/* ============================================
   TXT 轉 EPUB — Standalone
   Design System v1.9
   ============================================ */

:root {
  --rose: #D4A5A5;
  --lavender: #B8A9C9;
  --blush: #F5D0C5;
  --sage: #A8B5A0;
  --mist: #E8E4E1;

  --text-heading: #333333;
  --text-body: #4A4A4A;
  --text-muted: #888888;
  --text-note: #AAAAAA;

  --bg-page: #FAFAFA;
  --bg-card: #FFFFFF;
  --bg-secondary: #F5F3F1;

  --border-color: rgba(212, 165, 165, 0.15);
  --shadow-sm: 0 2px 8px rgba(212, 165, 165, 0.08);
  --shadow-md: 0 4px 16px rgba(212, 165, 165, 0.10);

  --gradient-brand: linear-gradient(135deg, #D4A5A5, #B8A9C9);
}

html.dark {
  --text-heading: #EDE8E9;
  --text-body: #C4BBBF;
  --text-muted: #918A8D;
  --text-note: #6B6466;

  --bg-page: #1E181B;
  --bg-card: #282224;
  --bg-secondary: #3D3538;

  --border-color: rgba(61, 53, 56, 0.6);
  --rose: #DAAEB0;
  --lavender: #C2B4D0;

  --shadow-sm: 0 2px 8px rgba(30, 24, 27, 0.3);
  --shadow-md: 0 4px 16px rgba(30, 24, 27, 0.4);
}

@font-face { font-family: 'GenSenRounded'; src: url('https://lab.helloruru.com/fonts/GenSenRounded-Regular.woff2') format('woff2'); font-weight: 400; font-display: swap; }
@font-face { font-family: 'GenSenRounded'; src: url('https://lab.helloruru.com/fonts/GenSenRounded-Medium.woff2') format('woff2'); font-weight: 500; font-display: swap; }
@font-face { font-family: 'GenSenRounded'; src: url('https://lab.helloruru.com/fonts/GenSenRounded-Bold.woff2') format('woff2'); font-weight: 700; font-display: swap; }

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: 'GenSenRounded', 'Noto Sans TC', sans-serif;
  font-weight: 500;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-body);
  background-color: var(--bg-page);
  -webkit-font-smoothing: antialiased;
}

a { text-decoration: none; color: inherit; }

.page-wrapper { min-height: 100vh; padding: 48px 24px; transition: background-color 0.5s, color 0.5s; }
.container { max-width: 760px; margin: 0 auto; }
hello-ruru-header { display: block; margin-bottom: 28px; }

/* Theme Toggle */
.theme-toggle-wrap { position: fixed; top: 16px; right: 16px; z-index: 100; }
.theme-toggle {
  width: 40px; height: 40px; border-radius: 50%;
  border: 1px solid var(--border-color); background: var(--bg-card);
  cursor: pointer; display: flex; align-items: center; justify-content: center;
  transition: background 0.3s, border-color 0.3s; color: var(--text-muted);
}
.theme-toggle:hover { border-color: var(--rose); color: var(--rose); }
.theme-toggle svg { width: 20px; height: 20px; }
html:not(.dark) .icon-sun { display: none; }
html.dark .icon-moon { display: none; }

/* Back Link */
.back-link {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 14px; color: var(--rose); margin-bottom: 24px; transition: opacity 0.3s;
}
.back-link:hover { opacity: 0.7; }

/* Cards */
.card {
  padding: 32px; border-radius: 24px; background: var(--bg-card);
  border: 1px solid var(--border-color); box-shadow: var(--shadow-sm);
  margin-bottom: 24px; transition: background 0.5s, border-color 0.5s;
}

/* Step Indicator */
.step-indicator { display: flex; align-items: center; justify-content: center; gap: 8px; margin-bottom: 24px; }
.step-dot {
  width: 36px; height: 36px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 14px; font-weight: 700; transition: all 0.3s;
}
.step-dot.active { background: var(--gradient-brand); color: #fff; box-shadow: var(--shadow-sm); }
.step-dot.inactive { background: var(--bg-secondary); color: var(--text-muted); }
.step-line { width: 40px; height: 2px; transition: background 0.3s; }
.step-line.active { background: var(--gradient-brand); }
.step-line.inactive { background: var(--border-color); }
.step-label { text-align: center; font-size: 14px; color: var(--text-muted); margin-bottom: 24px; }

