/*
 * qinghai.video - Pixel-Perfect Aesthetic Optimization
 * 像素级美学优化系统 - 2026 Edition
 * 
 * Focus Areas:
 * 1. 光影逻辑自然化（Naturalized Light/Shadow Logic）
 * 2. 边缘处理精细化（Refined Edge Processing）
 * 3. 动态反馈细腻化（Delicate Interaction Feedback）
 * 4. 加载体验优雅化（Elegant Loading Experience）
 * 5. 响应式美感完美化（Perfect Responsive Beauty）
 */

/* ============================================
   SECTION 1: CSS Custom Properties (Design Tokens)
   ============================================ */

:root {
  /* ----- Core Color System ----- */
  --color-bg-base: #f8fafc;
  --color-bg-elevated: #ffffff;
  --color-bg-pressed: #f1f5f9;
  --color-text-primary: #0f172a;
  --color-text-secondary: #475569;
  --color-text-tertiary: #94a3b8;
  --color-text-muted: #64748b;
  --color-accent: #0ea5e9;
  --color-accent-subtle: rgba(14, 165, 233, 0.08);
  --color-accent-hover: #0284c7;
  --color-border-light: rgba(226, 232, 240, 0.8);
  --color-border-medium: rgba(203, 213, 225, 0.6);
  
  /* ----- 4pt Spacing Grid System ----- */
  --space-unit: 0.25rem;      /* 4px */
  --space-1: 0.25rem;         /* 4px */
  --space-2: 0.5rem;          /* 8px */
  --space-3: 0.75rem;         /* 12px */
  --space-4: 1rem;            /* 16px */
  --space-5: 1.25rem;         /* 20px */
  --space-6: 1.5rem;          /* 24px */
  --space-8: 2rem;            /* 32px */
  --space-10: 2.5rem;         /* 40px */
  --space-12: 3rem;           /* 48px */
  --space-16: 4rem;           /* 64px */
  --space-20: 5rem;           /* 80px */
  --space-24: 6rem;           /* 96px */
  
  /* ----- Unified Border Radius System ----- */
  --radius-none: 0;
  --radius-sm: 0.375rem;      /* 6px - badges, pills */
  --radius-md: 0.5rem;        /* 8px - buttons, inputs */
  --radius-lg: 0.75rem;       /* 12px - small cards */
  --radius-xl: 1rem;          /* 16px - medium cards */
  --radius-2xl: 1.5rem;       /* 24px - main cards */
  --radius-3xl: 2rem;         /* 32px - featured cards */
  --radius-full: 9999px;
  
  /* ----- Physical Light Shadow System ----- */
  /* Light source: top-left, consistent physics */
  --shadow-color: 220 13% 46%;
  --shadow-alpha-base: 0.04;
  --shadow-alpha-elevated: 0.06;
  
  /* Static shadows (resting state) */
  --shadow-xs: 0 1px 2px rgba(var(--shadow-color), 0.03);
  --shadow-sm: 0 1px 2px 0 rgba(var(--shadow-color), 0.04),
               0 1px 1px -1px rgba(var(--shadow-color), 0.02);
  --shadow-md: 0 4px 6px -1px rgba(var(--shadow-color), 0.04),
               0 2px 4px -2px rgba(var(--shadow-color), 0.02);
  --shadow-lg: 0 10px 15px -3px rgba(var(--shadow-color), 0.05),
               0 4px 6px -4px rgba(var(--shadow-color), 0.02);
  --shadow-xl: 0 20px 25px -5px rgba(var(--shadow-color), 0.06),
               0 8px 10px -6px rgba(var(--shadow-color), 0.03);
  
  /* Hover shadows (slightly elevated) */
  --shadow-hover-md: 0 6px 8px -1px rgba(var(--shadow-color), 0.05),
                    0 3px 5px -2px rgba(var(--shadow-color), 0.03);
  --shadow-hover-lg: 0 12px 18px -3px rgba(var(--shadow-color), 0.06),
                     0 5px 8px -4px rgba(var(--shadow-color), 0.03);
  
