/* ─────────────────────────────────────────────
   RESET & TOKENS
   ───────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --primary:       #1e3a5f;   /* dark navy  */
  --primary-fg:    #ffffff;
  --accent:        #c4841d;   /* warm amber */
  --accent-fg:     #ffffff;
  --bg:            #f9fafb;
  --card-bg:       #ffffff;
  --muted-bg:      #f3f4f6;
  --muted-fg:      #6b7280;
  --border:        #e5e7eb;
  --foreground:    #111827;
  --amber-light:   #fffbeb;
  --amber-border:  #f59e0b;
  --blue-light:    #eff6ff;
  --blue-border:   #60a5fa;
  --green-light:   #ecfdf5;
  --green-border:  #34d399;
  --red-light:     #fef2f2;
  --red-border:    #f87171;
  --font: 'Segoe UI', system-ui, -apple-system, sans-serif;
  --font-mono: 'Courier New', 'Consolas', monospace;
  --radius: 4px;
  --shadow: 0 1px 3px 0 rgb(0 0 0 / .1), 0 1px 2px -1px rgb(0 0 0 / .1);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / .1), 0 2px 4px -2px rgb(0 0 0 / .1);
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--foreground);
  font-size: 15px;
  line-height: 1.5;
  min-height: 100vh;
}

/* ─────────────────────────────────────────────
   APP LAYOUT
   ───────────────────────────────────────────── */
.app { display: flex; flex-direction: column; min-height: 100vh; }

.app-header {
  text-align: center;
  padding: 2rem 1rem 1.25rem;
}
.app-header h1 {
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: 700;
  color: var(--foreground);
  letter-spacing: -.025em;
}
.app-subtitle {
  color: var(--muted-fg);
  font-size: .9rem;
  margin-top: .35rem;
}

.app-main {
  flex: 1;
  width: 100%;
  max-width: 900px;
  margin: 0 auto;
  padding: 0 1rem 2.5rem;
}

.app-footer {
  text-align: center;
  padding: 1.25rem 1rem;
  font-size: .8rem;
  color: var(--muted-fg);
  border-top: 1px solid var(--border);
}

/* ─────────────────────────────────────────────
   TAB NAV
   ───────────────────────────────────────────── */
.tab-nav {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  border: 2px solid var(--primary);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 1.5rem;
  background: var(--card-bg);
}

.tab-btn {
  font-family: var(--font);
  font-size: clamp(.7rem, 1.5vw, .85rem);
  font-weight: 500;
  padding: .75rem .25rem;
  border: none;
  background: transparent;
  color: var(--foreground);
  cursor: pointer;
  transition: background .15s, color .15s;
  border-right: 1px solid var(--border);
  line-height: 1.25;
  text-align: center;
}
.tab-btn:last-child { border-right: none; }
.tab-btn:hover { background: var(--muted-bg); }
.tab-btn.active {
  background: var(--primary);
  color: var(--primary-fg);
}

/* ─────────────────────────────────────────────
   TAB PANELS
   ───────────────────────────────────────────── */
.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* ─────────────────────────────────────────────
   CARD
   ───────────────────────────────────────────── */
.card {
  background: var(--card-bg);
  border: 2px solid var(--primary);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.card-header {
  background: var(--primary);
  color: var(--primary-fg);
  padding: .85rem 1.25rem;
  font-size: 1rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.card-badge {
  font-size: .78rem;
  font-weight: 400;
  opacity: .75;
  font-family: var(--font-mono);
}

.card-body { padding: 1.5rem; }

/* ─────────────────────────────────────────────
   DESCRIPTION
   ───────────────────────────────────────────── */
.description {
  font-size: .85rem;
  color: var(--muted-fg);
  margin-bottom: 1.25rem;
}

/* ─────────────────────────────────────────────
   GRIDS
   ───────────────────────────────────────────── */
.input-grid {
  display: grid;
  gap: 1rem;
  margin-bottom: 1.25rem;
}
.input-grid.one-col  { grid-template-columns: 1fr; max-width: 220px; }
.input-grid.two-cols { grid-template-columns: repeat(2, 1fr); }
.input-grid.three-cols { grid-template-columns: repeat(3, 1fr); }
.input-grid.four-cols  { grid-template-columns: repeat(4, 1fr); }
.input-grid.five-cols  { grid-template-columns: repeat(5, 1fr); }

