/* ===== CSS VARIABLES ===== */
:root {
  --primary: #171717;
  --bg: #FFFFFF;
  --bg-secondary: #F9FAFB;
  --surface: #F3F4F6;
  --card: #FFFFFF;
  --text-primary: #111827;
  --text-secondary: #4B5563;
  --text-tertiary: #6B7280;
  --border: #E5E7EB;
  --success: #16A34A;
  --warning: #CA8A04;
  --error: #DC2626;
  --info: #2563EB;
  --accent: #2B7FFF;
  --accent-light: #EFF6FF;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --primary: #FFFFFF;
    --bg: #000000;
    --bg-secondary: #0A0A0A;
    --surface: #111111;
    --card: #1A1A1A;
    --text-primary: #FFFFFF;
    --text-secondary: #A3A3A3;
    --text-tertiary: #737373;
    --border: #262626;
    --success: #86EFAC;
    --warning: #FCD34D;
    --error: #FCA5A5;
    --info: #93C5FD;
    --accent: #2B7FFF;
    --accent-light: rgba(43, 127, 255, 0.15);
  }
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background-color: var(--bg);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* ===== NAVIGATION ===== */
nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

@media (prefers-color-scheme: dark) {
  nav { background: rgba(0, 0, 0, 0.85); }
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.nav-logo {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
  letter-spacing: -0.5px;
  flex-shrink: 0;
}

.nav-search {
  flex: 1;
  max-width: 400px;
}

.nav-search input {
  width: 100%;
  padding: 10px 16px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-primary);
  font-size: 14px;
  outline: none;
  transition: border-color 0.2s;
}

.nav-search input:focus {
  border-color: var(--accent);
}

.nav-search input::placeholder {
  color: var(--text-tertiary);
}

.nav-links {
  display: flex;
  gap: 16px;
  align-items: center;
  flex-shrink: 0;
}

.nav-links a {
  font-size: 14px;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.2s;
  white-space: nowrap;
}

.nav-links a:hover { color: var(--text-primary); }

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--text-primary);
  color: var(--bg) !important;
  padding: 8px 16px;
  border-radius: var(--radius-md);
  font-size: 13px;
  font-weight: 600;
  transition: opacity 0.2s;
}

.nav-cta:hover { opacity: 0.85; }
.nav-cta svg { width: 16px; height: 16px; }

/* ===== FILTER BAR ===== */
.filter-bar {
  max-width: 1200px;
  margin: 72px auto 0;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.chips-scroll {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  flex: 1;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
  padding: 2px 0;
}

.chips-scroll::-webkit-scrollbar { display: none; }

.chip {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 8px 16px;
  border-radius: 20px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s;
}

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

.chip.active {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
}

.chip-count {
  font-size: 11px;
  opacity: 0.7;
}

.sort-btn {
  padding: 8px 16px;
  border-radius: 20px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s;
}

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

/* ===== OUTPUT GRID ===== */
.grid-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 8px 24px 80px;
}

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

/* ===== OUTPUT CARD ===== */
.output-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  transition: transform 0.2s, box-shadow 0.2s;
  display: flex;
  flex-direction: column;
}

.output-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.08);
}

@media (prefers-color-scheme: dark) {
  .output-card:hover { box-shadow: 0 8px 24px rgba(0,0,0,0.3); }
}

.card-thumbnail {
  width: 100%;
  aspect-ratio: 16/9;
  overflow: hidden;
  background: var(--surface);
}

.card-thumbnail img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.card-thumbnail-placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
}

.card-type-icon-lg { font-size: 40px; }

.card-body {
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  flex: 1;
}

.card-meta {
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
}

.card-type-badge {
  font-size: 12px;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-light);
  padding: 3px 10px;
  border-radius: 12px;
  text-decoration: none;
  cursor: pointer;
  transition: opacity 0.2s;
}
.card-type-badge:hover { opacity: 0.75; }

.card-category {
  font-size: 12px;
  color: var(--text-tertiary);
  background: var(--surface);
  padding: 3px 10px;
  border-radius: 12px;
  text-decoration: none;
  cursor: pointer;
  transition: opacity 0.2s;
}
.card-category:hover { opacity: 0.75; }

.card-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-footer {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: auto;
  padding-top: 4px;
}

.card-lang {
  font-size: 12px;
  color: var(--text-tertiary);
}

.card-views {
  font-size: 12px;
  color: var(--text-tertiary);
}

.card-count-badge {
  font-size: 11px;
  color: var(--text-tertiary);
  background: var(--surface);
  padding: 2px 8px;
  border-radius: 10px;
}

