/* =========================================================
   Brighterly Rounding Calculator
   ========================================================= */

:root {
  /* ── Brighterly Brand Purple ── */
  --color-purple-50:  #F3F1FF;
  --color-purple-100: #E9E6FF;
  --color-purple-200: #D4CFFF;
  --color-purple-300: #B8B0FF;
  --color-purple-400: #9B91FF;
  --color-purple-500: #7B69FF;
  --color-purple-600: #6655E8;
  --color-purple-700: #5042C7;
  --color-purple-800: #3A2FA0;
  --color-purple-900: #211C6B;

  /* ── Accents ── */
  --color-emerald-500: #00BC7D;
  --color-amber-400:   #FBBF24;
  --color-slate-400:   #90A1B9;
  --color-blue-500:    #3B82F6;

  /* ── Neutrals ── */
  --color-white:      #FFFFFF;
  --color-gray-text:  #1E1B4B;
  --color-gray-muted: #6B7280;

  --focus-ring: 0 0 0 3px rgba(123, 105, 255, 0.18);
}

/* =========================================================
   Base — scoped to .brighterly-round-root
   ========================================================= */

.brighterly-round-root,
.brighterly-round-root *,
.brighterly-round-root *::before,
.brighterly-round-root *::after { box-sizing: border-box; }

.brighterly-round-root {
  font-family: 'Rubik', system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  font-weight: 400;
  font-size: 18px;
  line-height: 24px;
  color: var(--color-gray-text);
  background: var(--color-purple-50);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  border-radius: 24px;
  padding: 8px;
}

.brighterly-round-root h1,
.brighterly-round-root h2,
.brighterly-round-root h3,
.brighterly-round-root h4,
.brighterly-round-root h5,
.brighterly-round-root h6,
.brighterly-round-root p { margin: 0; }

.brighterly-round-root button { font-family: inherit; }

/* =========================================================
   Page layout + card
   ========================================================= */

.page-container {
  max-width: 800px;
  margin: 0 auto;
  padding: 40px 24px 64px;
}

.calculator-card {
  background: var(--color-white);
  border: 1px solid var(--color-purple-200);
  border-radius: 24px;
  padding: 40px;
}

/* =========================================================
   Mode tabs
   ========================================================= */

.mode-tabs {
  display: flex;
  gap: 8px;
  background: var(--color-purple-50);
  border: 1px solid var(--color-purple-100);
  border-radius: 14px;
  padding: 6px;
  margin-bottom: 28px;
}

.mode-tab {
  flex: 1;
  border: none;
  background: transparent;
  border-radius: 10px;
  padding: 12px 10px;
  font-family: 'Rubik', sans-serif;
  font-weight: 600;
  font-size: 14px;
  color: var(--color-gray-muted);
  cursor: pointer;
  transition: background 0.2s, color 0.2s, box-shadow 0.2s;
}

.mode-tab:hover { color: var(--color-purple-600); }

.mode-tab.active {
  background: var(--color-white);
  color: var(--color-purple-700);
  box-shadow: 0 1px 3px rgba(33, 28, 107, 0.12);
}

.mode-tab:focus-visible { outline: none; box-shadow: var(--focus-ring); }

/* =========================================================
   Inputs
   ========================================================= */

.field-group { display: flex; flex-direction: column; margin-bottom: 20px; }
.field-group:last-of-type { margin-bottom: 0; }

.field-label {
  font-family: 'Rubik', sans-serif;
  font-weight: 600;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--color-gray-muted);
  margin-bottom: 10px;
}

.field-input,
.field-select {
  width: 100%;
  border: 1.5px solid var(--color-purple-200);
  border-radius: 12px;
  padding: 14px 16px;
  font-family: 'Rubik', sans-serif;
  font-size: 18px;
  line-height: 26px;
  font-weight: 500;
  color: var(--color-gray-text);
  background: var(--color-white);
  transition: border-color 0.2s, background 0.2s, box-shadow 0.2s;
}

.field-input::placeholder { color: var(--color-slate-400); font-weight: 400; opacity: 1; }

.field-input:focus,
.field-select:focus {
  outline: none;
  border-color: var(--color-purple-500);
  background: var(--color-purple-50);
  box-shadow: 0 0 0 3px rgba(123, 105, 255, 0.12);
}

.field-select {
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='14' height='14' viewBox='0 0 24 24' fill='none' stroke='%237B69FF' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 16px center;
  padding-right: 44px;
  cursor: pointer;
}

.field-hint { font-size: 12px; color: var(--color-gray-muted); margin-top: 8px; }

