/* ───────────────────────────────────────────────────────────────────────────
   T2D Risk Screener — stylesheet
   Aligned with the tysonjohnson.dev portfolio aesthetic:
   clean, system-font stack, blue accent #1f6feb, generous whitespace,
   ~10px rounded corners, subtle shadows, responsive, light/dark via
   prefers-color-scheme. Tuned for a clinical tool.
   ─────────────────────────────────────────────────────────────────────────── */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  /* Accent (portfolio blue) */
  --accent:        #1f6feb;
  --accent-hover:  #1a5fd0;
  --accent-soft:   #e8f1ff;
  --accent-border: #bcd6ff;
  --accent-text:   #15489c;

  /* Neutrals */
  --bg:            #f5f7fa;
  --surface:       #ffffff;
  --surface-2:     #f9fafb;
  --border:        #e4e8ee;
  --border-strong: #d3d9e2;
  --text:          #1f2733;
  --text-muted:    #5b6573;
  --text-faint:    #8a94a3;

  /* Status colors */
  --info-bg:    #e8f1ff;
  --info-border:#bcd6ff;
  --info-text:  #15489c;
  --warn-bg:    #fff8e6;
  --warn-border:#f3d488;
  --warn-text:  #8a5d09;
  --error-bg:   #fdecec;
  --error-border:#f4c0c0;
  --error-text: #b02525;

  --radius:    10px;
  --radius-sm: 8px;
  --radius-lg: 14px;
  --shadow-sm: 0 1px 2px rgba(16, 24, 40, 0.05), 0 1px 3px rgba(16, 24, 40, 0.06);
  --shadow:    0 4px 12px -2px rgba(16, 24, 40, 0.10), 0 2px 6px -2px rgba(16, 24, 40, 0.06);
  --shadow-lg: 0 12px 28px -6px rgba(16, 24, 40, 0.16);

  --maxw: 940px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --accent:        #4a90f7;
    --accent-hover:  #6aa5fa;
    --accent-soft:   #15233d;
    --accent-border: #244a82;
    --accent-text:   #9cc3ff;

    --bg:            #0d1117;
    --surface:       #161b22;
    --surface-2:     #1c222b;
    --border:        #2a313c;
    --border-strong: #3a424f;
    --text:          #e6edf3;
    --text-muted:    #aab3c0;
    --text-faint:    #7d8694;

    --info-bg:    #15233d;
    --info-border:#244a82;
    --info-text:  #9cc3ff;
    --warn-bg:    #2c2410;
    --warn-border:#5a4a18;
    --warn-text:  #e2c269;
    --error-bg:   #321a1a;
    --error-border:#5e2b2b;
    --error-text: #f3a3a3;

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
    --shadow:    0 4px 14px -2px rgba(0, 0, 0, 0.5);
    --shadow-lg: 0 14px 32px -6px rgba(0, 0, 0, 0.6);
  }
}

html { font-size: 16px; -webkit-text-size-adjust: 100%; }

body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto,
               "Helvetica Neue", "Apple SD Gothic Neo", "Noto Sans KR", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── Header ────────────────────────────────────────────────────────────── */
header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: saturate(180%) blur(6px);
}

/* ── Compact back-to-portfolio link (top-left of header) ───────────────── */
.back-link {
  display: inline-block;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0.4rem 1.5rem 0;
  width: 100%;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-faint);
  letter-spacing: 0.01em;
  transition: color 0.15s;
}
.back-link:hover { color: var(--accent); text-decoration: none; }

.header-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0.35rem 1.5rem 0.85rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem 1.5rem;
  flex-wrap: wrap;
}

.header-title {
  display: flex;
  align-items: center;
  gap: 0.8rem;
}

.header-icon {
  font-size: 1.6rem;
  line-height: 1;
  width: 2.6rem;
  height: 2.6rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--accent-soft);
  color: var(--accent);
  border-radius: var(--radius);
  flex-shrink: 0;
}

