/* =============================================================================
   liquid-glass.css — Full Design System & Liquid Glass UI
   Author: ZGQ Inc. | Stack: MDUI 2 Web Components + SVG Filter Pipeline
   Phase 1 Constraint: backdrop-filter ONLY via url(#filter-id), never blur()
   ============================================================================= */

/* ─── Google Fonts Import ──────────────────────────────────────────────────── */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;400;500;600;700&family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

/* ─── Material Design 3 Color Tokens (Light Mode) ──────────────────────────── */
:root {
  /* Primary palette — deep indigo-teal fusion */
  --md-sys-color-primary:             hsl(250, 72%, 62%);
  --md-sys-color-on-primary:          hsl(0, 0%, 100%);
  --md-sys-color-primary-container:   hsl(248, 100%, 92%);
  --md-sys-color-on-primary-container:hsl(248, 55%, 20%);

  /* Secondary palette — warm coral */
  --md-sys-color-secondary:           hsl(12, 80%, 58%);
  --md-sys-color-on-secondary:        hsl(0, 0%, 100%);
  --md-sys-color-secondary-container: hsl(14, 100%, 92%);

  /* Tertiary — mint teal */
  --md-sys-color-tertiary:            hsl(175, 60%, 45%);

  /* Surface & background */
  --md-sys-color-background:          hsl(240, 20%, 97%);
  --md-sys-color-on-background:       hsl(240, 10%, 10%);
  --md-sys-color-surface:             hsl(240, 20%, 98%);
  --md-sys-color-surface-variant:     hsl(240, 15%, 92%);
  --md-sys-color-on-surface:          hsl(240, 10%, 12%);
  --md-sys-color-on-surface-variant:  hsl(240, 8%, 40%);

  /* Outline */
  --md-sys-color-outline:             hsl(240, 6%, 65%);
  --md-sys-color-outline-variant:     hsl(240, 8%, 82%);

  /* Error */
  --md-sys-color-error:               hsl(0, 80%, 55%);

  /* Glass material */
  --glass-bg-light:    rgba(255, 255, 255, 0.07);
  --glass-bg-medium:   rgba(255, 255, 255, 0.12);
  --glass-border:      rgba(255, 255, 255, 0.22);
  --glass-shadow:      0 8px 40px rgba(0, 0, 0, 0.08), 0 2px 8px rgba(0, 0, 0, 0.06);
  --glass-shadow-lg:   0 20px 80px rgba(0, 0, 0, 0.12), 0 4px 20px rgba(0, 0, 0, 0.08);

  /* Typography */
  --font-sans:   'Inter', 'Noto Sans SC', system-ui, sans-serif;
  --font-mono:   'JetBrains Mono', 'Fira Code', monospace;

  /* Spacing scale */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;

  /* Border radius */
  --radius-sm:   8px;
  --radius-md:   16px;
  --radius-lg:   24px;
  --radius-xl:   32px;
  --radius-full: 9999px;

  /* Transition */
  --transition-fast:   150ms cubic-bezier(0.2, 0, 0, 1);
  --transition-normal: 300ms cubic-bezier(0.2, 0, 0, 1);
  --transition-slow:   500ms cubic-bezier(0.2, 0, 0, 1);

  /* Hero gradient */
  --hero-gradient: linear-gradient(
    135deg,
    hsl(248, 80%, 15%) 0%,
    hsl(220, 70%, 20%) 30%,
    hsl(175, 60%, 18%) 60%,
    hsl(248, 72%, 12%) 100%
  );
}

/* ─── Dark Mode Overrides ────────────────────────────────────────────────────── */
@media (prefers-color-scheme: dark) {
  :root {
    --md-sys-color-primary:             hsl(250, 80%, 75%);
    --md-sys-color-on-primary:          hsl(248, 55%, 15%);
    --md-sys-color-primary-container:   hsl(248, 50%, 25%);
    --md-sys-color-on-primary-container:hsl(248, 80%, 90%);

    --md-sys-color-secondary:           hsl(12, 90%, 75%);
    --md-sys-color-secondary-container: hsl(14, 50%, 22%);

    --md-sys-color-background:          hsl(240, 12%, 8%);
    --md-sys-color-on-background:       hsl(240, 10%, 92%);
    --md-sys-color-surface:             hsl(240, 12%, 10%);
    --md-sys-color-surface-variant:     hsl(240, 10%, 16%);
    --md-sys-color-on-surface:          hsl(240, 10%, 90%);
    --md-sys-color-on-surface-variant:  hsl(240, 8%, 62%);

