/*
 * PICUcalc — picu.ai Design System
 * All styling follows DESIGN_SYSTEM.md and design-tokens.css
 */

/* ── Design Tokens ─────────────────────────────────────────── */
:root {
  --color-ink:          #0d0d0d;
  --color-mist:         #f7f7f5;
  --color-white:        #ffffff;
  --color-accent:       #1a6eff;
  --color-accent-soft:  rgba(26,110,255,0.08);
  --color-accent-glow:  rgba(26,110,255,0.22);
  --color-border:       rgba(13,13,13,0.10);
  --color-border-hover: rgba(13,13,13,0.18);
  --color-text-muted:   #555555;
  --color-text-subtle:  #999999;
  --color-text-faint:   #aaaaaa;
  --color-text-body:    #3a3a3a;
  --color-text-strong:  #111111;

  --font-display: 'DM Serif Display', serif;
  --font-body:    'DM Sans', sans-serif;

  --border-radius: 3px;
  --ease-out-expo: cubic-bezier(0.22, 1, 0.36, 1);

  /* Severity colors (for medical results) */
  --color-severity-safe:   #1a8a4a;
  --color-severity-warn:   #c17d10;
  --color-severity-danger: #c9302c;
  --color-severity-info:   #1a6eff;
}

/* ── Keyframes ─────────────────────────────────────────────── */
@keyframes rise {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0);    }
}
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

/* ── Reset & Base ──────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-weight: 300;
  font-size: 1rem;
  line-height: 1.75;
  color: var(--color-text-body);
  background: linear-gradient(rgba(255,255,255,0.55), rgba(255,255,255,0.55)), url('https://picu.ai/background.jpeg') center / cover no-repeat fixed;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 400;
  letter-spacing: -0.02em;
  color: var(--color-ink);
  line-height: 1.15;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color 0.2s ease;
}
a:hover { color: var(--color-ink); }

/* ── Navigation ────────────────────────────────────────────── */
.site-nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 0 2rem;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: rgba(247, 247, 245, 0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  animation: fadeIn 0.6s 0.05s ease both;
}

.nav-wordmark {
  font-family: var(--font-display);
  font-size: 1.35rem;
  letter-spacing: -0.02em;
  color: var(--color-ink);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.2rem;
}
.nav-wordmark:hover { color: var(--color-ink); }
.nav-wordmark .accent { color: var(--color-accent); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 0.2rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a,
.nav-links .nav-link-btn {
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.10em;
  color: var(--color-text-muted);
  text-decoration: none;
  padding: 0.5rem 0.9rem;
  border-radius: var(--border-radius);
  transition: color 0.2s ease, background 0.2s ease;
  cursor: pointer;
  background: none;
  border: none;
  position: relative;
}
.nav-links a:hover,
.nav-links .nav-link-btn:hover {
  color: var(--color-ink);
  background: var(--color-accent-soft);
}
.nav-links a.active,
.nav-links .nav-link-btn.active {
  color: var(--color-accent);
}

/* Nav picu.ai return link */
.nav-return {
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.10em;
  color: var(--color-accent);
  text-decoration: none;
  padding: 0.5rem 1rem;
  border: 1.5px solid var(--color-accent);
  border-radius: var(--border-radius);
  transition: all 0.22s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}
.nav-return:hover {
  background: var(--color-accent);
  color: var(--color-white);
  transform: translateY(-1px);
}

/* Dropdown */
.nav-dropdown {
  position: relative;
}
.nav-dropdown-menu {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 240px;
  padding: 0.5rem 0;
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  box-shadow: 0 8px 32px rgba(0,0,0,0.08);
  z-index: 200;
  margin-top: 0.4rem;
}
.nav-dropdown:hover .nav-dropdown-menu,
.nav-dropdown.open .nav-dropdown-menu {
  display: block;
}
.nav-dropdown-menu a {
  display: block;
  padding: 0.55rem 1.2rem;
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 0.85rem;
  color: var(--color-text-body);
  text-transform: none;
  letter-spacing: 0;
  transition: background 0.15s ease;
}
.nav-dropdown-menu a:hover {
  background: var(--color-accent-soft);
  color: var(--color-ink);
}
.nav-dropdown-menu .dropdown-divider {
  height: 1px;
  background: var(--color-border);
  margin: 0.3rem 0;
}

