/* -------------------------------------------------------------
 * Bespoke Editorial Studio Design System for flashcardapps.info
 * ------------------------------------------------------------- */

/* Custom Properties / Design Tokens */
:root {
  /* Light theme defaults */
  --bg-studio: #f1f5f9;
  --bg-paper: #ffffff;
  --color-text: #0f172a;
  --color-text-muted: #475569;
  --line-grid: #e2e8f0;
  --line-grid-dark: #1e293b;
  --color-primary: #4f46e5;
  --color-primary-hover: #4338ca;
  --color-secondary: #0d9488;
  --color-secondary-hover: #0f766e;
  --color-success: #16a34a;
  --color-highlight: #fef08a;
  --color-card-shadow: rgba(15, 23, 42, 0.08);
  --color-glass-bg: rgba(255, 255, 255, 0.76);
  --color-glass-border: rgba(226, 232, 240, 0.9);
  --color-text-light: #0f172a;

  color-scheme: light dark;
  accent-color: var(--color-primary);

  /* Typography Stacks */
  --font-serif: Georgia, Cambria, "Times New Roman", Times, serif;
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  
  /* Layout Transitions */
  --transition-smooth: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --focus-outline: 3px solid var(--color-primary);
  --focus-offset: 3px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg-studio: #070a13;
    --bg-paper: #0f172a;
    --color-text: #f8fafc;
    --color-text-muted: #94a3b8;
    --line-grid: #1e293b;
    --line-grid-dark: #334155;
    --color-primary: #818cf8;
    --color-primary-hover: #a5b4fc;
    --color-secondary: #2dd4bf;
    --color-secondary-hover: #99f6e4;
    --color-success: #4ade80;
    --color-highlight: #ca8a04;
    --color-card-shadow: rgba(0, 0, 0, 0.32);
    --color-glass-bg: rgba(15, 23, 42, 0.78);
    --color-glass-border: rgba(30, 41, 59, 0.9);
    --color-text-light: #020617;
  }
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  height: 100%;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background-color: var(--bg-studio);
  line-height: 1.6;
  min-height: 100%;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  padding: 0;
  transition: background-color var(--transition-smooth);
}

/* Skip link for keyboard accessibility */
.skip-link {
  position: absolute;
  top: -10rem;
  left: 2rem;
  background: var(--color-primary);
  color: #fff;
  padding: 0.8rem 1.5rem;
  border-radius: 6px;
  z-index: 999;
  font-weight: 700;
  text-decoration: none;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
  transition: top var(--transition-smooth);
}

.skip-link:focus {
  top: 1.5rem;
  outline: none;
}

/* Accessible focus outlines */
a:focus-visible,
summary:focus-visible,
button:focus-visible {
  outline: var(--focus-outline);
  outline-offset: var(--focus-offset);
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-smooth), opacity var(--transition-smooth);
}

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

/* Global Content Layout */
.studio-wrapper {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.5rem 3rem 1.5rem;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

/* Top Live Status Editorial Dashboard Banner */
.status-banner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 1.5rem;
  background: var(--color-glass-bg);
  border: 1px solid var(--color-glass-border);
  border-radius: 0 0 12px 12px;
  margin-bottom: 2rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  backdrop-filter: blur(10px);
  box-shadow: 0 4px 12px var(--color-card-shadow);
}

.status-indicator {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  color: var(--color-text);
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--color-success);
  display: inline-block;
  box-shadow: 0 0 8px var(--color-success);
  animation: pulse-dot 2s infinite ease-in-out;
}

@keyframes pulse-dot {
  0% { opacity: 0.6; transform: scale(0.95); }
  50% { opacity: 1; transform: scale(1.1); }
  100% { opacity: 0.6; transform: scale(0.95); }
}

.status-stats {
  display: flex;
  gap: 1.5rem;
  color: var(--color-text-muted);
}

.stat-item {
  display: flex;
  gap: 0.25rem;
}

.stat-label {
  font-weight: 700;
  color: var(--color-primary);
}

/* Main Editorial Container */
.editorial-container {
  background: var(--bg-paper);
  border: 1px solid var(--line-grid);
  border-radius: 16px;
  box-shadow: 0 20px 40px var(--color-card-shadow);
  padding: 3.5rem 4rem;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
  transition: background-color var(--transition-smooth), border-color var(--transition-smooth);
}

