/* ========================================
   割り勘計算 - style.css
   スマホファースト / ダークモード対応
   ======================================== */

/* --- カスタムプロパティ --- */
:root {
  --color-primary: #2e7d32;
  --color-primary-light: #4caf50;
  --color-primary-dark: #1b5e20;
  --color-bg: #f5f5f5;
  --color-surface: #ffffff;
  --color-text: #212121;
  --color-text-secondary: #616161;
  --color-border: #e0e0e0;
  --color-input-bg: #ffffff;
  --color-result-bg: #e8f5e9;
  --color-result-text: #1b5e20;
  --color-line: #06c755;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
  --max-width: 480px;
  --tap-size: 44px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-primary: #66bb6a;
    --color-primary-light: #81c784;
    --color-primary-dark: #388e3c;
    --color-bg: #121212;
    --color-surface: #1e1e1e;
    --color-text: #e0e0e0;
    --color-text-secondary: #9e9e9e;
    --color-border: #333333;
    --color-input-bg: #2c2c2c;
    --color-result-bg: #1b3a1b;
    --color-result-text: #a5d6a7;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
  }
}

/* --- リセット --- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* --- ベース --- */
html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

/* --- ヘッダー --- */
.header {
  text-align: center;
  padding: 1.5rem 1rem 1rem;
}

.header__title {
  font-size: 1.5rem;
  color: var(--color-primary);
  font-weight: 700;
}

.header__desc {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  margin-top: 0.25rem;
}

/* --- メイン --- */
.main {
  flex: 1;
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1rem 2rem;
}

/* --- カード --- */
.card {
  background: var(--color-surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.25rem;
  margin-bottom: 1rem;
}

.card__title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--color-text);
}

.card__title--toggle {
  margin-bottom: 0;
  display: inline;
}

/* --- 結果カード --- */
.card--result {
  border: 2px solid var(--color-primary);
}

/* --- フォーム --- */
.form-group {
  margin-bottom: 1rem;
}

.form-group:last-child {
  margin-bottom: 0;
}

.form-label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  margin-bottom: 0.4rem;
}

.form-input {
  width: 100%;
  height: var(--tap-size);
  padding: 0 0.75rem;
  font-size: 1rem;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-input-bg);
  color: var(--color-text);
  transition: border-color 0.2s;
}

.form-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(76, 175, 80, 0.15);
}

.form-input--large {
  font-size: 1.25rem;
  height: 52px;
  font-weight: 700;
  text-align: right;
}

/* --- ステッパー --- */
.stepper {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.stepper__btn {
  width: var(--tap-size);
  height: var(--tap-size);
  border-radius: 50%;
  border: 1.5px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-primary);
  font-size: 1.25rem;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s, border-color 0.2s;
  flex-shrink: 0;
}

.stepper__btn:active {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

.stepper__input {
  width: 64px;
  height: var(--tap-size);
  text-align: center;
  font-size: 1.25rem;
  font-weight: 700;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-input-bg);
  color: var(--color-text);
}

.stepper__input:focus {
  outline: none;
  border-color: var(--color-primary);
}

/* --- ラジオチップ --- */
.radio-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.radio-row--vertical {
  flex-direction: column;
}

.radio-chip {
  cursor: pointer;
}

.radio-chip input {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

.radio-chip span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: var(--tap-size);
  padding: 0.5rem 0.85rem;
  font-size: 0.85rem;
  font-weight: 600;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  color: var(--color-text);
  transition: all 0.2s;
}

.radio-chip input:checked + span {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

.radio-chip--block {
  width: 100%;
}

.radio-chip--block span {
  width: 100%;
  justify-content: flex-start;
}

/* --- トグルボタン --- */
.toggle-btn {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
  color: var(--color-text);
}

.toggle-btn__icon {
  width: 24px;
  height: 24px;
  position: relative;
  flex-shrink: 0;
}

.toggle-btn__icon::before,
.toggle-btn__icon::after {
  content: "";
  position: absolute;
  background: var(--color-text-secondary);
  border-radius: 2px;
  transition: transform 0.3s;
}

.toggle-btn__icon::before {
  width: 14px;
  height: 2px;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.toggle-btn__icon::after {
  width: 2px;
  height: 14px;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.toggle-btn[aria-expanded="true"] .toggle-btn__icon::after {
  transform: translate(-50%, -50%) rotate(90deg);
}

/* --- 詳細パネル --- */
.advanced-panel {
  padding-top: 1rem;
}

.mode-settings {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--color-border);
}

/* --- 傾斜グループ --- */
.weighted-groups {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.weighted-group {
  display: grid;
  grid-template-columns: 1fr 80px 70px auto;
  gap: 0.5rem;
  align-items: center;
}

.weighted-group input {
  height: 40px;
  padding: 0 0.5rem;
  font-size: 0.85rem;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-input-bg);
  color: var(--color-text);
}

.weighted-group input:focus {
  outline: none;
  border-color: var(--color-primary);
}

.btn-remove-group {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: none;
  background: none;
  color: var(--color-text-secondary);
  font-size: 1.25rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-remove-group:hover {
  color: #e53935;
}

/* --- ボタン --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: var(--tap-size);
  padding: 0.6rem 1.25rem;
  font-size: 0.9rem;
  font-weight: 700;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  text-decoration: none;
  transition: opacity 0.2s, transform 0.1s;
}

