:root {
  --color-bg: #f4f6f8;
  --color-card: #ffffff;
  --color-border: #dde2e8;
  --color-text: #1f2937;
  --color-muted: #6b7280;
  --color-primary: #1d4ed8;
  --color-primary-hover: #1e40af;
  --color-danger: #b91c1c;
  --color-danger-bg: #fef2f2;
  --color-success: #15803d;
  --color-success-bg: #f0fdf4;
  --color-warning: #92400e;
  --color-warning-bg: #fffbeb;
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

.page {
  max-width: 640px;
  margin: 0 auto;
  padding: 32px 20px 64px;
}

.page-header {
  text-align: center;
  margin-bottom: 24px;
}

.page-header h1 {
  font-size: 1.5rem;
  margin: 0 0 4px;
}

.subtitle {
  color: var(--color-muted);
  margin: 0;
  font-size: 0.95rem;
}

.card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
}

.field {
  margin-bottom: 18px;
}

label {
  display: block;
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 6px;
}

.req {
  color: var(--color-danger);
}

input[type="text"],
input[type="email"],
input[type="tel"],
input[type="number"] {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-size: 1rem;
  background: #fff;
  color: var(--color-text);
}

input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(29, 78, 216, 0.15);
}

input.computed {
  background: #f3f4f6;
  color: var(--color-text);
  font-weight: 600;
}

.input-prefix,
.input-suffix {
  display: flex;
  align-items: center;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  background: #fff;
}

.input-prefix span,
.input-suffix span {
  padding: 0 12px;
  color: var(--color-muted);
  font-weight: 600;
  background: #f9fafb;
  align-self: stretch;
  display: flex;
  align-items: center;
}

.input-prefix input,
.input-suffix input {
  border: none;
  flex: 1;
  min-width: 0;
}

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

.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

@media (max-width: 480px) {
  .grid-2 {
    grid-template-columns: 1fr;
  }
}

.divider {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: 24px 0;
}

.radio-group {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.radio-option {
  display: flex;
  align-items: center;
  gap: 6px;
  font-weight: 400;
  border: 1px solid var(--color-border);
  padding: 8px 14px;
  border-radius: var(--radius);
  cursor: pointer;
}

.radio-option input {
  margin: 0;
}

.actions {
  display: flex;
  gap: 12px;
  justify-content: flex-end;
  margin-top: 24px;
}

.btn {
  border: none;
  border-radius: var(--radius);
  padding: 11px 22px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
}

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

.btn-primary:hover {
  background: var(--color-primary-hover);
}

.btn-primary:disabled {
  background: #93a3c9;
  cursor: not-allowed;
}

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

.btn-secondary:hover {
  background: #f3f4f6;
}

.error-text {
  color: var(--color-danger);
  background: var(--color-danger-bg);
  border: 1px solid #fecaca;
  padding: 10px 14px;
  border-radius: var(--radius);
  font-size: 0.9rem;
  margin: 0 0 12px;
}

.muted {
  color: var(--color-muted);
  font-size: 0.9rem;
  margin-top: 0;
}

.summary {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 8px 16px;
  margin: 20px 0;
}

.summary dt {
  color: var(--color-muted);
  font-size: 0.85rem;
}

.summary dd {
  margin: 0;
  font-weight: 600;
}

.result-box {
  padding: 16px;
  border-radius: var(--radius);
  font-size: 0.95rem;
}

.result-success {
  background: var(--color-success-bg);
  border: 1px solid #bbf7d0;
  color: var(--color-success);
}

.result-error {
  background: var(--color-danger-bg);
  border: 1px solid #fecaca;
  color: var(--color-danger);
}

.result-safe-mode {
  background: var(--color-warning-bg);
  border: 1px solid #fde68a;
  color: var(--color-warning);
}

.result-box pre {
  white-space: pre-wrap;
  word-break: break-word;
  font-size: 0.8rem;
  background: rgba(0, 0, 0, 0.04);
  padding: 10px;
  border-radius: 6px;
  margin-top: 10px;
}