/* Mobile nav toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  color: var(--color-ink);
  font-size: 1.4rem;
  line-height: 1;
}

@media (max-width: 768px) {
  .nav-toggle { display: block; }
  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0; right: 0;
    flex-direction: column;
    background: rgba(247, 247, 245, 0.96);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
    padding: 1rem;
    gap: 0.2rem;
  }
  .nav-links.show { display: flex; }
  .nav-links a,
  .nav-links .nav-link-btn {
    padding: 0.7rem 1rem;
    width: 100%;
  }
  .nav-dropdown-menu {
    position: static;
    box-shadow: none;
    border: none;
    padding-left: 1rem;
    margin-top: 0;
  }
  .nav-right {
    width: 100%;
    justify-content: center;
    margin-top: 0.5rem;
  }
}

/* ── Body offset for fixed nav ─────────────────────────────── */
.page-body {
  padding-top: 64px;
}

/* ── Disclaimer Banner ─────────────────────────────────────── */
.disclaimer-banner {
  background: var(--color-accent-soft);
  border-bottom: 1px solid rgba(26,110,255,0.12);
  padding: 0.6rem 2rem;
  text-align: center;
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  letter-spacing: 0.02em;
}
.disclaimer-banner strong {
  font-weight: 500;
  color: var(--color-ink);
}

/* ── Buttons ───────────────────────────────────────────────── */
.btn-ds,
.btn-ds-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  padding: 0.75rem 1.8rem;
  border-radius: var(--border-radius);
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.22s ease;
  border: 1.5px solid var(--color-ink);
  background: var(--color-ink);
  color: var(--color-white);
}
.btn-ds-primary:hover {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-white);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px var(--color-accent-glow);
}

.btn-ds-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  padding: 0.75rem 1.8rem;
  border-radius: var(--border-radius);
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.22s ease;
  background: rgba(255,255,255,0.92);
  color: var(--color-ink);
  border: 1.5px solid var(--color-border-hover);
}
.btn-ds-ghost:hover {
  background: var(--color-white);
  border-color: var(--color-ink);
  transform: translateY(-2px);
}

/* Full-width button */
.btn-block { width: 100%; }

/* ── Section Label ─────────────────────────────────────────── */
.section-label {
  font-family: var(--font-body);
  font-size: 0.75rem;
  font-weight: 500;
  letter-spacing: 0.20em;
  text-transform: uppercase;
  color: var(--color-text-subtle);
  margin-bottom: 2rem;
}

/* ── Divider ───────────────────────────────────────────────── */
.divider {
  margin: 2rem auto;
  width: 40px;
  height: 1px;
  background: var(--color-border);
}

/* ── Hero Section ──────────────────────────────────────────── */
.hero {
  text-align: center;
  padding: 5rem 2rem 3.5rem;
  position: relative;
  overflow: hidden;
}
.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.6rem, 7vw, 5rem);
  letter-spacing: -0.03em;
  color: var(--color-ink);
  margin: 0 0 0.4rem;
  animation: rise 0.9s 0.10s var(--ease-out-expo) both;
}
.hero h1 .accent { color: var(--color-accent); }
.hero .tagline {
  font-family: var(--font-body);
  font-weight: 300;
  font-size: clamp(1rem, 2.4vw, 1.25rem);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin: 0;
  animation: rise 0.9s 0.30s var(--ease-out-expo) both;
}
.hero .hero-desc {
  font-family: var(--font-body);
  font-weight: 300;
  font-size: clamp(0.95rem, 2.2vw, 1.1rem);
  line-height: 1.8;
  color: var(--color-text-body);
  max-width: 560px;
  margin: 0 auto;
  animation: rise 0.9s 0.55s var(--ease-out-expo) both;
}
.hero .hero-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 2rem;
  animation: rise 0.9s 0.75s var(--ease-out-expo) both;
}