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

.btn--primary {
  background: var(--color-primary);
  color: #fff;
  width: 100%;
  margin-bottom: 1rem;
}

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

.btn--large {
  font-size: 1.1rem;
  min-height: 52px;
  border-radius: var(--radius);
}

.btn--secondary {
  background: var(--color-surface);
  color: var(--color-primary);
  border: 1.5px solid var(--color-primary);
}

.btn--small {
  font-size: 0.8rem;
  min-height: 36px;
  padding: 0.4rem 0.75rem;
}

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

/* --- 結果表示 --- */
.result-main {
  text-align: center;
  padding: 1rem 0;
}

.result-amount {
  font-size: 2rem;
  font-weight: 800;
  color: var(--color-result-text);
  background: var(--color-result-bg);
  border-radius: var(--radius-sm);
  padding: 0.75rem;
  margin-bottom: 0.5rem;
}

.result-amount small {
  font-size: 1rem;
  font-weight: 600;
}

.result-sub {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
}

.result-detail {
  margin: 1rem 0;
}

.result-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
}

.result-table th,
.result-table td {
  padding: 0.5rem 0.4rem;
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}

.result-table th {
  color: var(--color-text-secondary);
  font-weight: 600;
}

.result-table td:last-child {
  text-align: right;
  font-weight: 700;
}

.result-actions {
  display: flex;
  gap: 0.5rem;
  margin-top: 1rem;
}

.result-actions .btn {
  flex: 1;
}

/* --- 広告枠 --- */
.ad-slot {
  margin-bottom: 1rem;
  min-height: 100px;
}

.ad-slot__placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100px;
  background: var(--color-surface);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text-secondary);
  font-size: 0.8rem;
}

/* --- FAQ --- */
.faq-item {
  border-bottom: 1px solid var(--color-border);
}

.faq-item:last-child {
  border-bottom: none;
}

.faq-item__q {
  padding: 0.85rem 0;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}

.faq-item__q::-webkit-details-marker {
  display: none;
}

.faq-item__q::before {
  content: "Q. ";
  color: var(--color-primary);
  font-weight: 700;
}

.faq-item__a {
  padding: 0 0 0.85rem;
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* --- リンクリスト --- */
.link-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.link-list li {
  border-bottom: 1px solid var(--color-border);
}

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

.link-list a {
  display: block;
  padding: 0.85rem 0;
  font-size: 0.9rem;
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 600;
}

.link-list a::after {
  content: " ›";
  color: var(--color-text-secondary);
}

.link-list a:hover {
  text-decoration: underline;
}

/* --- パンくず --- */
.breadcrumb {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.5rem 1rem 0;
  font-size: 0.75rem;
  color: var(--color-text-secondary);
}

.breadcrumb a {
  color: var(--color-text-secondary);
  text-decoration: none;
}

.breadcrumb a:hover {
  text-decoration: underline;
}

.breadcrumb__sep {
  margin: 0 0.3rem;
}

/* --- 記事本文 --- */
.article {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1rem;
}

.article h1 {
  font-size: 1.4rem;
  line-height: 1.4;
  margin-bottom: 0.75rem;
  color: var(--color-text);
}

.article h2 {
  font-size: 1.1rem;
  margin: 1.75rem 0 0.75rem;
  padding-left: 0.6rem;
  border-left: 4px solid var(--color-primary);
  color: var(--color-text);
}

.article h3 {
  font-size: 1rem;
  margin: 1.25rem 0 0.5rem;
  color: var(--color-text);
}

.article p {
  font-size: 0.9rem;
  line-height: 1.8;
  margin-bottom: 0.85rem;
  color: var(--color-text);
}

.article ul,
.article ol {
  padding-left: 1.25rem;
  margin-bottom: 0.85rem;
  font-size: 0.9rem;
  line-height: 1.8;
}

.article table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  margin-bottom: 1rem;
}

.article th,
.article td {
  padding: 0.5rem 0.6rem;
  border: 1px solid var(--color-border);
  text-align: left;
}

.article th {
  background: var(--color-result-bg);
  color: var(--color-result-text);
  font-weight: 700;
}

.cta-card {
  background: var(--color-result-bg);
  border-radius: var(--radius);
  padding: 1.25rem;
  margin: 1.5rem 0;
  text-align: center;
}

.cta-card__title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-result-text);
  margin-bottom: 0.75rem;
}

/* --- フッター --- */
.footer {
  text-align: center;
  padding: 1.5rem 1rem;
  font-size: 0.75rem;
  color: var(--color-text-secondary);
}

.footer__nav {
  margin-bottom: 0.5rem;
}

.footer__nav a {
  color: var(--color-text-secondary);
  text-decoration: none;
}

.footer__nav a:hover {
  text-decoration: underline;
}

.footer__copy {
  opacity: 0.7;
}

/* --- コピー完了トースト --- */
.toast {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--color-text);
  color: var(--color-bg);
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-size: 0.85rem;
  font-weight: 600;
  opacity: 0;
  transition: transform 0.3s, opacity 0.3s;
  z-index: 100;
  pointer-events: none;
}

.toast--visible {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

/* --- PC対応 --- */
@media (min-width: 600px) {
  .header {
    padding: 2rem 1rem 1.5rem;
  }

  .header__title {
    font-size: 1.75rem;
  }

  .card {
    padding: 1.5rem;
  }
}