/* ══════════════════════════════════════════════════════════════
   PHOTONLINK – Optical Data Transmission
   Dark theme · Glassmorphism · Neon accents
   ══════════════════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=JetBrains+Mono:wght@400;600&display=swap');

/* ── Tokens ────────────────────────────────────────────────── */
:root {
  --bg-deep:      #060a13;
  --bg-surface:   #0d1320;
  --bg-card:      rgba(14, 22, 40, 0.75);
  --bg-glass:     rgba(18, 28, 52, 0.55);
  --border-glass: rgba(100, 160, 255, 0.12);
  --border-dim:   rgba(255, 255, 255, 0.06);

  --accent-cyan:    #00d4ff;
  --accent-blue:    #3b82f6;
  --accent-purple:  #7b2ff7;
  --accent-pink:    #f637ec;
  --success:        #00ff88;
  --danger:         #ff3366;
  --warning:        #ffaa00;

  --text:           #e0e6ef;
  --text-muted:     #6b7f99;
  --text-dim:       rgba(255,255,255,0.35);

  --radius:         14px;
  --radius-sm:      8px;
  --font:           'Inter', system-ui, sans-serif;
  --mono:           'JetBrains Mono', monospace;

  --glow-cyan:      0 0 20px rgba(0,212,255,0.35), 0 0 60px rgba(0,212,255,0.10);
  --glow-purple:    0 0 20px rgba(123,47,247,0.35), 0 0 60px rgba(123,47,247,0.10);
  --glow-success:   0 0 20px rgba(0,255,136,0.35);
}

/* ── Reset ────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; -webkit-font-smoothing: antialiased; }
body {
  font-family: var(--font);
  background: var(--bg-deep);
  color: var(--text);
  min-height: 100vh;
  overflow-x: hidden;
}

/* animated noise background */
body::before {
  content: '';
  position: fixed; inset: 0; z-index: -2;
  background:
    radial-gradient(ellipse 80% 60% at 20% 10%, rgba(0,212,255,0.07), transparent 60%),
    radial-gradient(ellipse 60% 50% at 80% 85%, rgba(123,47,247,0.07), transparent 60%);
}

/* ── App shell ────────────────────────────────────────────── */
.app {
  max-width: 960px;
  margin: 0 auto;
  padding: 24px 20px 60px;
}

/* ── Header ───────────────────────────────────────────────── */
.header {
  text-align: center;
  padding: 28px 0 8px;
}
.logo-icon {
  display: inline-block;
  font-size: 2.4rem;
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  filter: drop-shadow(0 0 12px rgba(0,212,255,0.5));
  animation: pulse-glow 3s ease-in-out infinite;
}
.header h1 {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: 3px;
  color: var(--text);
  margin: 4px 0 0;
}
.header h1 .accent {
  background: linear-gradient(90deg, var(--accent-cyan), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.tagline {
  display: block;
  font-size: 0.78rem;
  font-weight: 400;
  letter-spacing: 4px;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-top: 2px;
}

@keyframes pulse-glow {
  0%, 100% { filter: drop-shadow(0 0 12px rgba(0,212,255,0.5)); }
  50%      { filter: drop-shadow(0 0 24px rgba(123,47,247,0.7)); }
}

/* ── Mode toggle ──────────────────────────────────────────── */
.mode-toggle {
  display: flex;
  justify-content: center;
  gap: 4px;
  margin: 28px auto 28px;
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border-glass);
  border-radius: 50px;
  padding: 4px;
  width: fit-content;
}
.mode-btn {
  font-family: var(--font);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  padding: 10px 28px;
  border: none;
  border-radius: 46px;
  cursor: pointer;
  transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  color: var(--text-muted);
  background: transparent;
  display: flex;
  align-items: center;
  gap: 8px;
}
.mode-btn:hover { color: var(--text); }
.mode-btn.active {
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-purple));
  color: #fff;
  box-shadow: var(--glow-cyan);
}
.mode-icon { font-size: 1.05rem; }

/* ── Glass card ───────────────────────────────────────────── */
.glass-card {
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 20px;
}
.glass-card h3 {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--accent-cyan);
  margin-bottom: 18px;
}

/* ── Panel switching ──────────────────────────────────────── */
.panel {
  display: none;
  animation: fadeSlideIn 0.4s ease;
}
.panel.active { display: block; }

@keyframes fadeSlideIn {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ── Layout grid (settings sidebar + main area) ──────────── */
.panel-grid {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 20px;
  align-items: start;
}
@media (max-width: 740px) {
  .panel-grid { grid-template-columns: 1fr; }
}

