/* ========== RESET & BASE ========== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #09090B;
  --surface: #141419;
  --surface2: #1C1C24;
  --border: #27272A;
  --border-hover: #3F3F46;
  --text: #FAFAFA;
  --text-muted: #A1A1AA;
  --primary: #06B6D4;
  --primary-glow: rgba(6, 182, 212, 0.15);
  --accent: #8B5CF6;
  --accent-glow: rgba(139, 92, 246, 0.15);
  --gradient: linear-gradient(135deg, #06B6D4, #8B5CF6);
  --error: #EF4444;
  --success: #22C55E;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
  --font: 'Inter', system-ui, -apple-system, sans-serif;
}

/* Font loaded via <link> tag in HTML */

html {
  font-size: 16px;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 0 20px;
  -webkit-font-smoothing: antialiased;
}

/* ========== HEADER / BRAND ========== */
.header {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 40px 0 12px;
}

.logo {
  width: 44px;
  height: 44px;
  flex-shrink: 0;
}

.brand {
  font-size: 1.75rem;
  font-weight: 700;
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.02em;
}

.tagline {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 36px;
}

/* ========== MAIN CARD ========== */
.card {
  width: 100%;
  max-width: 520px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
}

/* ========== INPUT ROW ========== */
.input-group {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
}

.input-group input {
  flex: 1;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  color: var(--text);
  font-size: 0.95rem;
  font-family: var(--font);
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.input-group input::placeholder {
  color: var(--text-muted);
  opacity: 0.6;
}

.input-group input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-glow);
}

.btn-primary {
  background: var(--gradient);
  border: none;
  color: #fff;
  font-weight: 600;
  font-size: 0.9rem;
  font-family: var(--font);
  padding: 12px 22px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: opacity 0.2s, transform 0.15s;
  white-space: nowrap;
}

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

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

/* ========== QR DISPLAY ========== */
.qr-area {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  min-height: 200px;
  justify-content: center;
}

.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 40px 0;
  color: var(--text-muted);
}

.empty-state[hidden] {
  display: none !important;
}

#qr-display[hidden] {
  display: none !important;
}

.empty-icon {
  width: 48px;
  height: 48px;
  opacity: 0.3;
  margin-bottom: 4px;
}

.empty-state span {
  font-size: 0.9rem;
}

#qr-display {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  animation: fadeIn 0.3s ease;
}

#qr-canvas {
  max-width: 280px;
  max-height: 280px;
  width: 100%;
  height: auto;
  border-radius: var(--radius-sm);
  /* Checkerboard pattern for transparent bg */
  background-image:
    linear-gradient(45deg, #1a1a24 25%, transparent 25%),
    linear-gradient(-45deg, #1a1a24 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #1a1a24 75%),
    linear-gradient(-45deg, transparent 75%, #1a1a24 75%);
  background-size: 16px 16px;
  background-position: 0 0, 0 8px, 8px -8px, -8px 0px;
  image-rendering: pixelated;
}

#qr-svg-wrap {
  display: none;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(8px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ========== DOWNLOAD BUTTONS ========== */
.dl-row {
  display: flex;
  gap: 10px;
  width: 100%;
  max-width: 280px;
}

.btn-dl {
  flex: 1;
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text);
  font-family: var(--font);
  font-size: 0.85rem;
  font-weight: 500;
  padding: 10px 0;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  transition: border-color 0.2s, background 0.2s;
}

.btn-dl:hover {
  border-color: var(--border-hover);
  background: var(--border);
}

.btn-dl svg {
  width: 16px;
  height: 16px;
}

/* ========== SETTINGS ========== */
.settings {
  margin-top: 20px;
  border-top: 1px solid var(--border);
  padding-top: 20px;
}

.settings-title {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.setting-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 0;
}

.setting-row+.setting-row {
  border-top: 1px solid var(--border);
  padding-top: 12px;
  margin-top: 4px;
}

.setting-label {
  font-size: 0.88rem;
  color: var(--text);
}

/* Toggle switch */
.toggle {
  position: relative;
  width: 44px;
  height: 24px;
}

.toggle input {
  opacity: 0;
  width: 0;
  height: 0;
  position: absolute;
}

.toggle-track {
  position: absolute;
  inset: 0;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 12px;
  cursor: pointer;
  transition: background 0.25s, border-color 0.25s;
}

.toggle-track::after {
  content: '';
  position: absolute;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--text-muted);
  top: 2px;
  left: 2px;
  transition: transform 0.25s, background 0.25s;
}

.toggle input:checked+.toggle-track {
  background: var(--primary);
  border-color: var(--primary);
}

.toggle input:checked+.toggle-track::after {
  transform: translateX(20px);
  background: #fff;
}

/* Select */
.select-wrap select {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  font-family: var(--font);
  font-size: 0.85rem;
  padding: 6px 28px 6px 10px;
  appearance: none;
  cursor: pointer;
  outline: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23A1A1AA' d='M3 5l3 3 3-3'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
  transition: border-color 0.2s;
}

.select-wrap select:hover {
  border-color: var(--border-hover);
}

.select-wrap select:focus {
  border-color: var(--primary);
}

/* Color input */
.color-input {
  display: flex;
  align-items: center;
  gap: 8px;
}

.color-input input[type="color"] {
  -webkit-appearance: none;
  appearance: none;
  width: 32px;
  height: 28px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: transparent;
  cursor: pointer;
  padding: 2px;
}

.color-input input[type="color"]::-webkit-color-swatch-wrapper {
  padding: 0;
}

.color-input input[type="color"]::-webkit-color-swatch {
  border: none;
  border-radius: 4px;
}

/* ========== FEEDBACK ========== */
.feedback {
  font-size: 0.82rem;
  font-weight: 500;
  padding: 8px 14px;
  border-radius: 6px;
  margin-top: 12px;
  text-align: center;
  animation: fadeIn 0.2s ease;
}

.feedback.success {
  background: rgba(34, 197, 94, 0.1);
  color: var(--success);
}

.feedback.error {
  background: rgba(239, 68, 68, 0.1);
  color: var(--error);
}

/* ========== FOOTER ========== */
.footer {
  margin-top: auto;
  padding: 32px 0 24px;
  color: var(--text-muted);
  font-size: 0.78rem;
  opacity: 0.5;
  text-align: center;
}

/* ========== RESPONSIVE ========== */
@media (max-width: 520px) {
  .card {
    padding: 20px;
  }

  .input-group {
    flex-direction: column;
  }

  .btn-primary {
    width: 100%;
  }

  .header {
    padding-top: 28px;
  }

  .brand {
    font-size: 1.5rem;
  }

  #qr-canvas {
    max-width: 240px;
    max-height: 240px;
  }
}

/* ========== AMBIENT GLOW ========== */
body::before {
  content: '';
  position: fixed;
  top: -120px;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 400px;
  background: radial-gradient(ellipse, var(--primary-glow) 0%, transparent 70%);
  pointer-events: none;
  z-index: -1;
}

body::after {
  content: '';
  position: fixed;
  top: -60px;
  right: 20%;
  width: 400px;
  height: 300px;
  background: radial-gradient(ellipse, var(--accent-glow) 0%, transparent 70%);
  pointer-events: none;
  z-index: -1;
}