:root {
  --bg: #ffffff;
  --surface: #ffffff;
  --surface2: #f5f4ff;
  --border: #e4e2f5;
  --border-hover: #b8b3e8;
  --accent: #5b4fe9;
  --accent-glow: rgba(91, 79, 233, 0.10);
  --accent-dim: rgba(91, 79, 233, 0.30);
  --text: #16113a;
  --text-muted: #5e587a;
  --text-dim: #a39ec4;
  --success: #00a86b;
  --error: #e8354a;
  --warning: #e07b00;
  --font-display: 'Syne', sans-serif;
  --font-mono: 'DM Mono', monospace;
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-display);
  min-height: 100vh;
  line-height: 1.6;
  overflow-x: hidden;
}

/* Background grid */
.bg-grid {
  position: fixed;
  inset: 0;
  background-image:
    linear-gradient(rgba(91, 79, 233, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(91, 79, 233, 0.06) 1px, transparent 1px);
  background-size: 40px 40px;
  opacity: 1;
  pointer-events: none;
  z-index: 0;
}

/* Header */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 32px;
  background: rgba(255, 255, 255, 0.90);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--text);
}

.header-tag {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-muted);
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 4px 10px;
  border-radius: 20px;
}

/* Main layout */
.main {
  position: relative;
  z-index: 1;
  max-width: 720px;
  margin: 0 auto;
  padding: 40px 24px 80px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

/* Cards */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: border-color var(--transition), box-shadow var(--transition);
  box-shadow: 0 1px 4px rgba(0,0,0,0.06);
}
.card:hover { border-color: var(--border-hover); box-shadow: 0 4px 16px rgba(0,0,0,0.09); }

/* Step labels */
.step-label {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.2px;
}
.step-num {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  color: #3d2fd4;
  background: var(--accent-glow);
  border: 1px solid var(--accent-dim);
  padding: 2px 8px;
  border-radius: 20px;
}

.section-hint {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 16px;
  font-family: var(--font-mono);
}

.optional-tag {
  font-size: 11px;
  font-weight: 400;
  color: var(--text-muted);
  background: var(--surface2);
  border: 1px solid var(--border);
  padding: 2px 8px;
  border-radius: 20px;
  margin-left: 8px;
  vertical-align: middle;
}

/* Tabs */
.tabs {
  display: flex;
  gap: 4px;
  margin-bottom: 20px;
  background: var(--surface2);
  padding: 4px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}
.tab {
  flex: 1;
  padding: 8px 16px;
  border: none;
  border-radius: 6px;
  background: transparent;
  color: var(--text-muted);
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
}
.tab.active {
  background: var(--accent);
  color: #ffffff;
  box-shadow: 0 2px 12px var(--accent-glow);
}
.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* Dropzone */
.dropzone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 48px 24px;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition);
  background: var(--surface2);
}
.dropzone:hover, .dropzone.drag-over {
  border-color: var(--accent);
  background: var(--accent-glow);
}
.drop-icon { margin-bottom: 12px; }
.drop-text {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 6px;
}
.link-text {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 3px;
  cursor: pointer;
}
.drop-hint {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-muted);
}

/* Preview */
.preview-area {
  display: flex;
  align-items: center;
  gap: 16px;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 16px;
}
.preview-area img {
  width: 64px;
  height: 64px;
  object-fit: cover;
  border-radius: 8px;
  border: 1px solid var(--border);
}
.preview-info {
  flex: 1;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}
.preview-info span {
  font-size: 13px;
  color: var(--text-muted);
  font-family: var(--font-mono);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.hidden { display: none !important; }

/* URL input */
.url-input-wrap {
  display: flex;
  gap: 10px;
}
.input-field {
  flex: 1;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 13px;
  outline: none;
  transition: border-color var(--transition);
}
.input-field:focus { border-color: var(--accent); }
.input-full { width: 100%; }

