/* ================================================
   DesktopTranslation — Japanese Minimal Aesthetic
   ================================================ */

/* --- CSS Custom Properties (Light Theme) --- */
:root {
  --bg-primary: #FAFBFC;
  --bg-secondary: #F2F3F5;
  --bg-tertiary: #EBEDF0;
  --bg-card: #FFFFFF;

  --text-primary: #1B1F23;
  --text-secondary: #586069;
  --text-tertiary: #8B949E;
  --text-inverse: #FAFBFC;

  --accent: #4A6FA5;
  --accent-hover: #3D5F91;
  --accent-active: #33507A;
  --accent-subtle: #EEF2F7;

  --separator: #E1E4E8;
  --separator-strong: #D1D5DA;

  --shadow-color: rgba(27, 31, 35, 0.15);
  --shadow-soft: 0 6px 24px var(--shadow-color);

  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-xl: 12px;

  --font-stack: "Segoe UI", "Yu Gothic UI", "Microsoft JhengHei UI", sans-serif;
  --font-mono: "Cascadia Code", "Consolas", monospace;

  --transition-fast: 100ms ease-out;
  --transition-normal: 200ms cubic-bezier(0.33, 1, 0.68, 1);
  --transition-relaxed: 300ms cubic-bezier(0.33, 1, 0.68, 1);
}

/* --- Dark Theme --- */
[data-theme="dark"] {
  --bg-primary: #1E2128;
  --bg-secondary: #262A32;
  --bg-tertiary: #2E333C;
  --bg-card: #2A2F38;

  --text-primary: #E2E5E9;
  --text-secondary: #8B949E;
  --text-tertiary: #6B7380;
  --text-inverse: #1E2128;

  --accent: #7EB0E0;
  --accent-hover: #93BFE8;
  --accent-active: #6A9FD4;
  --accent-subtle: #282E3A;

  --separator: #363B44;
  --separator-strong: #444C56;

  --shadow-color: rgba(0, 0, 0, 0.30);
}

/* --- Reset & Base --- */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 72px;
}

body {
  font-family: var(--font-stack);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: background-color var(--transition-normal), color var(--transition-normal);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--bg-tertiary);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
}

/* --- Layout --- */
.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 24px;
}

/* --- Header --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-primary);
  border-bottom: 1px solid var(--separator);
  backdrop-filter: blur(12px);
  background: color-mix(in srgb, var(--bg-primary) 85%, transparent);
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

.header-inner {
  display: flex;
  align-items: center;
  height: 56px;
  gap: 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 600;
  font-size: 15px;
  flex-shrink: 0;
}

.logo:hover {
  color: var(--text-primary);
  text-decoration: none;
}

.logo-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background: var(--accent);
  color: var(--text-inverse);
  border-radius: var(--radius-md);
  font-weight: 700;
  font-size: 14px;
}

.header-nav {
  display: flex;
  gap: 20px;
  margin-left: auto;
}

.header-nav a {
  color: var(--text-secondary);
  font-size: 14px;
  text-decoration: none;
  padding: 4px 0;
  position: relative;
}

.header-nav a::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--accent);
  transform: scaleX(0);
  transition: transform var(--transition-normal);
  border-radius: 1px;
}

.header-nav a:hover {
  color: var(--text-primary);
  text-decoration: none;
}

.header-nav a:hover::after {
  transform: scaleX(1);
}

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: none;
  background: transparent;
  border-radius: var(--radius-sm);
  cursor: pointer;
  color: var(--text-secondary);
  font-size: 18px;
  transition: background var(--transition-fast), color var(--transition-fast);
  flex-shrink: 0;
}

.theme-toggle:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.theme-icon--dark { display: none; }

[data-theme="dark"] .theme-icon--light { display: none; }
[data-theme="dark"] .theme-icon--dark { display: inline; }

/* --- Hero --- */
.hero {
  padding: 80px 0 64px;
  text-align: center;
}

.hero-inner {
  max-width: 600px;
}

.hero-badge {
  display: inline-block;
  font-size: 12px;
  color: var(--accent);
  background: var(--accent-subtle);
  padding: 4px 14px;
  border-radius: 100px;
  margin-bottom: 24px;
  letter-spacing: 0.3px;
}

.hero-title {
  font-size: clamp(32px, 6vw, 48px);
  font-weight: 700;
  line-height: 1.15;
  margin-bottom: 12px;
  letter-spacing: -0.5px;
}

.hero-slogan {
  font-size: clamp(18px, 3vw, 22px);
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 8px;
}

.hero-sub {
  font-size: 16px;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

.hero-meta {
  font-size: 13px;
  color: var(--text-tertiary);
  margin-top: 16px;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-stack);
  font-size: 14px;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  text-decoration: none;
  transition: background var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
}

.btn:hover {
  text-decoration: none;
}

.btn-primary {
  background: var(--accent);
  color: var(--text-inverse);
  padding: 10px 24px;
}

