:root {
  --bg-color: #ffffff;
  --panel-bg: #ffffff;
  --text-main: #000000;
  --text-muted: #64748b;
  --accent-color: #921f1e;
  --sidebar-width: 50vw;
}

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

/* Global Rule: Hide scrollbars across the entire application for all browsers */
* {
  -ms-overflow-style: none;  /* IE and Edge */
  scrollbar-width: none;  /* Firefox */
}

*::-webkit-scrollbar {
  display: none; /* Chrome, Safari, Opera */
  width: 0;
  height: 0;
}

body {
  font-family: 'Jost', system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  height: 100vh;
  overflow: hidden;
  text-transform: uppercase;
}

.app-container {
  display: flex;
  height: 100vh;
  width: 100vw;
  background-color: var(--bg-color);
}

/* Status & Loading Overlay */
.status-overlay {
  position: fixed;
  inset: 0;
  background: var(--bg-color);
  z-index: 100;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  padding: 2rem;
  text-align: center;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

/* Loading Circle Spinner */
.spinner {
  width: 48px;
  height: 48px;
  border: 4px solid #f3f3f3;
  border-top: 4px solid var(--accent-color);
  border-radius: 50%;
  animation: spin 0.9s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* Error Box State */
.error-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.25rem;
  max-width: 400px;
}

.error-box p {
  color: var(--accent-color);
  font-size: 1rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  line-height: 1.5;
}

.btn-retry {
  background-color: var(--accent-color);
  color: #ffffff;
  font-family: inherit;
  font-weight: 600;
  text-transform: uppercase;
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  font-size: 0.85rem;
  letter-spacing: 0.05em;
  transition: opacity 0.2s ease, transform 0.1s ease;
}

.btn-retry:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

/* Sidebar / TOC */
.sidebar {
  width: var(--sidebar-width);
  background-color: var(--bg-color);
  border-right: none;
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  z-index: 10;
  text-align: center;
}

.sidebar-header {
  padding: 1.5rem 1.25rem 0.5rem;
  border-bottom: none;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.sidebar-logo {
  max-width: 280px;
  max-height: 160px;
  width: auto;
  height: auto;
  margin-bottom: 0.75rem;
  object-fit: contain;
  display: block;
}

.sidebar-header h2 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: 0.05em;
}

.toc-list {
  flex: 1;
  overflow-y: auto;
  padding: 1rem 0;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.toc-item {
  display: block;
  margin: 0.2rem 0;
  padding: 0.4rem 10px;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  border-radius: 4px;
  transition: all 0.2s ease;
  white-space: nowrap;
  text-align: center;
  letter-spacing: 0.03em;
  font-weight: 400;
}

.toc-item:hover {
  color: var(--text-main);
  background-color: #f8fafc;
}

/* Active TOC Item */
.toc-item.active {
  color: var(--accent-color);
  background-color: transparent;
  font-size: 1.05rem;
  font-weight: 400;
}

/* Sidebar Footer & Shortcut Hints */
.sidebar-footer {
  padding: 1.25rem;
  text-align: center;
}

.shortcut-hint {
  font-size: 0.75rem;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

.shortcut-hint kbd {
  background-color: #ffffff;
  border: 1px solid #cbd5e1;
  border-radius: 3px;
  padding: 1px 6px;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-color);
  font-family: inherit;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

/* Stream Panel */
.image-stream {
  flex: 1;
  height: 100vh;
  overflow-y: scroll;
  overflow-x: hidden; /* Prevents horizontal scrollbars */
  padding: 50vh 0;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 15px;
  background-color: var(--bg-color);
}

.image-card {
  margin-left: 0;
  display: flex;
  justify-content: flex-start;
  background: transparent;
  border: none;
  box-shadow: none;
  padding: 0;
  will-change: transform, opacity;
  transform-origin: 0% 50%;
  cursor: pointer;
}

/* Progressive Image Fade-In */
.image-card img {
  max-width: 48vw;
  height: auto;
  max-height: 75vh;
  object-fit: contain;
  object-position: left center;
  border-radius: 0;
  display: block;
  box-shadow: 10px 10px 25px rgba(0, 0, 0, 0.45);
  opacity: 0;
  transition: opacity 0.35s ease-in-out;
}

.image-card img.loaded {
  opacity: 1;
}

/* Lightbox Modal Backdrop */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background-color: rgba(0, 0, 0, 0.85);
  z-index: 200;
  cursor: pointer;
  backdrop-filter: blur(4px);
  
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.5s ease, visibility 0.5s ease;
}

.modal-backdrop.active {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

/* Dynamic Animated Image Clone */
.expanding-clone {
  position: fixed;
  z-index: 201;
  object-fit: contain;
  border-radius: 0;
  box-shadow: 10px 10px 25px rgba(0, 0, 0, 0.45);
  will-change: transform, box-shadow;
  transform-origin: top left;
  cursor: pointer;
  opacity: 1 !important;
}

.hidden {
  display: none !important;
}