/* ==========================================================================
   FIL — Fluorescence Imaging Laboratory
   Full-color Design System with Light/Dark Themes
   ========================================================================== */

/* --- Google Fonts --- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

/* --- Dark Theme (default) --- */
:root,
[data-theme="dark"] {
  /* Primary — soft chartreuse */
  --color-chartreuse:       #9AB86A;
  --color-chartreuse-light: #B8D08E;
  --color-chartreuse-pale:  rgba(154, 184, 106, 0.14);
  --color-chartreuse-dark:  #C0D898;

  /* Accent — muted cyan */
  --color-cyan:             #7AAFB5;
  --color-cyan-light:       #5C9BA0;
  --color-cyan-pale:        rgba(122, 175, 181, 0.12);
  --color-cyan-dark:        #A0CDD2;

  /* Accent — muted magenta */
  --color-magenta:          #C08A9C;
  --color-magenta-light:    #A87488;
  --color-magenta-pale:     rgba(192, 138, 156, 0.14);
  --color-magenta-dark:     #D8AAB8;

  /* Sidebar — deep olive-green */
  --sidebar-bg:             #1A2C16;
  --sidebar-bg-hover:       #233820;
  --sidebar-text:           #B8D08E;
  --sidebar-text-active:    #E8F0D8;
  --sidebar-accent:         #C08A9C;
  --sidebar-border:         rgba(255, 255, 255, 0.08);
  --sidebar-header-bg:      #142410;

  /* Main area — dark warm charcoal */
  --content-bg:             #1C1E20;
  --content-bg-alt:         #242628;
  --card-bg:                #282A2E;
  --card-shadow:            rgba(0, 0, 0, 0.25);

  /* Text */
  --text-primary:           #E0DEDA;
  --text-secondary:         #A8A5A0;
  --text-muted:             #706E6A;
  --text-inverse:           #1C1E20;

  /* Borders */
  --border-color:           #383C34;
  --border-color-strong:    #50544C;

  /* Headings — chartreuse primary, cyan secondary */
  --h1-accent:              var(--color-chartreuse);
  --h2-accent:              var(--color-cyan);
  --h3-color:               var(--color-magenta-dark);

  /* Links */
  --link-color:             var(--color-cyan);
  --link-hover:             var(--color-magenta);

  /* Blockquote */
  --blockquote-bg:          var(--color-chartreuse-pale);
  --blockquote-border:      var(--color-chartreuse);
  --blockquote-text:        var(--text-secondary);

  /* Table */
  --table-header-bg:        rgba(192, 138, 156, 0.2);
  --table-header-text:      var(--color-magenta-dark);
  --table-row-alt:          rgba(154, 184, 106, 0.04);
  --table-row-hover:        var(--color-chartreuse-pale);
  --table-border:           var(--border-color);

  /* Code */
  --code-bg:                rgba(255, 255, 255, 0.07);
  --code-text:              var(--color-magenta);
  --pre-bg:                 #0E100D;
  --pre-text:               #C8D0C0;

  /* Footer */
  --footer-bg:              var(--content-bg-alt);
  --footer-text:            var(--text-muted);

  /* Controls */
  --toggle-bg:              rgba(255, 255, 255, 0.08);
  --toggle-active-bg:       var(--color-magenta);
  --toggle-active-text:     #1A2C16;
  --toggle-text:            var(--sidebar-text);

  /* Loading spinner */
  --spinner-color:          var(--color-magenta);
}

/* --- Light Theme --- */
[data-theme="light"] {
  /* Primary — muted chartreuse */
  --color-chartreuse:       #8A9D6A;
  --color-chartreuse-light: #B5C49A;
  --color-chartreuse-pale:  #E6EBD8;
  --color-chartreuse-dark:  #687E4E;

  /* Accent — muted cyan */
  --color-cyan:             #6A9CA0;
  --color-cyan-light:       #A5C8CC;
  --color-cyan-pale:        #DBE9EB;
  --color-cyan-dark:        #4A8084;

  /* Accent — muted magenta */
  --color-magenta:          #B0788A;
  --color-magenta-light:    #D8AAB8;
  --color-magenta-pale:     #F0D8E0;
  --color-magenta-dark:     #8A5468;

  /* Sidebar — deep olive-green */
  --sidebar-bg:             #3A5428;
  --sidebar-bg-hover:       #446230;
  --sidebar-text:           #D4E4B0;
  --sidebar-text-active:    #FFFFFF;
  --sidebar-accent:         #C87A94;
  --sidebar-border:         rgba(255, 255, 255, 0.12);
  --sidebar-header-bg:      #304820;

