/* ==========================================================================
   TARO. AI Academy — 共通トークン・リセット・ヘッダー/フッター/フォーム
   依存ライブラリなし。01_本棚サイト/02_購入者特典ページと同じ配色体系を継承。
   ========================================================================== */

:root {
  /* カラー（既存サイトと同じ値） */
  --color-navy-deep: #07111f;
  --color-slate-black: #132033;
  --color-slate-light: #f2f6fb;
  --color-white: #ffffff;
  --color-cobalt: #176bff;
  --color-cyan: #34d6e9;
  --color-orange: #ffb36b;

  --color-text-body: var(--color-slate-black);
  --color-text-muted: #4b5568;
  --color-border: #e2e8f0;

  /* 受講画面など暗色レイヤー用 */
  --color-navy-panel: #0f1830;
  --color-navy-panel-raised: #141f3c;
  --color-border-oncolor: rgba(243, 246, 250, 0.16);
  --color-text-oncolor: var(--color-slate-light);
  --color-text-oncolor-muted: rgba(243, 246, 250, 0.7);

  /* タイポグラフィ */
  --font-sans: 'Hiragino Sans', 'Hiragino Kaku Gothic ProN', 'Noto Sans JP', 'Yu Gothic UI', 'Meiryo',
    -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  /* レイアウト */
  --content-max-width: 1240px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --shadow-soft: 0 8px 24px rgba(11, 18, 32, 0.08);
  --shadow-panel: 0 16px 40px rgba(2, 6, 20, 0.4);

  --transition-fast: 160ms ease;
}

/* ---- モーション配慮（最優先で定義） ---- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

/* ---- リセット・ベース ---- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background-color: var(--color-white);
  color: var(--color-text-body);
  font-family: var(--font-sans);
  font-weight: 500;
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img,
svg {
  max-width: 100%;
  display: block;
}

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

a {
  color: var(--color-cobalt);
  text-decoration-thickness: 2px;
  text-underline-offset: 2px;
}

h1,
h2,
h3,
h4 {
  font-weight: 800;
  line-height: 1.4;
  margin: 0;
}

p {
  margin: 0;
}

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

button {
  font-family: inherit;
}

/* ---- アクセシビリティ共通部品 ---- */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -48px;
  left: 12px;
  z-index: 200;
  background: var(--color-navy-deep);
  color: var(--color-white);
  padding: 12px 20px;
  border-radius: var(--radius-md);
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 12px;
}

:focus-visible {
  outline: 3px solid var(--color-cyan);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ---- レイアウト共通 ---- */
.container {
  max-width: var(--content-max-width);
  margin-inline: auto;
  padding-inline: 20px;
}

.section {
  padding-block: 76px;
}

.section-heading {
  font-size: clamp(1.375rem, 1.1rem + 1.2vw, 1.875rem);
  color: var(--color-navy-deep);
  margin-bottom: 12px;
}

.section-lead {
  color: var(--color-text-muted);
  font-weight: 400;
  max-width: 56em;
  margin-bottom: 24px;
}

.eyebrow {
  color: var(--color-cobalt);
  font-size: 0.8125rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  margin-bottom: 8px;
}

.eyebrow--oncolor {
  color: var(--color-cyan);
}

/* ---- ヘッダー・ナビゲーション ---- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background-color: var(--color-navy-deep);
  border-bottom: 1px solid var(--color-border-oncolor);
}

.site-header__inner {
  max-width: var(--content-max-width);
  margin-inline: auto;
  padding-inline: 20px;
  padding-block: 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  color: var(--color-white);
  font-size: clamp(1rem, 0.9rem + 0.4vw, 1.1875rem);
  font-weight: 800;
  letter-spacing: 0.01em;
  margin: 0;
  text-decoration: none;
  white-space: nowrap;
}

.brand--small {
  font-size: 1rem;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 20px;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: 20px;
}

.site-nav__link {
  color: var(--color-text-oncolor);
  font-size: 0.9375rem;
  font-weight: 700;
  text-decoration: none;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

.site-nav__link:hover {
  color: var(--color-cyan);
}

.site-nav__link[aria-current='page'] {
  color: var(--color-cyan);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
  border: none;
  background: transparent;
  cursor: pointer;
}

.menu-toggle__bar {
  display: block;
  height: 2px;
  width: 100%;
  background-color: var(--color-white);
  border-radius: 2px;
}

@media (max-width: 899px) {
  .menu-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    background-color: var(--color-navy-deep);
    border-bottom: 1px solid var(--color-border-oncolor);
    padding: 12px 20px 20px;
    display: none;
  }

  .site-nav.site-nav--open {
    display: flex;
  }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .site-nav__link {
    padding-block: 10px;
    border-bottom: 1px solid var(--color-border-oncolor);
  }

  .site-nav__cta {
    margin-top: 12px;
    width: 100%;
    justify-content: center;
  }
}

/* ---- ボタン ---- */
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 48px;
  padding: 10px 24px;
  border-radius: var(--radius-md);
  font-weight: 800;
  font-size: 0.9375rem;
  text-decoration: none;
  border: 2px solid transparent;
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.button--primary {
  background-color: var(--color-orange);
  color: var(--color-navy-deep);
}

