:root {
  /* Common Palette */
  --red: #ea4335;
  --blue: #4285f4;
  --yellow: #fbbc05;
  --green: #34a853;
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  
  /* Light Theme Variables */
  --bg-gradient: linear-gradient(135deg, #f1f5f9 0%, #e2e8f0 100%);
  --panel-bg: rgba(255, 255, 255, 0.75);
  --panel-border: rgba(255, 255, 255, 0.6);
  --text-main: #0f172a;
  --text-muted: #64748b;
  --border-color: rgba(15, 23, 42, 0.08);
  --card-bg: rgba(255, 255, 255, 0.45);
  --input-bg: #ffffff;
  --shadow: 0 20px 40px -15px rgba(15, 23, 42, 0.08), 0 0 0 1px rgba(15, 23, 42, 0.03);
  --shadow-hover: 0 30px 60px -15px rgba(15, 23, 42, 0.12), 0 0 0 1px rgba(15, 23, 42, 0.05);
  --btn-secondary-bg: rgba(15, 23, 42, 0.05);
  --btn-secondary-hover: rgba(15, 23, 42, 0.08);
  --divider-color: rgba(15, 23, 42, 0.06);
}

[data-theme="dark"] {
  /* Dark Theme Variables */
  --bg-gradient: linear-gradient(135deg, #090d16 0%, #111827 100%);
  --panel-bg: rgba(17, 24, 39, 0.7);
  --panel-border: rgba(255, 255, 255, 0.06);
  --text-main: #f3f4f6;
  --text-muted: #9ca3af;
  --border-color: rgba(255, 255, 255, 0.06);
  --card-bg: rgba(31, 41, 55, 0.4);
  --input-bg: #1f2937;
  --shadow: 0 20px 40px -15px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(255, 255, 255, 0.02);
  --shadow-hover: 0 30px 60px -15px rgba(0, 0, 0, 0.65), 0 0 0 1px rgba(255, 255, 255, 0.04);
  --btn-secondary-bg: rgba(255, 255, 255, 0.06);
  --btn-secondary-hover: rgba(255, 255, 255, 0.1);
  --divider-color: rgba(255, 255, 255, 0.06);
}

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

body {
  min-height: 100vh;
  font-family: "Outfit", "Plus Jakarta Sans", sans-serif;
  color: var(--text-main);
  background: var(--bg-gradient);
  background-attachment: fixed;
  transition: background var(--transition-normal), color var(--transition-normal);
  overflow-x: hidden;
}

/* Header Styling */
.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background: var(--panel-bg);
  border-bottom: 1px solid var(--panel-border);
  transition: background var(--transition-normal), border-color var(--transition-normal);
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 6px;
  font-weight: 800;
  font-size: 1.3rem;
  letter-spacing: -0.02em;
}

.logo-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.logo-dot.blue { background-color: var(--blue); }
.logo-dot.red { background-color: var(--red); }
.logo-dot.yellow { background-color: var(--yellow); }
.logo-dot.green { background-color: var(--green); }

.logo-text {
  background: linear-gradient(90deg, var(--blue) 25%, var(--red) 50%, var(--yellow) 75%, var(--green) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-left: 4px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Button Styling */
.icon-button {
  background: var(--btn-secondary-bg);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 8px 14px;
  border-radius: 12px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: inherit;
  font-weight: 600;
  font-size: 0.85rem;
  transition: background var(--transition-fast), transform var(--transition-fast), border-color var(--transition-fast);
}

.icon-button:hover {
  background: var(--btn-secondary-hover);
  transform: translateY(-1px);
}

.icon-button svg {
  width: 16px;
  height: 16px;
}

/* Hide unneeded icon based on theme */
[data-theme="light"] .sun-icon { display: none; }
[data-theme="dark"] .moon-icon { display: none; }

/* Page Layout */
.page {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.hero {
  text-align: center;
  margin-bottom: 40px;
}

.eyebrow {
  display: inline-block;
  margin-bottom: 12px;
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--blue);
  background: rgba(66, 133, 244, 0.08);
  padding: 4px 12px;
  border-radius: 100px;
}

.hero h1 {
  font-size: clamp(2rem, 3.5vw, 3.2rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 16px;
  color: var(--text-main);
}

.hero-copy {
  max-width: 720px;
  margin: 0 auto;
  font-size: 1.05rem;
  line-height: 1.6;
  color: var(--text-muted);
}

/* Workspace Grid */
.workspace {
  display: grid;
  grid-template-columns: 420px 1fr;
  gap: 32px;
  align-items: start;
}

.panel {
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  border-radius: 24px;
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition-normal), background var(--transition-normal), border-color var(--transition-normal);
}

.panel:hover {
  box-shadow: var(--shadow-hover);
}

.controls {
  padding: 32px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.preview-panel {
  padding: 32px;
}

h2 {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 4px;
}

h3 {
  font-size: 0.95rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.panel-copy {
  font-size: 0.9rem;
  line-height: 1.5;
  color: var(--text-muted);
  margin-bottom: 8px;
}

/* Upload Zone */
.upload-zone {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 36px 24px;
  border: 2px dashed rgba(66, 133, 244, 0.25);
  border-radius: 18px;
  background: var(--card-bg);
  cursor: pointer;
  text-align: center;
  transition: border-color var(--transition-fast), background var(--transition-fast), transform var(--transition-fast);
}

.upload-zone:hover,
.upload-zone.dragover {
  border-color: var(--blue);
  background: rgba(66, 133, 244, 0.04);
  transform: translateY(-2px);
}

.upload-zone input {
  display: none;
}

.upload-icon-wrapper {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: rgba(66, 133, 244, 0.08);
  color: var(--blue);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 14px;
  transition: transform var(--transition-fast);
}

