/* Reset & Base Variables */
:root {
  --bg-color: #0f1117;
  --surface-color: #171b24;
  --surface-hover: #1f2430;
  --card-bg: rgba(23, 27, 36, 0.7);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-active: #4f46e5;
  --primary-color: #6366f1;
  --primary-hover: #4f46e5;
  --accent-color: #38bdf8;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --radius-lg: 16px;
  --radius-md: 10px;
  --radius-sm: 6px;
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow-lg: 0 20px 40px -15px rgba(0, 0, 0, 0.7);
  --shadow-md: 0 10px 25px -5px rgba(0, 0, 0, 0.5);
}

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

body {
  font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, sans-serif;
  background-color: var(--bg-color);
  background-image: 
    radial-gradient(at 0% 0%, rgba(99, 102, 241, 0.12) 0px, transparent 50%),
    radial-gradient(at 100% 100%, rgba(56, 189, 248, 0.08) 0px, transparent 50%);
  background-attachment: fixed;
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

.app-container {
  width: 100%;
  max-width: 1200px;
  padding: 2.5rem 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 2rem;
  margin: 0 auto;
}

/* Header */
.gallery-header {
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.badge {
  display: inline-block;
  padding: 0.35rem 0.85rem;
  border-radius: 9999px;
  background: rgba(99, 102, 241, 0.15);
  color: var(--accent-color);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  border: 1px solid rgba(56, 189, 248, 0.2);
  margin-bottom: 0.3rem;
}

.gallery-title {
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, #ffffff 30%, #94a3b8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.gallery-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  max-width: 600px;
}

/* Slider Section */
.slider-wrapper {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  width: 100%;
}

.slider-container {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 10;
  max-height: 680px;
  background-color: var(--surface-color);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  backdrop-filter: blur(8px);
  user-select: none;
}

.slide-stage {
  position: relative;
  width: 100%;
  height: 100%;
}

.slide-item {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.4s ease, transform 0.4s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: zoom-in;
  overflow: hidden;
}

.slide-item.active {
  opacity: 1;
  visibility: visible;
}

.slide-item img {
  max-width: 100%;
  max-height: 100%;
  width: auto;
  height: auto;
  object-fit: contain;
  transition: transform 0.35s cubic-bezier(0.2, 0, 0.2, 1);
}

.slide-item:hover img {
  transform: scale(1.02);
}

/* Navigation Buttons */
.nav-btn svg,
.modal-btn svg,
.action-btn svg,
.zoom-trigger-btn svg,
.modal-nav-btn svg {
  display: block;
  flex-shrink: 0;
}

#autoplayIcon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.nav-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 48px;
  height: 48px;
  background: rgba(15, 17, 23, 0.7);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.4rem;
  transition: var(--transition);
  z-index: 10;
}

.nav-btn:hover {
  background: var(--primary-color);
  color: white;
  box-shadow: 0 0 15px rgba(99, 102, 241, 0.5);
  transform: translateY(-50%) scale(1.08);
}

.prev-btn {
  left: 1.25rem;
}

.next-btn {
  right: 1.25rem;
}

/* Stage Overlay (Counter & Quick Zoom) */
.stage-overlay {
  position: absolute;
  bottom: 1.25rem;
  left: 1.25rem;
  right: 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  pointer-events: none;
  z-index: 10;
}

.image-counter {
  background: rgba(15, 17, 23, 0.75);
  backdrop-filter: blur(8px);
  padding: 0.4rem 0.85rem;
  border-radius: 9999px;
  font-size: 0.85rem;
  font-weight: 500;
  border: 1px solid var(--border-color);
  color: var(--text-muted);
}

.zoom-trigger-btn {
  pointer-events: auto;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  background: rgba(15, 17, 23, 0.8);
  backdrop-filter: blur(8px);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  padding: 0.45rem 0.9rem;
  border-radius: 9999px;
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
}

.zoom-trigger-btn:hover {
  background: var(--primary-color);
  border-color: var(--primary-hover);
  box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
}

/* Controls & Indicator Strip */
.slider-controls {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.controls-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 0.5rem;
}

.action-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: var(--surface-color);
  color: var(--text-muted);
  border: 1px solid var(--border-color);
  padding: 0.45rem 0.85rem;
  border-radius: var(--radius-md);
  font-size: 0.85rem;
  cursor: pointer;
  transition: var(--transition);
}

.action-btn:hover,
.action-btn.active {
  background: var(--surface-hover);
  color: var(--text-main);
  border-color: rgba(255, 255, 255, 0.2);
}

.dots-container {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
  cursor: pointer;
  transition: var(--transition);
}

.dot:hover {
  background: rgba(255, 255, 255, 0.5);
}

.dot.active {
  background: var(--primary-color);
  width: 26px;
  border-radius: 6px;
}

/* Thumbnails Strip */
.thumbnails-track {
  display: flex;
  gap: 1rem;
  overflow-x: auto;
  padding: 0.5rem 0.25rem;
  scrollbar-width: thin;
  scrollbar-color: rgba(255, 255, 255, 0.2) transparent;
}