.btn-primary:hover {
  background: var(--accent-hover);
  color: var(--text-inverse);
  box-shadow: 0 4px 12px var(--shadow-color);
}

.btn-primary:active {
  background: var(--accent-active);
  transform: translateY(1px);
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  padding: 10px 24px;
  border: 1px solid var(--separator);
}

.btn-secondary:hover {
  background: var(--separator);
  color: var(--text-primary);
  box-shadow: 0 4px 12px var(--shadow-color);
}

.btn-secondary:active {
  background: var(--separator-strong);
  transform: translateY(1px);
}

.btn-lg {
  font-size: 16px;
  padding: 14px 32px;
  border-radius: var(--radius-lg);
}

/* --- Section Titles --- */
.section-title {
  font-size: 24px;
  font-weight: 600;
  text-align: center;
  margin-bottom: 40px;
  letter-spacing: -0.3px;
}

/* --- Features --- */
.features {
  padding: 64px 0;
  background: var(--bg-secondary);
  transition: background-color var(--transition-normal);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
}

.feature-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  border: 1px solid var(--separator);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal), background-color var(--transition-normal), border-color var(--transition-normal);
}

.feature-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-soft);
}

.feature-icon {
  font-size: 28px;
  margin-bottom: 14px;
  line-height: 1;
}

.feature-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
}

.feature-desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* --- Preview (Simulated Window) --- */
.preview {
  padding: 64px 0;
}

.preview-window {
  max-width: 640px;
  margin: 0 auto;
  border-radius: var(--radius-xl);
  border: 1px solid var(--separator);
  overflow: hidden;
  box-shadow: var(--shadow-soft);
  background: var(--bg-card);
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

/* Title bar */
.pw-titlebar {
  display: flex;
  align-items: center;
  height: 36px;
  padding: 0 12px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--separator);
  font-size: 12px;
  gap: 8px;
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

.pw-titlebar-left {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-shrink: 0;
}

.pw-logo {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  background: var(--accent);
  color: var(--text-inverse);
  border-radius: 3px;
  font-size: 10px;
  font-weight: 700;
}

.pw-title {
  font-weight: 600;
  color: var(--text-primary);
  font-size: 11px;
}

.pw-titlebar-center {
  display: flex;
  margin: 0 auto;
  background: var(--bg-tertiary);
  border-radius: var(--radius-md);
  padding: 2px;
  gap: 2px;
}

.pw-seg {
  padding: 2px 10px;
  border-radius: var(--radius-sm);
  font-size: 11px;
  color: var(--text-secondary);
  cursor: default;
  transition: background var(--transition-fast), color var(--transition-fast);
}

.pw-seg--active {
  background: var(--accent);
  color: var(--text-inverse);
}

.pw-titlebar-right {
  display: flex;
  gap: 4px;
  flex-shrink: 0;
}

.pw-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
  border-radius: var(--radius-sm);
  font-size: 12px;
  color: var(--text-tertiary);
  cursor: default;
}

.pw-btn--close {
  font-size: 16px;
}

/* Language row */
.pw-lang-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  padding: 8px 12px;
  border-bottom: 1px solid var(--separator);
  font-size: 13px;
  transition: border-color var(--transition-normal);
}

.pw-lang {
  color: var(--text-secondary);
  font-weight: 500;
}

.pw-swap {
  color: var(--accent);
  font-size: 16px;
  cursor: default;
}

/* Content area */
.pw-content {
  display: flex;
  min-height: 120px;
}

.pw-panel {
  flex: 1;
  padding: 16px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.pw-divider {
  width: 1px;
  background: var(--separator);
  transition: background-color var(--transition-normal);
}

.pw-text {
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-primary);
}

.pw-text--result {
  color: var(--text-primary);
}

.pw-actions {
  display: flex;
  gap: 8px;
  margin-top: 12px;
}

.pw-action-btn {
  font-size: 14px;
  color: var(--text-tertiary);
  cursor: default;
  padding: 4px;
  border-radius: var(--radius-sm);
}

/* History bar */
.pw-history-bar {
  padding: 6px 12px;
  border-top: 1px solid var(--separator);
  background: var(--bg-secondary);
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

.pw-history-label {
  font-size: 11px;
  color: var(--text-tertiary);
  cursor: default;
}

/* --- Download --- */
.download {
  padding: 64px 0;
  background: var(--bg-secondary);
  transition: background-color var(--transition-normal);
}

.download-inner {
  text-align: center;
}

.download-desc {
  color: var(--text-secondary);
  margin-bottom: 28px;
  font-size: 15px;
}

.download-buttons {
  display: flex;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
  margin-bottom: 36px;
}

.download-option {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
}

.download-btn {
  min-width: 220px;
}

.download-option-note {
  font-size: 12px;
  color: var(--text-tertiary);
}

.download-option-note a {
  color: var(--accent);
  text-decoration: underline;
}

.download-info {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 24px;
  margin-bottom: 24px;
}

