/* ── CSS variables / themes ─────────────────────────────────────────────── */

:root {
  --bg:          #faf8f2;
  --bg-card:     #ffffff;
  --bg-output:   #fffef8;
  --text:        #1a1a1a;
  --text-muted:  #6b6b6b;
  --border:      #ddd8cc;
  --accent:      #4a7c59;
  --accent-dark: #3a6347;
  --accent-text: #ffffff;
  --btn-sec-bg:  #f0ede5;
  --btn-sec-text:#1a1a1a;
  --shadow:      0 1px 4px rgba(0,0,0,0.08);
  --radius:      8px;
  --font-ui:     system-ui, -apple-system, "Helvetica Neue", sans-serif;
}

[data-theme="dark"] {
  --bg:          #1a1917;
  --bg-card:     #242220;
  --bg-output:   #1e1c1a;
  --text:        #e8e4dc;
  --text-muted:  #9a9488;
  --border:      #3a3730;
  --accent:      #6aab7f;
  --accent-dark: #5a9b6f;
  --accent-text: #0e1f14;
  --btn-sec-bg:  #2e2c28;
  --btn-sec-text:#e8e4dc;
  --shadow:      0 1px 4px rgba(0,0,0,0.3);
}

/* ── Reset ──────────────────────────────────────────────────────────────── */

*, *::before, *::after { box-sizing: border-box; }

body {
  margin: 0;
  font-family: var(--font-ui);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background 0.2s, color 0.2s;
}

/* ── Header ─────────────────────────────────────────────────────────────── */

.header {
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.header-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.header-title h1 {
  margin: 0;
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text);
}

.subtitle {
  margin: 2px 0 0;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.header-actions {
  display: flex;
  gap: 8px;
  align-items: center;
}

/* ── Main layout ────────────────────────────────────────────────────────── */

.main {
  max-width: 900px;
  width: 100%;
  margin: 0 auto;
  padding: 24px 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* ── Card ────────────────────────────────────────────────────────────────── */

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
}

/* ── Controls ────────────────────────────────────────────────────────────── */

.controls {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 16px;
  align-items: end;
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.control-group--count {
  grid-column: span 2;
}

.control-group label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.control-actions {
  display: flex;
  gap: 8px;
  align-items: flex-end;
  flex-wrap: wrap;
}

.count-inputs {
  display: flex;
  align-items: center;
  gap: 10px;
}

/* ── Form elements ──────────────────────────────────────────────────────── */

.select,
.input-number {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  font-size: 0.9rem;
  padding: 8px 10px;
  outline: none;
  transition: border-color 0.15s;
  width: 100%;
}

.select:focus,
.input-number:focus {
  border-color: var(--accent);
}

.input-number {
  width: 80px;
  flex-shrink: 0;
}

.slider {
  flex: 1;
  accent-color: var(--accent);
  cursor: pointer;
}

/* ── Buttons ─────────────────────────────────────────────────────────────── */

.btn {
  padding: 9px 20px;
  border-radius: 6px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: background 0.15s, opacity 0.15s;
  white-space: nowrap;
}

.btn:disabled {
  opacity: 0.6;
  cursor: default;
}

.btn-primary {
  background: var(--accent);
  color: var(--accent-text);
}

.btn-primary:hover:not(:disabled) {
  background: var(--accent-dark);
}

.btn-secondary {
  background: var(--btn-sec-bg);
  color: var(--btn-sec-text);
  border: 1px solid var(--border);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--border);
}

.btn-icon {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 10px;
  cursor: pointer;
  font-size: 0.85rem;
  color: var(--text-muted);
  transition: border-color 0.15s, color 0.15s;
}

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

/* ── Output ──────────────────────────────────────────────────────────────── */

.output-section {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.output-header {
  display: flex;
  justify-content: flex-end;
  min-height: 20px;
}

.output-meta {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.output-area {
  background: var(--bg-output);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  min-height: 300px;
  line-height: 1.9;
  font-size: 1rem;
  color: var(--text);
  white-space: pre-wrap;
  word-break: break-all;
  box-shadow: var(--shadow);
}

.output-area.placeholder {
  color: var(--text-muted);
  font-style: italic;
}

/* ── Font variants ──────────────────────────────────────────────────────── */

.font-serif {
  font-family: "游明朝", "Yu Mincho", "YuMincho", "HGS明朝E", "MS PMincho", Georgia, serif;
}

.font-sans {
  font-family: "游ゴシック", "Yu Gothic", "YuGothic", "メイリオ", Meiryo, "Hiragino Kaku Gothic ProN", sans-serif;
}

.font-mono {
  font-family: "Osaka-Mono", "MS Gothic", "Courier New", Courier, monospace;
  font-size: 0.95rem;
}

/* ── Footer ──────────────────────────────────────────────────────────────── */

.footer {
  border-top: 1px solid var(--border);
  text-align: center;
  padding: 16px 20px;
  font-size: 0.78rem;
  color: var(--text-muted);
}

.footer a {
  color: var(--accent);
  text-decoration: none;
}

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

/* ── Responsive ──────────────────────────────────────────────────────────── */

@media (max-width: 600px) {
  .controls {
    grid-template-columns: 1fr 1fr;
  }
  .control-group--count {
    grid-column: span 2;
  }
  .control-actions {
    grid-column: span 2;
  }
  .header-title h1 {
    font-size: 1.1rem;
  }
  .output-area {
    font-size: 0.95rem;
    padding: 16px;
  }
}

@media (max-width: 400px) {
  .controls {
    grid-template-columns: 1fr;
  }
  .control-group--count {
    grid-column: span 1;
  }
  .control-actions {
    grid-column: span 1;
  }
}