:root {
  /* Light Mode (Default) */
  --bg-color: #f9fafb;
  --bg-gradient: radial-gradient(circle at 50% -20%, rgba(0,0,0,0.03) 0%, transparent 60%);
  --card-bg: #ffffff;
  --card-border: #e5e7eb;
  --card-shadow: 0 10px 25px rgba(0, 0, 0, 0.05);
  --text-primary: #111827;
  --text-secondary: #6b7280;
  --accent-color: #000000;
  --accent-text: #ffffff;
  --accent-hover: #333333;
  --success-color: #10b981;
  --success-bg: rgba(16, 185, 129, 0.1);
  --success-border: rgba(16, 185, 129, 0.2);
  --error-color: #ef4444;
  --error-bg: rgba(239, 68, 68, 0.1);
  --error-border: rgba(239, 68, 68, 0.2);
  --input-bg: #ffffff;
  --input-border: #d1d5db;
  --input-focus: #9ca3af;
  --input-placeholder: #9ca3af;
  --icon-bg: #f3f4f6;
  --icon-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

body.dark {
  /* Dark Mode */
  --bg-color: #000000;
  --bg-gradient: radial-gradient(circle at 50% -20%, rgba(255,255,255,0.08) 0%, transparent 60%);
  --card-bg: rgba(255, 255, 255, 0.03);
  --card-border: rgba(255, 255, 255, 0.08);
  --card-shadow: 0 20px 40px rgba(0, 0, 0, 0.4);
  --text-primary: #ededed;
  --text-secondary: #a1a1aa;
  --accent-color: #ffffff;
  --accent-text: #000000;
  --accent-hover: #e5e5e5;
  --success-color: #34d399;
  --success-bg: rgba(52, 211, 153, 0.1);
  --success-border: rgba(52, 211, 153, 0.2);
  --error-color: #f87171;
  --error-bg: rgba(248, 113, 113, 0.1);
  --error-border: rgba(248, 113, 113, 0.2);
  --input-bg: rgba(255, 255, 255, 0.03);
  --input-border: rgba(255, 255, 255, 0.1);
  --input-focus: rgba(255, 255, 255, 0.2);
  --input-placeholder: #555555;
  --icon-bg: rgba(255, 255, 255, 0.04);
  --icon-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  background-color: var(--bg-color);
  background-image: var(--bg-gradient);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
  width: 100%;
  max-width: 400px;
}

.header {
  text-align: center;
  margin-bottom: 32px;
  position: relative;
  animation: fadeInDown 0.6s ease-out;
}

.header-controls {
  position: absolute;
  top: 0;
  right: 0;
  display: flex;
  align-items: center;
  gap: 8px;
}

.lang-toggle-btn, .theme-toggle-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 8px;
  border-radius: 8px;
  display: flex;
  justify-content: center;
  align-items: center;
  transition: all 0.2s ease;
  font-family: inherit;
  font-size: 12px;
  font-weight: 600;
  outline: none;
}

.lang-toggle-btn {
  appearance: none;
  -webkit-appearance: none;
  padding-right: 12px;
}

.lang-toggle-btn option {
  background: var(--card-bg);
  color: var(--text-primary);
}

.lang-toggle-btn:hover, .theme-toggle-btn:hover {
  background: var(--icon-bg);
  color: var(--text-primary);
}

.logo-circle {
  width: 48px;
  height: 48px;
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 0 auto 12px;
  color: var(--text-primary);
  background: var(--icon-bg);
  border-radius: 12px;
  border: 1px solid var(--card-border);
  box-shadow: var(--icon-shadow);
  transition: all 0.3s ease;
}

.tool-name {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1.5px;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.version-badge {
  display: inline-block;
  background-color: var(--icon-bg);
  color: var(--text-secondary);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 9px;
  font-weight: 600;
  vertical-align: middle;
  margin-left: 4px;
  border: 1px solid var(--card-border);
}

.header h1 {
  font-size: 22px;
  font-weight: 500;
  letter-spacing: -0.02em;
  margin-bottom: 6px;
}

.header p {
  color: var(--text-secondary);
  font-size: 14px;
}

.card {
  position: relative;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  padding: 32px;
  backdrop-filter: blur(16px);
  box-shadow: var(--card-shadow);
  animation: fadeInUp 0.6s ease-out 0.1s both;
  transition: all 0.3s ease;
}

.btn-back {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  cursor: pointer;
  transition: color 0.2s;
  margin-bottom: 20px;
}

.btn-back:hover {
  color: var(--text-primary);
}

/* WIZARD STEPPER */
.wizard-stepper {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 32px;
  padding: 0 10px;
  position: relative;
}

.step-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  position: relative;
  z-index: 2;
  gap: 8px;
  width: 60px;
}

.step-circle {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--input-bg);
  border: 2px solid var(--border-color);
  display: flex;
  justify-content: center;
  align-items: center;
  font-weight: bold;
  color: var(--text-secondary);
  font-size: 14px;
  transition: all 0.3s ease;
}

