:root {
  color-scheme: dark;
  --bg: #0b0f1a;
  --bg-soft: #111728;
  --card: #151c30;
  --card-strong: #1b2440;
  --accent: #55e0b8;
  --accent-2: #69b8ff;
  --text: #f4f6fb;
  --muted: #a6b2c4;
  --warning: #f6c760;
  --border: rgba(255, 255, 255, 0.08);
  --shadow: 0 30px 80px rgba(4, 6, 12, 0.6);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Space Grotesk", sans-serif;
  background: radial-gradient(circle at top, #1b2542 0%, #0b0f1a 60%);
  color: var(--text);
  min-height: 100vh;
}

.glow {
  position: fixed;
  inset: 0;
  background: radial-gradient(circle at 20% 10%, rgba(85, 224, 184, 0.18), transparent 40%),
    radial-gradient(circle at 80% 30%, rgba(105, 184, 255, 0.18), transparent 45%),
    radial-gradient(circle at 50% 90%, rgba(246, 199, 96, 0.15), transparent 50%);
  pointer-events: none;
  z-index: 0;
}

.top-nav {
  position: relative;
  z-index: 1;
  max-width: 1100px;
  margin: 0 auto;
  padding: 1.25rem clamp(1.5rem, 4vw, 3.5rem) 0;
  display: flex;
  gap: 0.75rem;
}

.nav-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 1rem;
  background: var(--card-strong);
  color: var(--accent);
  border: 1px solid var(--border);
  border-radius: 10px;
  font-family: "Space Grotesk", sans-serif;
  font-size: 0.85rem;
  text-decoration: none;
  transition: background 0.2s ease;
}

.nav-btn:hover {
  background: var(--card);
}

.feedback-btn {
  color: var(--accent-2);
}

header,
main,
footer {
  position: relative;
  z-index: 1;
  max-width: 1100px;
  margin: 0 auto;
  padding: 2.5rem clamp(1.5rem, 4vw, 3.5rem);
}

.hero {
  display: grid;
  gap: 2rem;
  align-items: center;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.2em;
  font-size: 0.75rem;
  color: var(--accent);
  margin: 0 0 0.5rem;
}

h1 {
  font-size: clamp(2.4rem, 4vw, 3.5rem);
  margin: 0 0 1rem;
}

.subtitle {
  color: var(--muted);
  font-size: 1rem;
  margin: 0;
}

.hero-card {
  background: linear-gradient(150deg, rgba(85, 224, 184, 0.08), rgba(105, 184, 255, 0.12));
  border: 1px solid rgba(255, 255, 255, 0.12);
  padding: 1.5rem;
  border-radius: 18px;
  box-shadow: var(--shadow);
  display: grid;
  gap: 1.25rem;
}

.hero-card .label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.2em;
  color: var(--muted);
}

.hero-card .value {
  font-size: 1.1rem;
  font-weight: 600;
}

.panel {
  background: var(--card);
  border-radius: 20px;
  border: 1px solid var(--border);
  padding: 2rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow);
}

.panel h2 {
  margin: 0 0 1.5rem;
  font-size: 1.4rem;
}

.panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.panel-header h2 {
  margin: 0;
}

.grid {
  display: grid;
  gap: 1.2rem;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  grid-template-rows: auto;
}

.grid + .grid {
  margin-top: 1.2rem;
}

.grid-2 {
  grid-template-columns: repeat(2, 1fr);
  grid-template-rows: auto auto auto;
}

.grid-3 {
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: auto auto auto;
}

.grid-2 > label,
.grid-3 > label {
  display: grid;
  grid-row: 1 / -1;
  grid-template-rows: subgrid;
  gap: 0.35rem;
}

@media (max-width: 600px) {
  .grid-2,
  .grid-3 {
    grid-template-columns: 1fr;
    grid-template-rows: auto;
  }
  .grid-2 > label,
  .grid-3 > label {
    grid-row: auto;
    grid-template-rows: auto auto auto;
  }
}

label {
  display: flex;
  flex-direction: column;
  color: var(--muted);
  font-size: 0.85rem;
  min-width: 0;
  gap: 0.35rem;
}

label .hint {
  margin-top: 0;
}

input,
select {
  background: var(--card-strong);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 0.75rem 0.9rem;
  font-size: 1rem;
  font-family: "IBM Plex Mono", monospace;
  width: 100%;
  max-width: 100%;
  height: 2.75rem;
  flex-shrink: 0;
}

input:focus,
select:focus {
  outline: 2px solid rgba(85, 224, 184, 0.6);
  outline-offset: 2px;
}

input[readonly] {
  opacity: 0.6;
  cursor: not-allowed;
}

.results {
  display: grid;
  gap: 1.2rem;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.result-card {
  background: rgba(12, 16, 28, 0.6);
  border-radius: 16px;
  padding: 1.2rem;
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.result-card .label {
  color: var(--muted);
  margin: 0 0 0.5rem;
  font-size: 0.85rem;
}