.download-info-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.download-info-label {
  font-size: 12px;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.download-info-value {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
}

.download-note {
  font-size: 13px;
  color: var(--text-tertiary);
  max-width: 480px;
  margin: 0 auto;
}

/* --- Footer --- */
.site-footer {
  padding: 24px 0;
  border-top: 1px solid var(--separator);
  transition: border-color var(--transition-normal);
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.footer-copy {
  font-size: 13px;
  color: var(--text-tertiary);
}

.footer-links {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--text-tertiary);
}

.footer-links a {
  color: var(--text-secondary);
}

.footer-sep {
  color: var(--separator-strong);
}

/* --- Scroll Reveal --- */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--transition-relaxed), transform var(--transition-relaxed);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Responsive --- */
@media (max-width: 640px) {
  .header-nav {
    gap: 14px;
  }

  .hero {
    padding: 56px 0 48px;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  .pw-content {
    flex-direction: column;
  }

  .pw-divider {
    width: auto;
    height: 1px;
  }

  .download-info {
    gap: 16px;
  }

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .logo-text {
    display: none;
  }

  .header-nav a {
    font-size: 13px;
  }

  .hero-title {
    font-size: 28px;
  }
}

/* --- Reduced Motion --- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition-duration: 0ms !important;
    animation-duration: 0ms !important;
  }

  html {
    scroll-behavior: auto;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}

/* --- Guide Section --- */
.guide { padding: 5rem 0; }
.guide .section-desc { text-align: center; color: var(--text-secondary); margin-bottom: 3rem; }

.guide-steps { max-width: 720px; margin: 0 auto; }

.guide-step {
  display: flex;
  gap: 1.5rem;
  margin-bottom: 2.5rem;
  padding-bottom: 2.5rem;
  border-bottom: 1px solid var(--separator);
}
.guide-step:last-child { border-bottom: none; margin-bottom: 0; }

.guide-step-number {
  flex-shrink: 0;
  width: 36px; height: 36px;
  border-radius: 50%;
  background: var(--accent-primary);
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 1rem; font-weight: 700;
  margin-top: 0.2rem;
}

.guide-step-content h3 {
  font-size: 1.15rem; font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}
.guide-step-content p {
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 0.75rem;
}

.guide-visual { margin-top: 0.75rem; }

/* Tray icon demo */
.guide-tray-demo {
  display: inline-flex; align-items: center; gap: 0.75rem;
  background: var(--bg-secondary);
  padding: 0.5rem 1rem;
  border-radius: 8px;
}
.guide-tray-icon {
  width: 28px; height: 28px;
  background: var(--accent-primary);
  color: #fff; font-weight: 700; font-size: 0.9rem;
  display: flex; align-items: center; justify-content: center;
  border-radius: 4px;
}
.guide-tray-label { color: var(--text-tertiary); font-size: 0.85rem; }

/* Keyboard keys demo */
.guide-keys {
  display: flex; align-items: center; gap: 0.4rem;
  flex-wrap: wrap;
}
.guide-keys kbd {
  display: inline-block;
  padding: 0.3rem 0.6rem;
  background: var(--bg-secondary);
  border: 1px solid var(--separator);
  border-radius: 6px;
  font-family: "Segoe UI", monospace;
  font-size: 0.85rem;
  color: var(--text-primary);
  box-shadow: 0 1px 2px rgba(0,0,0,0.08);
}
.guide-keys-then { color: var(--text-tertiary); font-size: 1.2rem; margin: 0 0.2rem; }
.guide-keys-result { color: var(--accent-primary); font-weight: 600; margin-left: 0.5rem; }

/* Context menu demo */
.guide-menu-demo {
  display: inline-block;
  background: var(--bg-card);
  border: 1px solid var(--separator);
  border-radius: 8px;
  padding: 0.4rem 0;
  min-width: 180px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}
.guide-menu-item {
  padding: 0.4rem 1rem;
  font-size: 0.85rem;
  color: var(--text-primary);
  display: flex; justify-content: space-between;
}
.guide-menu-item.highlight {
  background: var(--accent-primary);
  color: #fff;
  font-weight: 500;
}
.guide-menu-arrow { opacity: 0.5; }
.guide-menu-sep { height: 1px; background: var(--separator); margin: 0.25rem 0.5rem; }

/* Settings list */
.guide-settings { margin-top: 0.5rem; }
.guide-setting-item {
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--separator);
}
.guide-setting-item:last-child { border-bottom: none; }
.guide-setting-label {
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.3rem;
  font-size: 0.95rem;
}
.guide-setting-desc {
  color: var(--text-secondary);
  font-size: 0.88rem;
  line-height: 1.7;
}
.guide-setting-desc a { color: var(--accent-primary); }
.guide-setting-desc em { opacity: 0.7; }

@media (max-width: 640px) {
  .guide-step { flex-direction: column; gap: 0.75rem; }
  .guide-step-number { width: 30px; height: 30px; font-size: 0.85rem; }
}