:root {
  --bg: #f4f6f8;
  --surface: #ffffff;
  --text: #1f2937;
  --text-muted: #6b7280;
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #dbeafe;
  --danger: #dc2626;
  --danger-bg: #fef2f2;
  --success: #16a34a;
  --success-bg: #f0fdf4;
  --warning: #d97706;
  --warning-bg: #fffbeb;
  --border: #d1d5db;
  --radius: 0.75rem;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --font: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
}

* {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

.app {
  max-width: 720px;
  margin: 0 auto;
  padding: 1.5rem 1rem 3rem;
}

.app-header {
  text-align: center;
  margin-bottom: 1.5rem;
}

.app-header h1 {
  margin: 0;
  font-size: 1.75rem;
  color: var(--primary-dark);
}

.subtitle {
  margin: 0.25rem 0 0;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.card {
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.25rem;
  margin-bottom: 1.25rem;
}

.card h2,
.card h3 {
  margin-top: 0;
  margin-bottom: 1rem;
  font-size: 1.125rem;
}

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

@media (min-width: 640px) {
  .form-grid {
    grid-template-columns: 1fr 1fr;
  }

  .field.optional:nth-child(8),
  .field.optional:nth-child(9) {
    grid-column: span 2;
  }
}

.field {
  display: flex;
  flex-direction: column;
}

.field label {
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 0.35rem;
}

.field .unit {
  font-weight: 400;
  color: var(--text-muted);
}

.field input {
  padding: 0.6rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  font-size: 1rem;
  font-family: var(--font);
  transition: border-color 0.15s, box-shadow 0.15s;
}

.field input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
}

.field input.error-border {
  border-color: var(--danger);
}

.field .hint,
.field .error {
  font-size: 0.8rem;
  margin-top: 0.25rem;
}

.field .hint {
  color: var(--text-muted);
}

.field .error {
  color: var(--danger);
  min-height: 1.1em;
}

.actions {
  display: flex;
  gap: 0.75rem;
  margin-top: 1.25rem;
}

.actions button {
  flex: 1;
  padding: 0.75rem 1rem;
  border: none;
  border-radius: 0.5rem;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s, transform 0.05s;
}

.actions button:active {
  transform: translateY(1px);
}

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

.btn-primary:hover,
.btn-primary:focus {
  background: var(--primary-dark);
}

.btn-secondary {
  background: #e5e7eb;
  color: var(--text);
}

.btn-secondary:hover,
.btn-secondary:focus {
  background: #d1d5db;
}

.results {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.result-list {
  display: grid;
  gap: 0.75rem;
  margin: 0;
}

.result-list > div {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 0.6rem 0;
  border-bottom: 1px solid #f3f4f6;
}

.result-list > div:last-child {
  border-bottom: none;
}

.result-list dt {
  font-weight: 500;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.result-list dd {
  margin: 0;
  font-family: var(--mono);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
}

.status-card {
  border-left: 5px solid var(--success);
}

.status-card.has-warning {
  border-left-color: var(--warning);
}

.status-card.has-danger {
  border-left-color: var(--danger);
}

.status-message {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  border-radius: 0.5rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
}

.status-message.ok {
  background: var(--success-bg);
  color: var(--success);
}

.status-message.warn {
  background: var(--warning-bg);
  color: var(--warning);
}

.status-message.danger {
  background: var(--danger-bg);
  color: var(--danger);
}

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

.recommendation-list li {
  padding: 0.4rem 0;
  border-bottom: 1px solid #f3f4f6;
  font-size: 0.95rem;
}

.recommendation-list li:last-child {
  border-bottom: none;
}

.info-card {
  background: #f8fafc;
}

.info-card ul {
  padding-left: 1.25rem;
  margin: 0;
}

.info-card li {
  margin-bottom: 0.5rem;
  font-size: 0.95rem;
}

.info-card code {
  font-family: var(--mono);
  background: #e2e8f0;
  padding: 0.15rem 0.35rem;
  border-radius: 0.25rem;
  font-size: 0.85em;
}

.app-footer {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-top: 1rem;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

[hidden] {
  display: none !important;
}