.result-card .value {
  margin: 0 0 0.35rem;
  font-size: 1.5rem;
  font-weight: 600;
}

.hint {
  color: var(--muted);
  font-size: 0.75rem;
  margin: 0;
}

.note {
  margin-top: 1.25rem;
  color: var(--muted);
  font-size: 0.85rem;
}

.chart-wrap {
  margin-top: 1.5rem;
  background: rgba(8, 11, 20, 0.7);
  border-radius: 18px;
  padding: 1rem;
  border: 1px solid rgba(255, 255, 255, 0.08);
  overflow: hidden;
  position: relative;
}

canvas {
  width: 100%;
  height: 360px;
  display: block;
}

.chart-tooltip {
  position: absolute;
  pointer-events: none;
  background: rgba(15, 22, 38, 0.95);
  border: 1px solid rgba(255, 255, 255, 0.12);
  color: var(--text);
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.75rem;
  padding: 0.45rem 0.6rem;
  border-radius: 8px;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.35);
  opacity: 0;
  transform: translate(-50%, -110%);
  transition: opacity 120ms ease;
  white-space: nowrap;
}

.chart-tooltip.visible {
  opacity: 1;
}

.pill {
  display: inline-flex;
  align-items: center;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  background: rgba(105, 184, 255, 0.16);
  color: var(--accent-2);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  white-space: nowrap;
}

footer {
  color: var(--muted);
  font-size: 0.8rem;
  text-align: center;
  padding-bottom: 3rem;
}

/* Collapsible panels (BRS, TSP) */
.collapsible-panel {
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  padding-top: 0;
  padding-bottom: 0;
  margin-bottom: 0;
  border-color: transparent;
  transition: max-height 0.4s ease, opacity 0.3s ease, padding 0.3s ease, margin 0.3s ease;
}

.collapsible-panel.visible {
  max-height: 1200px;
  opacity: 1;
  padding: 2rem;
  margin-bottom: 2rem;
  border-color: var(--border);
}

/* Validation warnings */
.validation-messages {
  margin-top: 0.75rem;
}

.validation-messages .warning {
  color: var(--warning);
  font-size: 0.85rem;
  padding: 0.5rem 0.75rem;
  background: rgba(246, 199, 96, 0.1);
  border-left: 3px solid var(--warning);
  border-radius: 4px;
  margin-bottom: 0.5rem;
}

/* Print button */
.print-btn {
  background: var(--card-strong);
  color: var(--accent);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 0.6rem 1.2rem;
  font-family: "Space Grotesk", sans-serif;
  font-size: 0.85rem;
  cursor: pointer;
  transition: background 0.2s ease;
}

.print-btn:hover {
  background: var(--card);
}

/* Screen reader only */
.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;
}

@media (max-width: 720px) {
  header,
  main,
  footer {
    padding: 2rem 1.4rem;
  }

  .panel {
    padding: 1.5rem;
  }

  .collapsible-panel.visible {
    padding: 1.5rem;
  }
}

/* Print styles */
@media print {
  .glow,
  .print-btn,
  .chart-tooltip,
  .validation-messages,
  .top-nav {
    display: none !important;
  }

  body {
    background: white;
    color: #111;
    font-size: 11pt;
  }

  header,
  main,
  footer {
    max-width: 100%;
    padding: 1rem;
  }

  .panel {
    background: white;
    border: 1px solid #ccc;
    box-shadow: none;
    break-inside: avoid;
    page-break-inside: avoid;
  }

  .collapsible-panel:not(.visible) {
    display: none !important;
  }

  .collapsible-panel.visible {
    max-height: none;
    opacity: 1;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    border-color: #ccc;
  }

  .result-card {
    background: #f8f8f8;
    border: 1px solid #ddd;
  }

  .result-card .value {
    color: #111;
  }

  .hero-card {
    background: #f0f0f0;
    border: 1px solid #ccc;
    box-shadow: none;
  }

  canvas {
    max-width: 100%;
  }

  .pill {
    background: #e0e0e0;
    color: #333;
  }

  h1,
  h2 {
    color: #111;
  }

  .label,
  .hint,
  .note,
  .muted {
    color: #555;
  }
}