/* Header Section */
.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--line-grid);
  padding-bottom: 2rem;
  margin-bottom: 3.5rem;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--color-text);
  text-decoration: none !important;
}

.logo-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  padding: 0.5rem;
  background: var(--color-glass-bg);
  border: 1px solid var(--color-glass-border);
  border-radius: 8px;
  transition: transform var(--transition-smooth);
}

.logo-link:hover .logo-icon {
  transform: rotate(-10deg) scale(1.1);
}

.logo-branding {
  display: flex;
  flex-direction: column;
}

.logo-text {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--color-text);
  line-height: 1.1;
}

.logo-sub {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--color-text-muted);
  margin-top: 0.15rem;
}

.site-nav {
  display: flex;
}

.nav-list {
  display: flex;
  list-style: none;
  gap: 2.5rem;
}

.nav-link {
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-text-muted);
  position: relative;
  padding: 0.5rem 0;
  text-decoration: none !important;
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.nav-link:hover {
  color: var(--color-primary);
}

.nav-link.active {
  color: var(--color-text);
  font-weight: 700;
}

.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--color-primary);
}

.nav-num {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--color-primary);
  font-weight: 700;
}

/* Main Site Content Grid */
.site-content {
  flex-grow: 1;
}

/* Homepage Split Grid */
.home-container {
  width: 100%;
}

.home-grid {
  display: grid;
  grid-template-columns: 1.25fr 0.75fr;
  gap: 4rem;
  align-items: start;
}

.home-main {
  min-width: 0;
}

.home-header {
  margin-bottom: 2.5rem;
}

.home-title {
  font-family: var(--font-serif);
  font-size: 3rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 0.75rem;
  line-height: 1.15;
  text-wrap: balance;
  color: var(--color-text);
}

.home-subtitle {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 1.25rem;
  color: var(--color-text-muted);
  line-height: 1.5;
  text-wrap: balance;
}

.home-body {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  line-height: 1.75;
  color: var(--color-text);
}

.home-body p {
  margin-bottom: 1.5rem;
  text-wrap: pretty;
}

/* Dropcap for beautiful editorial layout */
.home-body p:first-of-type::first-letter {
  font-size: 3.8rem;
  float: left;
  line-height: 0.8;
  margin-right: 0.6rem;
  margin-top: 0.2rem;
  font-family: var(--font-serif);
  font-weight: 800;
  color: var(--color-primary);
}

.home-body h3 {
  font-family: var(--font-sans);
  font-size: 1.35rem;
  font-weight: 700;
  margin: 2.5rem 0 1rem 0;
  color: var(--color-text);
  border-bottom: 1px solid var(--line-grid);
  padding-bottom: 0.5rem;
}

.home-body ul, .home-body ol {
  margin: 1rem 0 1.5rem 1.5rem;
}

.home-body li {
  margin-bottom: 0.5rem;
}

.home-body code {
  font-family: var(--font-mono);
  background: var(--bg-studio);
  padding: 0.15rem 0.35rem;
  font-size: 0.85em;
  border-radius: 4px;
  color: var(--color-primary);
}

.home-body pre {
  font-family: var(--font-mono);
  background: var(--color-text-light); /* Enforce dark theme code block */
  color-scheme: dark;
  color: #e2e8f0;
  padding: 1.25rem;
  border-radius: 8px;
  overflow-x: auto;
  margin: 1.5rem 0;
  font-size: 0.875rem;
  border: 1px solid var(--line-grid-dark);
}

/* Interactive Memory Lab Widget Deck */
.home-aside {
  background: var(--bg-studio);
  border: 1px solid var(--line-grid);
  border-radius: 12px;
  padding: 2rem;
  box-shadow: inset 0 2px 4px rgba(0,0,0,0.02);
  transition: background-color var(--transition-smooth), border-color var(--transition-smooth);
}

.memory-lab {
  display: flex;
  flex-direction: column;
}

.lab-widget-header {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 1rem;
  border-bottom: 2px solid var(--color-primary);
  padding-bottom: 0.75rem;
}

.lab-indicator {
  color: var(--color-primary);
  font-size: 0.75rem;
  animation: pulse-dot 2s infinite ease-in-out;
}

.lab-title {
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text);
}

.lab-intro {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  margin-bottom: 1.5rem;
  line-height: 1.5;
}