    --md-sys-color-outline:             hsl(240, 6%, 38%);
    --md-sys-color-outline-variant:     hsl(240, 8%, 22%);

    --glass-bg-light:    rgba(255, 255, 255, 0.04);
    --glass-bg-medium:   rgba(255, 255, 255, 0.08);
    --glass-border:      rgba(255, 255, 255, 0.10);
    --glass-shadow:      0 8px 40px rgba(0, 0, 0, 0.30), 0 2px 8px rgba(0, 0, 0, 0.20);
    --glass-shadow-lg:   0 20px 80px rgba(0, 0, 0, 0.45), 0 4px 20px rgba(0, 0, 0, 0.25);
  }
}

/* mdui theme-auto class dark mode */
.mdui-theme-auto:is([data-mdui-theme="dark"], [class*="dark"]) {
  --md-sys-color-primary:             hsl(250, 80%, 75%);
  --md-sys-color-background:          hsl(240, 12%, 8%);
  --md-sys-color-surface:             hsl(240, 12%, 10%);
  --glass-bg-light:    rgba(255, 255, 255, 0.04);
  --glass-border:      rgba(255, 255, 255, 0.10);
}

/* ─── Reset & Base ────────────────────────────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--md-sys-color-background);
  color: var(--md-sys-color-on-background);
  margin: 0;
  padding: 0;
  min-height: 100vh;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ─── Hero Background ─────────────────────────────────────────────────────────── */
.site-hero {
  background: var(--hero-gradient);
  min-height: 100vh;
  position: relative;
  overflow: hidden;
}

/* Animated mesh gradient overlay */
.site-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 20% 40%, hsla(250, 80%, 50%, 0.15) 0%, transparent 60%),
    radial-gradient(ellipse 60% 40% at 80% 60%, hsla(175, 70%, 40%, 0.12) 0%, transparent 55%),
    radial-gradient(ellipse 70% 60% at 50% 80%, hsla(12, 80%, 50%, 0.08) 0%, transparent 65%);
  animation: heroMesh 8s ease-in-out infinite alternate;
  pointer-events: none;
}

@keyframes heroMesh {
  0%   { opacity: 0.6; transform: scale(1);     }
  100% { opacity: 1;   transform: scale(1.05);  }
}

/* ─── Liquid Glass Core Surfaces ─────────────────────────────────────────────── */

/* Card-level glass — applies full optical pipeline */
.liquid-glass-card {
  /* Phase 1 核心: 通过 url() 挂载 SVG 光学滤镜，绝对禁止 backdrop-filter: blur() */
  backdrop-filter: url(#liquid-glass-filter);
  -webkit-backdrop-filter: url(#liquid-glass-filter);

  background: var(--glass-bg-light);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--glass-shadow);

  /* Phase 1 性能红线: contain: strict 隔离光栅化成本 */
  contain: layout style paint;

  position: relative;
  overflow: hidden;
  transition:
    transform var(--transition-normal),
    box-shadow var(--transition-normal),
    border-color var(--transition-normal);
}

.liquid-glass-card::before {
  /* Specular edge highlight — top-left inner glow */
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.18) 0%,
    rgba(255, 255, 255, 0.04) 40%,
    transparent 70%
  );
  pointer-events: none;
  z-index: 1;
}

.liquid-glass-card:hover {
  transform: translateY(-3px) scale(1.005);
  box-shadow: var(--glass-shadow-lg);
  border-color: rgba(255, 255, 255, 0.35);
}

/* Navigation / AppBar glass — subtle version */
.liquid-glass-panel {
  backdrop-filter: url(#liquid-glass-subtle);
  -webkit-backdrop-filter: url(#liquid-glass-subtle);

  background: var(--glass-bg-medium);
  border-bottom: 1px solid var(--glass-border);
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.08);

  contain: layout style paint;
  position: sticky;
  top: 0;
  z-index: 100;
  width: 100%;
}

/* ─── MDUI Component Overrides ───────────────────────────────────────────────── */

