/* Visual Canvas - 无限视觉画布 */
/* Inspired by Figma 白板 + Pinterest + 艺术杂志 */

:root {
  --canvas-bg: #fafafa;
  --canvas-text: #1a1a1a;
  --canvas-text-light: #666;
  --canvas-border: rgba(0,0,0,0.08);
  --canvas-shadow: rgba(0,0,0,0.12);
  --canvas-shadow-hover: rgba(0,0,0,0.18);
  --canvas-radius: 12px;
  --canvas-radius-lg: 20px;
  --canvas-padding: 8px;
  --canvas-gap: 24px;
  --canvas-transition: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  background: var(--canvas-bg);
  font-family: 'Segoe UI', 'Helvetica Neue', -apple-system, BlinkMacSystemFont, sans-serif;
  color: var(--canvas-text);
  overflow-x: hidden;
}

/* Navigation - Minimal floating design */
.canvas-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--canvas-border);
  transition: all var(--canvas-transition);
}

.canvas-nav.scrolled {
  box-shadow: 0 4px 20px var(--canvas-shadow);
}

.canvas-nav-inner {
  max-width: 1400px;
  margin: 0 auto;
  padding: 16px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.canvas-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--canvas-text);
  font-weight: 600;
  font-size: 20px;
  letter-spacing: -0.02em;
}

.canvas-logo-mark {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  color: white;
}

.canvas-nav-links {
  display: flex;
  gap: 32px;
  list-style: none;
  padding: 0;
  margin: 0;
}

.canvas-nav-links a {
  color: var(--canvas-text-light);
  text-decoration: none;
  font-size: 15px;
  font-weight: 500;
  transition: color 0.2s;
  position: relative;
}

.canvas-nav-links a:hover {
  color: var(--canvas-text);
}

.canvas-nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
  transition: width 0.3s ease;
}

.canvas-nav-links a:hover::after {
  width: 100%;
}

.canvas-nav-right {
  display: flex;
  gap: 16px;
}

.canvas-search-btn {
  width: 40px;
  height: 40px;
  background: transparent;
  border: 1px solid var(--canvas-border);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s;
}

.canvas-search-btn:hover {
  background: rgba(99,102,241,0.08);
  border-color: rgba(99,102,241,0.3);
}

.canvas-search-btn svg {
  width: 20px;
  height: 20px;
  stroke: var(--canvas-text-light);
}

/* Search Overlay */
.canvas-search-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(255,255,255,0.98);
  backdrop-filter: blur(30px);
  z-index: 2000;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 80px;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
}

.canvas-search-overlay.active {
  opacity: 1;
  visibility: visible;
}

.canvas-search-box {
  position: relative;
  width: 600px;
  max-width: 90%;
  background: white;
  border: 2px solid var(--canvas-border);
  border-radius: 16px;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  gap: 16px;
  box-shadow: 0 8px 40px rgba(0,0,0,0.15);
}

.canvas-search-box svg {
  width: 24px;
  height: 24px;
  stroke: var(--canvas-text-light);
}

.canvas-search-input {
  width: 100%;
  border: none;
  font-size: 18px;
  color: var(--canvas-text);
  background: transparent;
  outline: none;
}

.canvas-search-input::placeholder {
  color: var(--canvas-text-light);
}

.canvas-search-close {
  position: absolute;
  top: -60px;
  right: 20px;
  width: 40px;
  height: 40px;
  background: white;
  border: none;
  border-radius: 10px;
  font-size: 28px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 20px rgba(0,0,0,0.15);
}

.canvas-search-results {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  margin-top: 16px;
  background: white;
  border-radius: 12px;
  box-shadow: 0 8px 40px rgba(0,0,0,0.15);
  max-height: 400px;
  overflow-y: auto;
}

/* Hero Section - Today's Focus */
.canvas-hero {
  padding: 80px 32px 40px;
  text-align: center;
}

.canvas-hero-label {
  font-size: 13px;
  color: var(--canvas-text-light);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
}

.canvas-hero-label::before,
.canvas-hero-label::after {
  content: '';
  width: 40px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--canvas-border), transparent);
}

.canvas-hero-title {
  font-size: 48px;
  font-weight: 700;
  letter-spacing: -0.04em;
  margin: 0 0 40px 0;
  background: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #ec4899 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Canvas Container - The main infinite canvas */
.canvas-container {
  padding: 40px 32px 80px;
  max-width: 1600px;
  margin: 0 auto;
}

/* Masonry-like Grid with irregular sizes */
.canvas-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--canvas-gap);
  grid-auto-flow: dense;
  align-items: start;
}

/* Individual Canvas Item - News Card */
.canvas-item {
  position: relative;
  background: white;
  border-radius: var(--canvas-radius);
  overflow: hidden;
  transition: all var(--canvas-transition);
  cursor: pointer;
  box-shadow: 0 4px 20px var(--canvas-shadow);
  
  /* Irregular sizes - using CSS Grid span */
  grid-column-end: span 1;
  grid-row-end: span 1;
}

/* Make some items larger (every 3rd, 7th, etc.) */
.canvas-item:nth-child(3n+1) {
  grid-column-end: span 2;
}

.canvas-item:nth-child(7n+3) {
  grid-row-end: span 2;
}

.canvas-item:nth-child(11n+5) {
  grid-column-end: span 2;
  grid-row-end: span 2;
}

.canvas-item:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: 0 12px 40px var(--canvas-shadow-hover);
  z-index: 10;
}