.cards-stack {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

/* Interactive Flashcard Component */
.flashcard {
  background: var(--bg-paper);
  border: 1px solid var(--line-grid);
  border-radius: 8px;
  box-shadow: 0 4px 6px var(--color-card-shadow);
  transition: transform var(--transition-smooth), border-color var(--transition-smooth), box-shadow var(--transition-smooth);
  cursor: pointer;
  overflow: hidden;
}

.flashcard:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 20px var(--color-card-shadow);
  border-color: var(--color-primary);
}

.flashcard summary {
  list-style: none;
  padding: 1.25rem;
  user-select: none;
  outline: none;
}

.flashcard summary::-webkit-details-marker {
  display: none;
}

.card-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.card-tag {
  font-family: var(--font-sans);
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
}

.tag-lang {
  background-color: light-dark(rgba(79, 70, 229, 0.08), rgba(129, 140, 248, 0.15));
  color: var(--color-primary);
}

.tag-code {
  background-color: light-dark(rgba(13, 148, 136, 0.08), rgba(45, 212, 191, 0.15));
  color: var(--color-secondary);
}

.tag-theory {
  background-color: light-dark(rgba(22, 163, 74, 0.08), rgba(74, 222, 128, 0.15));
  color: var(--color-success);
}

.card-num {
  font-size: 0.75rem;
  font-family: var(--font-mono);
  color: var(--color-text-muted);
}

.card-prompt {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.prompt-label {
  font-family: var(--font-sans);
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--color-text-muted);
  letter-spacing: 0.05em;
}

.chinese-char {
  font-size: 2.25rem;
  font-family: var(--font-serif);
  font-weight: 700;
  color: var(--color-text);
  line-height: 1.1;
  letter-spacing: 0.05em;
}

.code-prompt,
.theory-prompt {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--color-text);
}

.flip-action {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  text-transform: uppercase;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--color-primary);
  text-align: right;
  margin-top: 1rem;
  border-top: 1px dotted var(--line-grid);
  padding-top: 0.5rem;
  display: block;
  transition: color var(--transition-smooth);
}

.flashcard:hover .flip-action {
  color: var(--color-primary-hover);
}

/* Card Open State styling */
.flashcard[open] {
  border-color: var(--color-primary);
  background: var(--bg-paper);
}

.flashcard[open] .flip-action {
  display: none;
}

.flashcard-back {
  padding: 1.25rem;
  border-top: 1px solid var(--line-grid);
  background-color: var(--bg-paper);
  animation: slide-up-reveal 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes slide-up-reveal {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.card-answer {
  margin-bottom: 0.75rem;
}

.pinyin {
  font-size: 1.25rem;
  color: var(--color-primary);
  font-family: var(--font-sans);
  font-weight: 700;
  display: block;
  margin-bottom: 0.25rem;
}

.translation {
  font-family: var(--font-serif);
  font-style: italic;
  color: var(--color-text);
  font-size: 1.05rem;
}

.card-explanation,
.flashcard-back-explanation {
  font-family: var(--font-serif);
  font-size: 0.9rem;
  color: var(--color-text-muted);
  border-left: 3px solid var(--color-primary);
  padding-left: 0.75rem;
  margin-top: 0.75rem;
}

.card-explanation p,
.flashcard-back-explanation p {
  margin-bottom: 0.5rem;
}

.card-explanation p:last-child,
.flashcard-back-explanation p:last-child {
  margin-bottom: 0;
}

.code-block {
  margin: 0;
  padding: 0.75rem;
  background: var(--color-text-light); /* Enforce dark theme syntax box */
  color: #e2e8f0;
  border-radius: 6px;
  overflow-x: auto;
  font-size: 0.825rem;
  font-family: var(--font-mono);
  border: 1px solid var(--line-grid-dark);
}

/* Single Article Layout */
.post-article {
  max-width: 760px;
  margin: 0 auto;
}

.article-header {
  border-bottom: 1px solid var(--line-grid);
  padding-bottom: 2rem;
  margin-bottom: 3rem;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 700;
}

.article-date {
  color: var(--color-text-muted);
}

.meta-divider {
  color: var(--color-primary);
}

.article-category {
  color: var(--color-primary);
}

.article-title {
  font-family: var(--font-serif);
  font-size: 2.75rem;
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 1rem;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

.article-lead {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  line-height: 1.5;
  color: var(--color-text-muted);
}

