/* Shared styles for Hardy-Weinberg and Blood Type calculators.
   Reuses the same design tokens as punnett.css. */

:root {
  --paper: #FAFAF8; --ink: #1D1D1F; --ink-soft: #6E6E73;
  --pine: #2C5F4F; --pine-soft: #E4ECE8;
  --amber: #C4622D; --amber-soft: #F5E4D9;
  --red: #B3261E; --red-soft: #FBEAE9;
  --line: #E8E6DE; --line-strong: #D8D5CB; --white: #FFFFFF;
  --font-display: 'Fraunces', Georgia, serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, monospace;
  --radius-sm: 8px; --radius-md: 14px; --radius-lg: 20px;
  --shadow-soft: 0 1px 2px rgba(29,29,31,0.04), 0 8px 24px rgba(29,29,31,0.06);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; background: var(--paper); color: var(--ink); font-family: var(--font-body); -webkit-font-smoothing: antialiased; }
h1,h2,h3 { font-family: var(--font-display); font-weight: 600; margin: 0; letter-spacing: -0.01em; }
p { margin: 0; }

/* ===== TOPBAR ===== */
.topbar { height: 64px; display: flex; align-items: center; justify-content: space-between; padding: 0 24px; border-bottom: 1px solid var(--line); background: var(--white); position: sticky; top: 0; z-index: 30; }
.topbar__brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); }
.topbar__mark { color: var(--pine); width: 26px; height: 26px; flex-shrink: 0; }
.topbar__name { font-family: var(--font-display); font-size: 19px; font-weight: 600; }
.topbar__actions { display: flex; align-items: center; gap: 6px; }
.btn { font-size: 14px; font-weight: 600; border-radius: 100px; border: none; cursor: pointer; white-space: nowrap; display: inline-flex; align-items: center; text-decoration: none; transition: background 0.15s, color 0.15s, opacity 0.15s; }
.btn--primary { background: var(--ink); color: var(--white); padding: 10px 18px; }
.btn--primary:hover { opacity: 0.88; }
.btn--ghost { background: none; color: var(--ink-soft); padding: 9px 14px; }
.btn--ghost:hover { background: var(--paper); color: var(--ink); }
.btn--current { color: var(--pine); background: var(--pine-soft); }
.btn:focus-visible { outline: 2px solid var(--pine); outline-offset: 2px; }

/* ===== PAGE LAYOUT ===== */
.page-shell { max-width: 760px; margin: 0 auto; padding: 48px 24px 80px; }
.eyebrow { display: inline-flex; align-items: center; gap: 8px; font-size: 12.5px; font-weight: 600; color: var(--pine); text-transform: uppercase; letter-spacing: 0.04em; margin-bottom: 16px; }
.eyebrow__dot { width: 6px; height: 6px; border-radius: 50%; background: var(--amber); }
.page-shell h1 { font-family: var(--font-display); font-size: 36px; line-height: 1.15; font-weight: 600; letter-spacing: -0.01em; margin: 0 0 14px; }
.page-dek { font-size: 17px; line-height: 1.55; color: var(--ink-soft); margin: 0 0 36px; }

/* ===== SETUP CARD ===== */
.setup-card { background: var(--white); border: 1px solid var(--line); border-radius: var(--radius-lg); padding: 28px; box-shadow: var(--shadow-soft); margin-bottom: 28px; }
.setup-card__title { font-family: var(--font-display); font-size: 17px; font-weight: 600; margin: 0 0 20px; }

/* Mode toggle */
.mode-row { display: flex; gap: 8px; margin-bottom: 24px; }
.mode-btn { flex: 1; padding: 10px 14px; border: 1.5px solid var(--line-strong); border-radius: var(--radius-sm); background: var(--white); font-family: var(--font-body); font-size: 14px; font-weight: 600; color: var(--ink); cursor: pointer; transition: border-color 0.15s, background 0.15s; text-align: center; }
.mode-btn:hover { border-color: var(--pine); background: var(--pine-soft); }
.mode-btn.is-active { border-color: var(--pine); background: var(--pine-soft); color: var(--pine); }