.button--primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(253, 186, 116, 0.4);
}

.button--secondary {
  background-color: transparent;
  border-color: var(--color-cobalt);
  color: var(--color-cobalt);
}

.button--secondary:hover {
  background-color: rgba(37, 99, 235, 0.08);
}

.button--oncolor-secondary {
  background-color: transparent;
  border-color: var(--color-border-oncolor);
  color: var(--color-white);
}

.button--oncolor-secondary:hover {
  border-color: var(--color-cyan);
  color: var(--color-cyan);
}

.button--ghost {
  background-color: transparent;
  color: var(--color-cobalt);
  padding-inline: 12px;
}

.button:disabled,
.button[aria-disabled='true'] {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
  box-shadow: none !important;
}

.button--block {
  width: 100%;
}

/* ---- バッジ ---- */
.badge {
  display: inline-flex;
  align-items: center;
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  padding: 4px 10px;
  border-radius: 999px;
  white-space: nowrap;
}

.badge--status-published {
  background-color: rgba(37, 99, 235, 0.12);
  color: var(--color-cobalt);
}

.badge--status-coming-soon {
  background-color: rgba(23, 32, 51, 0.08);
  color: var(--color-text-muted);
}

.badge--access-free {
  background-color: rgba(253, 186, 116, 0.22);
  color: #9a4a06;
}

.badge--access-member {
  background-color: rgba(34, 211, 238, 0.14);
  color: #075985;
}

.badge--category {
  background-color: rgba(37, 99, 235, 0.1);
  color: var(--color-cobalt);
}

.badge--oncolor {
  background-color: rgba(34, 211, 238, 0.16);
  color: var(--color-cyan);
}

.badge--level {
  background-color: rgba(23, 32, 51, 0.06);
  color: var(--color-text-muted);
}

/* ---- フォーム共通 ---- */
.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 18px;
}

.field__label {
  font-weight: 800;
  font-size: 0.9375rem;
  color: var(--color-navy-deep);
}

.field__hint {
  font-weight: 400;
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

.field__input,
.field__textarea,
.field__select {
  font: inherit;
  font-weight: 400;
  font-size: 1rem;
  padding: 12px 14px;
  min-height: 48px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  background-color: var(--color-white);
  color: var(--color-text-body);
  width: 100%;
}

.field__textarea {
  min-height: 96px;
  resize: vertical;
}

.choice-group {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.choice-group--row {
  flex-direction: row;
  flex-wrap: wrap;
}

.choice-option {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  cursor: pointer;
}

.choice-option input {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

.choice-option:has(input:checked) {
  border-color: var(--color-cobalt);
  background-color: rgba(37, 99, 235, 0.06);
}

.choice-option--oncolor {
  border-color: var(--color-border-oncolor);
  color: var(--color-text-oncolor);
}

.choice-option--oncolor:has(input:checked) {
  border-color: var(--color-cyan);
  background-color: rgba(34, 211, 238, 0.12);
}

.field__error {
  color: #b91c1c;
  font-size: 0.8125rem;
  font-weight: 700;
}

/* ---- フッター ---- */
.site-footer {
  background-color: var(--color-navy-deep);
  color: var(--color-slate-light);
}

.site-footer__inner {
  max-width: var(--content-max-width);
  margin-inline: auto;
  padding-inline: 20px;
  padding-block: 40px;
  display: grid;
  gap: 24px;
}

@media (min-width: 720px) {
  .site-footer__inner {
    grid-template-columns: 1.2fr 2fr;
    align-items: start;
  }
}

.site-footer__brand {
  display: grid;
  gap: 8px;
}

.site-footer__note {
  font-weight: 400;
  font-size: 0.875rem;
  color: rgba(243, 246, 250, 0.72);
  max-width: 32em;
}

.site-footer__navs {
  display: grid;
  gap: 12px 32px;
}

@media (min-width: 480px) {
  .site-footer__navs {
    grid-template-columns: repeat(2, 1fr);
  }
}

.site-footer__list {
  display: grid;
  gap: 10px;
}

.site-footer__list a {
  color: rgba(243, 246, 250, 0.85);
  font-size: 0.9375rem;
  min-height: 32px;
  display: inline-flex;
  align-items: center;
}

.site-footer__list a:hover {
  color: var(--color-cyan);
}

/* ---- 汎用ノート・空状態 ---- */
.notice {
  padding: 16px 20px;
  border-radius: var(--radius-md);
  background-color: var(--color-slate-light);
  color: var(--color-text-muted);
  font-weight: 400;
  font-size: 0.9375rem;
}

.notice--oncolor {
  background-color: var(--color-navy-panel-raised);
  color: var(--color-text-oncolor-muted);
}

.empty-state {
  padding: 32px 20px;
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-md);
  text-align: center;
  color: var(--color-text-muted);
  font-weight: 400;
}

/* ---- パンくず ---- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--color-text-muted);
  margin-bottom: 16px;
}

.breadcrumb a {
  color: var(--color-text-muted);
}

.breadcrumb__sep {
  color: var(--color-border);
}

.breadcrumb--oncolor,
.breadcrumb--oncolor a {
  color: var(--color-text-oncolor-muted);
}