/* ── Cards / Grid Panels ───────────────────────────────────── */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5px;
  border: 1.5px solid var(--color-border);
  margin-bottom: 3rem;
}
.card-grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.card-ds {
  padding: 2.4rem 2rem;
  background: var(--color-mist);
  border-right: 1.5px solid var(--color-border);
  text-decoration: none;
  color: inherit;
  transition: background 0.2s ease;
  position: relative;
  overflow: hidden;
  display: block;
}
.card-ds:last-child { border-right: none; }
.card-ds::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0;
  width: 0; height: 2px;
  background: var(--color-accent);
  transition: width 0.35s var(--ease-out-expo);
}
.card-ds:hover {
  background: var(--color-white);
  color: inherit;
}
.card-ds:hover::after { width: 100%; }

.card-ds .card-icon {
  font-size: 1.5rem;
  margin-bottom: 1.2rem;
  display: block;
  color: var(--color-ink);
}
.card-ds .card-title {
  font-family: var(--font-display);
  font-size: 1.35rem;
  letter-spacing: -0.02em;
  color: var(--color-ink);
  margin: 0 0 0.6rem;
  line-height: 1.2;
}
.card-ds .card-desc {
  font-family: var(--font-body);
  font-weight: 300;
  font-size: 0.85rem;
  line-height: 1.65;
  color: #666;
  margin: 0 0 1.2rem;
}
.card-ds .card-cta {
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-accent);
}

/* ── Page Content Container ────────────────────────────────── */
.page-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 2rem;
}
.page-container-fluid {
  padding: 1.5rem 2rem;
}

/* ── Breadcrumb ────────────────────────────────────────────── */
.breadcrumb-ds {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 0.78rem;
  color: var(--color-text-faint);
  margin-bottom: 1.5rem;
  padding: 0;
  list-style: none;
}
.breadcrumb-ds a {
  color: var(--color-text-subtle);
  text-decoration: none;
}
.breadcrumb-ds a:hover { color: var(--color-accent); }
.breadcrumb-ds .sep { color: var(--color-text-faint); }
.breadcrumb-ds .current { color: var(--color-text-muted); }

/* ── Calculator / Simulator Page Layout ────────────────────── */
.calc-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: start;
}
.calc-layout-wide {
  grid-template-columns: 1.3fr 1fr;
}
.sim-layout {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 1.5rem;
  align-items: start;
}

@media (max-width: 768px) {
  .calc-layout,
  .calc-layout-wide,
  .sim-layout {
    grid-template-columns: 1fr;
  }
}

/* ── Panel (form card, result card, info card) ─────────────── */
.panel {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  overflow: hidden;
}
.panel-header {
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  gap: 0.6rem;
}
.panel-header h4,
.panel-header h5,
.panel-header h6 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.15rem;
  color: var(--color-ink);
}
.panel-body {
  padding: 1.5rem;
}
.panel-body-sm {
  padding: 1rem 1.5rem;
}

/* ── Form Controls ─────────────────────────────────────────── */
.form-group {
  margin-bottom: 1rem;
}
.form-group label,
.form-label-ds {
  display: block;
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 0.82rem;
  color: var(--color-text-muted);
  margin-bottom: 0.35rem;
}
.form-section-title {
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.10em;
  color: var(--color-accent);
  margin: 1.2rem 0 0.6rem;
  padding-bottom: 0.3rem;
  border-bottom: 1px solid var(--color-border);
}

input[type="number"],
input[type="text"],
select,
.form-control,
.form-select {
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 0.9rem;
  padding: 0.55rem 0.8rem;
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  background: var(--color-white);
  color: var(--color-ink);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
  width: 100%;
}
input:focus,
select:focus,
.form-control:focus,
.form-select:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-soft);
}