.thumbnails-track::-webkit-scrollbar {
  height: 6px;
}

.thumbnails-track::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.2);
  border-radius: 4px;
}

.thumbnail-item {
  flex: 0 0 110px;
  height: 75px;
  border-radius: var(--radius-md);
  overflow: hidden;
  cursor: pointer;
  border: 2px solid transparent;
  background: var(--surface-color);
  position: relative;
  transition: var(--transition);
  opacity: 0.6;
}

.thumbnail-item:hover {
  opacity: 0.9;
  transform: translateY(-2px);
}

.thumbnail-item.active {
  opacity: 1;
  border-color: var(--primary-color);
  box-shadow: 0 0 12px rgba(99, 102, 241, 0.4);
  transform: translateY(-2px);
}

.thumbnail-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* Modal Zoom Viewer (Lightbox) */
.zoom-modal {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.zoom-modal.open {
  opacity: 1;
  visibility: visible;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(8, 10, 15, 0.94);
  backdrop-filter: blur(16px);
}

.modal-header {
  position: relative;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border-color);
  background: rgba(15, 17, 23, 0.6);
}

.modal-info {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.modal-counter {
  font-weight: 600;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.modal-filename {
  font-size: 0.9rem;
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.05);
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-sm);
  max-width: 300px;
  text-overflow: ellipsis;
  overflow: hidden;
  white-space: nowrap;
}

.modal-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.divider {
  width: 1px;
  height: 20px;
  background: var(--border-color);
  margin: 0 0.25rem;
}

.modal-btn {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  min-width: 38px;
  height: 38px;
  padding: 0 0.6rem;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  font-size: 1.1rem;
  cursor: pointer;
  transition: var(--transition);
}

.modal-btn:hover {
  background: rgba(255, 255, 255, 0.15);
  color: white;
}

.modal-btn.close-btn:hover {
  background: #ef4444;
  border-color: #dc2626;
}

.zoom-level-text {
  font-size: 0.8rem;
  font-weight: 600;
}

/* Viewport & Canvas */
.modal-viewport {
  position: relative;
  flex: 1;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: grab;
}

.modal-viewport.dragging {
  cursor: grabbing;
}

.zoom-canvas {
  position: absolute;
  top: 50%;
  left: 50%;
  transform-origin: 0 0;
  display: flex;
  align-items: center;
  justify-content: center;
  will-change: transform;
  user-select: none;
}

.zoom-canvas img {
  display: block;
  max-width: 85vw;
  max-height: 80vh;
  object-fit: contain;
  pointer-events: none;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
  border-radius: var(--radius-sm);
}

/* Modal Nav Buttons */
.modal-nav-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 52px;
  height: 52px;
  background: rgba(23, 27, 36, 0.6);
  backdrop-filter: blur(8px);
  border: 1px solid var(--border-color);
  border-radius: 50%;
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  cursor: pointer;
  z-index: 10;
  transition: var(--transition);
}

.modal-nav-btn:hover {
  background: var(--primary-color);
  transform: translateY(-50%) scale(1.1);
  box-shadow: 0 0 20px rgba(99, 102, 241, 0.5);
}

.modal-prev {
  left: 1.5rem;
}

.modal-next {
  right: 1.5rem;
}

/* Modal Bottom Guide */
.modal-guide {
  position: absolute;
  bottom: 1.2rem;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(15, 17, 23, 0.75);
  backdrop-filter: blur(10px);
  padding: 0.5rem 1.25rem;
  border-radius: 9999px;
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  gap: 1.25rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  pointer-events: none;
  z-index: 10;
}

.modal-guide span {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.modal-guide i {
  font-size: 1rem;
  color: var(--accent-color);
}

/* Responsive */
@media (max-width: 768px) {
  .app-container {
    padding: 1.5rem 1rem;
    gap: 1.25rem;
  }

  .gallery-title {
    font-size: 1.6rem;
  }

  .slider-container {
    aspect-ratio: 4 / 3;
  }

  .nav-btn svg,
.modal-btn svg,
.action-btn svg,
.zoom-trigger-btn svg,
.modal-nav-btn svg {
  display: block;
  flex-shrink: 0;
}

#autoplayIcon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.nav-btn {
    width: 40px;
    height: 40px;
    font-size: 1.2rem;
  }

  .prev-btn {
    left: 0.75rem;
  }

  .next-btn {
    right: 0.75rem;
  }

  .modal-guide {
    display: none;
  }

  .modal-nav-btn {
    width: 42px;
    height: 42px;
    font-size: 1.2rem;
  }

  .modal-prev {
    left: 0.75rem;
  }

  .modal-next {
    right: 0.75rem;
  }

  .thumbnail-item {
    flex: 0 0 85px;
    height: 60px;
  }

  .modal-filename {
    max-width: 140px;
  }
}