.article-body {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  line-height: 1.75;
  color: var(--color-text);
}

.article-body p {
  margin-bottom: 1.5rem;
  text-wrap: pretty;
}

.article-body h3 {
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 1.35rem;
  margin: 2.5rem 0 1rem 0;
  color: var(--color-text);
}

.article-body ul, .article-body ol {
  margin: 1rem 0 1.5rem 1.5rem;
}

.article-body li {
  margin-bottom: 0.5rem;
}

.article-body code {
  font-family: var(--font-mono);
  background: var(--bg-studio);
  padding: 0.15rem 0.35rem;
  font-size: 0.85em;
  border-radius: 4px;
  color: var(--color-primary);
}

.article-body blockquote {
  border-left: 4px solid var(--color-primary);
  padding-left: 1.25rem;
  margin: 2rem 0;
  font-style: italic;
  color: var(--color-text-muted);
}

.article-footer {
  border-top: 1px solid var(--line-grid);
  padding-top: 2rem;
  margin-top: 4rem;
}

.back-to-guides {
  display: inline-block;
}

.back-link {
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none !important;
}

.back-link:hover .arrow {
  transform: translateX(-4px);
}

.arrow {
  display: inline-block;
  transition: transform var(--transition-smooth);
}

/* List Directory Layout */
.list-container {
  max-width: 800px;
  margin: 0 auto;
}

.list-header {
  border-bottom: 1px solid var(--line-grid);
  padding-bottom: 2rem;
  margin-bottom: 3.5rem;
}

.list-title {
  font-family: var(--font-serif);
  font-size: 2.75rem;
  font-weight: 800;
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

.list-lead {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  color: var(--color-text-muted);
}

.posts-list {
  display: flex;
  flex-direction: column;
  gap: 3rem;
}

.post-item {
  border-bottom: 1px dashed var(--line-grid);
  padding-bottom: 2.5rem;
}

.post-item:last-child {
  border-bottom: none;
}

.post-item-meta {
  font-size: 0.8rem;
  font-family: var(--font-mono);
  color: var(--color-primary);
  font-weight: 700;
  margin-bottom: 0.5rem;
  letter-spacing: 0.05em;
}

.post-item-title {
  font-family: var(--font-serif);
  font-size: 1.85rem;
  font-weight: 800;
  margin-bottom: 0.75rem;
  letter-spacing: -0.01em;
}

.post-item-title a {
  color: var(--color-text);
  text-decoration: none !important;
}

.post-item-title a:hover {
  color: var(--color-primary);
}

.post-item-description {
  font-family: var(--font-serif);
  color: var(--color-text-muted);
  font-size: 1.05rem;
  margin-bottom: 1.25rem;
  line-height: 1.6;
}

.read-more-link {
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  text-decoration: none !important;
}

.read-more-link:hover .arrow {
  transform: translateX(4px);
}

/* Footer Styling */
.site-footer {
  border-top: 1px solid var(--line-grid);
  padding-top: 3rem;
  margin-top: 5rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: start;
}

.footer-info {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.footer-title {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--color-text);
}

.footer-desc {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  max-width: 400px;
}

.footer-meta {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.footer-motto {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 0.9rem;
  color: var(--color-primary);
}

/* Responsive Breakpoints & Refinements */
@media (max-width: 992px) {
  .editorial-container {
    padding: 3rem;
  }
  
  .home-grid {
    grid-template-columns: 1fr;
    gap: 3.5rem;
  }
}

@media (max-width: 768px) {
  .status-banner {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
    border-radius: 0;
    margin-bottom: 1.5rem;
  }
  
  .status-stats {
    flex-wrap: wrap;
    gap: 0.5rem 1rem;
  }
  
  .editorial-container {
    padding: 2rem 1.5rem;
    border-radius: 12px;
  }
  
  .site-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 1.5rem;
    margin-bottom: 2.5rem;
  }
  
  .site-nav {
    width: 100%;
  }
  
  .nav-list {
    width: 100%;
    flex-wrap: wrap;
    gap: 1rem 1.5rem;
  }
  
  .home-title {
    font-size: 2.25rem;
  }
  
  .article-title {
    font-size: 2.15rem;
  }
  
  .list-title {
    font-size: 2.15rem;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  
  .footer-meta {
    align-items: flex-start;
  }
}