  /* Main area — warm cream with green tint */
  --content-bg:             #F2F0E8;
  --content-bg-alt:         #E8E6DC;
  --card-bg:                #FFFFFF;
  --card-shadow:            rgba(0, 0, 0, 0.06);

  /* Text */
  --text-primary:           #2D2D2D;
  --text-secondary:         #555555;
  --text-muted:             #888888;
  --text-inverse:           #FFFFFF;

  /* Borders */
  --border-color:           #D0CCC0;
  --border-color-strong:    #B5B0A5;

  /* Headings — chartreuse primary, cyan secondary */
  --h1-accent:              var(--color-chartreuse);
  --h2-accent:              var(--color-cyan);
  --h3-color:               var(--color-magenta-dark);

  /* Links */
  --link-color:             var(--color-cyan-dark);
  --link-hover:             var(--color-magenta-dark);

  /* Blockquote */
  --blockquote-bg:          var(--color-chartreuse-pale);
  --blockquote-border:      var(--color-chartreuse);
  --blockquote-text:        var(--text-secondary);

  /* Table */
  --table-header-bg:        var(--color-magenta);
  --table-header-text:      #FFFFFF;
  --table-row-alt:          rgba(138, 157, 106, 0.06);
  --table-row-hover:        var(--color-chartreuse-pale);
  --table-border:           var(--border-color);

  /* Code */
  --code-bg:                #E4E0D4;
  --code-text:              var(--color-magenta-dark);
  --pre-bg:                 #2A2E26;
  --pre-text:               #DCE0D8;

  /* Footer */
  --footer-bg:              var(--color-chartreuse-pale);
  --footer-text:            var(--text-secondary);

  /* Controls */
  --toggle-bg:              rgba(255, 255, 255, 0.18);
  --toggle-active-bg:       var(--color-magenta);
  --toggle-active-text:     #FFFFFF;
  --toggle-text:            var(--sidebar-text);

  /* Loading spinner */
  --spinner-color:          var(--color-magenta);
}

/* --- Layout Variables (shared) --- */
:root {
  --sidebar-width: 280px;
  --header-height: 56px;
  --content-max-width: 820px;
  --content-padding: 2.5rem;
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-size-base: 16px;
  --line-height: 1.7;
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
  --transition-theme: 0.35s ease;
}

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

html {
  font-size: var(--font-size-base);
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family);
  color: var(--text-primary);
  background-color: var(--content-bg);
  line-height: var(--line-height);
  display: flex;
  min-height: 100vh;
  transition: background-color var(--transition-theme), color var(--transition-theme);
}

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

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

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* --- Sidebar --- */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-width);
  height: 100vh;
  background-color: var(--sidebar-bg);
  display: flex;
  flex-direction: column;
  z-index: 100;
  overflow-y: auto;
  transition: transform var(--transition-normal), background-color var(--transition-theme);
}

.sidebar-header {
  padding: 1.5rem 1.25rem;
  border-bottom: 1px solid var(--sidebar-border);
  background-color: var(--sidebar-header-bg);
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-shrink: 0;
  transition: background-color var(--transition-theme);
}

.sidebar-logo {
  width: 44px;
  height: 44px;
  border-radius: 8px;
  object-fit: cover;
  background: rgba(255, 255, 255, 0.1);
  padding: 2px;
}

.sidebar-title {
  display: flex;
  flex-direction: column;
}

.sidebar-title-name {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--sidebar-text-active);
  letter-spacing: 0.04em;
}

.sidebar-title-sub {
  font-size: 0.7rem;
  color: var(--sidebar-text);
  font-weight: 400;
  line-height: 1.3;
  margin-top: 2px;
  opacity: 0.8;
}

/* Navigation */
.sidebar-nav {
  flex: 1;
  padding: 0.75rem 0;
}

.sidebar-nav ul {
  list-style: none;
}

.sidebar-nav a {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.6rem 1.25rem;
  color: var(--sidebar-text);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  border-left: 3px solid transparent;
  transition: all var(--transition-fast);
}

.sidebar-nav a:hover {
  color: var(--sidebar-text-active);
  background-color: var(--sidebar-bg-hover);
  text-decoration: none;
}

