:root {
  --background: 0 0% 100%;
  --foreground: 0 0% 3.9%;
  --card: 0 0% 100%;
  --card-foreground: 0 0% 3.9%;
  --popover: 0 0% 100%;
  --popover-foreground: 0 0% 3.9%;
  --primary: 0 0% 9%;
  --primary-foreground: 0 0% 98%;
  --secondary: 0 0% 96.1%;
  --secondary-foreground: 0 0% 9%;
  --muted: 0 0% 96.1%;
  --muted-foreground: 0 0% 45.1%;
  --accent: 0 0% 96.1%;
  --accent-foreground: 0 0% 9%;
  --destructive: 0 84.2% 60.2%;
  --destructive-foreground: 0 0% 98%;
  --border: 0 0% 89.8%;
  --input: 0 0% 89.8%;
  --ring: 0 0% 3.9%;
  --radius: 0.5rem;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  background-color: hsl(var(--background));
  color: hsl(var(--foreground));
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  max-width: 480px;
  margin: 0 auto;
  padding: 0 16px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.header {
  padding: 32px 0 24px;
  text-align: center;
  border-bottom: 1px solid hsl(var(--border));
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  color: hsl(var(--foreground));
}

.tagline {
  font-size: 0.875rem;
  color: hsl(var(--muted-foreground));
  margin-top: 4px;
}

.main {
  flex: 1;
  padding: 24px 0;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.card {
  background-color: hsl(var(--card));
  border: 1px solid hsl(var(--border));
  border-radius: var(--radius);
  overflow: hidden;
}

.card-header {
  padding: 16px 20px 0;
}

.card-title {
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.card-content {
  padding: 16px 20px 20px;
}

.toggle-group {
  display: flex;
  gap: 0;
  border: 1px solid hsl(var(--border));
  border-radius: var(--radius);
  overflow: hidden;
}

.toggle-item {
  flex: 1;
  padding: 10px 16px;
  font-size: 0.875rem;
  font-weight: 500;
  background-color: transparent;
  border: none;
  cursor: pointer;
  transition: all 0.15s ease;
  color: hsl(var(--muted-foreground));
}

.toggle-item:not(:last-child) {
  border-right: 1px solid hsl(var(--border));
}

.toggle-item:hover {
  background-color: hsl(var(--muted));
}

.toggle-item.active {
  background-color: hsl(var(--primary));
  color: hsl(var(--primary-foreground));
}

/* 風向きトグルと風速入力欄の間隔 */
.wind-direction-toggle {
  margin-bottom: 8px;
}

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

.form-group:last-of-type {
  margin-bottom: 24px;
}

.form-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 8px;
  color: hsl(var(--foreground));
}

.optional-badge {
  font-size: 0.75rem;
  font-weight: 400;
  color: hsl(var(--muted-foreground));
  background-color: hsl(var(--muted));
  padding: 2px 6px;
  border-radius: 4px;
}

.form-input,
.form-select {
  width: 100%;
  padding: 10px 12px;
  font-size: 0.875rem;
  font-family: inherit;
  background-color: hsl(var(--background));
  border: 1px solid hsl(var(--input));
  border-radius: var(--radius);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
  color: hsl(var(--foreground));
}

.form-input:focus,
.form-select:focus {
  outline: none;
  border-color: hsl(var(--ring));
  box-shadow: 0 0 0 2px hsl(var(--ring) / 0.1);
}

.form-input::placeholder {
  color: hsl(var(--muted-foreground));
}

.form-select {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%23666' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 40px;
}

.form-hint {
  font-size: 0.75rem;
  color: hsl(var(--muted-foreground));
  margin-top: 6px;
}

.error-message {
  background-color: hsl(0 84% 60% / 0.1);
  border: 1px solid hsl(0 84% 60%);
  border-radius: var(--radius);
  padding: 8px 12px;
  margin-top: 8px;
  color: hsl(0 84% 40%);
  font-size: 0.75rem;
  animation: slideDown 0.2s ease;
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.form-input.error {
  border-color: hsl(0 84% 60%);
  box-shadow: 0 0 0 2px hsl(0 84% 60% / 0.1);
}

@media (prefers-color-scheme: dark) {
  .error-message {
    background-color: hsl(0 84% 60% / 0.15);
    border-color: hsl(0 70% 60%);
    color: hsl(0 70% 70%);
  }

  .form-input.error {
    border-color: hsl(0 70% 60%);
    box-shadow: 0 0 0 2px hsl(0 70% 60% / 0.15);
  }
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  padding: 12px 24px;
  font-size: 0.875rem;
  font-weight: 500;
  font-family: inherit;
  border-radius: var(--radius);
  cursor: pointer;
  transition: all 0.15s ease;
  border: none;
}

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

.btn-primary:hover {
  background-color: hsl(var(--primary) / 0.9);
}

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

/* リンクをボタンとして使う場合に下線を消す（404ページの「トップへ戻る」等） */
a.btn {
  text-decoration: none;
}

/* キーボード操作時の可視フォーカスリング（アクセシビリティ） */
.btn:focus-visible {
  outline: 2px solid hsl(var(--ring));
  outline-offset: 2px;
}