  /* ----- Animation Timing System ----- */
  --duration-instant: 100ms;
  --duration-fast: 150ms;
  --duration-normal: 250ms;
  --duration-slow: 400ms;
  --duration-slower: 600ms;
  
  /* Easing curves - Material Design 3 inspired */
  --ease-linear: linear;
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
  --ease-in-out: cubic-bezier(0.4, 0, 0.2, 1);
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --ease-spring-gentle: cubic-bezier(0.17, 0.89, 0.32, 1.27);
  --ease-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);
  
  /* ----- Luminance Gradients ----- */
  --gradient-surface: linear-gradient(180deg, rgba(255,255,255,0) 0%, rgba(248,250,252,0.5) 100%);
  --gradient-elevated: linear-gradient(180deg, #ffffff 0%, #fafbfc 100%);
  --gradient-subtle: linear-gradient(135deg, rgba(14, 165, 233, 0.03) 0%, rgba(99, 102, 241, 0.02) 100%);
  
  /* ----- Typography Scale (Golden Ratio) ----- */
  --font-display: clamp(2.5rem, 5vw, 4rem);
  --font-h1: clamp(2rem, 4vw, 3rem);
  --font-h2: clamp(1.5rem, 3vw, 2.25rem);
  --font-h3: clamp(1.25rem, 2vw, 1.5rem);
  --font-body: clamp(0.875rem, 1.5vw, 1rem);
  --font-caption: 0.875rem;
  --font-micro: 0.75rem;
}

/* ============================================
   SECTION 2: Sophisticated Glass Morphism
   ============================================ */

.glass-card {
  position: relative;
  background: rgba(255, 255, 255, 0.72);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid rgba(226, 232, 240, 0.6);
  border-radius: var(--radius-3xl);
  box-shadow: var(--shadow-lg);
  transition: 
    transform var(--duration-normal) var(--ease-out),
    box-shadow var(--duration-normal) var(--ease-out),
    border-color var(--duration-fast) var(--ease-out);
  will-change: transform, box-shadow;
}

.glass-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-3xl);
  padding: 1px;
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.8) 0%,
    rgba(255, 255, 255, 0.1) 50%,
    rgba(255, 255, 255, 0.3) 100%
  );
  -webkit-mask: 
    linear-gradient(#fff 0 0) content-box, 
    linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
}

.glass-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
  border-color: rgba(14, 165, 233, 0.2);
}

.glass-card:active {
  transform: translateY(-2px) scale(0.995);
  transition: transform var(--duration-fast) var(--ease-out);
}

/* Glass variant for dark overlays */
.glass-overlay {
  background: rgba(15, 23, 42, 0.75);
  backdrop-filter: blur(24px) saturate(120%);
  -webkit-backdrop-filter: blur(24px) saturate(120%);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

/* ============================================
   SECTION 3: Refined Button System
   ============================================ */

.btn-refined {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  font-size: 0.9375rem;
  font-weight: 500;
  line-height: 1.5;
  letter-spacing: -0.01em;
  color: var(--color-text-primary);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border-medium);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  transition: 
    transform var(--duration-fast) var(--ease-spring-gentle),
    background var(--duration-fast) var(--ease-out),
    border-color var(--duration-fast) var(--ease-out),
    box-shadow var(--duration-normal) var(--ease-out);
  will-change: transform;
}

.btn-refined:hover {
  background: var(--color-bg-base);
  border-color: var(--color-accent);
  box-shadow: var(--shadow-hover-md);
  transform: translateY(-1px);
}

.btn-refined:active {
  transform: translateY(0) scale(0.98);
  transition: transform var(--duration-instant) var(--ease-out);
}

.btn-primary {
  color: white;
  background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
  border-color: transparent;
  box-shadow: 0 1px 2px rgba(14, 165, 233, 0.2);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #0284c7 0%, #0c4a6e 100%);
  box-shadow: 0 4px 12px rgba(14, 165, 233, 0.25);
}

/* ============================================
   SECTION 4: Elegant Skeleton Loading
   ============================================ */