/* Toggle group (fold) */
.toggle-group {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}
.toggle-option {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  background: var(--surface2);
}
.toggle-option.active {
  border-color: var(--accent);
  background: var(--accent-glow);
}
.toggle-option:hover { border-color: var(--border-hover); }
.toggle-option.active:hover { border-color: var(--accent); }
.toggle-icon { flex-shrink: 0; }
.toggle-title { font-size: 14px; font-weight: 700; }
.toggle-desc { font-size: 11px; color: var(--text-muted); font-family: var(--font-mono); margin-top: 2px; }

/* Device checkboxes */
.checkbox-group {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}
.check-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 16px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  text-align: center;
  background: var(--surface2);
  color: var(--text-muted);
}
.check-card.active {
  border-color: var(--accent);
  color: var(--text);
  background: var(--accent-glow);
}
.check-card:hover { border-color: var(--border-hover); }
.check-card.active:hover { border-color: var(--accent); }
.check-card span { font-size: 13px; font-weight: 700; }
.check-card small { font-size: 11px; color: var(--text-muted); font-family: var(--font-mono); }

/* Format list */
.format-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.format-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 12px 16px;
  background: var(--surface2);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: grab;
  transition: all var(--transition);
  opacity: 0.45;
}
.format-item.active {
  opacity: 1;
  border-color: var(--border-hover);
}
.format-item.dragging {
  opacity: 0.3;
  border-style: dashed;
}
.format-item.drag-target { border-color: var(--accent); background: var(--accent-glow); }
.drag-handle {
  color: var(--text-dim);
  font-size: 16px;
  user-select: none;
  cursor: grab;
}
.format-badge {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  padding: 3px 8px;
  border-radius: 4px;
  min-width: 46px;
  text-align: center;
}
.format-badge.avif { background: rgba(103, 58, 183, 0.08); color: #5e35b1; border: 1px solid rgba(103, 58, 183, 0.2); }
.format-badge.webp { background: rgba(0, 150, 136, 0.08); color: #00796b; border: 1px solid rgba(0, 150, 136, 0.25); }
.format-badge.jpeg { background: rgba(230, 81, 0, 0.08); color: #bf360c; border: 1px solid rgba(230, 81, 0, 0.2); }
.format-badge.png  { background: rgba(21, 101, 192, 0.08); color: #1565c0; border: 1px solid rgba(21, 101, 192, 0.2); }
.format-desc { flex: 1; font-size: 13px; color: var(--text-muted); }

/* Format toggle switch */
.fmt-toggle { position: relative; display: inline-block; width: 36px; height: 20px; flex-shrink: 0; }
.fmt-toggle input { opacity: 0; width: 0; height: 0; }
.fmt-switch {
  position: absolute;
  inset: 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 20px;
  cursor: pointer;
  transition: all var(--transition);
}
.fmt-switch::after {
  content: '';
  position: absolute;
  left: 3px; top: 3px;
  width: 12px; height: 12px;
  background: var(--text-muted);
  border-radius: 50%;
  transition: all var(--transition);
}
.fmt-toggle input:checked + .fmt-switch { background: var(--accent); border-color: var(--accent); }
.fmt-toggle input:checked + .fmt-switch::after { left: 19px; background: #ffffff; }

/* Sizes */
.sizes-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}
.size-field label {
  display: block;
  font-size: 12px;
  font-family: var(--font-mono);
  color: var(--text-muted);
  margin-bottom: 6px;
}
.input-px {
  display: flex;
  align-items: center;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: border-color var(--transition);
}
.input-px:focus-within { border-color: var(--accent); }
.input-px input {
  flex: 1;
  background: transparent;
  border: none;
  padding: 9px 12px;
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 13px;
  outline: none;
  width: 0;
}
.input-px span {
  padding: 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text-muted);
  border-left: 1px solid var(--border);
}

/* Variant counter */
.variant-counter {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
}
.counter-inner {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}
.counter-num {
  font-family: var(--font-mono);
  font-size: 24px;
  font-weight: 500;
  color: var(--accent);
  min-width: 2.5ch;
}
.counter-label {
  font-size: 13px;
  color: var(--text-muted);
  flex: 1;
}
.counter-bar {
  width: 100%;
  height: 3px;
  background: var(--surface2);
  border-radius: 3px;
  overflow: hidden;
  margin-top: 8px;
}
.counter-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 3px;
  transition: width 0.4s ease, background 0.3s ease;
}
.counter-num.warn { color: var(--error); }
.counter-fill.warn { background: var(--error); }