/* Input rows */
.input-group { margin-bottom: 18px; }
.input-group label { display: block; font-size: 12.5px; font-weight: 600; color: var(--ink-soft); text-transform: uppercase; letter-spacing: 0.04em; margin-bottom: 8px; }
.input-group input[type="number"],
.input-group input[type="text"] { width: 100%; padding: 10px 14px; border: 1.5px solid var(--line-strong); border-radius: var(--radius-sm); font-family: var(--font-mono); font-size: 17px; background: var(--white); color: var(--ink); transition: border-color 0.15s; }
.input-group input:focus { outline: none; border-color: var(--pine); }
.input-group input.is-invalid { border-color: var(--red); background: var(--red-soft); }
.input-hint { font-size: 12.5px; color: var(--ink-soft); margin-top: 6px; }
.input-error { font-size: 12.5px; color: var(--red); margin-top: 6px; display: none; }
.input-error.is-visible { display: block; }

/* Select inputs (blood type) */
.select-input { width: 100%; padding: 10px 14px; border: 1.5px solid var(--line-strong); border-radius: var(--radius-sm); font-family: var(--font-body); font-size: 16px; background: var(--white); color: var(--ink); transition: border-color 0.15s; appearance: none; background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%236E6E73' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: right 14px center; }
.select-input:focus { outline: none; border-color: var(--pine); }

.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.three-col { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 16px; align-items: end; }

.calc-btn { width: 100%; margin-top: 22px; padding: 13px; font-size: 15px; }

/* ===== RESULTS ===== */
.results-area { display: none; }
.results-area.is-visible { display: block; }

.hw-card { background: var(--white); border: 1px solid var(--line); border-radius: var(--radius-lg); padding: 28px; box-shadow: var(--shadow-soft); margin-bottom: 20px; }
.hw-card__title { font-family: var(--font-display); font-size: 17px; font-weight: 600; margin: 0 0 18px; }

/* Frequency bars */
.hw-freq-row { display: flex; align-items: center; gap: 12px; margin-bottom: 10px; }
.hw-freq-label { font-family: var(--font-mono); font-size: 13px; min-width: 220px; flex-shrink: 0; color: var(--ink); }
.hw-freq-track { flex: 1; height: 24px; background: var(--paper); border-radius: 4px; overflow: hidden; border: 1px solid var(--line); }
.hw-freq-bar { height: 100%; border-radius: 3px; transition: width 0.4s ease; min-width: 2px; }
.hw-freq-bar--dominant { background: var(--pine); }
.hw-freq-bar--recessive { background: var(--amber); }
.hw-freq-bar--het { background: #7a5c9e; }
.hw-freq-val { font-family: var(--font-mono); font-size: 13px; font-weight: 600; min-width: 52px; }

.hw-equation { font-family: var(--font-mono); font-size: 13px; color: var(--ink-soft); margin-top: 12px; text-align: right; }

/* Obs/expected table */
.hw-obs-table { width: 100%; border-collapse: collapse; font-size: 14.5px; }
.hw-obs-table th { text-align: left; font-size: 12px; font-weight: 600; color: var(--ink-soft); text-transform: uppercase; letter-spacing: 0.04em; padding: 6px 10px; border-bottom: 1px solid var(--line); }
.hw-obs-table td { padding: 10px 10px; border-bottom: 1px solid var(--line); }
.hw-table-geno { font-family: var(--font-mono); font-weight: 500; }
.hw-total td { font-weight: 600; color: var(--ink-soft); font-size: 13px; }
.hw-excess { color: var(--amber); font-weight: 600; }
.hw-deficit { color: var(--pine); font-weight: 600; }

/* Chi-square */
.hw-stat-row { display: flex; justify-content: space-between; align-items: center; padding: 10px 0; border-bottom: 1px solid var(--line); font-size: 15px; }
.hw-stat-row strong { font-family: var(--font-mono); font-size: 16px; }
.hw-verdict { margin-top: 16px; font-size: 15.5px; font-weight: 600; }
.hw-pass { color: var(--pine); }
.hw-fail { color: var(--amber); }
.hw-note { font-size: 13px; color: var(--ink-soft); line-height: 1.6; margin-top: 12px; }