.header-title h1 {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.015em;
  line-height: 1.2;
}

.header-sub {
  font-size: 0.8rem;
  color: var(--text-faint);
  margin-top: 0.15rem;
}

.header-controls {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 0.75rem;
  flex-wrap: nowrap;
}

.header-nav {
  display: flex;
  gap: 0.3rem;
  background: var(--surface-2);
  padding: 0.25rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.nav-btn {
  background: none;
  border: none;
  border-radius: var(--radius-sm);
  padding: 0.42rem 0.95rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
  white-space: nowrap;
}

.nav-btn:hover { color: var(--text); }
.nav-btn.active {
  background: var(--surface);
  color: var(--accent);
  box-shadow: var(--shadow-sm);
}

/* ── Language switch (sliding segmented toggle) ────────────────────────── */
.lang-switch {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: stretch;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 9999px;
  padding: 1px;
  font-size: 0.66rem;
  line-height: 1.6;
}
.lang-switch button {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 2px 8px;
  border: 0;
  background: transparent;
  border-radius: 9999px;
  color: var(--text-faint);
  cursor: pointer;
  font: inherit;
  font-weight: 600;
  white-space: nowrap;
  transition: color 0.2s;
}
.lang-switch::before {
  content: "";
  position: absolute;
  top: 1px;
  left: 1px;
  width: calc(50% - 1px);
  bottom: 1px;
  border-radius: 9999px;
  background: var(--accent);
  transition: transform 0.2s ease;
}
.lang-switch[data-lang="ko"]::before { transform: translateX(100%); }
.lang-switch[data-lang="en"] button[data-lang="en"],
.lang-switch[data-lang="ko"] button[data-lang="ko"] { color: #fff; }

/* ── Layout ────────────────────────────────────────────────────────────── */
.tab-content { flex: 1; }
.tab-content[hidden] { display: none; }

.page-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 2.25rem 1.5rem 4rem;
}

/* ── Banners ───────────────────────────────────────────────────────────── */
.banner-info,
.banner-warning,
.banner-error {
  border-radius: var(--radius);
  padding: 0.85rem 1.05rem;
  font-size: 0.875rem;
  line-height: 1.55;
  border: 1px solid transparent;
}

.banner-info {
  background: var(--info-bg);
  border-color: var(--info-border);
  color: var(--info-text);
}
.banner-warning {
  background: var(--warn-bg);
  border-color: var(--warn-border);
  color: var(--warn-text);
}
.banner-error {
  background: var(--error-bg);
  border-color: var(--error-border);
  color: var(--error-text);
  margin-top: 1rem;
}

.disclaimer { margin-bottom: 1.6rem; }
.banner-info strong, .banner-warning strong { font-weight: 700; }

/* ── Form sections (cards) ─────────────────────────────────────────────── */
.form-section {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.4rem 1.6rem;
  margin-bottom: 1.1rem;
  box-shadow: var(--shadow-sm);
}

.section-title {
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 1.15rem;
  display: flex;
  align-items: center;
  gap: 0.55rem;
  letter-spacing: -0.01em;
}

.optional-badge {
  font-size: 0.7rem;
  font-weight: 600;
  background: var(--accent-soft);
  color: var(--accent-text);
  border-radius: 9999px;
  padding: 0.18rem 0.65rem;
  letter-spacing: 0;
}

.section-hint {
  font-size: 0.84rem;
  color: var(--text-muted);
  margin-bottom: 1.15rem;
  line-height: 1.55;
}

/* ── Collapsible sections ──────────────────────────────────────────────── */
.collapsible { padding: 0; overflow: hidden; }

.section-toggle {
  width: 100%;
  background: none;
  border: none;
  cursor: pointer;
  padding: 1.25rem 1.6rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  text-align: left;
  font-family: inherit;
  transition: background 0.15s;
}

.section-toggle:hover { background: var(--surface-2); }
.section-toggle .section-title { margin-bottom: 0; flex-wrap: wrap; }

