@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+TC:wght@400;500;700&family=Noto+Serif+TC:wght@400;700&display=swap');

:root {
  /* === Spacing === */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;

  /* === Typography === */
  --font-ui: 'Noto Sans TC', 'PingFang TC', 'Microsoft JhengHei', sans-serif;
  --font-story: 'Noto Serif TC', 'Source Han Serif TC', Georgia, serif;
  --text-sm: 14px;
  --text-base: 17px;
  --text-lg: 19px;
  --text-xl: 21px;
  --text-2xl: 26px;
  --text-3xl: 32px;
  --lh-ui: 1.5;
  --lh-story: 1.9;
  --lh-story-wide: 2.1;
  --max-content-width: 680px;
  --max-ui-width: 1100px;

  /* === Font size settings (controlled by JS) === */
  --story-font-size: var(--text-base);

  /* === Light theme colors === */
  --color-bg: #faf9f7;
  --color-surface: #ffffff;
  --color-surface-raised: #f5f3ef;
  --color-border: #e2ddd6;
  --color-border-subtle: #ede9e3;
  --color-text-primary: #1a1714;
  --color-text-secondary: #5c564f;
  --color-text-muted: #8a8178;
  --color-text-disabled: #b5afa8;
  --color-accent: #8b5e3c;
  --color-accent-light: #f0e6da;
  --color-accent-hover: #724d30;
  --color-danger: #b33a3a;
  --color-danger-light: #faeaea;
  --color-success: #3a7a4a;
  --color-success-light: #e8f4ea;
  --color-warning: #7a5a1a;
  --color-warning-light: #faf0da;
  --color-clue-key: #6b3fa0;
  --color-clue-key-light: #f0eaf8;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 2px 8px rgba(0,0,0,0.10);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.12);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
}

[data-theme='dark'] {
  --color-bg: #0f0e0c;
  --color-surface: #1a1916;
  --color-surface-raised: #211f1c;
  --color-border: #302d28;
  --color-border-subtle: #262320;
  --color-text-primary: #e8e4de;
  --color-text-secondary: #a09890;
  --color-text-muted: #6b635b;
  --color-text-disabled: #4a4540;
  --color-accent: #c4966a;
  --color-accent-light: #2a2018;
  --color-accent-hover: #d4a87a;
  --color-danger: #e06060;
  --color-danger-light: #2a1010;
  --color-success: #60b070;
  --color-success-light: #0d1f10;
  --color-warning: #c4a04a;
  --color-warning-light: #1e1800;
  --color-clue-key: #a07ad0;
  --color-clue-key-light: #1a1030;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 2px 8px rgba(0,0,0,0.4);
  --shadow-lg: 0 4px 16px rgba(0,0,0,0.5);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; }
body { font-family: var(--font-ui); background: var(--color-bg); color: var(--color-text-primary); transition: background var(--transition-normal), color var(--transition-normal); min-height: 100vh; -webkit-font-smoothing: antialiased; }
img { max-width: 100%; display: block; }
button { cursor: pointer; font-family: inherit; border: none; background: none; }
a { color: inherit; text-decoration: none; }

.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); }
.emoji { font-family: 'Apple Color Emoji', 'Segoe UI Emoji', sans-serif; font-style: normal; }
.text-muted { color: var(--color-text-muted); }
.text-accent { color: var(--color-accent); }

