/* ================================================================
   FaceCut — Dark Industrial Theme
   ================================================================ */

:root {
  --bg:        #0a0a0a;
  --surface:   #111113;
  --border:    #1e1e22;
  --text:      #d4d4d8;
  --text-dim:  #71717a;
  --accent:    #00e5a0;
  --accent-dim:#00e5a033;
  --danger:    #ef4444;
  --mono:      'JetBrains Mono', monospace;
  --sans:      'IBM Plex Sans', system-ui, sans-serif;
  --radius:    8px;
}

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

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  /* subtle grid texture */
  background-image:
    linear-gradient(rgba(255,255,255,.015) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.015) 1px, transparent 1px);
  background-size: 40px 40px;
}

/* ----------------------------------------------------------------
   Hidden helper
   ---------------------------------------------------------------- */
.hidden {
  display: none !important;
}

/* ----------------------------------------------------------------
   TOP PANEL
   ---------------------------------------------------------------- */
#top-panel {
  padding: 2.5rem 2rem 1.5rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
  flex-shrink: 0;
}

#brand h1 {
  font-family: var(--mono);
  font-size: 2.4rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-align: center;
  text-transform: uppercase;
}

#brand .accent {
  color: var(--accent);
}

.tagline {
  text-align: center;
  color: var(--text-dim);
  font-size: 0.95rem;
  margin-top: 0.25rem;
  letter-spacing: 0.04em;
}

/* ----------------------------------------------------------------
   Upload Zone
   ---------------------------------------------------------------- */
#upload-zone {
  width: 100%;
  max-width: 540px;
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 2.5rem 2rem;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.25s, background 0.25s, box-shadow 0.25s;
  position: relative;
  overflow: hidden;
}

#upload-zone::before {
  content: '';
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 2px,
    rgba(0,229,160,0.02) 2px,
    rgba(0,229,160,0.02) 4px
  );
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.3s;
}

#upload-zone:hover,
#upload-zone.zone-hover {
  border-color: var(--accent);
  background: rgba(0,229,160,0.04);
  box-shadow: 0 0 30px rgba(0,229,160,0.08);
}

#upload-zone:hover::before,
#upload-zone.zone-hover::before {
  opacity: 1;
}

#upload-zone.zone-uploading {
  border-color: var(--accent);
  pointer-events: none;
  opacity: 0.6;
}

.zone-icon {
  width: 48px;
  height: 48px;
  color: var(--text-dim);
  margin-bottom: 0.75rem;
  transition: color 0.25s;
}

#upload-zone:hover .zone-icon,
#upload-zone.zone-hover .zone-icon {
  color: var(--accent);
}

.zone-label {
  font-size: 1rem;
  color: var(--text);
  margin-bottom: 0.3rem;
}

.zone-sub {
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* ----------------------------------------------------------------
   Controls Panel
   ---------------------------------------------------------------- */
#controls-panel {
  width: 100%;
  max-width: 540px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.25rem;
}

.controls-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.9rem;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.checkbox-mask {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--sans);
  font-size: 0.8rem;
  color: var(--text-dim);
  cursor: pointer;
  user-select: none;
}

.checkbox-mask input[type="checkbox"] {
  width: 16px;
  height: 16px;
  accent-color: var(--accent);
  cursor: pointer;
}

.checkbox-mask:hover {
  color: var(--text);
}

.controls-header h3 {
  font-family: var(--mono);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.btn-rescan {
  font-family: var(--mono);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.45rem 1rem;
  border: 1px solid var(--accent);
  border-radius: 4px;
  background: transparent;
  color: var(--accent);
  cursor: pointer;
  transition: background 0.2s, color 0.2s, transform 0.15s, opacity 0.2s;
}

.btn-rescan:hover:not(:disabled) {
  background: var(--accent);
  color: #0a0a0a;
  transform: translateY(-1px);
}

.btn-rescan:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

.sliders-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem 1.5rem;
}

.slider-group {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.slider-label {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--text);
}

.slider-value {
  color: var(--accent);
  font-weight: 700;
  font-size: 0.72rem;
}

.slider-hint {
  font-size: 0.65rem;
  color: var(--text-dim);
  line-height: 1.3;
}

/* Custom range slider */
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  outline: none;
  cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg);
  cursor: pointer;
  transition: box-shadow 0.2s;
}

input[type="range"]::-webkit-slider-thumb:hover {
  box-shadow: 0 0 8px rgba(0,229,160,0.4);
}

input[type="range"]::-moz-range-thumb {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg);
  cursor: pointer;
}

@media (max-width: 600px) {
  .sliders-grid {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }
}

/* ----------------------------------------------------------------
   Progress Panel
   ---------------------------------------------------------------- */
#progress-panel {
  width: 100%;
  max-width: 540px;
}

#progress-info {
  display: flex;
  justify-content: space-between;
  font-family: var(--mono);
  font-size: 0.82rem;
  margin-bottom: 0.5rem;
  color: var(--text-dim);
}