.form-control-sm {
  padding: 0.4rem 0.6rem;
  font-size: 0.82rem;
}

.form-check-input {
  accent-color: var(--color-accent);
}

/* Range sliders */
input[type="range"],
.form-range {
  appearance: none;
  -webkit-appearance: none;
  width: 100%;
  height: 4px;
  background: var(--color-border);
  border-radius: 2px;
  outline: none;
  border: none;
  padding: 0;
}
input[type="range"]::-webkit-slider-thumb {
  appearance: none;
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--color-accent);
  cursor: pointer;
  border: 2px solid var(--color-white);
  box-shadow: 0 1px 4px rgba(0,0,0,0.15);
}
input[type="range"]::-moz-range-thumb {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--color-accent);
  cursor: pointer;
  border: 2px solid var(--color-white);
  box-shadow: 0 1px 4px rgba(0,0,0,0.15);
}

/* ── Results Display ───────────────────────────────────────── */
.result-big {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 5vw, 3.5rem);
  letter-spacing: -0.03em;
  color: var(--color-ink);
  line-height: 1;
}
.result-label {
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.10em;
  color: var(--color-text-subtle);
}
.result-sub {
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 0.92rem;
  color: var(--color-text-muted);
}

/* ── Vital Cards (Simulators) ──────────────────────────────── */
.vital-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}
.vital-card {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-accent);
  border-radius: var(--border-radius);
  text-align: center;
  padding: 0.6rem 0.4rem;
}
.vital-card .vital-value {
  font-family: var(--font-display);
  font-size: 1.3rem;
  color: var(--color-ink);
  line-height: 1.2;
}
.vital-card .vital-label {
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 0.7rem;
  color: var(--color-text-subtle);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

/* ── Severity Colors ───────────────────────────────────────── */
.severity-safe   { color: var(--color-severity-safe); }
.severity-warn   { color: var(--color-severity-warn); }
.severity-danger { color: var(--color-severity-danger); }
.severity-info   { color: var(--color-severity-info); }

.badge-ds {
  display: inline-block;
  padding: 0.35rem 0.9rem;
  border-radius: var(--border-radius);
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.badge-safe   { background: rgba(26,138,74,0.1); color: var(--color-severity-safe); }
.badge-warn   { background: rgba(193,125,16,0.1); color: var(--color-severity-warn); }
.badge-danger { background: rgba(201,48,44,0.1); color: var(--color-severity-danger); }
.badge-info   { background: var(--color-accent-soft); color: var(--color-accent); }

/* ── Tables ────────────────────────────────────────────────── */
.table-ds {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--font-body);
  font-size: 0.85rem;
}
.table-ds th {
  font-weight: 500;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-subtle);
  padding: 0.6rem 0.8rem;
  border-bottom: 1.5px solid var(--color-border);
  text-align: left;
}
.table-ds td {
  padding: 0.5rem 0.8rem;
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text-body);
}
.table-ds tr:last-child td { border-bottom: none; }
.table-ds .text-end { text-align: right; }

/* ── Tabs (Oxygenation page) ───────────────────────────────── */
.tabs-ds {
  display: flex;
  gap: 0;
  border-bottom: 1.5px solid var(--color-border);
  margin-bottom: 1.5rem;
  list-style: none;
  padding: 0;
}
.tabs-ds .tab-link {
  font-family: var(--font-body);
  font-weight: 500;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-subtle);
  padding: 0.7rem 1.2rem;
  cursor: pointer;
  border-bottom: 2px solid transparent;
  margin-bottom: -1.5px;
  transition: color 0.2s, border-color 0.2s;
  background: none;
  border-top: none;
  border-left: none;
  border-right: none;
  text-decoration: none;
}
.tabs-ds .tab-link:hover { color: var(--color-ink); }
.tabs-ds .tab-link.active {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

/* Tab panes */
.tab-pane { display: none; }
.tab-pane.active { display: block; }