/* ── Settings ─────────────────────────────────────────────── */
.setting { margin-bottom: 18px; }
.setting label {
  display: block;
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 8px;
}
.setting .slider-row {
  display: flex;
  align-items: center;
  gap: 12px;
}
.setting input[type=range] {
  -webkit-appearance: none;
  appearance: none;
  flex: 1;
  height: 4px;
  background: rgba(255,255,255,0.1);
  border-radius: 4px;
  outline: none;
}
.setting input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px; height: 16px;
  border-radius: 50%;
  background: var(--accent-cyan);
  box-shadow: 0 0 8px rgba(0,212,255,0.5);
  cursor: pointer;
  transition: transform 0.15s;
}
.setting input[type=range]::-webkit-slider-thumb:hover {
  transform: scale(1.25);
}
.slider-val {
  font-family: var(--mono);
  font-size: 0.82rem;
  color: var(--accent-cyan);
  min-width: 62px;
  text-align: right;
}

/* ── Select input (camera picker, etc.) ───────────────────── */
.select-input {
  width: 100%;
  font-family: var(--font);
  font-size: 0.82rem;
  padding: 10px 14px;
  background: rgba(0,0,0,0.3);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-sm);
  color: var(--text);
  outline: none;
  cursor: pointer;
  transition: border-color 0.2s;
  -webkit-appearance: none;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%236b7f99' stroke-width='1.5' fill='none'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 32px;
}
.select-input:focus {
  border-color: var(--accent-cyan);
  box-shadow: 0 0 0 2px rgba(0,212,255,0.15);
}
.select-input option {
  background: var(--bg-surface);
  color: var(--text);
}

/* ── Stats grid ───────────────────────────────────────────── */
.stats-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 16px;
}
.stat-card {
  background: rgba(0,0,0,0.25);
  border: 1px solid var(--border-dim);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  text-align: center;
}
.stat-card.wide { grid-column: 1 / -1; }
.stat-card .stat-label {
  display: block;
  font-size: 0.62rem;
  font-weight: 500;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 3px;
}
.stat-card .stat-value {
  font-family: var(--mono);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text);
}
.stat-card.highlight .stat-value {
  background: linear-gradient(90deg, var(--accent-cyan), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ── Dropzone ─────────────────────────────────────────────── */
.dropzone {
  border: 2px dashed rgba(0,212,255,0.25);
  border-radius: var(--radius);
  padding: 60px 24px;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s;
  position: relative;
  overflow: hidden;
}
.dropzone::before {
  content: '';
  position: absolute; inset: 0;
  background: radial-gradient(circle at center, rgba(0,212,255,0.05) 0%, transparent 70%);
  opacity: 0; transition: opacity 0.3s;
}
.dropzone:hover, .dropzone.drag-over {
  border-color: var(--accent-cyan);
  background: rgba(0,212,255,0.04);
}
.dropzone:hover::before, .dropzone.drag-over::before { opacity: 1; }
.drop-icon {
  display: block;
  font-size: 2.8rem;
  margin-bottom: 12px;
  filter: drop-shadow(0 0 10px rgba(0,212,255,0.4));
}
.dropzone p { font-size: 0.95rem; color: var(--text-muted); }
.drop-hint {
  display: block;
  font-size: 0.72rem;
  color: var(--text-dim);
  margin-top: 8px;
}

/* ── File info ────────────────────────────────────────────── */
.file-info {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  padding: 16px 20px;
  background: rgba(0,212,255,0.06);
  border: 1px solid rgba(0,212,255,0.15);
  border-radius: var(--radius-sm);
  margin-bottom: 16px;
}
.file-icon { font-size: 1.6rem; }
.file-meta { flex: 1; min-width: 0; }
.file-name {
  display: block;
  font-weight: 600;
  font-size: 0.92rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.file-size { font-size: 0.78rem; color: var(--text-muted); }

/* ── Buttons ──────────────────────────────────────────────── */
.btn {
  font-family: var(--font);
  font-weight: 600;
  font-size: 0.82rem;
  letter-spacing: 1px;
  text-transform: uppercase;
  border: none;
  border-radius: 50px;
  padding: 12px 28px;
  cursor: pointer;
  transition: all 0.25s;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}
.btn-primary {
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
  color: #fff;
  box-shadow: 0 4px 20px rgba(0,212,255,0.25);
}
.btn-primary:hover {
  box-shadow: var(--glow-cyan);
  transform: translateY(-1px);
}
.btn-primary:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}
.btn-secondary {
  background: rgba(255,255,255,0.07);
  color: var(--text);
  border: 1px solid var(--border-glass);
}
.btn-secondary:hover {
  background: rgba(255,255,255,0.12);
}
.btn-danger {
  background: rgba(255,51,102,0.15);
  color: var(--danger);
  border: 1px solid rgba(255,51,102,0.25);
}
.btn-danger:hover { background: rgba(255,51,102,0.25); }
.btn-success {
  background: linear-gradient(135deg, var(--success), #00cc6a);
  color: #000;
  box-shadow: 0 4px 20px rgba(0,255,136,0.25);
}
.btn-success:hover {
  box-shadow: var(--glow-success);
  transform: translateY(-1px);
}
.btn-block { width: 100%; justify-content: center; }

