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

:root {
  --bg: #f5f5f5;
  --surface: #ffffff;
  --border: #e0e0e0;
  --text: #1a1a1a;
  --text-secondary: #5a5a5a;
  --accent-a: #2563eb;
  --accent-a-light: #dbeafe;
  --accent-b: #d97706;
  --accent-b-light: #fef3c7;
  --success: #16a34a;
  --success-light: #dcfce7;
  --danger: #dc2626;
  --danger-light: #fee2e2;
  --radius: 10px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-lg: 0 4px 12px rgba(0,0,0,0.1);
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
}

/* Header */
header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 2rem 1.5rem;
  text-align: center;
}

.header-inner { max-width: 700px; margin: 0 auto; }

h1 {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
}

.subtitle {
  margin-top: 0.5rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* Main */
main {
  max-width: 960px;
  margin: 0 auto;
  padding: 1.5rem 1rem 3rem;
}

h2 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text);
}

/* Ownership Section */
.ownership-section {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow);
}

.ownership-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

/* Fields */
.field { margin-bottom: 0.75rem; }
.field label {
  display: block;
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 0.3rem;
}

.field .optional {
  font-weight: 400;
  color: #999;
}

input[type="number"],
input[type="text"],
select {
  width: 100%;
  padding: 0.55rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.9rem;
  font-family: inherit;
  color: var(--text);
  background: var(--surface);
  transition: border-color 0.15s;
}

input:focus, select:focus {
  outline: none;
  border-color: var(--accent-a);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
}

.input-prefix {
  display: flex;
  align-items: center;
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
  transition: border-color 0.15s;
}

.input-prefix:focus-within {
  border-color: var(--accent-a);
  box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
}

.input-prefix span {
  padding: 0.55rem 0.6rem;
  background: #f9f9f9;
  color: var(--text-secondary);
  font-size: 0.9rem;
  border-right: 1px solid var(--border);
}

.input-prefix input {
  border: none;
  border-radius: 0;
  flex: 1;
}

.input-prefix input:focus {
  box-shadow: none;
}

.input-row {
  display: flex;
  gap: 0.5rem;
}

.input-row select { flex: 1; }
.input-row input { flex: 1; }

.field-group {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 0.75rem;
}

/* Vehicle Cards */
.vehicles-section { margin-bottom: 1.5rem; }

.vehicle-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
  margin-bottom: 1.25rem;
}

.vehicle-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.card-header {
  padding: 0.75rem 1.25rem;
  font-weight: 600;
  font-size: 0.9rem;
}

.card-header-a { background: var(--accent-a-light); color: var(--accent-a); }
.card-header-b { background: var(--accent-b-light); color: var(--accent-b); }

.card-body { padding: 1.25rem; }

.ev-cost-preview {
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.65rem 0.85rem;
  font-size: 0.82rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
  line-height: 1.6;
}

.ev-cost-preview:empty { display: none; }

.hidden { display: none !important; }

/* Buttons */
.action-buttons {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  padding: 0.65rem 1.75rem;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  border: none;
  transition: all 0.15s;
}

.btn-primary {
  background: var(--accent-a);
  color: #fff;
}

.btn-primary:hover { background: #1d4ed8; }

.btn-outline {
  background: var(--surface);
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.btn-outline:hover { background: #f0f0f0; }

/* Results */
.results-section { margin-top: 2rem; }

/* Decision Cards */
.decision-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.decision-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem 1.25rem;
  box-shadow: var(--shadow);
  text-align: center;
}

.decision-card .dc-label {
  font-size: 0.75rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-secondary);
  margin-bottom: 0.4rem;
}

.decision-card .dc-value {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text);
}

.decision-card .dc-detail {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-top: 0.3rem;
}

.decision-card.highlight {
  border-color: var(--success);
  background: var(--success-light);
}

.decision-card.highlight .dc-value { color: var(--success); }

/* Worth It Card */
.worth-it-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow);
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--text);
}

.worth-it-card:empty { display: none; }

.worth-it-card .wit-title {
  font-weight: 700;
  font-size: 1rem;
  margin-bottom: 0.5rem;
}

/* Premium Card */
.premium-card {
  background: #f0f4ff;
  border: 1px solid #c7d6f5;
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  margin-bottom: 1.5rem;
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--text);
}

.premium-card:empty { display: none; }

.premium-card .pc-title {
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: 0.35rem;
}

/* Chart */
.chart-container {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow);
}

.chart-container canvas {
  width: 100% !important;
  max-height: 400px;
}

/* Summary Grid */
.summary-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.summary-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.summary-card .sc-header {
  padding: 0.65rem 1rem;
  font-weight: 600;
  font-size: 0.85rem;
}

.summary-card.vehicle-a .sc-header { background: var(--accent-a-light); color: var(--accent-a); }
.summary-card.vehicle-b .sc-header { background: var(--accent-b-light); color: var(--accent-b); }

.summary-card .sc-body { padding: 1rem; }

.sc-row {
  display: flex;
  justify-content: space-between;
  padding: 0.35rem 0;
  font-size: 0.85rem;
}

.sc-row .sc-label { color: var(--text-secondary); }
.sc-row .sc-val { font-weight: 600; }

.sc-row.sc-total {
  border-top: 1px solid var(--border);
  margin-top: 0.35rem;
  padding-top: 0.6rem;
  font-size: 0.95rem;
}

/* Milestone Table */
.milestone-section {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow);
}

.table-wrap { overflow-x: auto; }

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
}

th {
  text-align: left;
  padding: 0.6rem 0.75rem;
  border-bottom: 2px solid var(--border);
  font-weight: 600;
  font-size: 0.8rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

td {
  padding: 0.6rem 0.75rem;
  border-bottom: 1px solid #f0f0f0;
}

tr:last-child td { border-bottom: none; }

td.positive { color: var(--success); font-weight: 500; }
td.negative { color: var(--danger); font-weight: 500; }

.scope-note {
  text-align: center;
  font-size: 0.8rem;
  color: #999;
  margin-top: 0.5rem;
}

/* Footer */
footer {
  text-align: center;
  padding: 2rem 1rem;
  color: #aaa;
  font-size: 0.8rem;
}

/* Mobile */
@media (max-width: 700px) {
  header { padding: 1.5rem 1rem; }
  h1 { font-size: 1.4rem; }

  .ownership-grid { grid-template-columns: 1fr; }
  .vehicle-grid { grid-template-columns: 1fr; }
  .decision-cards { grid-template-columns: 1fr; }
  .summary-grid { grid-template-columns: 1fr; }
  .field-group { grid-template-columns: 1fr; }

  main { padding: 1rem 0.75rem 2rem; }

  .decision-card .dc-value { font-size: 1.15rem; }

  table { font-size: 0.82rem; }
  th, td { padding: 0.5rem; }
}

/* Remove number input spinners for cleaner look */
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  -webkit-appearance: none;
  margin: 0;
}
input[type="number"] { -moz-appearance: textfield; }