.toggle-icon {
  font-size: 0.75rem;
  color: var(--text-faint);
  transition: transform 0.2s ease;
  flex-shrink: 0;
}
.section-toggle[aria-expanded="true"] .toggle-icon { transform: rotate(90deg); }

.collapsible-content {
  padding: 0.25rem 1.6rem 1.4rem;
  border-top: 1px solid var(--border);
}

/* ── Field grid ────────────────────────────────────────────────────────── */
.field-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 1.1rem 1.2rem;
}

.field { display: flex; flex-direction: column; gap: 0.4rem; }

.field label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 0.3rem;
  flex-wrap: wrap;
}

.unit { font-weight: 400; color: var(--text-faint); font-size: 0.82rem; }

.tooltip {
  font-size: 0.78rem;
  color: var(--accent);
  cursor: help;
  user-select: none;
}

.field input,
.field select {
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  padding: 0.6rem 0.75rem;
  font-size: 0.92rem;
  font-family: inherit;
  color: var(--text);
  background: var(--surface);
  transition: border-color 0.15s, box-shadow 0.15s;
  width: 100%;
}

.field select { cursor: pointer; }

.field input::placeholder { color: var(--text-faint); }

.field input:hover,
.field select:hover { border-color: var(--accent-border); }

.field input:focus,
.field select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(31, 111, 235, 0.18);
}

.field input.invalid { border-color: #e0534d; }

/* Missing required-field highlight (set by validation in app.js) */
.field input.field-error,
.field select.field-error {
  border-color: var(--error-border);
  background: var(--error-bg);
}
.field input.field-error:focus,
.field select.field-error:focus {
  border-color: var(--error-text);
  box-shadow: 0 0 0 3px rgba(176, 37, 37, 0.18);
}

/* ── Buttons ───────────────────────────────────────────────────────────── */
.form-actions {
  display: flex;
  gap: 0.75rem;
  margin-top: 1.75rem;
  align-items: center;
  flex-wrap: wrap;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  padding: 0.7rem 1.9rem;
  font-size: 0.95rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: background 0.15s, box-shadow 0.15s, transform 0.05s;
  box-shadow: var(--shadow-sm);
}
.btn-primary:hover { background: var(--accent-hover); box-shadow: var(--shadow); }
.btn-primary:active { transform: translateY(1px); }
.btn-primary:disabled {
  background: var(--border-strong);
  color: var(--text-faint);
  cursor: not-allowed;
  box-shadow: none;
}

.btn-secondary {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  padding: 0.7rem 1.3rem;
  font-size: 0.9rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
}
.btn-secondary:hover { background: var(--surface-2); border-color: var(--accent-border); }
.btn-sm { padding: 0.45rem 0.95rem; font-size: 0.85rem; }

/* ── Results ───────────────────────────────────────────────────────────── */
#results-panel { margin-top: 2.75rem; }

.results-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.15rem;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.results-header h2 {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.015em;
}

.tier-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 5px solid var(--border-strong);
  border-radius: var(--radius);
  padding: 1.6rem 1.75rem;
  margin-bottom: 1.3rem;
  box-shadow: var(--shadow);
}

.tier-label-row {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  margin-bottom: 0.85rem;
  flex-wrap: wrap;
}

.tier-badge {
  font-size: 1.05rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
  padding: 0.35rem 1rem;
  color: #fff;
  letter-spacing: 0.01em;
}

.screen-status {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-muted);
}

.probability-display {
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-bottom: 0.7rem;
}

.recommendation-text {
  font-size: 0.96rem;
  line-height: 1.65;
  color: var(--text);
}

.chart-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.6rem 1.75rem;
  box-shadow: var(--shadow-sm);
  margin-top: 1.3rem;
}

.chart-card h3 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.45rem;
  letter-spacing: -0.01em;
}

.chart-hint {
  font-size: 0.83rem;
  color: var(--text-muted);
  line-height: 1.55;
  margin-bottom: 1.1rem;
}

