/* ==================================================
   CSS Variables & Design System
================================================== */
:root {
  --primary-color: #2563EB;
  --primary-hover: #1D4ED8;
  --bg-color: #F8FAFC;
  --surface-color: #FFFFFF;
  --surface-hover: #F1F5F9;
  --text-main: #0F172A;
  --text-muted: #64748B;
  --border-color: #E2E8F0;
  --grid-line-color: #F1F5F9;
  --radius-lg: 18px;
  --radius-md: 10px;
  --radius-sm: 6px;
  --radius-full: 9999px;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
  --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.05), 0 8px 10px -6px rgba(0, 0, 0, 0.03);
  --transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

a {
  text-decoration: none;
  color: inherit;
  transition: var(--transition);
}

/* ==================================================
   Header & Navigation
================================================== */
.navbar {
  background-color: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text-main);
}

.nav-links {
  display: flex;
  gap: 2rem;
}

.nav-links a {
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--text-muted);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--primary-color);
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.social-link {
  font-weight: 600;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.social-link:hover {
  color: var(--text-main);
}

/* ==================================================
   Buttons & UI Elements
================================================== */
.btn-primary {
  background-color: var(--primary-color);
  color: #FFFFFF;
  padding: 0.6rem 1.25rem;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.875rem;
  border: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
  transition: var(--transition);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(37, 99, 235, 0.3);
}

.btn-secondary {
  background-color: var(--surface-hover);
  color: var(--text-main);
  padding: 0.6rem 1.25rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.875rem;
  border: 1px solid var(--border-color);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  transition: var(--transition);
  width: 100%;
}

.btn-secondary:hover {
  background-color: #E2E8F0;
  border-color: #CBD5E1;
}

.full-width {
  width: 100%;
  border-radius: var(--radius-md);
}

/* ==================================================
   Main Workspace Layout
================================================== */
.main-content {
  flex: 1;
  display: flex;
  justify-content: center;
  padding: 2.5rem 2rem;
}

.workspace-container {
  max-width: 1100px;
  width: 100%;
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 2rem;
  align-items: start;
}

/* Sidebar Toolbar Card */
.toolbar-card {
  background-color: var(--surface-color);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.section-title {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}

.divider {
  border: none;
  border-top: 1px solid var(--border-color);
}

/* Tool Buttons */
.tool-group {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.tool-btn {
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  padding: 0.75rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.875rem;
  color: var(--text-main);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  transition: var(--transition);
}

.tool-btn:hover {
  background-color: var(--surface-hover);
}

.tool-btn.active {
  background-color: rgba(37, 99, 235, 0.1);
  border-color: var(--primary-color);
  color: var(--primary-color);
  box-shadow: 0 0 0 1px var(--primary-color);
}

/* Color Picker & Swatches */
.control-group {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.control-label {
  font-weight: 600;
  font-size: 0.875rem;
  color: var(--text-main);
}

.color-picker-wrapper {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background-color: var(--surface-hover);
  padding: 0.5rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

input[type="color"] {
  /* -webkit-appearance: none; */
  border: none;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  background: transparent;
}

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

input[type="color"]::-webkit-color-swatch {
  border: none;
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-sm);
}

.color-value {
  font-family: monospace;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-muted);
}

.swatches {
  display: flex;
  gap: 0.5rem;
  justify-content: space-between;
}

.swatch {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  border: 2px solid transparent;
  box-shadow: var(--shadow-sm);
}

.swatch:hover {
  transform: scale(1.15);
}

.swatch.active {
  border-color: var(--text-main);
  transform: scale(1.1);
}

/* Grid Size Slider */
.slider-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.grid-dimensions {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--primary-color);
  background-color: rgba(37, 99, 235, 0.1);
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-sm);
}

input[type="range"] {
  /* -webkit-appearance: none; */
  width: 100%;
  height: 6px;
  background: var(--border-color);
  border-radius: var(--radius-full);
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--primary-color);
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  transition: transform 0.15s ease;
}

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

.action-group {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

/* ==================================================
   Canvas Workspace Card
================================================== */
.canvas-card {
  background-color: var(--surface-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
}

.canvas-header {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 1rem;
}

.canvas-title {
  font-weight: 700;
  font-size: 1.1rem;
}

.pixel-counter {
  font-size: 0.875rem;
  color: var(--text-muted);
  font-weight: 500;
}

.counter-highlight {
  font-weight: 700;
  color: var(--primary-color);
}

.grid-wrapper {
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 1rem;
  background-color: var(--bg-color);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  width: 100%;
  max-width: 520px;
  aspect-ratio: 1 / 1;
}

/* Pixel Grid Layout */
.pixel-grid {
  display: grid;
  width: 100%;
  height: 100%;
  background-color: #FFFFFF;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  animation: fadeIn 0.4s ease-out;
}

.pixel-cell {
  background-color: #FFFFFF;
  border-right: 1px solid var(--grid-line-color);
  border-bottom: 1px solid var(--grid-line-color);
  cursor: pointer;
  user-select: none;
  transition: background-color 0.05s ease;
}

.pixel-cell:hover {
  outline: 2px solid rgba(37, 99, 235, 0.4);
  z-index: 2;
}

@keyframes fadeIn {
  from { opacity: 0; transform: scale(0.98); }
  to { opacity: 1; transform: scale(1); }
}

/* ==================================================
   Footer & Toast Notifications
================================================== */
.footer {
  background-color: var(--surface-color);
  border-top: 1px solid var(--border-color);
  padding: 2rem;
  text-align: center;
}

.footer-content {
  max-width: 1280px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.footer-links {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.85rem;
}

.footer-links a {
  color: var(--text-main);
  font-weight: 500;
}

.footer-links a:hover {
  color: var(--primary-color);
}

.dot {
  color: var(--border-color);
}

/* Toast Notification */
.toast {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background-color: var(--text-main);
  color: #FFFFFF;
  padding: 0.875rem 1.5rem;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.875rem;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  pointer-events: none;
  transform: translateY(20px);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  z-index: 1000;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}