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

:root {
  --bg: #f2f2f7;
  --card: #ffffff;
  --black: #1a1a1a;
  --gray-dark: #555;
  --gray: #888;
  --gray-light: #c8c8cc;
  --border: #e8e8ed;
  --accent: #c8e600;
  --accent-dark: #a8c200;
  --radius: 16px;
  --radius-sm: 12px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang TC", "Microsoft JhengHei", sans-serif;
  background: var(--bg);
  color: var(--black);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 480px;
  margin: 0 auto;
  min-height: 100vh;
  padding-bottom: 40px;
}

/* Header */
.header {
  background: var(--black);
  color: #fff;
  padding: 48px 24px 36px;
  text-align: center;
  border-radius: 0 0 24px 24px;
}

.header h1 {
  font-size: 30px;
  font-weight: 800;
  margin-bottom: 4px;
  letter-spacing: -0.5px;
}

.header .subtitle {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 16px;
}

.header .highlight {
  color: var(--accent);
}

.header .stats {
  font-size: 12px;
  color: #777;
  letter-spacing: 0.5px;
}

/* Form Section */
.form-section {
  margin: 16px;
  background: var(--card);
  border-radius: var(--radius);
  padding: 24px 20px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.04);
}

.form-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 24px;
  flex-wrap: wrap;
  gap: 8px;
}

.form-header h2 {
  font-size: 20px;
  font-weight: 800;
  color: var(--black);
}

.accuracy-badge {
  font-size: 11px;
  color: var(--gray);
  background: var(--bg);
  padding: 4px 10px;
  border-radius: 20px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--gray-dark);
}

.required {
  color: var(--accent-dark);
  margin-right: 2px;
  font-weight: 700;
}

.select-row {
  display: flex;
  gap: 10px;
}

.select-row select {
  flex: 1;
}

select,
input[type="number"] {
  width: 100%;
  height: 48px;
  padding: 0 14px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 15px;
  color: var(--black);
  background: var(--bg);
  appearance: none;
  -webkit-appearance: none;
  transition: border-color 0.2s;
}

select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%23999' stroke-width='1.5' fill='none'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  background-color: var(--bg);
  padding-right: 36px;
}

select:disabled {
  background-color: var(--bg);
  color: var(--gray-light);
}

select:focus,
input:focus {
  outline: none;
  border-color: var(--black);
}

.input-with-unit {
  position: relative;
}

.input-with-unit input {
  padding-right: 72px;
}

.input-with-unit .unit {
  position: absolute;
  right: 14px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 13px;
  color: var(--gray);
  font-weight: 500;
}

.btn-submit {
  width: 100%;
  height: 52px;
  background: var(--black);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 17px;
  font-weight: 700;
  cursor: pointer;
  margin-top: 4px;
  transition: background 0.2s, transform 0.1s;
  letter-spacing: 0.5px;
}

.btn-submit:hover {
  background: #333;
}

.btn-submit:active {
  transform: scale(0.98);
}

.btn-submit:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Result Section */
.result-section {
  margin: 16px;
  animation: fadeInUp 0.4s ease;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.result-title {
  text-align: center;
  font-size: 18px;
  font-weight: 800;
  padding: 20px 0 12px;
  color: var(--black);
}

.result-card {
  background: var(--card);
  border-radius: var(--radius);
  padding: 28px 20px;
  text-align: center;
  box-shadow: 0 1px 3px rgba(0,0,0,0.04);
}

.result-label {
  font-size: 14px;
  font-weight: 600;
  color: var(--gray-dark);
  margin-bottom: 12px;
}

.result-price {
  margin-bottom: 16px;
}

.price {
  font-size: 38px;
  font-weight: 900;
  color: var(--black);
  letter-spacing: -1px;
}

.price-separator {
  font-size: 22px;
  color: var(--gray);
  margin: 0 6px;
}

.price-tag {
  font-size: 13px;
  color: var(--gray);
}

.result-desc {
  font-size: 13px;
  color: var(--gray);
  margin-bottom: 24px;
}

/* Condition Tabs */
.condition-tabs {
  display: flex;
  gap: 6px;
  justify-content: center;
  flex-wrap: wrap;
}

.condition-tab {
  padding: 8px 14px;
  border: 1.5px solid var(--border);
  border-radius: 24px;
  font-size: 13px;
  background: var(--card);
  color: var(--gray-dark);
  cursor: pointer;
  transition: all 0.2s;
  font-weight: 500;
}

.condition-tab:hover {
  border-color: var(--black);
  color: var(--black);
}

.condition-tab.active {
  background: var(--black);
  color: #fff;
  border-color: var(--black);
}

/* Car Summary */
.car-summary {
  margin-top: 16px;
  padding: 16px 20px;
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: 0 1px 3px rgba(0,0,0,0.04);
}

.summary-title {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 6px;
  color: var(--black);
}

.summary-details {
  font-size: 13px;
  color: var(--gray);
}

.summary-details .sep {
  margin: 0 6px;
  color: var(--gray-light);
}

/* Action Buttons */
.action-buttons {
  display: flex;
  gap: 12px;
  margin-top: 16px;
}

.btn-action {
  flex: 1;
  height: 52px;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.1s, opacity 0.2s;
  letter-spacing: 0.3px;
}

.btn-action:hover {
  opacity: 0.9;
}

.btn-action:active {
  transform: scale(0.97);
}

.btn-sell {
  background: var(--accent);
  color: var(--black);
}

.btn-loan {
  background: var(--black);
  color: #fff;
}

/* Responsive */
@media (max-width: 480px) {
  .container {
    max-width: 100%;
  }

  .header {
    padding: 40px 20px 28px;
  }

  .form-section,
  .result-section {
    margin-left: 12px;
    margin-right: 12px;
  }

  .price {
    font-size: 32px;
  }

  .condition-tab {
    padding: 6px 11px;
    font-size: 12px;
  }
}