.skeleton {
  position: relative;
  background: linear-gradient(
    90deg,
    rgba(226, 232, 240, 0.6) 0%,
    rgba(241, 245, 249, 0.8) 50%,
    rgba(226, 232, 240, 0.6) 100%
  );
  background-size: 200% 100%;
  border-radius: var(--radius-md);
  overflow: hidden;
}

.skeleton::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.4),
    transparent
  );
  animation: skeleton-shimmer 1.5s infinite;
}

@keyframes skeleton-shimmer {
  0% {
    transform: translateX(-100%);
  }
  100% {
    transform: translateX(100%);
  }
}

/* Skeleton variants */
.skeleton-text {
  height: 1em;
  margin-bottom: var(--space-2);
}

.skeleton-title {
  height: 1.5em;
  width: 70%;
  margin-bottom: var(--space-3);
  border-radius: var(--radius-sm);
}

.skeleton-avatar {
  width: 3rem;
  height: 3rem;
  border-radius: var(--radius-full);
}

.skeleton-card {
  border-radius: var(--radius-2xl);
  min-height: 200px;
}

/* ============================================
   SECTION 5: Smooth Micro-interactions
   ============================================ */

/* Smooth link transitions */
a {
  transition: color var(--duration-fast) var(--ease-out),
              opacity var(--duration-fast) var(--ease-out);
}

/* Card hover lift with depth */
.card-refined {
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-md);
  transition: 
    transform var(--duration-normal) var(--ease-out),
    box-shadow var(--duration-normal) var(--ease-out),
    border-color var(--duration-fast) var(--ease-out);
  will-change: transform, box-shadow;
}

.card-refined:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover-lg);
  border-color: rgba(14, 165, 233, 0.15);
}

/* Subtle scale on click */
.interactive-element {
  cursor: pointer;
  transition: transform var(--duration-fast) var(--ease-spring-gentle);
}

.interactive-element:active {
  transform: scale(0.97);
}

/* Focus states with glow */
.focus-ring:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px var(--color-accent-subtle),
              0 0 0 1px var(--color-accent);
}

/* ============================================
   SECTION 6: Responsive Grid with Golden Ratio
   ============================================ */

/* Golden ratio breakpoints */
@media (max-width: 639px) { /* Mobile */
  :root {
    --section-gap: var(--space-8);
    --card-padding: var(--space-4);
  }
}

@media (min-width: 640px) { /* Mobile landscape */
  :root {
    --section-gap: var(--space-10);
    --card-padding: var(--space-5);
  }
}

@media (min-width: 768px) { /* Tablet */
  :root {
    --section-gap: var(--space-12);
    --card-padding: var(--space-6);
  }
}

@media (min-width: 1024px) { /* Laptop */
  :root {
    --section-gap: var(--space-16);
    --card-padding: var(--space-6);
  }
}

@media (min-width: 1280px) { /* Desktop */
  :root {
    --section-gap: 5.5rem;
    --card-padding: var(--space-8);
  }
}

@media (min-width: 1536px) { /* Large screens */
  :root {
    --section-gap: var(--space-24);
    --card-padding: var(--space-8);
  }
}

/* ============================================
   SECTION 7: Image Loading Animation
   ============================================ */

.image-container {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-xl);
  background: var(--color-bg-pressed);
}

.image-container img {
  transition: opacity var(--duration-slow) var(--ease-out),
              transform var(--duration-slow) var(--ease-out);
}

.image-container img.lazy {
  opacity: 0;
  transform: scale(1.05);
}

.image-container img.loaded {
  opacity: 1;
  transform: scale(1);
}

/* Blur up effect */
.image-blur-up {
  filter: blur(20px);
  transition: filter var(--duration-slow) var(--ease-out);
}

.image-blur-up.loaded {
  filter: blur(0);
}

/* ============================================
   SECTION 8: Text Refinements
   ============================================ */

/* Gradient text for headings */
.text-gradient {
  background: linear-gradient(135deg, #0f172a 0%, #475569 50%, #0ea5e9 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.text-gradient-accent {
  background: linear-gradient(135deg, #0ea5e9 0%, #6366f1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Refined headings */
.heading-display {
  font-size: var(--font-display);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -0.03em;
}