/* Instruction Card */
.instruction-card .card-title {
  font-size: 20px; font-weight: 500; color: var(--text-heading);
  display: flex; align-items: center; gap: 12px; margin-bottom: 16px;
}
.icon-circle {
  width: 40px; height: 40px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center; flex-shrink: 0;
}
.icon-circle.lavender { background: linear-gradient(135deg, rgba(184,169,201,0.2), rgba(212,165,165,0.2)); color: var(--lavender); }
.instruction-steps { display: grid; gap: 16px; }
@media (min-width: 768px) { .instruction-steps { grid-template-columns: repeat(3, 1fr); } }
.instruction-step { display: flex; gap: 12px; font-size: 14px; }
.step-num {
  width: 32px; height: 32px; border-radius: 50%; border: 2px solid var(--rose);
  display: flex; align-items: center; justify-content: center;
  font-size: 14px; font-weight: 700; color: var(--rose); flex-shrink: 0;
}
.step-title { font-weight: 500; color: var(--text-heading); margin-bottom: 2px; }
.step-desc { color: var(--text-muted); }

/* Upload Area */
.upload-header { text-align: center; margin-bottom: 24px; }
.upload-header h2 { font-size: 24px; font-weight: 500; color: var(--text-heading); margin-bottom: 12px; }
.upload-hints { display: flex; flex-direction: column; align-items: center; gap: 6px; font-size: 14px; color: var(--text-muted); }
.drop-zone {
  display: flex; flex-direction: column; align-items: center;
  padding: 48px 24px; border: 2px dashed var(--border-color);
  border-radius: 24px; cursor: pointer; transition: border-color 0.3s, background 0.3s;
  margin-top: 16px;
}
.drop-zone:hover, .drop-zone.dragging { border-color: var(--rose); background: rgba(212,165,165,0.05); }
.drop-zone.loading { opacity: 0.5; pointer-events: none; }
.upload-icon { color: var(--rose); margin-bottom: 16px; }
.drop-text { font-weight: 500; color: var(--text-heading); margin-bottom: 4px; }
.drop-hint { color: var(--text-muted); font-size: 14px; }
.encoding-info {
  display: flex; align-items: center; gap: 8px; margin-top: 16px;
  padding: 12px 16px; border-radius: 16px; font-size: 14px;
  background: var(--bg-secondary); color: var(--text-muted);
}
.encoding-info svg { color: var(--rose); }

/* Chapter Preview */
.chapter-header { margin-bottom: 16px; }
.chapter-header h2 { font-size: 20px; font-weight: 500; color: var(--text-heading); margin-bottom: 8px; }
.chapter-mode-selector { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 16px; }
.mode-btn {
  padding: 8px 16px; border-radius: 12px; border: 1px solid var(--border-color);
  background: transparent; color: var(--text-muted); font-family: inherit;
  font-size: 14px; cursor: pointer; transition: all 0.3s;
}
.mode-btn:hover { border-color: var(--rose); color: var(--rose); }
.mode-btn.active { border-color: var(--rose); background: rgba(212,165,165,0.1); color: var(--text-heading); }
.separator-input {
  display: flex; align-items: center; gap: 8px; margin-bottom: 16px;
  padding: 8px 12px; border-radius: 12px; background: var(--bg-secondary);
}
.separator-input input {
  flex: 1; border: none; background: transparent; color: var(--text-heading);
  font-family: inherit; font-size: 14px; outline: none;
}
.chapter-list { max-height: 400px; overflow-y: auto; }
.chapter-item {
  display: flex; align-items: center; gap: 12px;
  padding: 12px 16px; border-radius: 12px; margin-bottom: 8px;
  background: var(--bg-secondary); transition: background 0.2s;
}
.chapter-num {
  width: 28px; height: 28px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 12px; font-weight: 700; flex-shrink: 0;
  background: var(--gradient-brand); color: #fff;
}
.chapter-title { font-weight: 500; color: var(--text-heading); font-size: 14px; flex: 1; }
.chapter-delete-btn {
  width: 28px; height: 28px; border-radius: 50%; border: none;
  background: transparent; color: var(--text-muted); cursor: pointer;
  font-size: 14px; display: flex; align-items: center; justify-content: center;
  flex-shrink: 0; transition: all 0.2s; opacity: 0.4;
}
.chapter-delete-btn:hover { background: var(--rose); color: #fff; opacity: 1; }
.chapter-count { font-size: 14px; color: var(--text-muted); margin-bottom: 16px; }

