty__title { margin-top: 14px; font-size: 1.05rem; font-weight: 700; color: var(--ink-soft); }
.empty__text { margin-top: 6px; font-size: 0.9rem; max-width: 34ch; margin-left: auto; margin-right: auto; }
.empty__text em { font-style: normal; font-weight: 700; color: var(--ink-soft); }

/* ============================================================
   DIAGNOSIS CARDS
   ============================================================ */
.results { display: flex; flex-direction: column; gap: 18px; }

.diag {
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  background: var(--panel);
  padding: 16px 18px 18px;
}
.diag--primary {
  border-color: var(--signal);
  background:
    linear-gradient(180deg, var(--signal-wash), transparent 46%),
    var(--panel);
  box-shadow: var(--shadow);
}
.diag--primary:focus { outline: 3px solid var(--signal); outline-offset: 3px; }
.diag--heuristic {
  border-color: var(--cause);
  background: linear-gradient(180deg, var(--cause-wash), transparent 46%), var(--panel);
}
.diag--none {
  border-color: var(--rule);
  background: var(--panel);
}

.diag__head {
  display: flex; align-items: flex-start; gap: 12px;
  margin-bottom: 10px;
}
.diag__titlewrap { min-width: 0; flex: 1; }
.diag__badge {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.64rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.1em;
  color: #fff; background: var(--signal-dk);
  border-radius: 999px; padding: 3px 10px;
  margin-bottom: 8px;
}
.diag__badge--soft { background: var(--cause); }
.diag--none .diag__badge--soft { background: var(--ink-faint); }
.diag__title { font-size: 1.18rem; letter-spacing: -0.02em; }
.diag__meaning { margin-top: 8px; color: var(--ink-soft); font-size: 0.95rem; line-height: 1.55; }
.diag__caveat {
  margin-top: 12px;
  font-size: 0.82rem; color: var(--ink-faint);
  border-top: 1px dashed var(--rule); padding-top: 10px;
  line-height: 1.5;
}

.chip {
  font-family: var(--mono);
  font-size: 0.68rem; font-weight: 600;
  border-radius: 999px;
  padding: 3px 10px;
  white-space: nowrap;
  flex: none;
}
.chip--lang {
  color: var(--signal-dk);
  background: var(--signal-wash);
  border: 1px solid var(--signal);
}
.chip--tag {
  color: var(--ink-faint);
  background: var(--panel2);
  border: 1px solid var(--rule);
}

/* cause / fix blocks */
.diag__body { margin-top: 14px; display: flex; flex-direction: column; gap: 14px; }
.block__label {
  font-size: 0.68rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.09em;
  font-family: var(--mono);
  margin-bottom: 7px;
}
.block--causes .block__label { color: var(--cause); }
.block--fixes .block__label { color: var(--signal-dk); }

.block__list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 7px; }
.block__list li {
  position: relative;
  padding-left: 22px;
  font-size: 0.92rem;
  color: var(--ink);
  line-height: 1.5;
}
.block__list li::before {
  position: absolute; left: 0; top: 0.06em;
  font-family: var(--mono); font-weight: 700;
}
.block__list--causes li::before { content: "›"; color: var(--cause); font-size: 1.05em; }
.block__list--fixes li { counter-increment: fixnum; }
.block__list--fixes { counter-reset: fixnum; }
.block__list--fixes li::before {
  content: counter(fixnum);
  color: var(--signal-dk);
  font-size: 0.72em;
  top: 0.28em;
  font-weight: 800;
}

.tags { margin-top: 14px; display: flex; flex-wrap: wrap; gap: 6px; padding-top: 12px; border-top: 1px solid var(--rule2); }

/* "other possibilities" */
.also { }
.also__label {
  font-size: 0.68rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.1em;
  color: var(--ink-faint); font-family: var(--mono);
  margin-bottom: 10px;
}
.also__grid { display: flex; flex-direction: column; gap: 10px; }
.also .diag { padding: 13px 15px; background: var(--panel2); }
.also .diag__meaning { margin-top: 6px; font-size: 0.88rem; }
.diag__promote {
  margin-top: 10px;
  font-family: var(--mono);
  font-size: 0.78rem; font-weight: 700;
  color: var(--signal-dk);
  background: transparent;
  border: 1px solid var(--signal);
  border-radius: 8px;
  padding: 5px 12px;
  cursor: pointer;
  transition: background 0.14s var(--ease), color 0.14s var(--ease);
}
.diag__promote:hover { background: var(--signal-wash); }

/* ============================================================
   FOOTER
   ============================================================ */
.foot { border-top: 1px solid var(--rule); background: var(--panel); margin-top: 16px; }
.foot__inner { max-width: var(--wrap); margin: 0 auto; padding: 26px clamp(20px, 5vw, 44px) 38px; }
.foot__disclaimer { font-size: 0.85rem; color: var(--ink-soft); max-width: 88ch; line-height: 1.55; }
.foot__disclaimer strong { color: var(--ink); }
.foot__meta {
  margin-top: 15px; display: flex; flex-wrap: wrap; gap: 6px 10px;
  font-size: 0.78rem; color: var(--ink-faint); font-family: var(--mono);
}
.foot__dot { color: var(--rule); }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 860px) {
  .grid { grid-template-columns: 1fr; }
  .panel--input { position: static; }
  .editor__area { min-height: 180px; }
}
@media (max-width: 520px) {
  .panel { padding: 16px 14px 18px; }
  .hero__langs span { font-size: 0.72rem; }
}

/* ============================================================
   REDUCED MOTION
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
  html { scroll-behavior: auto; }
}