#progress-pct {
  color: var(--accent);
  font-weight: 700;
}

#progress-track {
  position: relative;
  height: 6px;
  background: var(--surface);
  border-radius: 3px;
  overflow: hidden;
}

#progress-bar {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), #00b880);
  border-radius: 3px;
  transition: width 0.3s ease;
}

/* Scanline effect */
#scanline {
  position: absolute;
  top: 0;
  left: -20%;
  width: 20%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(0,229,160,0.4), transparent);
  animation: scanline-move 1.5s linear infinite;
}

@keyframes scanline-move {
  0%   { left: -20%; }
  100% { left: 120%; }
}

#progress-stats {
  display: flex;
  justify-content: space-between;
  font-size: 0.78rem;
  color: var(--text-dim);
  margin-top: 0.5rem;
  font-family: var(--mono);
}

/* ----------------------------------------------------------------
   BOTTOM PANEL — Gallery
   ---------------------------------------------------------------- */
#bottom-panel {
  flex: 1;
  padding: 1rem 2rem 6rem;
  overflow-y: auto;
}

#gallery-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

#gallery-header h2 {
  font-family: var(--mono);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

#gallery-actions {
  display: flex;
  gap: 0.5rem;
}

.btn-sm {
  font-family: var(--mono);
  font-size: 0.72rem;
  padding: 0.35rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--surface);
  color: var(--text-dim);
  cursor: pointer;
  transition: border-color 0.2s, color 0.2s;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

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

/* Face grid */
#gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
  gap: 12px;
}

.face-card {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  cursor: pointer;
  border: 2px solid var(--border);
  transition: border-color 0.2s, box-shadow 0.2s, transform 0.2s;
  aspect-ratio: 3 / 5;
  background: var(--surface);

  /* staggered entrance */
  animation: face-in 0.35s ease both;
}

.face-card:hover {
  border-color: rgba(0,229,160,0.4);
  box-shadow: 0 0 16px rgba(0,229,160,0.1);
  transform: translateY(-2px);
}

.face-card.selected {
  border-color: var(--accent);
  box-shadow: 0 0 20px rgba(0,229,160,0.2);
}

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

/* Checkbox overlay */
.face-check {
  position: absolute;
  top: 6px;
  right: 6px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  border: 2px solid rgba(255,255,255,0.3);
  background: rgba(0,0,0,0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: border-color 0.2s, background 0.2s;
}

.face-card.selected .face-check {
  border-color: var(--accent);
  background: var(--accent);
}

.face-check svg {
  width: 12px;
  height: 12px;
  stroke: white;
  stroke-width: 3;
  fill: none;
  opacity: 0;
  transition: opacity 0.15s;
}

.face-card.selected .face-check svg {
  opacity: 1;
}

@keyframes face-in {
  from {
    opacity: 0;
    transform: scale(0.85) translateY(10px);
  }
  to {
    opacity: 1;
    transform: scale(1) translateY(0);
  }
}

/* Empty state */
#empty-state {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--text-dim);
  font-size: 0.9rem;
}

/* ----------------------------------------------------------------
   EXPORT BAR (sticky footer)
   ---------------------------------------------------------------- */
#export-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 0.8rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  z-index: 100;
  backdrop-filter: blur(12px);
  background: rgba(17,17,19,0.92);
}

#selected-count {
  font-family: var(--mono);
  font-size: 0.85rem;
  color: var(--text-dim);
}

#btn-export {
  font-family: var(--mono);
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.6rem 1.5rem;
  border: none;
  border-radius: 4px;
  background: var(--accent);
  color: #0a0a0a;
  cursor: pointer;
  transition: opacity 0.2s, transform 0.15s;
}

#btn-export:hover:not(:disabled) {
  transform: translateY(-1px);
  opacity: 0.9;
}

#btn-export:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

/* ----------------------------------------------------------------
   TOAST
   ---------------------------------------------------------------- */
#toast-container {
  position: fixed;
  top: 1.5rem;
  right: 1.5rem;
  z-index: 200;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.toast {
  font-family: var(--mono);
  font-size: 0.8rem;
  padding: 0.7rem 1.2rem;
  border-radius: 4px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  animation: toast-in 0.3s ease, toast-out 0.3s ease 2.7s forwards;
}

.toast.toast-success {
  border-color: var(--accent);
  color: var(--accent);
}

.toast.toast-error {
  border-color: var(--danger);
  color: var(--danger);
}

@keyframes toast-in {
  from { opacity: 0; transform: translateX(20px); }
  to   { opacity: 1; transform: translateX(0); }
}

@keyframes toast-out {
  from { opacity: 1; }
  to   { opacity: 0; }
}

/* ----------------------------------------------------------------
   Responsive
   ---------------------------------------------------------------- */
@media (max-width: 600px) {
  #top-panel { padding: 1.5rem 1rem 1rem; }
  #bottom-panel { padding: 1rem 1rem 5rem; }
  #gallery { grid-template-columns: repeat(auto-fill, minmax(85px, 1fr)); gap: 8px; }
  #brand h1 { font-size: 1.6rem; }
  #export-bar { padding: 0.6rem 1rem; }
}