.step-item.active .step-circle {
  background: var(--accent-color);
  border-color: var(--accent-color);
  color: var(--accent-text);
  box-shadow: 0 0 15px rgba(0, 0, 0, 0.2);
}

.step-item.completed .step-circle {
  background: var(--success-color);
  border-color: var(--success-color);
  color: white;
}

.step-label {
  font-size: 11px;
  color: var(--text-secondary);
  text-align: center;
  font-weight: 600;
  transition: color 0.3s ease;
}

.step-item.active .step-label,
.step-item.completed .step-label {
  color: var(--text-primary);
}

.step-line {
  flex-grow: 1;
  height: 2px;
  background: var(--border-color);
  margin-top: 15px;
  z-index: 1;
  transition: background 0.3s ease;
}

.step-line.completed {
  background: var(--success-color);
}

.form-group-row {
  display: flex;
  gap: 12px;
}

.flex-1 { flex: 1; }
.flex-2 { flex: 2; }

.form-group {
  margin-bottom: 20px;
}

label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  margin-bottom: 8px;
  color: var(--text-secondary);
}

input, select {
  width: 100%;
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  color: var(--text-primary);
  padding: 12px 16px;
  border-radius: 10px;
  font-size: 14px;
  font-family: inherit;
  transition: all 0.2s ease;
  outline: none;
}

input::placeholder {
  color: var(--input-placeholder);
}

input:focus, select:focus {
  border-color: var(--input-focus);
}

body.dark input:focus, body.dark select:focus {
  background: rgba(255, 255, 255, 0.05);
}

.status-text {
  font-size: 12px;
  margin-top: 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.status-text.success { color: var(--success-color); }
.status-text.error { color: var(--error-color); }

.btn {
  width: 100%;
  padding: 12px;
  border: none;
  border-radius: 10px;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  transition: all 0.2s ease;
  margin-top: 8px;
}

.primary-btn {
  background: var(--accent-color);
  color: var(--accent-text);
}

.primary-btn:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
}

.primary-btn:active {
  transform: translateY(0);
}

.primary-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.hidden {
  display: none !important;
}

/* Progress Area */
.progress-container {
  text-align: center;
  animation: fadeIn 0.4s ease;
  padding: 10px 0;
}

.progress-container h3 {
  font-size: 16px;
  font-weight: 500;
  margin-bottom: 4px;
}

.progress-container p {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 20px;
}

.progress-bar-wrapper {
  height: 4px;
  background-color: var(--input-bg);
  border-radius: 2px;
  overflow: hidden;
  margin-bottom: 16px;
  border: 1px solid var(--card-border);
}

.progress-bar {
  height: 100%;
  background: var(--accent-color);
  width: 0%;
  transition: width 0.3s ease;
  position: relative;
}

.progress-stats {
  font-size: 20px;
  font-weight: 500;
  letter-spacing: -0.03em;
}

.alert {
  margin-top: 20px;
  padding: 12px;
  border-radius: 10px;
  font-size: 13px;
  animation: fadeIn 0.3s ease;
  text-align: center;
}

.alert.success {
  background-color: var(--success-bg);
  color: var(--success-color);
  border: 1px solid var(--success-border);
}

.alert.error {
  background-color: var(--error-bg);
  color: var(--error-color);
  border: 1px solid var(--error-border);
}

/* Animations */
@keyframes fadeInDown {
  from { opacity: 0; transform: translateY(-10px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@media (max-width: 480px) {
  .card {
    padding: 24px;
    border-radius: 12px;
  }
}

/* Wizard Styles */
.wizard-step {
  animation: fadeIn 0.4s ease;
}

.text-center { text-align: center; }
.mt-2 { margin-top: 8px; }
.mt-4 { margin-top: 16px; }

.step-desc {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 20px;
  line-height: 1.5;
}

/* Step 1: Models Grid */
.models-grid {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 16px;
}

.model-card {
  display: flex;
  align-items: center;
  padding: 12px 16px;
  border: 1px solid var(--input-border);
  border-radius: 10px;
  cursor: pointer;
  background: var(--input-bg);
  transition: all 0.2s ease;
}

.model-card:hover {
  border-color: var(--input-focus);
}

.model-card.selected {
  border-color: var(--success-color);
  background: var(--success-bg);
}

.model-img {
  width: 48px;
  height: 48px;
  object-fit: cover;
  border-radius: 6px;
  margin-right: 12px;
  background: var(--icon-bg);
}

.model-info {
  flex: 1;
}

.model-name {
  font-weight: 500;
  font-size: 14px;
}

.model-firmware {
  font-size: 11px;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* Step 2: LED Verification */
.led-illustration {
  display: flex;
  justify-content: center;
  align-items: center;
  margin-bottom: 24px;
  height: 60px;
}

.led-dot-only {
  width: 16px;
  height: 16px;
  background-color: var(--success-color);
  border-radius: 50%;
  box-shadow: 0 0 15px var(--success-color);
  animation: pulse-green 2s infinite;
}

