/* ============================================================
   青松 English Learning Tools — 共通スタイル
   ============================================================ */

/* --- CSS変数（カラーパレット・タイポグラフィ） --- */
:root {
  --color-bg:          #f8f7f4;
  --color-surface:     #ffffff;
  --color-surface-alt: #f0ede8;
  --color-border:      #e2ddd8;
  --color-text:        #1a1714;
  --color-text-muted:  #6b645c;
  --color-accent:      #2d6a4f;
  --color-accent-light:#52b788;
  --color-accent-dim:  #d8f3dc;
  --color-tag-bg:      #edf6f0;
  --color-tag-text:    #2d6a4f;
  --color-shadow:      rgba(0,0,0,0.07);
  --color-shadow-hover:rgba(0,0,0,0.13);

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP",
               "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
  --font-mono: "SF Mono", "Fira Code", Consolas, monospace;

  --radius-sm:  6px;
  --radius-md:  12px;
  --radius-lg:  20px;

  --transition: 0.2s ease;

  --max-width: 1200px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.65;
  min-height: 100vh;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* ============================================================
   HEADER
   ============================================================ */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.site-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: -0.01em;
}

.logo-mark {
  width: 36px;
  height: 36px;
  background: var(--color-accent);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.logo-text { color: var(--color-text); }
.logo-sub   { color: var(--color-text-muted); font-weight: 400; font-size: 0.85rem; margin-left: 2px; }

/* ============================================================
   HERO
   ============================================================ */
.hero {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 24px 24px 16px;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 32px;
  align-items: end;
}

.hero-title {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.2;
}

.hero-title em {
  font-style: normal;
  color: var(--color-accent);
}

.hero-desc {
  color: var(--color-text-muted);
  font-size: 1rem;
  margin-top: 12px;
  max-width: 520px;
}

.hero-stat {
  text-align: right;
  flex-shrink: 0;
}

.hero-stat .num {
  font-size: 3rem;
  font-weight: 800;
  color: var(--color-accent);
  line-height: 1;
  letter-spacing: -0.04em;
}

.hero-stat .label {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-top: 4px;
}

/* ============================================================
   FILTER BAR
   ============================================================ */
.filter-section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px 32px;
}

.filter-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  margin-bottom: 10px;
}

.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.filter-btn {
  padding: 6px 16px;
  border: 1.5px solid var(--color-border);
  border-radius: 999px;
  background: var(--color-surface);
  color: var(--color-text-muted);
  font-size: 0.85rem;
  font-family: var(--font-sans);
  cursor: pointer;
  transition: all var(--transition);
  font-weight: 500;
}

.filter-btn:hover {
  border-color: var(--color-accent-light);
  color: var(--color-accent);
}

.filter-btn.active {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: #fff;
}

/* ============================================================
   APP GRID
   ============================================================ */
.app-grid-section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px 80px;
}

.app-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

/* --- カード --- */
.app-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  position: relative;
  display: flex;
  gap: 16px;
  align-items: flex-start;
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
  cursor: pointer;
}

.app-card:hover {
  box-shadow: 0 8px 24px var(--color-shadow-hover);
  transform: translateY(-2px);
  border-color: var(--color-accent-light);
}

/* カード全体をリンク化するトリック */
.card-link {
  position: absolute;
  inset: 0;
  border-radius: var(--radius-md);
}

.card-link:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-sm);
  background: var(--color-accent-dim);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  flex-shrink: 0;
}

.card-body { flex: 1; min-width: 0; }

.card-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 6px;
  line-height: 1.35;
}

.card-desc {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  line-height: 1.6;
  margin-bottom: 14px;
}

.card-meta { display: flex; flex-wrap: wrap; gap: 6px; }

.tag {
  display: inline-block;
  padding: 2px 10px;
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
  border-radius: 999px;
  font-size: 0.75rem;
  font-weight: 600;
}

/* Coming soon状態 */
.app-card.coming-soon {
  opacity: 0.5;
  pointer-events: none;
}

.app-card.coming-soon .card-icon { background: var(--color-surface-alt); }

.badge-coming {
  position: absolute;
  top: 14px;
  right: 14px;
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  padding: 2px 8px;
}

/* 非表示（フィルタ用） */
.app-card.hidden {
  display: none;
}

/* ============================================================
   EMPTY STATE
   ============================================================ */
.empty-state {
  display: none;
  text-align: center;
  padding: 60px 0;
  color: var(--color-text-muted);
  grid-column: 1 / -1;
}

.empty-state.visible { display: block; }
.empty-state p { font-size: 1.05rem; margin-top: 8px; }

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  border-top: 1px solid var(--color-border);
  background: var(--color-surface);
  padding: 32px 24px;
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.82rem;
}

.site-footer a {
  color: var(--color-accent);
  text-decoration: underline;
  text-underline-offset: 2px;
}

/* ============================================================
   レスポンシブ
   ============================================================ */
@media (max-width: 768px) {
  .hero {
    grid-template-columns: 1fr;
    padding: 40px 16px 28px;
    gap: 16px;
  }
  .hero-stat { text-align: left; }
  .filter-section { padding: 0 16px 24px; }
  .app-grid-section { padding: 0 16px 60px; }
  .app-grid { grid-template-columns: 1fr; }
  .header-inner { padding: 0 16px; }
}

@media (min-width: 769px) and (max-width: 1023px) {
  .app-grid { grid-template-columns: repeat(2, 1fr); }
}

/* ============================================================
   ユーティリティ
   ============================================================ */
.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
}