.sidebar-nav a.active {
  color: var(--sidebar-text-active);
  background-color: rgba(255, 255, 255, 0.1);
  border-left-color: var(--sidebar-accent);
  font-weight: 600;
}

.sidebar-nav .nav-icon {
  font-size: 1.05rem;
  width: 1.4rem;
  text-align: center;
  flex-shrink: 0;
}

/* Sidebar footer — controls */
.sidebar-footer {
  padding: 0.75rem 1.25rem 1rem;
  border-top: 1px solid var(--sidebar-border);
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.sidebar-footer-label {
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--sidebar-text);
  opacity: 0.5;
  font-weight: 600;
}

/* Toggle buttons (shared style for lang and theme) */
.toggle-group {
  display: flex;
  gap: 0;
  border-radius: 6px;
  overflow: hidden;
  border: 1px solid var(--sidebar-border);
}

.toggle-btn {
  flex: 1;
  padding: 0.4rem 0.6rem;
  font-size: 0.78rem;
  font-weight: 600;
  font-family: var(--font-family);
  background: var(--toggle-bg);
  color: var(--toggle-text);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-align: center;
  white-space: nowrap;
}

.toggle-btn:not(:last-child) {
  border-right: 1px solid var(--sidebar-border);
}

.toggle-btn:hover {
  background-color: rgba(255, 255, 255, 0.2);
}

.toggle-btn.active {
  background-color: var(--toggle-active-bg);
  color: var(--toggle-active-text);
}

/* --- Main Content --- */
.main {
  margin-left: var(--sidebar-width);
  flex: 1;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: margin-left var(--transition-normal);
}

/* Top bar (mobile) */
.topbar {
  display: none;
  align-items: center;
  justify-content: space-between;
  padding: 0 1rem;
  height: var(--header-height);
  background-color: var(--sidebar-bg);
  border-bottom: 1px solid var(--sidebar-border);
  position: sticky;
  top: 0;
  z-index: 90;
  transition: background-color var(--transition-theme);
}

.topbar-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--sidebar-text-active);
}

.hamburger {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 6px;
  cursor: pointer;
  font-size: 1.2rem;
  color: var(--sidebar-text-active);
  transition: all var(--transition-fast);
}

.hamburger:hover {
  background-color: rgba(255, 255, 255, 0.2);
}

/* Content area */
.content {
  flex: 1;
  max-width: var(--content-max-width);
  width: 100%;
  margin: 0 auto;
  padding: var(--content-padding);
}

/* Loading indicator */
.content-loading {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 200px;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.content-loading::before {
  content: '';
  width: 20px;
  height: 20px;
  border: 2px solid var(--border-color);
  border-top-color: var(--spinner-color);
  border-radius: 50%;
  margin-right: 0.75rem;
  animation: spin 0.8s linear infinite;
}

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

/* Footer */
.footer {
  padding: 1.25rem var(--content-padding);
  max-width: var(--content-max-width);
  margin: 0 auto;
  width: 100%;
  border-top: 1px solid var(--border-color);
  color: var(--footer-text);
  background-color: var(--footer-bg);
  font-size: 0.8rem;
  text-align: center;
  transition: background-color var(--transition-theme), color var(--transition-theme);
}

/* Full-width footer background */
.main::after {
  content: '';
  display: block;
  background-color: var(--footer-bg);
  transition: background-color var(--transition-theme);
}

/* --- Markdown Rendered Content --- */
.content h1 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1rem;
  padding-bottom: 0.6rem;
  border-bottom: 3px solid var(--h1-accent);
  line-height: 1.3;
}

.content h2 {
  font-size: 1.45rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-top: 2.2rem;
  margin-bottom: 0.6rem;
  padding-bottom: 0.35rem;
  border-bottom: 2px solid var(--h2-accent);
}

.content h3 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--h3-color);
  margin-top: 1.8rem;
  margin-bottom: 0.5rem;
}

.content h4 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-top: 1.5rem;
  margin-bottom: 0.4rem;
}

.content p {
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.content ul,
.content ol {
  margin-bottom: 1rem;
  padding-left: 1.5rem;
}

.content li {
  margin-bottom: 0.35rem;
  color: var(--text-primary);
}

.content li > ul,
.content li > ol {
  margin-top: 0.35rem;
  margin-bottom: 0;
}

.content blockquote {
  margin: 1.25rem 0;
  padding: 0.85rem 1.25rem;
  border-left: 4px solid var(--blockquote-border);
  background-color: var(--blockquote-bg);
  color: var(--blockquote-text);
  border-radius: 0 8px 8px 0;
}