.upload-zone:hover .upload-icon-wrapper {
  transform: scale(1.1);
}

.upload-icon-wrapper svg {
  width: 24px;
  height: 24px;
}

.upload-title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.upload-subtitle {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Presets */
.presets-section {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.presets-grid {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.preset-item {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: 2px solid transparent;
  cursor: pointer;
  overflow: hidden;
  transition: transform var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
  background: var(--input-bg);
  padding: 2px;
}

.preset-item:hover {
  transform: scale(1.1) translateY(-2px);
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
}

.preset-item.active {
  border-color: var(--blue);
  transform: scale(1.05);
}

.preset-item img {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  object-fit: cover;
}

.divider {
  border: none;
  height: 1px;
  background-color: var(--divider-color);
}

/* Settings Sliders */
.settings-group {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.control-row {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.control-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.9rem;
  font-weight: 600;
}

.control-value {
  color: var(--blue);
  font-weight: 700;
}

.sub-label {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 4px;
}

/* Color Palette Picker */
.palette-options {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px;
}

.palette-btn {
  background: var(--btn-secondary-bg);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 10px;
  border-radius: 10px;
  font-family: inherit;
  font-weight: 600;
  font-size: 0.8rem;
  cursor: pointer;
  transition: all var(--transition-fast);
}

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

.palette-btn.active {
  background: var(--text-main);
  color: var(--panel-bg);
  border-color: var(--text-main);
}

/* Range Input styling */
input[type="range"] {
  -webkit-appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 10px;
  background: var(--divider-color);
  outline: none;
  margin: 8px 0;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--text-main);
  cursor: pointer;
  border: 2px solid var(--panel-bg);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.15);
  transition: transform var(--transition-fast), background var(--transition-fast);
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.2);
  background: var(--blue);
}

/* Buttons */
.primary-button {
  display: block;
  width: 100%;
  border: none;
  border-radius: 14px;
  padding: 16px 20px;
  font-family: inherit;
  font-weight: 700;
  font-size: 1rem;
  color: #ffffff;
  background: linear-gradient(90deg, var(--blue), var(--red), var(--yellow), var(--green));
  background-size: 300% 100%;
  cursor: pointer;
  box-shadow: 0 10px 20px -8px rgba(66, 133, 244, 0.4);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), background-position var(--transition-normal);
}

.primary-button:hover:enabled {
  transform: translateY(-2px);
  box-shadow: 0 15px 24px -8px rgba(66, 133, 244, 0.5);
  background-position: 100% 0;
}

.primary-button:active:enabled {
  transform: translateY(-0.5px);
}

.primary-button:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  box-shadow: none;
}

.secondary-button {
  display: block;
  width: 100%;
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 12px 20px;
  font-family: inherit;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--text-main);
  background: var(--btn-secondary-bg);
  cursor: pointer;
  transition: transform var(--transition-fast), background var(--transition-fast);
}

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

.actions {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 8px;
}

.status {
  font-size: 0.85rem;
  line-height: 1.4;
  color: var(--text-muted);
  text-align: center;
  margin-top: 8px;
  padding: 8px 12px;
  border-radius: 8px;
  background: var(--btn-secondary-bg);
  border: 1px solid var(--border-color);
  word-break: break-word;
}

/* Preview Section */
.preview-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.preview-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.preview-card h2 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-main);
}

.preview-surface {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  aspect-ratio: 1 / 1;
  border-radius: 18px;
  overflow: hidden;
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.03);
  /* Checkerboard background for transparency preview */
  background-image: 
    linear-gradient(45deg, var(--divider-color) 25%, transparent 25%, transparent 75%, var(--divider-color) 75%),
    linear-gradient(45deg, var(--divider-color) 25%, var(--card-bg) 25%, var(--card-bg) 75%, var(--divider-color) 75%);
  background-size: 20px 20px;
  background-position: 0 0, 10px 10px;
}

#input-preview,
#output-canvas {
  max-width: 90%;
  max-height: 90%;
  width: auto;
  height: auto;
  border-radius: 8px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
  display: none;
  animation: scale-up 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
}

#output-canvas {
  /* Ensure canvas displays round inside the preview so they see the circular crop aspect */
  border-radius: 50%;
}

.placeholder-wrapper {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 24px;
  text-align: center;
  color: var(--text-muted);
}

.placeholder-icon {
  width: 48px;
  height: 48px;
  opacity: 0.4;
  color: var(--text-muted);
}

.placeholder {
  font-size: 0.9rem;
  line-height: 1.5;
  max-width: 200px;
}

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

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

@keyframes scale-up {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.animate-fade-in {
  animation: fadeIn 0.6s ease-out forwards;
}

.animate-slide-up {
  animation: slideUp 0.6s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

/* Footer Styling */
.app-footer {
  margin-top: 60px;
  padding: 32px 24px;
  text-align: center;
  border-top: 1px solid var(--divider-color);
  font-size: 0.85rem;
  color: var(--text-muted);
  transition: border-color var(--transition-normal), color var(--transition-normal);
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.author-credits a {
  color: var(--blue);
  text-decoration: none;
  font-weight: 600;
  transition: color var(--transition-fast);
}

.author-credits a:hover {
  color: var(--red);
  text-decoration: underline;
}

/* Responsive Rules */
@media (max-width: 1024px) {
  .workspace {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  
  .page {
    padding-top: 20px;
  }
}

@media (max-width: 640px) {
  .header-container {
    padding: 12px 16px;
  }
  
  .page {
    padding: 16px 16px 40px;
  }
  
  .hero {
    margin-bottom: 24px;
  }
  
  .controls, .preview-panel {
    padding: 20px;
  }
  
  .preview-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  
  .preview-surface {
    max-width: 320px;
    margin: 0 auto;
  }
}