/* ── Alerts ────────────────────────────────────────────────── */
.alert-ds {
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius);
  font-family: var(--font-body);
  font-size: 0.82rem;
  margin-bottom: 0.5rem;
  border: 1px solid;
}
.alert-danger {
  background: rgba(201,48,44,0.06);
  border-color: rgba(201,48,44,0.15);
  color: var(--color-severity-danger);
}
.alert-warning {
  background: rgba(193,125,16,0.06);
  border-color: rgba(193,125,16,0.15);
  color: var(--color-severity-warn);
}
.alert-success {
  background: rgba(26,138,74,0.06);
  border-color: rgba(26,138,74,0.15);
  color: var(--color-severity-safe);
}
.alert-info {
  background: var(--color-accent-soft);
  border-color: rgba(26,110,255,0.12);
  color: var(--color-accent);
}

/* ── Footer ────────────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 2rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.78rem;
  color: var(--color-text-faint);
  margin-top: 4rem;
}
.site-footer a {
  color: var(--color-text-faint);
  text-decoration: none;
  transition: color 0.2s ease;
}
.site-footer a:hover { color: var(--color-ink); }
.footer-links {
  display: flex;
  gap: 1.5rem;
  align-items: center;
}

/* ── Utility: hidden/shown ─────────────────────────────────── */
.hidden { display: none !important; }

/* ── Utility: text alignment ───────────────────────────────── */
.text-center { text-align: center; }
.text-end { text-align: right; }

/* ── Utility: flex helpers ─────────────────────────────────── */
.flex-row { display: flex; gap: 1rem; }
.flex-row-wrap { display: flex; flex-wrap: wrap; gap: 1rem; }

/* ── Utility: spacing ──────────────────────────────────────── */
.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }

/* ── Utility: grid helpers ─────────────────────────────────── */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}
.grid-3 {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 1rem;
}
.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
}
@media (max-width: 768px) {
  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }
}
@media (min-width: 769px) and (max-width: 1024px) {
  .grid-3, .grid-4 {
    grid-template-columns: 1fr 1fr;
  }
}

/* ── Input group (conversions) ─────────────────────────────── */
.input-group-ds {
  display: flex;
  gap: 0;
}
.input-group-ds input {
  border-radius: var(--border-radius) 0 0 var(--border-radius);
  flex: 1;
}
.input-group-ds button {
  border-radius: 0 var(--border-radius) var(--border-radius) 0;
  white-space: nowrap;
}

/* ── Chart containers ──────────────────────────────────────── */
canvas {
  max-width: 100%;
}

/* ── List groups (for criteria display) ────────────────────── */
.list-ds {
  list-style: none;
  padding: 0;
  margin: 0;
}
.list-ds li {
  padding: 0.55rem 0.8rem;
  border-bottom: 1px solid var(--color-border);
  font-family: var(--font-body);
  font-size: 0.85rem;
  color: var(--color-text-body);
}
.list-ds li:last-child { border-bottom: none; }
.list-ds li.list-warn {
  background: rgba(193,125,16,0.06);
  color: var(--color-severity-warn);
}
.list-ds li.list-safe {
  background: rgba(26,138,74,0.06);
  color: var(--color-severity-safe);
}

/* ── Responsive: small form controls for simulators ────────── */
.form-sm input,
.form-sm select {
  padding: 0.4rem 0.6rem;
  font-size: 0.82rem;
}
.form-sm label {
  font-size: 0.78rem;
}

/* ── Horizontal rule ───────────────────────────────────────── */
hr {
  border: none;
  height: 1px;
  background: var(--color-border);
  margin: 1rem 0;
}

/* ── Page title (for calculator/simulator pages) ───────────── */
.page-title {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3.5vw, 2.2rem);
  letter-spacing: -0.02em;
  color: var(--color-ink);
  margin: 0 0 1.5rem;
}

/* ── Small text ────────────────────────────────────────────── */
small, .text-small {
  font-size: 0.82rem;
}
.text-muted {
  color: var(--color-text-muted);
}
.text-subtle {
  color: var(--color-text-subtle);
}
.text-faint {
  color: var(--color-text-faint);
}
.text-accent {
  color: var(--color-accent);
}
.text-strong {
  color: var(--color-text-strong);
  font-weight: 500;
}

/* ── Checkbox label ────────────────────────────────────────── */
.check-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1rem;
}
.check-group label {
  font-size: 0.85rem;
  color: var(--color-text-body);
  margin: 0;
}