/* ===== BLOOD TYPE SPECIFIC ===== */
.bt-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(120px, 1fr)); gap: 12px; margin-top: 4px; }
.bt-result-card { border: 1px solid var(--line); border-radius: var(--radius-md); padding: 14px 12px; background: var(--paper); text-align: center; }
.bt-result-card--possible { border-color: var(--pine); background: var(--pine-soft); }
.bt-type { font-family: var(--font-display); font-size: 22px; font-weight: 600; display: block; margin-bottom: 6px; }
.bt-type--dominant { color: var(--pine); }
.bt-type--pheno-Ab { color: var(--amber); }
.bt-type--pheno-aB { color: #7a5c9e; }
.bt-type--recessive { color: var(--ink-soft); }
.bt-prob { font-size: 15px; font-weight: 700; color: var(--ink); }
.bt-possible-label { font-size: 12px; font-weight: 600; color: var(--pine); text-transform: uppercase; letter-spacing: 0.04em; }
.bt-impossible { margin-top: 16px; font-size: 13.5px; color: var(--ink-soft); display: flex; flex-wrap: wrap; align-items: center; gap: 6px; }
.bt-impossible-type { font-family: var(--font-mono); background: var(--red-soft); color: var(--red); padding: 2px 8px; border-radius: 4px; font-size: 13px; }
.bt-parent-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-bottom: 16px; }
.bt-parent-label { font-size: 12.5px; font-weight: 600; color: var(--ink-soft); text-transform: uppercase; letter-spacing: 0.04em; margin-bottom: 8px; display: block; }
.bt-select-row { display: flex; gap: 8px; }
.bt-select-row .select-input { flex: 1; }

/* ===== FOOTER ===== */
.disclaimer { padding: 18px 24px; border-top: 1px solid var(--line); background: var(--white); font-size: 12.5px; line-height: 1.6; color: var(--ink-soft); text-align: center; }
.disclaimer strong { color: var(--ink); }

/* ===== RESPONSIVE ===== */
@media (max-width: 640px) {
  .topbar { padding: 0 14px; }
  .topbar__name { display: none; }
  .topbar__actions .btn--ghost { padding: 8px 10px; font-size: 12.5px; }
  .topbar__cta--hide-mobile { display: none !important; }
  .page-shell { padding: 32px 16px 60px; }
  .page-shell h1 { font-size: 26px; }
  .setup-card, .hw-card { padding: 20px; }
  .two-col, .three-col { grid-template-columns: 1fr; }
  .hw-freq-label { min-width: 160px; font-size: 11.5px; }
  .bt-parent-row { grid-template-columns: 1fr; }
}

@supports (padding: max(0px)) {
  .topbar { padding-left: max(16px, env(safe-area-inset-left)); padding-right: max(16px, env(safe-area-inset-right)); }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; } }

/* ===== EYE COLOR + HAIR COLOR ===== */
.ec-result-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
  gap: 14px;
  margin-top: 4px;
}
.ec-color-card {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 14px 12px;
  background: var(--paper);
  text-align: center;
}
.ec-eye {
  width: 48px; height: 48px;
  border-radius: 50%;
  margin: 0 auto 10px;
  border: 3px solid rgba(0,0,0,0.12);
  box-shadow: inset 0 2px 6px rgba(0,0,0,0.25);
}
.ec-hair-swatch {
  width: 48px; height: 48px;
  border-radius: var(--radius-sm);
  margin: 0 auto 10px;
  border: 2px solid rgba(0,0,0,0.12);
}
.ec-color-label {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 4px;
}
.ec-pct {
  font-size: 20px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 8px;
}

/* Color select inputs */
.color-select-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 20px;
}
.color-option {
  display: flex;
  align-items: center;
  gap: 8px;
}
.color-dot {
  width: 14px; height: 14px;
  border-radius: 50%;
  flex-shrink: 0;
  border: 1.5px solid rgba(0,0,0,0.15);
}

/* Grandparents section */
.gp-section {
  margin-top: 20px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}
.gp-section__title {
  font-size: 13px;
  font-weight: 600;
  color: var(--ink-soft);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 14px;
}
.gp-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}
.gp-col__label {
  font-size: 12px;
  font-weight: 600;
  color: var(--ink-soft);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 10px;
}
.gp-inputs {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

/* ===== HEIGHT PREDICTOR ===== */
.unit-toggle-row {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 22px;
}
.unit-toggle-row label {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--ink-soft);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.unit-toggle-row select {
  padding: 8px 12px;
  border: 1.5px solid var(--line-strong);
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: 14px;
  background: var(--white);
  color: var(--ink);
}
.height-input-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 4px;
}
.ft-in-row {
  display: flex;
  gap: 8px;
}
.ft-in-row input {
  flex: 1;
}
.ht-results-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 8px;
}
.ht-result-block {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 16px;
}
.ht-sex-label {
  font-size: 12px;
  font-weight: 600;
  color: var(--ink-soft);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 6px;
}
.ht-target {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 4px;
}
.ht-range-label {
  font-size: 13px;
  color: var(--ink-soft);
  margin-bottom: 10px;
}
.ht-range-bar {
  height: 10px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 5px;
  position: relative;
  overflow: hidden;
  margin-bottom: 8px;
}
.ht-range-fill {
  position: absolute;
  left: 15%; right: 15%;
  top: 0; bottom: 0;
  border-radius: 4px;
}
.ht-range-fill--dominant { background: var(--pine); opacity: 0.5; }
.ht-range-fill--pheno-aB { background: #7a5c9e; opacity: 0.5; }
.ht-range-marker {
  position: absolute;
  top: 0; bottom: 0;
  width: 3px;
  background: var(--ink);
  border-radius: 2px;
  transform: translateX(-50%);
}
.ht-parents-row {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
  font-size: 14px;
  color: var(--ink-soft);
  margin-bottom: 18px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}
.ht-parents-row strong { color: var(--ink); }
.ht-mid-parental {
  font-size: 13px;
  color: var(--ink-soft);
  margin-bottom: 4px;
}