.result-card {
  border: 2px solid hsl(var(--foreground));
}

.result-main {
  text-align: center;
  padding: 24px 0;
  border-bottom: 1px solid hsl(var(--border));
  margin-bottom: 16px;
}

.result-label {
  font-size: 0.875rem;
  color: hsl(var(--muted-foreground));
  margin-bottom: 8px;
}

.result-value {
  font-size: 3rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  font-variant-numeric: tabular-nums;
}

.result-details {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.result-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 8px 0;
}

.result-row.highlight {
  background-color: hsl(var(--muted));
  margin: 8px -20px 0;
  padding: 12px 20px;
  border-radius: 0;
}

.result-row-label {
  font-size: 0.875rem;
  color: hsl(var(--muted-foreground));
}

.result-row-value {
  font-size: 0.875rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

.result-note {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid hsl(var(--border));
}

.result-note p {
  font-size: 0.75rem;
  color: hsl(var(--muted-foreground));
  text-align: center;
}

.info-section {
  margin-bottom: 20px;
}

.info-section:last-child {
  margin-bottom: 0;
}

.info-title {
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.info-text {
  font-size: 0.8125rem;
  color: hsl(var(--muted-foreground));
  line-height: 1.7;
}

.info-text + .info-text {
  margin-top: 4px;
}

.footer {
  padding: 24px 0;
  text-align: center;
  border-top: 1px solid hsl(var(--border));
}

.footer p {
  font-size: 0.75rem;
  color: hsl(var(--muted-foreground));
}

@media (min-width: 640px) {
  .container {
    padding: 0 24px;
  }
  
  .header {
    padding: 48px 0 32px;
  }
  
  .logo {
    font-size: 1.75rem;
  }
  
  .main {
    padding: 32px 0;
    gap: 20px;
  }
  
  .card-header {
    padding: 20px 24px 0;
  }
  
  .card-content {
    padding: 20px 24px 24px;
  }
  
  .result-row.highlight {
    margin: 8px -24px 0;
    padding: 12px 24px;
  }
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: 0 0% 3.9%;
    --foreground: 0 0% 98%;
    --card: 0 0% 3.9%;
    --card-foreground: 0 0% 98%;
    --popover: 0 0% 3.9%;
    --popover-foreground: 0 0% 98%;
    --primary: 0 0% 98%;
    --primary-foreground: 0 0% 9%;
    --secondary: 0 0% 14.9%;
    --secondary-foreground: 0 0% 98%;
    --muted: 0 0% 14.9%;
    --muted-foreground: 0 0% 63.9%;
    --accent: 0 0% 14.9%;
    --accent-foreground: 0 0% 98%;
    --destructive: 0 62.8% 30.6%;
    --destructive-foreground: 0 0% 98%;
    --border: 0 0% 14.9%;
    --input: 0 0% 14.9%;
    --ring: 0 0% 83.1%;
  }
  
  .form-select {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%23999' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
  }
}

.fade-in {
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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;
}

.simulation-card {
  border: 1px solid hsl(var(--border));
}

/* シミュレーション表の補足文言（表の下に少し余白を空けて配置） */
.simulation-note {
  margin-top: 12px;
  line-height: 1.6;
}

.simulation-table-container {
  border: 1px solid hsl(var(--border));
  border-radius: var(--radius);
}

.simulation-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.8125rem;
}

.simulation-table thead {
  position: sticky;
  top: 0;
  background-color: hsl(var(--muted));
  z-index: 1;
}

.simulation-table th,
.simulation-table td {
  padding: 8px 12px;
  text-align: right;
  border-bottom: 1px solid hsl(var(--border));
}

.simulation-table th:first-child,
.simulation-table td:first-child {
  text-align: left;
}

.simulation-table th {
  font-weight: 600;
  color: hsl(var(--foreground));
}

.simulation-table td {
  font-variant-numeric: tabular-nums;
}

.simulation-table tbody tr:hover {
  background-color: hsl(var(--muted));
}

.simulation-table tbody tr.current-wind {
  background-color: hsl(var(--primary));
  color: hsl(var(--primary-foreground));
  font-weight: 600;
}

.simulation-table tbody tr.current-wind:hover {
  background-color: hsl(var(--primary));
}

.simulation-table tbody tr.zero-wind {
  background-color: hsl(var(--accent));
  font-weight: 500;
}

.wind-positive {
  color: hsl(142 76% 36%);
}

.wind-negative {
  color: hsl(0 84% 60%);
}

@media (prefers-color-scheme: dark) {
  .wind-positive {
    color: hsl(142 70% 50%);
  }

  .wind-negative {
    color: hsl(0 70% 60%);
  }
}

/* タッチデバイス（スマホ・タブレット）でフォーカス時の自動ズームを防ぐ。
   iOS Safari は input/select の font-size が16px未満だとフォーカス時にズームするため、
   タッチ環境のみ16pxに引き上げる（デスクトップの見た目は14pxのまま維持）。 */
@media (hover: none) and (pointer: coarse) {
  .form-input,
  .form-select {
    font-size: 16px;
  }
}