/* Buttons */
.btn-accent {
  background: var(--accent);
  color: #ffffff;
  border: none;
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}
.btn-accent:hover { background: #4338ca; box-shadow: 0 0 20px var(--accent-glow); }

.btn-ghost {
  background: transparent;
  color: var(--text-muted);
  border: 1px solid var(--border);
  padding: 9px 16px;
  border-radius: var(--radius-sm);
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
}
.btn-ghost:hover { border-color: var(--border-hover); color: var(--text); }
.btn-sm { padding: 5px 10px; font-size: 12px; }
.btn-full { width: 100%; margin-top: 16px; }

.generate-wrap {
  text-align: center;
  padding: 8px 0;
}
.btn-generate {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: var(--accent);
  color: #ffffff;
  border: none;
  padding: 16px 40px;
  border-radius: 40px;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--transition);
  letter-spacing: 0.3px;
  box-shadow: 0 4px 20px rgba(91, 79, 233, 0.30);
}
.btn-generate:hover {
  background: #4338ca;
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(91, 79, 233, 0.40);
}
.btn-generate:active { transform: translateY(0); }
.btn-generate:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}
.generate-note {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-muted);
}

/* Result area */
.result-area {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  text-align: center;
  box-shadow: 0 1px 4px rgba(0,0,0,0.06);
}
.progress-block { display: flex; flex-direction: column; align-items: center; gap: 16px; }
.progress-spinner {
  width: 36px; height: 36px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
#progress-text { font-size: 14px; color: var(--text-muted); font-family: var(--font-mono); }

.success-block, .error-block { display: flex; flex-direction: column; align-items: center; gap: 12px; }
.success-icon {
  width: 52px; height: 52px;
  background: rgba(0, 168, 107, 0.10);
  border: 2px solid var(--success);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 20px;
  color: var(--success);
}
.success-block h3 { font-size: 18px; font-weight: 700; }
.success-block > p { font-size: 13px; color: var(--text-muted); }

.error-icon {
  width: 52px; height: 52px;
  background: rgba(255, 94, 110, 0.15);
  border: 2px solid var(--error);
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 20px;
  color: var(--error);
}
#error-msg { font-size: 14px; color: var(--text); max-width: 400px; }

/* HTML output */
.html-output-wrap {
  width: 100%;
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  text-align: left;
  margin-top: 8px;
}
.html-output-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  font-size: 12px;
  color: var(--text-muted);
  font-family: var(--font-mono);
}
.html-output {
  padding: 16px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  color: #4338ca;
  white-space: pre-wrap;
  word-break: break-all;
  max-height: 300px;
  overflow-y: auto;
  line-height: 1.7;
}
.btn-copy {
  background: var(--accent-glow);
  border: 1px solid var(--accent-dim);
  color: var(--accent);
  padding: 4px 12px;
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 11px;
  cursor: pointer;
  transition: all var(--transition);
}
.btn-copy:hover { background: var(--accent); color: #ffffff; }
.btn-copy.copied { background: var(--success); border-color: var(--success); color: #fff; }

/* Footer */
.footer {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 20px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--surface2); }
::-webkit-scrollbar-thumb { background: var(--border-hover); border-radius: 3px; }

/* Responsive */
@media (max-width: 600px) {
  .header { padding: 12px 16px; }
  .main { padding: 24px 16px 60px; gap: 12px; }
  .card { padding: 20px; }
  .toggle-group { grid-template-columns: 1fr; }
  .checkbox-group { grid-template-columns: repeat(3, 1fr); }
  .sizes-grid { grid-template-columns: 1fr; }
  .btn-generate { padding: 14px 28px; font-size: 15px; }
  .html-output { font-size: 10px; }
}