@media (max-width: 640px) {
  .color-select-row { grid-template-columns: 1fr; }
  .gp-grid { grid-template-columns: 1fr; }
  .ht-results-grid { grid-template-columns: 1fr; }
  .ht-target { font-size: 22px; }
  .ec-result-grid { grid-template-columns: repeat(auto-fill, minmax(100px, 1fr)); }
}

/* ===== SEQUENCE TOOLS (GC Content, Reverse Complement, Transcription, MW) ===== */
.seq-textarea {
  width: 100%;
  min-height: 110px;
  padding: 12px 14px;
  border: 1.5px solid var(--line-strong);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.6;
  background: var(--white);
  color: var(--ink);
  resize: vertical;
  transition: border-color 0.15s;
  word-break: break-all;
}
.seq-textarea:focus { outline: none; border-color: var(--pine); }
.seq-textarea.is-invalid { border-color: var(--red); background: var(--red-soft); }

.tool-row { display: flex; gap: 10px; align-items: flex-end; margin-bottom: 18px; flex-wrap: wrap; }
.tool-row .input-group { flex: 1; min-width: 140px; }

.btn--secondary {
  background: var(--paper);
  color: var(--ink-soft);
  border: 1.5px solid var(--line-strong);
  padding: 10px 18px;
}
.btn--secondary:hover { border-color: var(--pine); color: var(--pine); background: var(--pine-soft); }

/* GC Content */
.gc-stats-row { display: flex; gap: 16px; margin-bottom: 20px; flex-wrap: wrap; }
.gc-stat { flex: 1; min-width: 80px; background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius-md); padding: 14px; text-align: center; }
.gc-stat--gc { border-color: var(--pine); background: var(--pine-soft); }
.gc-stat--at { border-color: var(--amber); background: var(--amber-soft); }
.gc-stat__val { font-family: var(--font-display); font-size: 24px; font-weight: 600; color: var(--ink); }
.gc-stat__label { font-size: 12px; font-weight: 600; color: var(--ink-soft); text-transform: uppercase; letter-spacing: 0.04em; margin-top: 4px; }
.gc-base-bars { margin-top: 8px; }

/* Reverse Complement */
.rc-block { border: 1px solid var(--line); border-radius: var(--radius-sm); overflow: hidden; margin-bottom: 10px; }
.rc-block__header { display: flex; justify-content: space-between; align-items: center; padding: 8px 12px; background: var(--paper); border-bottom: 1px solid var(--line); }
.rc-block__label { font-size: 12.5px; font-weight: 600; color: var(--ink-soft); text-transform: uppercase; letter-spacing: 0.04em; }
.rc-copy-btn { font-size: 12px; font-weight: 600; color: var(--pine); background: none; border: 1px solid var(--pine); border-radius: 4px; padding: 3px 10px; cursor: pointer; font-family: var(--font-body); transition: background 0.15s; }
.rc-copy-btn:hover { background: var(--pine-soft); }
.rc-sequence {
  padding: 12px;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.7;
  word-break: break-all;
  overflow-wrap: break-word;
  color: var(--ink);
  background: var(--white);
  /* Prevent horizontal overflow from long unbroken sequences */
  overflow-x: hidden;
  max-width: 100%;
  white-space: pre-wrap;
}