.heading-section {
  font-size: var(--font-h2);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.025em;
}

/* Body text with proper line height */
.text-body {
  font-size: var(--font-body);
  line-height: 1.7;
  color: var(--color-text-secondary);
}

/* ============================================
   SECTION 9: Scrollbar Styling
   ============================================ */

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: rgba(148, 163, 184, 0.3);
  border-radius: var(--radius-full);
  border: 2px solid transparent;
  background-clip: content-box;
}

::-webkit-scrollbar-thumb:hover {
  background: rgba(148, 163, 184, 0.5);
}

/* Firefox */
* {
  scrollbar-width: thin;
  scrollbar-color: rgba(148, 163, 184, 0.3) transparent;
}

/* ============================================
   SECTION 10: Section Transitions
   ============================================ */

.section-enter {
  opacity: 0;
  transform: translateY(20px);
  transition: 
    opacity var(--duration-slow) var(--ease-out),
    transform var(--duration-slow) var(--ease-out);
}

.section-enter.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger children */
.stagger-children > * {
  opacity: 0;
  transform: translateY(16px);
  transition: 
    opacity var(--duration-normal) var(--ease-out),
    transform var(--duration-normal) var(--ease-out);
}

.stagger-children.visible > *:nth-child(1) { transition-delay: 0ms; }
.stagger-children.visible > *:nth-child(2) { transition-delay: 80ms; }
.stagger-children.visible > *:nth-child(3) { transition-delay: 160ms; }
.stagger-children.visible > *:nth-child(4) { transition-delay: 240ms; }
.stagger-children.visible > *:nth-child(5) { transition-delay: 320ms; }
.stagger-children.visible > *:nth-child(6) { transition-delay: 400ms; }

.stagger-children.visible > * {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================
   SECTION 11: Badge System
   ============================================ */

.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-1) var(--space-2);
  font-size: var(--font-micro);
  font-weight: 500;
  letter-spacing: 0.02em;
  border-radius: var(--radius-sm);
  transition: all var(--duration-fast) var(--ease-out);
}

.badge-primary {
  background: var(--color-accent-subtle);
  color: var(--color-accent);
}

.badge-secondary {
  background: rgba(226, 232, 240, 0.6);
  color: var(--color-text-secondary);
}

/* ============================================
   SECTION 12: Form Input Refinements
   ============================================ */

.input-refined {
  padding: var(--space-3) var(--space-4);
  font-size: 0.9375rem;
  color: var(--color-text-primary);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border-medium);
  border-radius: var(--radius-lg);
  transition: 
    border-color var(--duration-fast) var(--ease-out),
    box-shadow var(--duration-fast) var(--ease-out);
}

.input-refined:hover {
  border-color: var(--color-border-medium);
}

.input-refined:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-subtle);
}

.input-refined::placeholder {
  color: var(--color-text-tertiary);
  transition: color var(--duration-fast) var(--ease-out);
}

.input-refined:focus::placeholder {
  color: var(--color-text-muted);
}

/* ============================================
   SECTION 13: Reduced Motion Support
   ============================================ */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
  
  .skeleton::after {
    animation: none;
  }
}

/* ============================================
   SECTION 14: Utility Classes
   ============================================ */

/* Hardware acceleration for smooth animations */
.gpu-accelerate {
  transform: translateZ(0);
  backface-visibility: hidden;
  perspective: 1000px;
}

/* Subtle lift effect */
.hover-lift {
  transition: transform var(--duration-normal) var(--ease-out);
}

.hover-lift:hover {
  transform: translateY(-2px);
}

/* Depth layers */
.depth-1 { box-shadow: var(--shadow-xs); }
.depth-2 { box-shadow: var(--shadow-sm); }
.depth-3 { box-shadow: var(--shadow-md); }
.depth-4 { box-shadow: var(--shadow-lg); }
.depth-5 { box-shadow: var(--shadow-xl); }

/* Text balance for better typography */
balance {
  text-wrap: balance;
}

.pretty {
  text-wrap: pretty;
}