#no-labs-warning { margin-top: 1.3rem; }

/* ── About page ────────────────────────────────────────────────────────── */
.about-article {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2.4rem 2.6rem;
  box-shadow: var(--shadow-sm);
}

.about-article h2 {
  font-size: 1.12rem;
  font-weight: 700;
  color: var(--text);
  margin-top: 2rem;
  margin-bottom: 0.7rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border);
  letter-spacing: -0.01em;
}
.about-article h2:first-child { margin-top: 0; }

.about-article p {
  font-size: 0.94rem;
  line-height: 1.75;
  color: var(--text-muted);
  margin-bottom: 0.9rem;
}

.about-article ul {
  padding-left: 1.3rem;
  margin-bottom: 0.9rem;
}

.about-article li {
  font-size: 0.94rem;
  line-height: 1.75;
  color: var(--text-muted);
  margin-bottom: 0.55rem;
}

.metrics-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
  margin: 0.85rem 0 1.1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.metrics-table th,
.metrics-table td {
  text-align: left;
  padding: 0.6rem 0.9rem;
  border-bottom: 1px solid var(--border);
}
.metrics-table tr:last-child td { border-bottom: none; }

.metrics-table th {
  font-weight: 700;
  color: var(--text);
  background: var(--surface-2);
  font-size: 0.85rem;
  letter-spacing: 0.01em;
}

.metrics-table td:last-child {
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  color: var(--text);
}

/* ── Footer ────────────────────────────────────────────────────────────── */
footer {
  border-top: 1px solid var(--border);
  background: var(--surface);
  text-align: center;
  padding: 1.25rem;
  font-size: 0.82rem;
  color: var(--text-faint);
  line-height: 1.6;
}
footer a { color: var(--accent); }

/* ── Spinner ───────────────────────────────────────────────────────────── */
.spinner {
  display: inline-block;
  width: 1rem;
  height: 1rem;
  border: 2px solid rgba(255, 255, 255, 0.45);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.65s linear infinite;
  vertical-align: -0.18em;
  margin-right: 0.45rem;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Responsive ────────────────────────────────────────────────────────── */
@media (max-width: 720px) {
  .header-inner {
    flex-direction: column;
    align-items: stretch;
  }
  .header-controls {
    width: 100%;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 0.6rem;
  }
}

@media (max-width: 560px) {
  html { font-size: 15px; }
  .back-link { padding: 0.4rem 1.1rem 0; }
  .header-inner { padding: 0.35rem 1.1rem 0.75rem; }
  .page-inner { padding: 1.6rem 1.1rem 3rem; }
  .form-section { padding: 1.15rem 1.2rem; }
  .section-toggle { padding: 1.1rem 1.2rem; }
  .collapsible-content { padding: 0.25rem 1.2rem 1.2rem; }
  .field-grid { grid-template-columns: 1fr; }
  .about-article { padding: 1.6rem 1.4rem; }
  .tier-card, .chart-card { padding: 1.3rem 1.3rem; }
  .header-controls { flex-direction: column; align-items: stretch; }
  .header-nav { width: 100%; }
  .nav-btn { flex: 1; text-align: center; }
  .lang-switch { align-self: flex-start; }

  /* Keep wide Plotly charts and tables inside the viewport */
  #waterfall-chart,
  #global-importance-chart { max-width: 100%; overflow-x: auto; }
  .metrics-table { display: block; overflow-x: auto; }
  .form-actions .btn-primary,
  .form-actions .btn-secondary { flex: 1; min-width: 0; }
}

/* Belt-and-suspenders: never allow horizontal page overflow */
html, body { overflow-x: hidden; }
.about-article { overflow-wrap: anywhere; }

/* mobile: anchor the language switch to the top-right of the header */
@media (max-width: 720px) {
  .lang-switch { position: absolute; top: 8px; right: 14px; font-size: 0.6rem; z-index: 5; }
}