/* Transcription & Translation */
.tt-step { margin-bottom: 20px; }
.tt-step__label { font-size: 13px; font-weight: 600; color: var(--ink-soft); text-transform: uppercase; letter-spacing: 0.04em; margin-bottom: 8px; display: flex; align-items: center; gap: 8px; }
.tt-frame-badge { background: var(--pine-soft); color: var(--pine); border-radius: 4px; padding: 2px 8px; font-size: 11.5px; text-transform: none; letter-spacing: 0; }
.tt-codon-row { display: flex; flex-wrap: wrap; gap: 4px; }
.tt-codon { display: flex; flex-direction: column; align-items: center; border: 1px solid var(--line); border-radius: 5px; background: var(--white); min-width: 36px; padding: 4px 2px; }
.tt-codon--start { border-color: var(--pine); background: var(--pine-soft); }
.tt-codon--stop  { border-color: var(--red);  background: var(--red-soft); opacity: 0.8; }
.tt-codon__bases { font-family: var(--font-mono); font-size: 11px; color: var(--ink-soft); }
.tt-codon__aa    { font-family: var(--font-mono); font-size: 13px; font-weight: 600; color: var(--ink); }
.dna-block  .rc-sequence { color: #1a5276; }
.mrna-block .rc-sequence { color: var(--pine); }

/* DNA Molecular Weight */
.mw-result-grid { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 18px; }
.mw-stat { flex: 1; min-width: 100px; background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius-md); padding: 14px; text-align: center; }
.mw-stat__val { font-family: var(--font-display); font-size: 20px; font-weight: 600; color: var(--ink); word-break: break-all; }
.mw-stat__label { font-size: 11.5px; font-weight: 600; color: var(--ink-soft); text-transform: uppercase; letter-spacing: 0.04em; margin-top: 4px; }

@media (max-width: 640px) {
  .gc-stats-row { gap: 10px; }
  .gc-stat__val { font-size: 20px; }
  .mw-stat__val { font-size: 17px; }
  .tt-codon { min-width: 30px; }
  .tt-codon__bases { font-size: 10px; }
  .tt-codon__aa    { font-size: 11px; }
  .rc-sequence { font-size: 12px; }
}

/* ===== SEQUENCE TOOLS (GC Content, Reverse Complement, Transcription, MW) ===== */
.seq-textarea {
  width: 100%;
  min-height: 110px;
  padding: 12px 14px;
  border: 1.5px solid var(--line-strong);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.6;
  background: var(--white);
  color: var(--ink);
  resize: vertical;
  transition: border-color 0.15s;
  word-break: break-all;
}
.seq-textarea:focus { outline: none; border-color: var(--pine); }
.seq-textarea.is-invalid { border-color: var(--red); background: var(--red-soft); }

.tool-row { display: flex; gap: 10px; align-items: flex-end; margin-bottom: 18px; flex-wrap: wrap; }
.tool-row .input-group { flex: 1; min-width: 140px; }

.btn--secondary {
  background: var(--paper);
  color: var(--ink-soft);
  border: 1.5px solid var(--line-strong);
  padding: 10px 18px;
}
.btn--secondary:hover { border-color: var(--pine); color: var(--pine); background: var(--pine-soft); }

/* GC Content */
.gc-stats-row { display: flex; gap: 16px; margin-bottom: 20px; flex-wrap: wrap; }
.gc-stat { flex: 1; min-width: 80px; background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius-md); padding: 14px; text-align: center; }
.gc-stat--gc { border-color: var(--pine); background: var(--pine-soft); }
.gc-stat--at { border-color: var(--amber); background: var(--amber-soft); }
.gc-stat__val { font-family: var(--font-display); font-size: 24px; font-weight: 600; color: var(--ink); }
.gc-stat__label { font-size: 12px; font-weight: 600; color: var(--ink-soft); text-transform: uppercase; letter-spacing: 0.04em; margin-top: 4px; }
.gc-base-bars { margin-top: 8px; }

/* Reverse Complement */
.rc-block { border: 1px solid var(--line); border-radius: var(--radius-sm); overflow: hidden; margin-bottom: 10px; }
.rc-block__header { display: flex; justify-content: space-between; align-items: center; padding: 8px 12px; background: var(--paper); border-bottom: 1px solid var(--line); }
.rc-block__label { font-size: 12.5px; font-weight: 600; color: var(--ink-soft); text-transform: uppercase; letter-spacing: 0.04em; }
.rc-copy-btn { font-size: 12px; font-weight: 600; color: var(--pine); background: none; border: 1px solid var(--pine); border-radius: 4px; padding: 3px 10px; cursor: pointer; font-family: var(--font-body); transition: background 0.15s; }
.rc-copy-btn:hover { background: var(--pine-soft); }
.rc-sequence {
  padding: 12px;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.7;
  word-break: break-all;
  overflow-wrap: break-word;
  color: var(--ink);
  background: var(--white);
  /* Prevent horizontal overflow from long unbroken sequences */
  overflow-x: hidden;
  max-width: 100%;
  white-space: pre-wrap;
}

