/**
 * デザインシステム
 * トークン（色・影・角丸・間隔）をカスタムプロパティで一元管理し、
 * 政府系デザインシステムの明快さと、モダンなSaaS/家計計算ツールの
 * 洗練さ（カード型の陰影・強調される合計金額・滑らかな操作感）を
 * 参考にしつつ、このサイト独自の配色・構成でまとめている。
 */
:root {
  --color-bg: #f3f5fa;
  --color-panel: #ffffff;
  --color-border: #e3e7ef;
  --color-border-strong: #7c8898;
  --color-primary: #21568f;
  --color-primary-dark: #133758;
  --color-primary-light: #eaf1fb;
  --color-accent: #096b4c;
  --color-accent-light: #e5f6ef;
  --color-text: #1a2130;
  --color-muted: #626c7e;
  --color-total-bg: #eef3fb;
  --color-warning-bg: #fdf6e3;
  --color-warning-border: #edd48a;
  --color-warning-text: #6b4e05;

  --shadow-xs: 0 1px 2px rgba(20, 30, 50, 0.05);
  --shadow-sm: 0 2px 6px rgba(20, 30, 50, 0.06), 0 1px 2px rgba(20, 30, 50, 0.04);
  --shadow-md: 0 8px 24px rgba(20, 30, 50, 0.08), 0 2px 6px rgba(20, 30, 50, 0.05);
  --shadow-lg: 0 16px 40px rgba(20, 30, 50, 0.12), 0 4px 10px rgba(20, 30, 50, 0.06);

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;

  --transition-fast: 120ms ease;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Hiragino Kaku Gothic ProN", "Yu Gothic", "Noto Sans JP", system-ui, sans-serif;
  background: var(--color-bg);
  background-image: radial-gradient(circle at 15% 0%, rgba(33, 86, 143, 0.06), transparent 45%),
    radial-gradient(circle at 85% 0%, rgba(14, 143, 104, 0.05), transparent 40%);
  background-attachment: fixed;
  color: var(--color-text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3 {
  letter-spacing: 0.01em;
}

/* ---------------------------------------------------------------------- */
/* ヘッダー                                                               */
/* ---------------------------------------------------------------------- */

.site-header {
  position: relative;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: #fff;
  padding: 40px 20px 36px;
  text-align: center;
  overflow: hidden;
}

.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(circle at 20% 120%, rgba(255, 255, 255, 0.14), transparent 55%),
    radial-gradient(circle at 85% -20%, rgba(255, 255, 255, 0.12), transparent 45%);
  pointer-events: none;
}

.site-header h1 {
  position: relative;
  margin: 0 0 8px;
  font-size: 1.75rem;
  font-weight: 700;
}

.subtitle {
  position: relative;
  margin: 0;
  font-size: 0.96rem;
  opacity: 0.92;
}

.subtitle + .subtitle {
  margin-top: 8px;
}

@media (max-width: 480px) {
  .site-header {
    padding: 32px 16px 28px;
  }

  .site-header h1 {
    font-size: 1.14rem;
    letter-spacing: 0;
  }

  .subtitle {
    font-size: 0.86rem;
  }
}

.header-link {
  color: #fff;
  font-weight: 600;
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 255, 255, 0.55);
  padding-bottom: 1px;
  transition: border-color var(--transition-fast), opacity var(--transition-fast);
}

.header-link:hover {
  border-color: #fff;
  opacity: 0.85;
}

/* ---------------------------------------------------------------------- */
/* 免責事項                                                               */
/* ---------------------------------------------------------------------- */

.disclaimer {
  max-width: 1000px;
  margin: 22px auto;
  padding: 16px 20px;
  background: var(--color-warning-bg);
  border: 1px solid var(--color-warning-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-xs);
  font-size: 0.88rem;
  color: var(--color-warning-text);
}

.disclaimer a {
  color: var(--color-primary-dark);
  font-weight: 600;
}

/* ---------------------------------------------------------------------- */
/* レイアウト・カード                                                     */
/* ---------------------------------------------------------------------- */

.layout {
  max-width: 1000px;
  margin: 0 auto 40px;
  padding: 0 20px;
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 22px;
  align-items: start;
}

@media (max-width: 760px) {
  .layout {
    grid-template-columns: 1fr;
  }
}

.panel {
  background: var(--color-panel);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: 24px 24px 22px;
}

fieldset {
  border: none;
  border-top: 1px solid var(--color-border);
  padding: 18px 0;
  margin: 0;
}

fieldset:first-of-type {
  border-top: none;
  padding-top: 0;
}

legend {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 1rem;
  color: var(--color-primary-dark);
  padding: 0;
  margin-bottom: 12px;
}

legend::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-primary);
  flex: none;
}

.field {
  margin-bottom: 14px;
}

.field label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-muted);
  margin-bottom: 5px;
}

/* ---------------------------------------------------------------------- */
/* フォーム部品                                                           */
/* ---------------------------------------------------------------------- */

select,
input[type="number"] {
  width: 100%;
  padding: 9px 12px;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-family: inherit;
  background: #fff;
  color: var(--color-text);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 20' fill='none' stroke='%23626c7e' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M5.5 8L10 12.5L14.5 8'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 10px center;
  background-size: 18px;
  padding-right: 34px;
}

select:disabled {
  color: var(--color-muted);
  background-color: var(--color-bg);
  cursor: not-allowed;
}

input[type="number"][readonly] {
  background: var(--color-bg);
  color: var(--color-text);
}

select:hover,
input[type="number"]:hover {
  border-color: var(--color-border-strong);
}

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

.field-label-text {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-muted);
  margin-bottom: 5px;
}

