:root {
  --bg:       #0f1117;
  --surface:  #181c26;
  --border:   #252b3b;
  --gold:     #c8a255;
  --gold-dim: #7a5f2e;
  --text:     #e8e4dc;
  --muted:    #6b7280;
  --danger:   #e05555;
  --radius:   10px;
}

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

body {
  font-family: 'DM Sans', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: grid;
  place-items: start center;
}

/* Subtle grid texture */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 48px 48px;
  opacity: 0.35;
  pointer-events: none;
  z-index: 0;
}

.page {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 1100px;
  padding: 2.5rem 2rem 4rem;
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

/* ── Header ── */
header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}

header img { height: 44px; }

.sim-select {
  font-family: 'DM Sans', sans-serif;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--gold);
  background: transparent;
  border: 1px solid var(--gold-dim);
  border-radius: 999px;
  padding: 0.35rem 2rem 0.35rem 0.9rem;
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6' viewBox='0 0 10 6'%3E%3Cpath d='M1 1l4 4 4-4' stroke='%237a5f2e' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.7rem center;
  transition: border-color 0.2s;
}

.sim-select:focus {
  outline: none;
  border-color: var(--gold);
}

.sim-select option {
  background: var(--surface);
  color: var(--text);
}

/* ── Layout ── */
.layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  align-items: stretch;
}

/* ── Panel ── */
.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
}

.panel-title {
  font-family: 'DM Serif Display', serif;
  font-size: 1.25rem;
  color: var(--text);
  margin-bottom: 1.75rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border);
}

/* ── Form ── */
.fields { display: flex; flex-direction: column; gap: 1.4rem; }

.field label {
  display: block;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 0.5rem;
}

.input-wrap { position: relative; }

.input-wrap .unit {
  position: absolute;
  right: 1rem;
  top: 50%;
  transform: translateY(-50%);
  font-size: 0.85rem;
  color: var(--muted);
  pointer-events: none;
}

input[type="number"] {
  width: 100%;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-family: 'DM Sans', sans-serif;
  font-size: 0.95rem;
  padding: 0.75rem 2.5rem 0.75rem 1rem;
  transition: border-color 0.2s;
  appearance: textfield;
}

input[type="number"]:focus {
  outline: none;
  border-color: var(--gold);
}

input[type="number"]::-webkit-inner-spin-button { display: none; }

/* Pill toggles */
.pills { display: flex; gap: 0.5rem; }

.pills input[type="radio"] { display: none; }

.pills label {
  flex: 1;
  text-align: center;
  padding: 0.65rem 0.5rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--muted);
  cursor: pointer;
  transition: all 0.18s;
  letter-spacing: 0;
  text-transform: none;
}

.pills input[type="radio"]:checked + label {
  background: var(--gold);
  border-color: var(--gold);
  color: #0f1117;
  font-weight: 600;
}

/* Submit */
.btn {
  width: 100%;
  margin-top: 0.5rem;
  padding: 0.9rem;
  background: var(--gold);
  color: #0f1117;
  border: none;
  border-radius: var(--radius);
  font-family: 'DM Sans', sans-serif;
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  cursor: pointer;
  transition: opacity 0.2s, transform 0.15s;
}

.btn:hover { opacity: 0.88; transform: translateY(-1px); }
.btn:active { transform: translateY(0); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; transform: none; }

/* Error */
.error-msg {
  display: none;
  font-size: 0.83rem;
  color: var(--danger);
  padding: 0.65rem 0.9rem;
  background: rgba(224, 85, 85, 0.08);
  border: 1px solid rgba(224, 85, 85, 0.25);
  border-radius: 8px;
}

/* ── Results panel ── */
#results-panel {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.4s ease, transform 0.4s ease;
  pointer-events: none;
  display: none;
}

#results-panel.visible {
  display: block;
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

/* Hero monthly */
.hero-monthly {
  text-align: center;
  padding: 1.75rem 1rem 1.5rem;
  margin-bottom: 1.5rem;
  background: linear-gradient(135deg, rgba(200, 162, 85, 0.08), rgba(200, 162, 85, 0.03));
  border: 1px solid var(--gold-dim);
  border-radius: var(--radius);
  position: relative;
  overflow: hidden;
}

.hero-monthly::before {
  content: '';
  position: absolute;
  top: -40px;
  right: -40px;
  width: 120px;
  height: 120px;
  background: radial-gradient(circle, rgba(200, 162, 85, 0.15), transparent 70%);
  pointer-events: none;
}

.hero-monthly .hero-label {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 0.6rem;
}

.hero-monthly .hero-amount {
  font-family: 'DM Serif Display', serif;
  font-size: 3rem;
  color: var(--text);
  line-height: 1;
  letter-spacing: -1px;
}

.hero-monthly .hero-sub {
  font-size: 0.78rem;
  color: var(--muted);
  margin-top: 0.5rem;
}

/* Detail rows */
.detail-rows { display: flex; flex-direction: column; }

.detail-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--border);
}

.detail-row:last-child { border-bottom: none; }

.detail-row .d-label {
  font-size: 0.8rem;
  color: var(--muted);
}

.detail-row .d-value {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}

.detail-row.accent .d-value { color: var(--gold); }

.tranche-tag {
  display: inline-block;
  margin-top: 1.25rem;
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--muted);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.3rem 0.85rem;
}

/* Placeholder state */
.placeholder-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  padding: 1.5rem 1rem;
  color: var(--muted);
  text-align: center;
}

.placeholder-state svg { opacity: 0.3; }
.placeholder-state p { font-size: 0.85rem; line-height: 1.5; }

/* Responsive */
@media (max-width: 720px) {
  .layout { grid-template-columns: 1fr; }
  .hero-monthly .hero-amount { font-size: 2.4rem; }
  .page { padding: 1.5rem 1rem 3rem; }
}