/* Settings */
.settings-section { margin-bottom: 24px; }
.settings-title {
  display: flex; align-items: center; gap: 12px; margin-bottom: 16px;
  font-size: 18px; font-weight: 500; color: var(--text-heading);
}
.settings-title .icon-circle { width: 36px; height: 36px; }
.settings-title .icon-circle.rose { background: linear-gradient(135deg, rgba(212,165,165,0.2), rgba(212,165,165,0.1)); color: var(--rose); }
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
@media (max-width: 767px) { .form-grid { grid-template-columns: 1fr; } }
.form-group { margin-bottom: 16px; }
.form-label { display: block; font-size: 14px; color: var(--text-muted); margin-bottom: 8px; }
.form-input {
  width: 100%; padding: 12px 16px; border-radius: 16px;
  border: 1px solid var(--border-color); background: var(--bg-secondary);
  color: var(--text-heading); font-family: inherit; font-size: 14px; outline: none;
  transition: border-color 0.3s;
}
.form-input:focus { border-color: var(--rose); }

/* Toggle */
.toggle-row {
  display: flex; align-items: center; justify-content: space-between;
  padding: 20px; border-radius: 16px; background: var(--bg-secondary);
  border: 1px solid var(--border-color); margin-bottom: 16px;
}
.toggle-label .toggle-title { font-weight: 500; color: var(--text-heading); }
.toggle-label .toggle-desc { font-size: 12px; color: var(--text-muted); }
.toggle-switch {
  position: relative; width: 52px; height: 28px; border-radius: 14px;
  border: none; cursor: pointer; transition: background 0.3s;
}
.toggle-switch.on { background: var(--gradient-brand); }
.toggle-switch.off { background: var(--border-color); }
.toggle-knob {
  position: absolute; top: 3px; width: 22px; height: 22px;
  border-radius: 50%; background: #fff; box-shadow: 0 1px 3px rgba(0,0,0,0.15);
  transition: left 0.3s;
}
.toggle-switch.on .toggle-knob { left: 27px; }
.toggle-switch.off .toggle-knob { left: 3px; }

/* Option Buttons */
.option-grid { display: flex; gap: 12px; margin-bottom: 16px; }
.option-btn {
  flex: 1; padding: 16px; border-radius: 16px;
  border: 1px solid var(--border-color); background: transparent;
  text-align: left; cursor: pointer; transition: all 0.3s; font-family: inherit;
}
.option-btn:hover { border-color: var(--lavender); }
.option-btn.active { border-color: var(--rose); background: rgba(212,165,165,0.1); }
.option-btn-title { font-weight: 500; color: var(--text-heading); margin-bottom: 4px; font-size: 14px; }
.option-btn-desc { font-size: 12px; color: var(--text-muted); }

/* Small Buttons */
.small-btn-grid { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 16px; }
.small-btn {
  padding: 8px 14px; border-radius: 12px; border: 1px solid var(--border-color);
  background: transparent; color: var(--text-muted); font-family: inherit;
  font-size: 14px; cursor: pointer; transition: all 0.3s;
}
.small-btn:hover { border-color: var(--rose); }
.small-btn.active { border-color: var(--rose); background: rgba(212,165,165,0.1); color: var(--text-heading); }

/* Font Selection */
.font-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-bottom: 16px; }