/* ===== LOADING & EMPTY STATES ===== */
.loading-spinner {
  text-align: center;
  padding: 40px;
  color: var(--text-tertiary);
  font-size: 14px;
  grid-column: 1 / -1;
}

.loading-spinner::after {
  content: '';
  display: inline-block;
  width: 24px;
  height: 24px;
  border: 2px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

.empty-state {
  text-align: center;
  padding: 60px 24px;
  color: var(--text-tertiary);
  font-size: 15px;
  grid-column: 1 / -1;
}

#feed-loader {
  text-align: center;
  padding: 20px;
  display: none;
}

#feed-loader::after {
  content: '';
  display: inline-block;
  width: 24px;
  height: 24px;
  border: 2px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

/* ===== TYPE/LANGUAGE SELECTOR ===== */
.selector-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
  padding: 4px 0;
}

.selector-types {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  flex: 1;
  scrollbar-width: none;
}

.selector-types::-webkit-scrollbar { display: none; }

.selector-chip {
  padding: 8px 16px;
  border-radius: 20px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s;
}

.selector-chip:hover { border-color: var(--accent); color: var(--accent); }

.selector-chip.active {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
}

.selector-lang select {
  padding: 8px 12px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-primary);
  font-size: 13px;
  cursor: pointer;
  outline: none;
}

.selector-lang-label {
  font-size: 13px;
  color: var(--text-secondary);
  padding: 8px 12px;
  background: var(--surface);
  border-radius: var(--radius-md);
  white-space: nowrap;
}

/* ===== OUTPUT DETAIL PAGE ===== */
#output-loading {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 60vh;
}

#output-loading::after {
  content: '';
  width: 32px;
  height: 32px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

.detail-container {
  max-width: 800px;
  margin: 72px auto 0;
  padding: 0 24px 80px;
}

.detail-back {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 14px;
  padding: 16px 0;
  transition: color 0.2s;
}

.detail-back:hover { color: var(--text-primary); }

.hero-image {
  width: 100%;
  border-radius: var(--radius-xl);
  margin-bottom: 24px;
}

.no-thumbnail { margin-bottom: 8px; }

#output-meta {
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.detail-type-badge {
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-light);
  padding: 4px 12px;
  border-radius: 12px;
}

.detail-category {
  font-size: 13px;
  color: var(--text-tertiary);
  background: var(--surface);
  padding: 4px 12px;
  border-radius: 12px;
  text-decoration: none;
  cursor: pointer;
  transition: opacity 0.2s;
}
.detail-category:hover { opacity: 0.75; }

.detail-lang {
  font-size: 13px;
  color: var(--text-secondary);
  background: var(--surface);
  padding: 4px 12px;
  border-radius: 12px;
}

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

#output-title {
  font-size: 28px;
  font-weight: 700;
  line-height: 1.3;
  letter-spacing: -0.5px;
  margin-bottom: 8px;
}

#output-date {
  font-size: 13px;
  color: var(--text-tertiary);
  margin-bottom: 24px;
}

/* ===== AUDIO PLAYER ===== */
.audio-player-wrapper {
  margin-bottom: 24px;
}

.audio-player {
  width: 100%;
  border-radius: var(--radius-lg);
}

.content-script {
  margin-top: 24px;
}

.content-script h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 12px;
}

/* ===== MARKDOWN BODY ===== */
.markdown-body {
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-primary);
}

.markdown-body h1 { font-size: 24px; font-weight: 700; margin: 24px 0 12px; }
.markdown-body h2 { font-size: 20px; font-weight: 600; margin: 20px 0 10px; }
.markdown-body h3 { font-size: 17px; font-weight: 600; margin: 16px 0 8px; }
.markdown-body p { margin-bottom: 12px; }
.markdown-body ul { padding-left: 24px; margin-bottom: 12px; }
.markdown-body li { margin-bottom: 4px; }
.markdown-body strong { font-weight: 600; }

/* ===== TRANSLATION ===== */
.translation-header {
  margin-bottom: 16px;
}

/* ===== FLASHCARDS ===== */
.flashcard-deck {
  max-width: 600px;
  margin: 0 auto;
}

.flashcard-counter {
  text-align: center;
  font-size: 14px;
  color: var(--text-tertiary);
  margin-bottom: 16px;
}

.flashcard-container {
  margin-bottom: 16px;
}

.flashcard {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  min-height: 200px;
  cursor: pointer;
  transition: transform 0.2s;
}