.content blockquote p:last-child {
  margin-bottom: 0;
}

.content code {
  font-family: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
  font-size: 0.88em;
  padding: 0.15em 0.4em;
  background-color: var(--code-bg);
  border-radius: 4px;
  color: var(--code-text);
}

.content pre {
  margin: 1.25rem 0;
  padding: 1rem 1.25rem;
  background-color: var(--pre-bg);
  color: var(--pre-text);
  border-radius: 8px;
  overflow-x: auto;
  font-size: 0.88rem;
  line-height: 1.6;
}

.content pre code {
  background: none;
  color: inherit;
  padding: 0;
  font-size: inherit;
}

.content table {
  width: 100%;
  margin: 1.25rem 0;
  border-collapse: collapse;
  font-size: 0.92rem;
  border-radius: 8px;
  overflow: hidden;
}

.content th {
  background-color: var(--table-header-bg);
  font-weight: 600;
  text-align: left;
  padding: 0.7rem 0.85rem;
  color: var(--table-header-text);
  border-bottom: none;
}

.content td {
  padding: 0.6rem 0.85rem;
  border-bottom: 1px solid var(--table-border);
  color: var(--text-primary);
}

.content tr:nth-child(even) td {
  background-color: var(--table-row-alt);
}

.content tr:hover td {
  background-color: var(--table-row-hover);
}

.content hr {
  margin: 2rem 0;
  border: none;
  border-top: 1px solid var(--border-color);
}

.content img {
  margin: 1.25rem 0;
  border-radius: 8px;
  box-shadow: 0 2px 12px var(--card-shadow);
}

.content strong {
  font-weight: 600;
  color: var(--text-primary);
}

.content em {
  font-style: italic;
  color: var(--text-secondary);
}

/* --- Ukraine Support Banner --- */
.ukraine-banner {
  display: block;
  width: 100%;
  text-decoration: none;
  border-radius: 10px;
  overflow: hidden;
  margin-bottom: 2rem;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
  transition: box-shadow var(--transition-normal), transform var(--transition-fast);
  cursor: pointer;
}

.ukraine-banner:hover {
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.25);
  transform: translateY(-2px);
  text-decoration: none;
}

.ukraine-banner-top {
  background-color: #0057B8;
  padding: 1rem 1.5rem;
  color: #000;
  font-size: 0.88rem;
  line-height: 1.6;
  text-align: center;
  font-weight: 500;
}

.ukraine-banner-bottom {
  background-color: #FFD700;
  padding: 1rem 1.5rem;
  color: #000;
  font-size: 1.15rem;
  font-weight: 700;
  text-align: center;
  letter-spacing: 0.04em;
}

/* --- Links Page — Card Grid --- */
.links-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.link-card {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  padding: 1.25rem 1.5rem;
  background-color: var(--card-bg);
  border-radius: 10px;
  border: 1px solid var(--border-color);
  box-shadow: 0 2px 8px var(--card-shadow);
  transition: box-shadow var(--transition-normal), transform var(--transition-fast),
              background-color var(--transition-theme), border-color var(--transition-theme);
  text-decoration: none;
  color: inherit;
}

.link-card:hover {
  box-shadow: 0 4px 18px var(--card-shadow);
  transform: translateY(-3px);
  border-color: var(--color-magenta);
  text-decoration: none;
}

.link-card-title {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--link-color);
}

.link-card:hover .link-card-title {
  color: var(--link-hover);
}

.link-card-desc {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* --- Responsive --- */
@media (max-width: 900px) {
  .sidebar {
    transform: translateX(-100%);
  }

  .sidebar.open {
    transform: translateX(0);
    box-shadow: 4px 0 24px rgba(0, 0, 0, 0.3);
  }

  .topbar {
    display: flex;
  }

  .main {
    margin-left: 0;
  }

  .content {
    padding: 1.5rem 1.25rem;
  }

  .footer {
    padding: 1rem 1.25rem;
  }
}

/* Overlay for mobile sidebar */
.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.45);
  z-index: 99;
  backdrop-filter: blur(2px);
}

.sidebar-overlay.visible {
  display: block;
}

/* --- Print styles --- */
@media print {
  .sidebar,
  .topbar,
  .sidebar-overlay {
    display: none !important;
  }

  .main {
    margin-left: 0;
  }

  .content {
    max-width: 100%;
  }
}