.btn { display: inline-flex; align-items: center; justify-content: center; gap: var(--space-sm); padding: 10px 20px; border-radius: var(--radius-md); font-size: var(--text-base); font-weight: 500; font-family: var(--font-ui); transition: all var(--transition-fast); cursor: pointer; border: 2px solid transparent; min-height: 44px; line-height: 1.3; white-space: nowrap; -webkit-tap-highlight-color: transparent; }
.btn:focus-visible { outline: 3px solid var(--color-accent); outline-offset: 2px; }
.btn:disabled { opacity: 0.45; cursor: not-allowed; }
.btn-primary { background: var(--color-accent); color: #fff; border-color: var(--color-accent); }
.btn-primary:hover:not(:disabled) { background: var(--color-accent-hover); border-color: var(--color-accent-hover); }
.btn-secondary { background: var(--color-surface); color: var(--color-text-primary); border-color: var(--color-border); }
.btn-secondary:hover:not(:disabled) { background: var(--color-surface-raised); border-color: var(--color-accent); }
.btn-danger { background: var(--color-danger); color: #fff; border-color: var(--color-danger); }
.btn-danger:hover:not(:disabled) { filter: brightness(0.9); }
.btn-ghost { background: transparent; color: var(--color-text-secondary); border-color: transparent; }
.btn-ghost:hover:not(:disabled) { background: var(--color-surface-raised); color: var(--color-text-primary); }
.btn-sm { padding: 6px 14px; font-size: var(--text-sm); min-height: 36px; }
.btn-lg { padding: 14px 28px; font-size: var(--text-lg); min-height: 52px; }
.btn-full { width: 100%; }
.btn-icon { padding: 8px; min-width: 44px; border-radius: var(--radius-md); }

.badge { display: inline-flex; align-items: center; padding: 2px 10px; border-radius: var(--radius-full); font-size: 12px; font-weight: 500; font-family: var(--font-ui); }
.badge-accent { background: var(--color-accent-light); color: var(--color-accent); }
.badge-success { background: var(--color-success-light); color: var(--color-success); }
.badge-danger { background: var(--color-danger-light); color: var(--color-danger); }
.badge-clue { background: var(--color-clue-key-light); color: var(--color-clue-key); }

.modal-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.55); z-index: 1000; display: flex; align-items: center; justify-content: center; padding: var(--space-md); opacity: 0; visibility: hidden; transition: opacity var(--transition-normal), visibility var(--transition-normal); }
.modal-overlay.is-open { opacity: 1; visibility: visible; }
.modal-box { background: var(--color-surface); border-radius: var(--radius-lg); padding: var(--space-xl); max-width: 480px; width: 100%; max-height: 85vh; overflow-y: auto; box-shadow: var(--shadow-lg); transform: translateY(20px); transition: transform var(--transition-normal); }
.modal-overlay.is-open .modal-box { transform: translateY(0); }
.modal-title { font-size: var(--text-xl); font-weight: 700; margin-bottom: var(--space-md); color: var(--color-text-primary); }
.modal-body { color: var(--color-text-secondary); line-height: var(--lh-ui); margin-bottom: var(--space-lg); }
.modal-actions { display: flex; gap: var(--space-sm); justify-content: flex-end; flex-wrap: wrap; }

.toast { position: fixed; bottom: var(--space-lg); left: 50%; transform: translateX(-50%) translateY(20px); background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius-md); padding: var(--space-sm) var(--space-md); font-size: var(--text-sm); color: var(--color-text-secondary); box-shadow: var(--shadow-md); z-index: 2000; opacity: 0; transition: opacity var(--transition-fast), transform var(--transition-fast); pointer-events: none; white-space: nowrap; max-width: 90vw; }
.toast.is-visible { opacity: 1; transform: translateX(-50%) translateY(0); }

.dev-panel { position: fixed; bottom: 0; right: 0; width: 340px; max-height: 60vh; background: #0d1117; color: #c9d1d9; font-family: 'Courier New', monospace; font-size: 12px; border-radius: var(--radius-md) 0 0 0; padding: var(--space-md); overflow-y: auto; z-index: 9999; border-top: 1px solid #30363d; border-left: 1px solid #30363d; }
.dev-panel summary { cursor: pointer; font-weight: bold; color: #58a6ff; margin-bottom: var(--space-sm); }
.dev-panel pre { font-size: 11px; overflow-x: auto; white-space: pre-wrap; word-break: break-all; }
.dev-tag { display: inline-block; background: #21262d; padding: 1px 6px; border-radius: 4px; margin: 2px; font-size: 11px; color: #58a6ff; }
[data-dev-mode='false'] .dev-panel { display: none; }

@media (prefers-reduced-motion: reduce) { * { transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; } }