.radio-group {
  display: flex;
  gap: 8px;
}

/* .field label（display:blockでtype+classの詳細度を持つ）に上書きされないよう、
   .radio-group を含めて詳細度をclass2つ分に上げている */
.radio-group .radio-option {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 12px;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
  font-weight: 400;
  color: var(--color-text);
  cursor: pointer;
  transition: background var(--transition-fast), border-color var(--transition-fast);
}

.radio-group .radio-option:hover {
  background: var(--color-primary-light);
}

.radio-group .radio-option:has(input:checked) {
  border-color: var(--color-primary);
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
  font-weight: 600;
}

.radio-group .radio-option input[type="radio"] {
  accent-color: var(--color-primary);
  width: 16px;
  height: 16px;
  flex: none;
}

.counter-input {
  display: flex;
  align-items: center;
  gap: 8px;
}

.counter-input input[type="number"] {
  flex: 1;
  text-align: center;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.counter-btn {
  flex: 0 0 auto;
  width: 38px;
  height: 38px;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  background: #fff;
  color: var(--color-primary-dark);
  font-size: 1.15rem;
  font-weight: 600;
  line-height: 1;
  cursor: pointer;
  transition: background var(--transition-fast), border-color var(--transition-fast),
    transform var(--transition-fast), box-shadow var(--transition-fast);
}

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

.counter-btn:active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
  transform: scale(0.94);
}

.step-buttons {
  display: flex;
  gap: 6px;
  margin-top: 8px;
}

.step-btn {
  flex: 1;
  padding: 7px 0;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  background: #fff;
  color: var(--color-primary-dark);
  font-size: 0.85rem;
  font-weight: 700;
  cursor: pointer;
  transition: background var(--transition-fast), border-color var(--transition-fast),
    transform var(--transition-fast);
}

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

.step-btn:active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
  transform: scale(0.96);
}

.form-actions {
  margin-top: 18px;
  padding-top: 16px;
  border-top: 1px solid var(--color-border);
}

.reset-button {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  background: #fff;
  color: var(--color-muted);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast);
}

.reset-button:hover {
  background: var(--color-warning-bg);
  border-color: var(--color-warning-border);
  color: var(--color-warning-text);
}

/* ---------------------------------------------------------------------- */
/* 補足テキスト・折りたたみ                                               */
/* ---------------------------------------------------------------------- */

.hint {
  font-size: 0.78rem;
  color: var(--color-muted);
  margin: 5px 0 0;
  line-height: 1.55;
}

.regional-rate-details {
  margin-top: 10px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  background: var(--color-bg);
}

.regional-rate-details summary {
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--color-primary-dark);
  list-style: none;
  display: flex;
  align-items: center;
  gap: 6px;
}

.regional-rate-details summary::-webkit-details-marker {
  display: none;
}

.regional-rate-details summary::before {
  content: "";
  width: 0;
  height: 0;
  border-left: 5px solid var(--color-primary-dark);
  border-top: 4px solid transparent;
  border-bottom: 4px solid transparent;
  transition: transform var(--transition-fast);
  flex: none;
}

.regional-rate-details[open] summary::before {
  transform: rotate(90deg);
}

.regional-rate-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 10px;
}

.regional-rate-table th,
.regional-rate-table td {
  text-align: left;
  padding: 7px 6px;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.85rem;
}

.regional-rate-table th {
  font-weight: 600;
  color: var(--color-muted);
}

/* ---------------------------------------------------------------------- */
/* 計算結果                                                               */
/* ---------------------------------------------------------------------- */

.result-panel {
  position: sticky;
  top: 20px;
}

.result-panel-heading {
  margin: 0 0 16px;
  color: var(--color-primary-dark);
  font-size: 1.2rem;
}

.result-hero {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 20px;
  margin-bottom: 20px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  box-shadow: var(--shadow-md);
  color: #fff;
}

.result-hero-label {
  font-size: 0.82rem;
  font-weight: 600;
  opacity: 0.88;
}

.result-hero-value {
  font-size: 2.1rem;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.01em;
}

.result-detail-heading {
  margin: 0 0 8px;
  font-size: 0.86rem;
  font-weight: 700;
  color: var(--color-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.result-table {
  width: 100%;
  border-collapse: collapse;
}

.result-table th,
.result-table td {
  text-align: left;
  padding: 9px 4px;
  border-bottom: 1px solid var(--color-border);
  font-size: 0.92rem;
}

.result-table th {
  font-weight: 500;
  color: var(--color-muted);
}

.result-table td {
  text-align: right;
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  color: var(--color-text);
}

.result-table .total-row th,
.result-table .total-row td {
  background: var(--color-total-bg);
  font-weight: 700;
}

.result-table .total-row th {
  border-radius: var(--radius-sm) 0 0 var(--radius-sm);
}

.result-table .total-row td {
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.result-table .grand-total th,
.result-table .grand-total td {
  background: var(--color-accent-light);
  color: var(--color-accent);
  font-size: 1rem;
}

/* ---------------------------------------------------------------------- */
/* フッター                                                               */
/* ---------------------------------------------------------------------- */

.site-footer {
  text-align: center;
  font-size: 0.8rem;
  color: var(--color-muted);
  padding: 8px 20px 36px;
}

.site-footer a {
  color: var(--color-primary);
  font-weight: 600;
  text-decoration: none;
}

.site-footer a:hover {
  text-decoration: underline;
}

.footer-heading {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--color-primary-dark);
  margin: 0 0 12px;
}

.link-list {
  list-style: none;
  padding: 0;
  margin: 0 0 16px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px 12px;
}

.link-list li {
  background: var(--color-panel);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  padding: 6px 14px;
  box-shadow: var(--shadow-xs);
  transition: box-shadow var(--transition-fast), border-color var(--transition-fast);
}

.link-list li:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.footer-note {
  max-width: 640px;
  margin: 0 auto;
}