:root {
  --primary: #6366f1;
  --primary-hover: #4f46e5;
  --bg: #0f172a;
  --card-bg: rgba(30, 41, 59, 0.7);
  --text: #f8fafc;
  --text-muted: #94a3b8;
  --border: rgba(255, 255, 255, 0.1);
  --accent-gradient: linear-gradient(135deg, #6366f1 0%, #a855f7 100%);
  --shadow:
    0 10px 25px -5px rgba(0, 0, 0, 0.3), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
}

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

body {
  font-family: "Inter", sans-serif;
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.6;
  overflow-x: hidden;
}

.app-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

header {
  text-align: center;
  margin-bottom: 3rem;
  animation: fadeInDown 0.8s ease-out;
}

.logo {
  font-family: "Outfit", sans-serif;
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
}

.gradient-text {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.subtitle {
  font-size: 1.1rem;
  color: var(--text-muted);
}

main {
  display: grid;
  grid-template-columns: 1fr 350px;
  gap: 2rem;
  flex-grow: 1;
}

@media (max-width: 1024px) {
  main {
    grid-template-columns: 1fr;
  }
}

.editor-section {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  min-width: 0;
}

#select-btn {
  visibility: hidden;
}

.dropzone {
  width: 100%;
  aspect-ratio: 16 / 9;
  max-height: 70vh;
  min-height: 0;
  background: var(--card-bg);
  border: 2px dashed var(--border);
  border-radius: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  backdrop-filter: blur(12px);
  cursor: pointer;
}

.dropzone.has-image {
  cursor: default;
}

.dropzone.drag-over {
  border-color: var(--primary);
  background: rgba(99, 102, 241, 0.1);
  transform: scale(1.01);
}

.upload-hint {
  text-align: center;
  padding: 2rem;
}

.upload-hint .icon {
  font-size: 3rem;
  margin-bottom: 1rem;
}

.upload-hint h3 {
  margin-bottom: 0.5rem;
  font-size: 1.5rem;
}

.upload-hint p {
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.canvas-container {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: #020617;
  border-radius: 1.5rem;
}

#main-canvas {
  cursor: crosshair;
  display: block;
}

.reset-btn {
  position: absolute;
  top: 1rem;
  right: 1rem;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.5);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.2rem;
  transition: all 0.2s;
  backdrop-filter: blur(4px);
  z-index: 10;
}

.reset-btn:hover {
  background: #ef4444;
  transform: scale(1.1);
}

.zoom-control {
  position: absolute;
  bottom: 1rem;
  right: 1rem;
  background: rgba(15, 23, 42, 0.8);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 2rem;
  padding: 0.25rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  backdrop-filter: blur(8px);
  box-shadow: var(--shadow);
  z-index: 10;
}

.zoom-btn {
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
  color: white;
  border: none;
  cursor: pointer;
  font-size: 1.2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
}

.zoom-btn:hover {
  background: var(--primary);
}

#zoom-level-val {
  font-size: 0.85rem;
  font-weight: 600;
  min-width: 3rem;
  text-align: center;
  color: var(--text);
}

.control-panel {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 1.5rem;
  padding: 1.5rem;
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow);
}

.control-group {
  margin-bottom: 0px;
}

.mt-1 {
  margin-top: 1.5rem;
}

.select-input {
  width: 100%;
  background: #1e293b;
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.75rem 1rem;
  border-radius: 0.75rem;
  font-family: inherit;
  font-size: 0.9rem;
  outline: none;
  cursor: pointer;
  appearance: none;
  transition: all 0.2s;
}

.select-input:focus {
  border-color: var(--primary);
  background-color: #2d3e5a;
}

.control-group label {
  display: block;
  font-weight: 500;
}

.label-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.75rem;
}

#stop-count-val,
#optimize-threshold-val {
  background: #1e293b;
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.25rem 0.5rem;
  border-radius: 0.5rem;
  width: 80px;
  font-weight: 600;
  text-align: center;
  outline: none;
  transition: border-color 0.2s;
}

#stop-count-val:focus,
#optimize-threshold-val:focus {
  border-color: var(--primary);
}

#stop-count-val::-webkit-inner-spin-button,
#stop-count-val::-webkit-outer-spin-button,
#optimize-threshold-val::-webkit-inner-spin-button,
#optimize-threshold-val::-webkit-outer-spin-button {
  -webkit-appearance: none;
  appearance: none;
  margin: 0;
}
#stop-count-val,
#optimize-threshold-val {
  -moz-appearance: textfield;
}

.control-hint {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.5rem;
}

.warning-text {
  color: #fbbf24; /* amber-400 */
  opacity: 0.9;
}


input[type="range"] {
  width: 100%;
  height: 6px;
  background: #334155;
  border-radius: 3px;
  appearance: none;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  appearance: none;
  width: 18px;
  height: 18px;
  background: var(--primary);
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 0 10px rgba(99, 102, 241, 0.5);
  transition: transform 0.2s;
}

.preview-section {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.preview-card,
.output-card {
  position: relative;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 1.5rem;
  padding: 1.5rem;
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow);
}

.preview-card h3,
.output-card h3 {
  font-size: 1.1rem;
  margin-bottom: 1rem;
  color: var(--text-muted);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.copy-btn {
  position: absolute;
  top: 1.25rem;
  right: 1.25rem;
  padding: 0.4rem 0.8rem;
  font-size: 0.75rem;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border);
  color: var(--text-muted);
  border-radius: 0.5rem;
  cursor: pointer;
  transition: all 0.2s;
}

.copy-btn:hover {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

.gradient-preview {
  width: 100%;
  height: 160px;
  border-radius: 1rem;
  border: 1px solid var(--border);
  background: #1e293b;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  position: relative;
}

.preview-segment {
  flex: 1;
  width: 100%;
  position: relative;
  transition: all 0.3s ease;
}

.preview-label {
  position: absolute;
  top: 0.5rem;
  left: 0.5rem;
  background: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(4px);
  padding: 0.2rem 0.5rem;
  border-radius: 0.4rem;
  font-size: 0.65rem;
  font-weight: 600;
  color: var(--text-muted);
  border: 1px solid rgba(255, 255, 255, 0.1);
  pointer-events: none;
  z-index: 5;
}

.preview-label.bottom {
  top: auto;
  bottom: 0.5rem;
}

#svg-output,
#css-output {
  background: #020617;
  padding: 1rem;
  border-radius: 0.75rem;
  font-family: "monospace";
  font-size: 0.85rem;
  color: #94a3b8;
  overflow-x: auto;
  white-space: pre-wrap;
  max-height: 150px;
}

footer {
  margin-top: 3rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.9rem;
  padding-bottom: 1rem;
}

.toast {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  background: var(--primary);
  color: white;
  padding: 1rem 2rem;
  border-radius: 2rem;
  font-weight: 600;
  box-shadow: var(--shadow);
  z-index: 1000;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.hidden {
  display: none !important;
}

@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}