/* ─────────────────────────────────────────────
   FIELD / LABEL / INPUT
   ───────────────────────────────────────────── */
.field { display: flex; flex-direction: column; gap: .4rem; }

label, .field-label {
  font-size: .85rem;
  font-weight: 600;
  color: var(--foreground);
  display: block;
  margin-bottom: .25rem;
}
.label-hint {
  font-weight: 400;
  color: var(--muted-fg);
}

input[type="number"] {
  width: 100%;
  padding: .5rem .65rem;
  font-family: var(--font);
  font-size: .9rem;
  border: 2px solid var(--primary);
  border-radius: var(--radius);
  background: var(--muted-bg);
  color: var(--foreground);
  transition: border-color .15s, background .15s;
  appearance: textfield;
}
input[type="number"]:focus {
  outline: none;
  border-color: var(--accent);
  background: #fff;
}
input.input-amber {
  border-color: var(--amber-border);
  background: var(--amber-light);
}
input.input-amber:focus { border-color: var(--accent); }

/* suffix wrap (% symbol) */
.input-suffix-wrap { position: relative; }
.input-suffix-wrap input { padding-right: 2rem; }
.input-suffix {
  position: absolute;
  right: .65rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--muted-fg);
  pointer-events: none;
  font-size: .9rem;
}

/* ─────────────────────────────────────────────
   PROB SELECTOR BUTTONS
   ───────────────────────────────────────────── */
.prob-selector { margin-bottom: 1.25rem; }

.prob-options {
  display: grid;
  gap: .5rem;
  margin-top: .5rem;
}
.prob-options.four-cols  { grid-template-columns: repeat(4, 1fr); }
.prob-options.three-cols { grid-template-columns: repeat(3, 1fr); }

.prob-btn {
  display: flex;
  flex-direction: column;
  gap: .15rem;
  padding: .65rem .75rem;
  border: 2px solid rgba(30,58,95,.25);
  border-radius: var(--radius);
  background: var(--muted-bg);
  cursor: pointer;
  text-align: left;
  transition: border-color .15s, background .15s;
  font-family: var(--font);
}
.prob-btn strong { font-size: .85rem; color: var(--foreground); }
.prob-btn small  { font-size: .72rem; color: var(--muted-fg); }
.prob-btn:hover  { border-color: rgba(30,58,95,.5); }
.prob-btn.active {
  border-color: var(--accent);
  background: var(--accent);
  color: #fff;
}
.prob-btn.active strong,
.prob-btn.active small  { color: #fff; }

/* ─────────────────────────────────────────────
   TOGGLE BUTTONS (generic)
   ───────────────────────────────────────────── */
.type-selector { margin-bottom: 1.25rem; }

.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem;
  margin-top: .4rem;
}
.btn-group.three-cols {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
}

.toggle-btn {
  font-family: var(--font);
  font-size: .82rem;
  font-weight: 500;
  padding: .45rem .75rem;
  border: 2px solid var(--border);
  border-radius: var(--radius);
  background: var(--card-bg);
  color: var(--foreground);
  cursor: pointer;
  transition: all .15s;
  white-space: nowrap;
}
.toggle-btn:hover { border-color: var(--primary); background: var(--muted-bg); }
.toggle-btn.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}

/* ─────────────────────────────────────────────
   RESULT BOX
   ───────────────────────────────────────────── */
.result-box {
  border: 2px solid var(--accent);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 1.25rem;
}
.result-box--green { border-color: var(--green-border); }

.result-top {
  background: var(--accent);
  color: #fff;
  padding: .75rem 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap .5rem;
  flex-wrap: wrap;
}
.result-box--green .result-top { background: var(--green-light); }
.result-box--green .result-top .result-mono { color: var(--foreground); }

.result-pct {
  font-family: var(--font-mono);
  font-size: 1.35rem;
  font-weight: 700;
}
.result-mono {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
}

.result-stats {
  background: var(--muted-bg);
  padding: .65rem 1rem;
  font-size: .85rem;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

/* ─────────────────────────────────────────────
   QUICK ALPHAS
   ───────────────────────────────────────────── */
.quick-alphas { margin-bottom: 1.25rem; }

/* ─────────────────────────────────────────────
   CHART BOX
   ───────────────────────────────────────────── */
.chart-box {
  border: 2px solid rgba(30,58,95,.2);
  border-radius: var(--radius);
  padding: 1rem;
  margin-bottom: 1.25rem;
}
.chart-box h3 {
  font-size: .9rem;
  font-weight: 600;
  margin-bottom: .75rem;
  color: var(--foreground);
}
.chart-center-title {
  text-align: center;
  font-size: .9rem;
  font-weight: 600;
  margin-bottom: .75rem;
}

canvas { display: block; width: 100% !important; }

.chart-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: .75rem;
  font-size: .78rem;
  color: var(--foreground);
}
.legend-item { display: flex; align-items: center; gap: .35rem; }
.legend-swatch {
  display: inline-block;
  width: 12px;
  height: 12px;
  border-radius: 2px;
  flex-shrink: 0;
}
.legend-swatch-border {
  display: inline-block;
  width: 12px;
  height: 12px;
  border-radius: 2px;
  border: 2px solid;
  flex-shrink: 0;
  background: transparent;
}
.legend-line {
  display: inline-block;
  width: 18px;
  height: 2px;
  flex-shrink: 0;
}