.canvas-item-img {
  width: 100%;
  aspect-ratio: 16/10;
  object-fit: cover;
  display: block;
  transition: transform var(--canvas-transition);
}

.canvas-item:nth-child(3n+1) .canvas-item-img {
  aspect-ratio: 16/9;
}

.canvas-item:nth-child(7n+3) .canvas-item-img {
  aspect-ratio: 3/4;
}

.canvas-item:nth-child(11n+5) .canvas-item-img {
  aspect-ratio: 16/8;
}

.canvas-item:hover .canvas-item-img {
  transform: scale(1.05);
}

/* Content overlay on hover */
.canvas-item-content {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: linear-gradient(to top, rgba(26,26,26,0.95) 0%, rgba(26,26,26,0.85) 60%, transparent 100%);
  color: white;
  padding: 80px 20px 20px;
  transform: translateY(60px);
  opacity: 0;
  transition: all var(--canvas-transition);
}

.canvas-item:hover .canvas-item-content {
  transform: translateY(0);
  opacity: 1;
}

.canvas-item-tag {
  display: inline-block;
  background: rgba(255,255,255,0.2);
  padding: 4px 12px;
  border-radius: 6px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.02em;
  margin-bottom: 8px;
  backdrop-filter: blur(10px);
}

.canvas-item-title {
  font-size: 18px;
  font-weight: 700;
  margin: 0 0 8px 0;
  letter-spacing: -0.02em;
  line-height: 1.3;
}

.canvas-item:nth-child(3n+1) .canvas-item-title {
  font-size: 22px;
}

.canvas-item:nth-child(11n+5) .canvas-item-title {
  font-size: 24px;
}

.canvas-item-excerpt {
  font-size: 14px;
  color: rgba(255,255,255,0.85);
  margin: 0;
  line-height: 1.5;
  opacity: 0;
  transform: translateY(10px);
  transition: all 0.4s ease 0.1s;
}

.canvas-item:hover .canvas-item-excerpt {
  opacity: 1;
  transform: translateY(0);
}

/* Footer */
.canvas-footer {
  background: white;
  border-top: 1px solid var(--canvas-border);
  padding: 40px 32px;
  text-align: center;
}

.canvas-footer-inner {
  max-width: 1200px;
  margin: 0 auto;
}

.canvas-footer-text {
  font-size: 14px;
  color: var(--canvas-text-light);
  margin-bottom: 24px;
}

.canvas-footer-links {
  display: flex;
  justify-content: center;
  gap: 32px;
  margin-bottom: 16px;
}

.canvas-footer-links a {
  color: var(--canvas-text);
  text-decoration: none;
  font-size: 15px;
  font-weight: 500;
  transition: color 0.2s;
}

.canvas-footer-links a:hover {
  color: #6366f1;
}

/* Responsive Design */
@media (max-width: 1200px) {
  .canvas-grid {
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  }
}

@media (max-width: 768px) {
  .canvas-nav-inner {
    padding: 12px 20px;
  }
  
  .canvas-nav-links {
    display: none;
  }
  
  .canvas-hero {
    padding: 60px 20px 30px;
  }
  
  .canvas-hero-title {
    font-size: 32px;
  }
  
  .canvas-container {
    padding: 30px 20px 60px;
  }
  
  .canvas-grid {
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 16px;
  }
  
  .canvas-item:nth-child(3n+1),
  .canvas-item:nth-child(11n+5) {
    grid-column-end: span 1;
  }
  
  .canvas-item:nth-child(7n+3) {
    grid-row-end: span 1;
  }
}

@media (max-width: 480px) {
  .canvas-grid {
    grid-template-columns: 1fr;
  }
  
  .canvas-item:nth-child(n) {
    grid-column-end: span 1;
    grid-row-end: span 1;
  }
}

/* Smooth scroll behavior */
html {
  scroll-behavior: smooth;
}

/* Custom scrollbar */
::-webkit-scrollbar {
  width: 12px;
}

::-webkit-scrollbar-track {
  background: var(--canvas-bg);
}

::-webkit-scrollbar-thumb {
  background: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
  border-radius: 6px;
}

::-webkit-scrollbar-thumb:hover {
  background: linear-gradient(135deg, #8b5cf6 0%, #a78bfa 100%);
}

/* Loading animation for images */
.canvas-item-img {
  background: linear-gradient(135deg, #f3f4f6 0%, #e5e7eb 100%);
}

.canvas-item-img.loaded {
  background: none;
}

/* Fade-in animation on scroll */
.canvas-item {
  opacity: 0;
  transform: translateY(30px);
  animation: fadeInUp 0.6s ease forwards;
}

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

/* Stagger animation delays */
.canvas-item:nth-child(1) { animation-delay: 0.05s; }
.canvas-item:nth-child(2) { animation-delay: 0.1s; }
.canvas-item:nth-child(3) { animation-delay: 0.15s; }
.canvas-item:nth-child(4) { animation-delay: 0.2s; }
.canvas-item:nth-child(5) { animation-delay: 0.25s; }
.canvas-item:nth-child(6) { animation-delay: 0.3s; }
.canvas-item:nth-child(7) { animation-delay: 0.35s; }
.canvas-item:nth-child(8) { animation-delay: 0.4s; }
.canvas-item:nth-child(9) { animation-delay: 0.45s; }
.canvas-item:nth-child(10) { animation-delay: 0.5s; }
.canvas-item:nth-child(11) { animation-delay: 0.55s; }
.canvas-item:nth-child(12) { animation-delay: 0.6s; }
.canvas-item:nth-child(n+13) { animation-delay: 0.65s; }