/* Transcription & Translation */
.tt-step { margin-bottom: 20px; }
.tt-step__label { font-size: 13px; font-weight: 600; color: var(--ink-soft); text-transform: uppercase; letter-spacing: 0.04em; margin-bottom: 8px; display: flex; align-items: center; gap: 8px; }
.tt-frame-badge { background: var(--pine-soft); color: var(--pine); border-radius: 4px; padding: 2px 8px; font-size: 11.5px; text-transform: none; letter-spacing: 0; }
.tt-codon-row { display: flex; flex-wrap: wrap; gap: 4px; }
.tt-codon { display: flex; flex-direction: column; align-items: center; border: 1px solid var(--line); border-radius: 5px; background: var(--white); min-width: 36px; padding: 4px 2px; }
.tt-codon--start { border-color: var(--pine); background: var(--pine-soft); }
.tt-codon--stop  { border-color: var(--red);  background: var(--red-soft); opacity: 0.8; }
.tt-codon__bases { font-family: var(--font-mono); font-size: 11px; color: var(--ink-soft); }
.tt-codon__aa    { font-family: var(--font-mono); font-size: 13px; font-weight: 600; color: var(--ink); }
.dna-block  .rc-sequence { color: #1a5276; }
.mrna-block .rc-sequence { color: var(--pine); }

/* DNA Molecular Weight */
.mw-result-grid { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 18px; }
.mw-stat { flex: 1; min-width: 100px; background: var(--paper); border: 1px solid var(--line); border-radius: var(--radius-md); padding: 14px; text-align: center; }
.mw-stat__val { font-family: var(--font-display); font-size: 20px; font-weight: 600; color: var(--ink); word-break: break-all; }
.mw-stat__label { font-size: 11.5px; font-weight: 600; color: var(--ink-soft); text-transform: uppercase; letter-spacing: 0.04em; margin-top: 4px; }

@media (max-width: 640px) {
  .gc-stats-row { gap: 10px; }
  .gc-stat__val { font-size: 20px; }
  .mw-stat__val { font-size: 17px; }
  .tt-codon { min-width: 30px; }
  .tt-codon__bases { font-size: 10px; }
  .tt-codon__aa    { font-size: 11px; }
  .rc-sequence { font-size: 12px; }
}

/* ===== SEO CONTENT SECTIONS ===== */
.tool-explainer,
.tool-faq,
.tool-related {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-soft);
  margin-bottom: 20px;
  max-width: 760px;
  margin-left: auto;
  margin-right: auto;
}
.tool-explainer h2,
.tool-faq h2,
.tool-related h2 {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 600;
  margin-bottom: 14px;
}
.tool-explainer h3 {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 600;
  margin: 18px 0 8px;
}
.tool-explainer p,
.tool-faq p,
.tool-related p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink);
  margin-bottom: 12px;
}
.tool-explainer p:last-child,
.tool-faq p:last-child { margin-bottom: 0; }

/* ===== FAQ ACCORDION ===== */
.faq-item {
  border-bottom: 1px solid var(--line);
}
.faq-item:last-child { border-bottom: none; }

.faq-item summary {
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 16px 0;
  cursor: pointer;
  user-select: none;
  font-family: var(--font-display);
  font-size: 15.5px;
  font-weight: 600;
  color: var(--ink);
  transition: color 0.15s;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::marker { display: none; }
.faq-item summary:hover { color: var(--pine); }
.faq-item summary:focus-visible { outline: 2px solid var(--pine); outline-offset: 2px; border-radius: 4px; }

.faq-item__chevron {
  width: 18px; height: 18px;
  flex-shrink: 0;
  color: var(--ink-soft);
  transition: transform 0.2s ease, color 0.15s;
}
.faq-item[open] .faq-item__chevron {
  transform: rotate(180deg);
  color: var(--pine);
}
.faq-item[open] summary { color: var(--pine); }

.faq-item p {
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--ink);
  margin: 0 0 16px;
  padding-right: 34px; /* align with summary text, not chevron */
}

.tool-related ul { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 10px; }
.tool-related li { font-size: 14.5px; color: var(--ink-soft); }
.tool-related a { color: var(--pine); font-weight: 600; text-decoration: none; }
.tool-related a:hover { text-decoration: underline; }

@media (max-width: 640px) {
  .tool-explainer, .tool-faq, .tool-related { padding: 20px; }
}