.panel { animation: panelFade 0.25s ease; }
.panel[hidden] { display: none; }

@keyframes panelFade {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}

.mode-hint {
  font-size: 13px;
  line-height: 20px;
  color: var(--color-gray-muted);
  background: var(--color-purple-50);
  border: 1px solid var(--color-purple-100);
  border-radius: 10px;
  padding: 12px 14px;
  margin: 4px 0 24px;
}

.mode-hint strong { color: var(--color-purple-700); font-weight: 600; }

.input-error {
  min-height: 16px;
  margin-top: 8px;
  color: #DC2626;
  font-size: 12px;
  font-weight: 500;
  line-height: 16px;
}

.number-group.has-error .field-input { border-color: #DC2626; }

/* Two-column row on wider screens */
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }

/* =========================================================
   Calculate button
   ========================================================= */

.calculate-btn {
  background: var(--color-purple-500);
  color: var(--color-white);
  border: none;
  border-radius: 12px;
  padding: 16px 40px;
  font-family: 'Rubik', sans-serif;
  font-weight: 600;
  font-size: 18px;
  cursor: pointer;
  width: 100%;
  margin-top: 24px;
  min-height: 56px;
  transition: transform 0.15s, background 0.2s, box-shadow 0.2s;
}

.calculate-btn:hover { background: var(--color-purple-600); transform: scale(1.02); }
.calculate-btn:active { transform: scale(0.98); }
.calculate-btn:focus-visible { outline: none; box-shadow: var(--focus-ring); }

/* =========================================================
   Result card
   ========================================================= */

.result-card {
  background: var(--color-white);
  border-radius: 20px;
  border: 1px solid var(--color-purple-200);
  border-left: 5px solid var(--color-emerald-500);
  padding: 24px 28px;
  margin-top: 24px;
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.35s ease, transform 0.35s ease;
  display: none;
}

.result-card.visible { display: block; opacity: 1; transform: translateY(0); }

.result-label {
  font-family: 'Rubik', sans-serif;
  font-weight: 600;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--color-emerald-500);
  margin-bottom: 16px;
  text-align: left;
}

.result-primary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 20px;
}

.result-primary-value {
  font-family: 'Rubik', sans-serif;
  font-size: 36px;
  font-weight: 700;
  color: var(--color-gray-text);
  line-height: 1.1;
}

.result-primary-caption { font-size: 14px; font-weight: 400; color: var(--color-gray-muted); }

.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

.stat-cell {
  background: var(--color-purple-50);
  border: 1px solid var(--color-purple-100);
  border-radius: 12px;
  padding: 14px 16px;
  text-align: left;
}

.stat-name {
  font-family: 'Rubik', sans-serif;
  font-weight: 600;
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--color-gray-muted);
  margin-bottom: 6px;
}

.stat-value {
  font-family: 'Rubik', sans-serif;
  font-weight: 600;
  font-size: 20px;
  color: var(--color-gray-text);
  line-height: 1.2;
  word-break: break-word;
}

/* =========================================================
   Step-by-step
   ========================================================= */

.steps-container { margin-top: 32px; }

.steps-heading {
  font-family: 'Rubik', sans-serif;
  font-weight: 700;
  font-size: 20px;
  color: var(--color-gray-text);
  margin-bottom: 20px;
}

.steps-list { list-style: none; margin: 0; padding: 0; }

.step-item { display: flex; gap: 16px; margin-bottom: 24px; align-items: flex-start; }

.step-badge {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--color-purple-500);
  color: var(--color-white);
  font-family: 'Rubik', sans-serif;
  font-weight: 600;
  font-size: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.step-body { flex: 1; min-width: 0; }

.step-title {
  font-family: 'Rubik', sans-serif;
  font-weight: 600;
  font-size: 16px;
  color: var(--color-blue-500);
  margin-bottom: 8px;
}

.step-content {
  font-size: 16px;
  line-height: 24px;
  color: var(--color-gray-text);
  word-break: break-word;
}

.step-content .muted { color: var(--color-gray-muted); }
.step-content strong { font-weight: 600; }

.step-formula {
  display: block;
  background: var(--color-purple-50);
  border-radius: 8px;
  padding: 10px 14px;
  margin-top: 8px;
  font-size: 15px;
  line-height: 22px;
  color: var(--color-gray-text);
}

/* =========================================================
   Responsive — mobile ≤ 768px
   ========================================================= */

@media (max-width: 768px) {
  .page-container { padding: 0 16px 48px; }
  .calculator-card { padding: 24px; border-radius: 20px; }

  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .result-primary-value { font-size: 30px; }

  .mode-tab { font-size: 13px; padding: 10px 6px; }

  .steps-heading { font-size: 18px; }
  .step-title { font-size: 15px; }
  .step-content { font-size: 15px; line-height: 22px; }
}

@media (max-width: 420px) {
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .field-row { grid-template-columns: 1fr; }
}