/* ─────────────────────────────────────────────
   INFO BOX
   ───────────────────────────────────────────── */
.info-box {
  background: var(--muted-bg);
  border: 1px solid rgba(30,58,95,.2);
  border-radius: var(--radius);
  padding: 1rem;
  font-size: .85rem;
  color: var(--muted-fg);
  margin-top: .5rem;
}
.info-box h4 {
  font-size: .9rem;
  font-weight: 600;
  color: var(--foreground);
  margin-bottom: .4rem;
}

/* ─────────────────────────────────────────────
   RESULTS SECTION (IC / HT)
   ───────────────────────────────────────────── */
.results-heading {
  font-size: .95rem;
  font-weight: 700;
  color: var(--foreground);
  border-bottom: 2px solid var(--primary);
  padding-bottom: .5rem;
  margin-bottom: 1rem;
}

.results-grid {
  display: grid;
  gap: .75rem;
  margin-bottom: .75rem;
}
.results-grid.two-cols { grid-template-columns: 1fr 1fr; }

.result-card {
  border-radius: var(--radius);
  padding: .75rem;
  margin-bottom: .75rem;
}
.result-card.blue   { background: var(--blue-light);  border: 1px solid var(--blue-border); }
.result-card.muted  { background: var(--muted-bg);    border: 1px solid rgba(107,114,128,.2); }

.rc-label  { font-size: .8rem; color: var(--muted-fg); margin-bottom: .2rem; }
.rc-value  { font-family: var(--font-mono); font-size: 1.2rem; font-weight: 700; color: var(--foreground); }
.rc-value--sm { font-size: 1rem; }

/* ─────────────────────────────────────────────
   DECISION BOX (H0 / No H0)
   ───────────────────────────────────────────── */
.decision-box {
  border-radius: var(--radius);
  border: 2px solid;
  padding: 1rem;
  text-align: center;
  margin-top: .75rem;
}
.decision-box.reject   { background: var(--red-light);   border-color: var(--red-border); }
.decision-box.no-reject{ background: var(--green-light);  border-color: var(--green-border); }

.decision-title  { font-size: 1.05rem; font-weight: 700; margin-bottom: .3rem; }
.decision-detail { font-size: .82rem; color: var(--muted-fg); }

/* ─────────────────────────────────────────────
   IC / HT PANELS (toggle)
   ───────────────────────────────────────────── */
.ic-panel, .ht-panel { /* shown/hidden via JS */ }

/* ─────────────────────────────────────────────
   RESPONSIVE
   ───────────────────────────────────────────── */
@media (max-width: 700px) {
  .tab-nav { grid-template-columns: repeat(3, 1fr); }
  .tab-btn:nth-child(3) { border-right: none; }
  .tab-btn:nth-child(4) { border-top: 1px solid var(--border); }

  .input-grid.three-cols,
  .input-grid.four-cols,
  .input-grid.five-cols { grid-template-columns: 1fr 1fr; }

  .input-grid.five-cols > :last-child { grid-column: span 2; }

  .prob-options.four-cols { grid-template-columns: 1fr 1fr; }
  .prob-options.three-cols { grid-template-columns: 1fr 1fr; }

  .btn-group.three-cols { grid-template-columns: 1fr; }

  .results-grid.two-cols { grid-template-columns: 1fr; }
}

@media (max-width: 420px) {
  .tab-nav { grid-template-columns: repeat(2, 1fr); }
  .tab-btn:nth-child(2) { border-right: none; }
  .tab-btn:nth-child(3) { border-top: 1px solid var(--border); border-right: 1px solid var(--border); }
  .tab-btn:nth-child(4) { border-right: none; }
  .tab-btn:nth-child(5) { border-top: 1px solid var(--border); border-right: 1px solid var(--border); }
  .tab-btn:nth-child(6) { border-right: none; border-top: 1px solid var(--border); }

  .input-grid.three-cols,
  .input-grid.four-cols,
  .input-grid.five-cols { grid-template-columns: 1fr; }

  .prob-options.four-cols { grid-template-columns: 1fr 1fr; }

  .card-header { flex-direction: column; align-items: flex-start; gap: .25rem; }
}