/* ── Grid container ───────────────────────────────────────── */
.grid-container {
  position: relative;
  display: flex;
  justify-content: center;
  padding: 8px 0;
}
.grid-container canvas {
  border-radius: 6px;
  box-shadow: var(--glow-cyan), 0 0 80px rgba(0,212,255,0.06);
  max-width: 100%;
}
.frame-counter {
  position: absolute;
  bottom: 16px;
  left: 50%;
  transform: translateX(-50%);
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--text-dim);
  background: rgba(0,0,0,0.6);
  padding: 4px 12px;
  border-radius: 20px;
  backdrop-filter: blur(8px);
}

/* ── Transmit controls ────────────────────────────────────── */
.transmit-controls {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-top: 16px;
}

/* ── Camera container (square for grid alignment) ─────────── */
.camera-container {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  background: #000;
  aspect-ratio: 1 / 1;
  max-width: 600px;
  margin: 0 auto 20px;
}
.camera-container video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.camera-container canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}
.camera-status {
  position: absolute;
  bottom: 12px;
  left: 50%;
  transform: translateX(-50%);
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--accent-cyan);
  background: rgba(0,0,0,0.7);
  padding: 5px 16px;
  border-radius: 20px;
  backdrop-filter: blur(8px);
  white-space: nowrap;
}

/* ── Alignment guide (when camera active but no grid detected) */
.alignment-guide {
  position: absolute;
  inset: 15%;
  border: 2px dashed rgba(0,212,255,0.3);
  border-radius: 8px;
  pointer-events: none;
  animation: align-pulse 2s ease-in-out infinite;
}
@keyframes align-pulse {
  0%, 100% { border-color: rgba(0,212,255,0.3); }
  50%      { border-color: rgba(0,212,255,0.6); }
}

/* ── Progress bar ─────────────────────────────────────────── */
.progress-bar {
  width: 100%;
  height: 8px;
  background: rgba(255,255,255,0.06);
  border-radius: 8px;
  overflow: hidden;
  margin: 12px 0;
}
.progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent-cyan), var(--accent-purple));
  border-radius: 8px;
  transition: width 0.3s ease;
  box-shadow: 0 0 12px rgba(0,212,255,0.4);
}
.progress-text {
  font-family: var(--mono);
  font-size: 0.82rem;
  color: var(--text-muted);
  text-align: center;
  margin-bottom: 4px;
}
.progress-stats {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--text-dim);
  text-align: center;
}

/* ── Download panel ───────────────────────────────────────── */
.download-panel {
  text-align: center;
  padding: 28px;
  background: rgba(0,255,136,0.04);
  border: 1px solid rgba(0,255,136,0.15);
  border-radius: var(--radius);
}
.download-panel h3 {
  color: var(--success);
  font-size: 1.1rem;
  margin-bottom: 6px;
}
.download-info {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 16px;
}

/* ── Receive controls ─────────────────────────────────────── */
.receive-controls {
  display: flex;
  gap: 12px;
  margin-top: 12px;
}

/* ── Toast ────────────────────────────────────────────────── */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 9999;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.toast {
  font-family: var(--font);
  font-size: 0.82rem;
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  background: var(--bg-card);
  border: 1px solid var(--border-glass);
  backdrop-filter: blur(16px);
  color: var(--text);
  box-shadow: 0 8px 32px rgba(0,0,0,0.4);
  animation: toastIn 0.35s ease, toastOut 0.35s ease 2.5s forwards;
}
.toast.error { border-color: rgba(255,51,102,0.4); color: var(--danger); }

@keyframes toastIn {
  from { opacity: 0; transform: translateX(30px); }
  to   { opacity: 1; transform: translateX(0); }
}
@keyframes toastOut {
  from { opacity: 1; }
  to   { opacity: 0; transform: translateY(10px); }
}

/* ── Utilities ────────────────────────────────────────────── */
.hidden  { display: none !important; }
.mt-12   { margin-top: 12px; }
.mt-16   { margin-top: 16px; }
.mt-20   { margin-top: 20px; }
.text-center { text-align: center; }

/* ── Scanning animation ──────────────────────────────────── */
.scanning-indicator {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  margin: 12px 0;
}
.scanning-indicator .dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent-cyan);
  animation: scan-blink 1.4s ease-in-out infinite;
}
.scanning-indicator .dot:nth-child(2) { animation-delay: 0.2s; }
.scanning-indicator .dot:nth-child(3) { animation-delay: 0.4s; }
@keyframes scan-blink {
  0%, 80%, 100% { opacity: 0.2; transform: scale(0.8); }
  40%           { opacity: 1;   transform: scale(1.2); }
}

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 480px) {
  .app { padding: 16px 12px 48px; }
  .header h1 { font-size: 1.5rem; letter-spacing: 2px; }
  .mode-btn { padding: 8px 18px; font-size: 0.72rem; }
  .glass-card { padding: 16px; }
}