.flashcard:hover { transform: scale(1.01); }

.flashcard-front,
.flashcard-back {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 32px 24px;
  min-height: 200px;
  text-align: center;
}

.flashcard-front p,
.flashcard-back p {
  font-size: 18px;
  line-height: 1.5;
}

.flashcard-hint {
  font-size: 12px;
  color: var(--text-tertiary);
  margin-top: 16px;
}

.flashcard-back {
  background: var(--accent-light);
  border-radius: var(--radius-xl);
}

.flashcard-nav {
  display: flex;
  gap: 12px;
  justify-content: center;
}

.fc-btn {
  padding: 10px 24px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-primary);
  font-size: 14px;
  cursor: pointer;
  transition: all 0.2s;
}

.fc-btn:hover:not(:disabled) { border-color: var(--accent); color: var(--accent); }
.fc-btn:disabled { opacity: 0.4; cursor: not-allowed; }

/* ===== QUIZ ===== */
.quiz-wrapper {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.quiz-question h4 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 12px;
  line-height: 1.4;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.quiz-option {
  text-align: left;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--surface);
  color: var(--text-primary);
  font-size: 15px;
  cursor: pointer;
  transition: all 0.2s;
}

.quiz-option:hover:not(:disabled) { border-color: var(--accent); }

.quiz-option.correct {
  border-color: var(--success);
  background: rgba(22, 163, 74, 0.1);
  color: var(--success);
}

.quiz-option.wrong {
  border-color: var(--error);
  background: rgba(220, 38, 38, 0.1);
  color: var(--error);
}

.quiz-option:disabled { cursor: default; }

.quiz-explanation {
  font-size: 14px;
  color: var(--text-secondary);
  margin-top: 8px;
  padding: 8px 12px;
  background: var(--surface);
  border-radius: var(--radius-md);
}

/* ===== APP CTA ===== */
.app-cta-inner {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 24px;
  text-align: center;
  margin-top: 40px;
}

.app-cta-inner p {
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: 16px;
}

.app-cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--text-primary);
  color: var(--bg);
  padding: 12px 28px;
  border-radius: var(--radius-lg);
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  transition: opacity 0.2s;
}

.app-cta-btn:hover { opacity: 0.85; }

/* ===== APP BANNER (sticky bottom) ===== */
#app-banner {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 200;
  background: var(--card);
  border-top: 1px solid var(--border);
  box-shadow: 0 -4px 12px rgba(0,0,0,0.08);
}

@media (prefers-color-scheme: dark) {
  #app-banner { box-shadow: 0 -4px 12px rgba(0,0,0,0.3); }
}

.app-banner-inner {
  max-width: 800px;
  margin: 0 auto;
  padding: 12px 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.app-banner-close {
  background: none;
  border: none;
  color: var(--text-tertiary);
  font-size: 20px;
  cursor: pointer;
  padding: 4px;
  line-height: 1;
}

.app-banner-icon {
  color: var(--accent);
  flex-shrink: 0;
}

.app-banner-text {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.app-banner-text strong {
  font-size: 14px;
  color: var(--text-primary);
}

.app-banner-text span {
  font-size: 12px;
  color: var(--text-tertiary);
}

.app-banner-btn {
  background: var(--accent);
  color: white;
  padding: 6px 18px;
  border-radius: 16px;
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  white-space: nowrap;
  transition: opacity 0.2s;
}

.app-banner-btn:hover { opacity: 0.85; }

/* ===== ERROR STATE ===== */
.error-state {
  text-align: center;
  padding: 80px 24px;
}

.error-state p {
  font-size: 16px;
  color: var(--text-secondary);
  margin-bottom: 20px;
}

.error-state a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 500;
}

/* ===== FOOTER ===== */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 40px 24px;
  text-align: center;
}

.footer-inner {
  max-width: 800px;
  margin: 0 auto;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.footer-links a {
  font-size: 14px;
  color: var(--text-secondary);
  text-decoration: none;
}

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

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

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .nav-search { display: none; }
  .nav-links { gap: 12px; }
  .nav-cta span { display: none; }

  .filter-bar {
    margin-top: 60px;
    padding: 12px 16px;
  }

  .grid-container { padding: 8px 16px 80px; }

  .output-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .detail-container { padding: 0 16px 80px; }

  #output-title { font-size: 22px; }
}

@media (max-width: 480px) {
  .output-grid {
    grid-template-columns: 1fr;
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .output-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}