/* Cover Upload */
.cover-section { margin-top: 24px; padding-top: 24px; border-top: 1px solid var(--border-color); }
.cover-zone {
  display: flex; flex-direction: column; align-items: center;
  padding: 32px; border: 2px dashed var(--border-color); border-radius: 16px;
  cursor: pointer; transition: border-color 0.3s;
}
.cover-zone:hover { border-color: var(--rose); }
.cover-preview { text-align: center; }
.cover-preview img { max-height: 200px; border-radius: 12px; box-shadow: var(--shadow-sm); margin-bottom: 12px; }

/* Export / Complete */
.export-section { text-align: center; padding: 32px 0; }
.export-section h2 { font-size: 24px; font-weight: 500; color: var(--text-heading); margin-bottom: 24px; }
.summary-card {
  max-width: 400px; margin: 0 auto 24px; padding: 24px;
  border-radius: 16px; background: var(--bg-secondary); text-align: left;
}
.summary-row { display: flex; justify-content: space-between; padding: 6px 0; }
.summary-label { color: var(--text-muted); font-size: 14px; }
.summary-value { color: var(--text-heading); font-size: 14px; }
.progress-info {
  max-width: 400px; margin: 0 auto 16px; padding: 16px;
  border-radius: 16px; background: var(--bg-secondary); border: 1px solid var(--border-color);
  display: flex; align-items: center; gap: 12px; font-size: 14px; color: var(--text-muted);
}
.complete-icon { color: var(--rose); margin-bottom: 24px; }

/* Buttons */
.nav-buttons { display: flex; justify-content: space-between; margin-top: 24px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 24px; border-radius: 24px; font-size: 14px; font-weight: 500;
  font-family: inherit; cursor: pointer; border: none; transition: all 0.3s;
}
.btn-secondary {
  background: var(--bg-secondary); border: 1px solid var(--border-color); color: var(--text-muted);
}
.btn-secondary:hover { border-color: var(--rose); color: var(--rose); }
.btn-primary { background: var(--gradient-brand); color: #fff; box-shadow: 0 4px 16px rgba(212,165,165,0.25); }
.btn-primary:hover { box-shadow: 0 6px 20px rgba(212,165,165,0.35); transform: translateY(-1px); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none !important; }
.btn.processing { background: var(--bg-secondary); color: var(--text-muted); box-shadow: none; cursor: wait; }
.btn-large { padding: 16px 48px; font-size: 16px; }
.btn-ghost { background: transparent; }

/* Advanced Toggle */
.advanced-toggle {
  width: 100%; padding: 16px; border-radius: 16px;
  border: 1px solid var(--border-color); background: transparent;
  color: var(--text-muted); font-family: inherit; font-size: 14px;
  cursor: pointer; transition: border-color 0.3s;
  display: flex; align-items: center; justify-content: center; gap: 8px;
}
.advanced-toggle:hover { border-color: var(--rose); }
.advanced-panel {
  padding: 20px; border-radius: 16px; background: var(--bg-secondary);
  border: 1px solid var(--border-color); margin-top: 16px;
}

/* Footer */
.site-footer { margin-top: 40px; padding: 32px 0; text-align: center; font-size: 14px; color: var(--text-muted); }
.site-footer a { color: var(--rose); transition: opacity 0.3s; }
.site-footer a:hover { opacity: 0.8; }
.footer-links { display: flex; justify-content: center; gap: 24px; margin-bottom: 12px; }
.footer-link { font-size: 14px; color: var(--text-muted); transition: color 0.3s; }
.footer-link:hover { color: var(--rose); }

/* Spinner */
@keyframes spin { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }
.spinner { animation: spin 1s linear infinite; }

/* Utility */
.hidden { display: none !important; }

@media (max-width: 767px) {
  .page-wrapper { padding: 32px 16px; }
  .card { padding: 24px 16px; }
  .upload-header h2 { font-size: 20px; }
  .form-grid { grid-template-columns: 1fr; }
  .font-grid { grid-template-columns: 1fr; }
  .option-grid { flex-direction: column; }
}