@keyframes pulse-green {
  0% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7); }
  70% { box-shadow: 0 0 0 15px rgba(16, 185, 129, 0); }
  100% { box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.btn-group {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.secondary-btn {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--card-border);
}

.secondary-btn:hover {
  background: var(--icon-bg);
}

/* Step 3: QR Scanner */
.qr-scanner-container {
  display: flex;
  flex-direction: column;
  align-items: center;
}

#qr-reader-wrapper {
  position: relative;
  width: 100%;
  max-width: 320px;
  border-radius: 16px;
  overflow: hidden;
  margin-bottom: 16px;
  background: #000;
  box-shadow: 0 10px 25px rgba(0,0,0,0.2);
}

.qr-reader {
  width: 100%;
  aspect-ratio: 1; /* Square */
}

/* Force the video inside html5-qrcode to fill the square */
.qr-reader video {
  width: 100% !important;
  height: 100% !important;
  object-fit: cover !important;
}

/* Hide the ugly default borders of html5-qrcode */
.qr-reader > div {
  border: none !important;
}

/* Overlay scan line animation */
.scan-overlay {
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  border: 2px solid rgba(16, 185, 129, 0.5);
  border-radius: 16px;
  pointer-events: none;
  z-index: 10;
}

.scan-overlay::after {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; height: 3px;
  background: var(--success-color);
  box-shadow: 0 0 15px var(--success-color);
  animation: scan-line 2s infinite linear;
}

@keyframes scan-line {
  0% { transform: translateY(0); opacity: 0; }
  10% { opacity: 1; }
  90% { opacity: 1; }
  100% { transform: translateY(100%); opacity: 0; }
}

.qr-btn {
  font-size: 15px;
  padding: 14px;
}

.btn-small {
  padding: 8px 16px;
  font-size: 12px;
  margin: 12px auto 0;
  display: block;
}

.divider {
  display: flex;
  align-items: center;
  text-align: center;
  margin: 24px 0;
  color: var(--text-secondary);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.divider::before, .divider::after {
  content: '';
  flex: 1;
  border-bottom: 1px solid var(--card-border);
}

.divider span {
  padding: 0 10px;
}

/* Step 4: Circular Progress */
.circular-progress-wrapper {
  position: relative;
  width: 120px;
  height: 120px;
  margin: 0 auto 20px;
}

.circular-progress {
  width: 100%;
  height: 100%;
  transform: rotate(-90deg);
}

.circular-bg {
  fill: none;
  stroke: var(--input-bg);
  stroke-width: 8;
}

.circular-value {
  fill: none;
  stroke: var(--success-color);
  stroke-width: 8;
  stroke-dasharray: 283; /* 2 * pi * 45 */
  stroke-dashoffset: 283;
  transition: stroke-dashoffset 0.5s ease;
  stroke-linecap: round;
}

.progress-stats {
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  font-weight: 600;
  color: var(--text-primary);
}

#success-check {
  transform: rotate(90deg) translate(0px, -100px);
  transform-origin: center;
  animation: drawCheck 0.5s ease forwards;
}

@keyframes drawCheck {
  from { stroke-dasharray: 0, 100; }
  to { stroke-dasharray: 100, 100; }
}

/* Pulsing Glow for 100% Waiting State */
.pulsing-glow {
  animation: pulseGlow 2s infinite ease-in-out;
}

@keyframes pulseGlow {
  0% { filter: drop-shadow(0 0 2px var(--success-color)); }
  50% { filter: drop-shadow(0 0 15px var(--success-color)); }
  100% { filter: drop-shadow(0 0 2px var(--success-color)); }
}

.waiting-messages-fade {
  animation: fadeInOut 3s infinite;
}

@keyframes fadeInOut {
  0% { opacity: 0; transform: translateY(5px); }
  20% { opacity: 1; transform: translateY(0); }
  80% { opacity: 1; transform: translateY(0); }
  100% { opacity: 0; transform: translateY(-5px); }
}

/* Square QR Scanner Button */
.qr-scan-square-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 150px;
  height: 150px;
  margin: 16px auto;
  border-radius: 24px;
  background: var(--card-bg);
  color: var(--text-primary);
  border: 2px dashed var(--accent-color);
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 4px 12px rgba(0,0,0,0.05);
  gap: 12px;
}

.qr-scan-square-btn:hover {
  transform: translateY(-4px) scale(1.02);
  box-shadow: 0 12px 24px rgba(16, 185, 129, 0.2);
  background: var(--success-bg);
  border-color: var(--success-color);
  color: var(--success-color);
}

.qr-scan-square-btn:active {
  transform: translateY(0) scale(0.98);
}

.qr-scan-square-btn svg {
  width: 48px !important;
  height: 48px !important;
  stroke-width: 1.5;
  transition: all 0.3s ease;
}

.qr-scan-square-btn:hover svg {
  stroke: var(--success-color);
}

.qr-scan-square-btn span {
  font-size: 13px;
  font-weight: 600;
  text-align: center;
  line-height: 1.3;
  padding: 0 10px;
}