/* Top App Bar — glass material */
mdui-top-app-bar {
  --mdui-comp-top-app-bar-color: transparent;
  backdrop-filter: url(#liquid-glass-subtle);
  -webkit-backdrop-filter: url(#liquid-glass-subtle);
  background: var(--glass-bg-medium) !important;
  border-bottom: 1px solid var(--glass-border);
  contain: layout style paint;
}

/* Navigation Drawer */
mdui-navigation-drawer {
  --mdui-comp-navigation-drawer-container-color: var(--md-sys-color-surface);
}

/* Cards */
mdui-card.glass-card {
  background: var(--glass-bg-light);
  backdrop-filter: url(#liquid-glass-filter);
  -webkit-backdrop-filter: url(#liquid-glass-filter);
  border: 1px solid var(--glass-border);
  contain: layout style paint;
  border-radius: var(--radius-lg) !important;
  overflow: hidden;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

mdui-card.glass-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--glass-shadow-lg);
}

/* Chips for tags */
mdui-chip {
  --mdui-comp-chip-container-color: var(--md-sys-color-surface-variant);
  border-radius: var(--radius-full) !important;
  font-size: 0.8125rem;
  font-family: var(--font-sans);
  transition: all var(--transition-fast);
}

mdui-chip:hover {
  --mdui-comp-chip-container-color: var(--md-sys-color-primary-container);
}

/* ─── Layout ──────────────────────────────────────────────────────────────────── */
.site-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-4);
}

.site-main {
  padding-top: 80px; /* Offset for sticky AppBar */
  min-height: calc(100vh - 80px);
}

/* Grid for post listing */
.posts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: var(--space-6);
  padding: var(--space-8) 0;
}

/* Post card inner content */
.post-card-inner {
  padding: var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  position: relative;
  z-index: 2;
}

.post-card-title {
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  font-weight: 600;
  line-height: 1.35;
  color: var(--md-sys-color-on-surface);
  margin: 0;
  text-decoration: none;
}

.post-card-title:hover {
  color: var(--md-sys-color-primary);
}

.post-card-excerpt {
  font-size: 0.9rem;
  color: var(--md-sys-color-on-surface-variant);
  line-height: 1.65;
  margin: 0;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.post-card-meta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-size: 0.8rem;
  color: var(--md-sys-color-on-surface-variant);
}

.post-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: auto;
}

/* ─── Hero Section ───────────────────────────────────────────────────────────── */
.hero-section {
  padding: var(--space-16) 0 var(--space-12);
  text-align: center;
  position: relative;
}

.hero-title {
  font-size: clamp(2rem, 6vw, 4rem);
  font-weight: 700;
  margin: 0 0 var(--space-4);
  background: linear-gradient(
    135deg,
    hsl(250, 80%, 75%) 0%,
    hsl(175, 70%, 65%) 50%,
    hsl(12, 90%, 70%) 100%
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.hero-subtitle {
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  color: rgba(255, 255, 255, 0.75);
  max-width: 600px;
  margin: 0 auto var(--space-8);
  line-height: 1.6;
}

/* ─── Article / Post Page ────────────────────────────────────────────────────── */
.article-wrapper {
  max-width: 760px;
  margin: var(--space-8) auto;
  padding: 0 var(--space-4);
}

.article-header {
  margin-bottom: var(--space-8);
}

.article-title {
  font-size: clamp(1.5rem, 4vw, 2.5rem);
  font-weight: 700;
  line-height: 1.25;
  margin: 0 0 var(--space-4);
  color: var(--md-sys-color-on-surface);
  letter-spacing: -0.015em;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3);
  color: var(--md-sys-color-on-surface-variant);
  font-size: 0.875rem;
}

/* Article body typography — prose styles */
.article-body {
  font-size: 1.0625rem;
  line-height: 1.8;
  color: var(--md-sys-color-on-surface);
}

.article-body h2 {
  font-size: 1.6rem;
  font-weight: 600;
  margin: var(--space-8) 0 var(--space-3);
  padding-bottom: var(--space-2);
  border-bottom: 2px solid var(--md-sys-color-outline-variant);
  letter-spacing: -0.01em;
}

.article-body h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin: var(--space-6) 0 var(--space-2);
}

.article-body p {
  margin: var(--space-4) 0;
}

.article-body a {
  color: var(--md-sys-color-primary);
  text-decoration: underline;
  text-decoration-color: transparent;
  text-underline-offset: 3px;
  transition: text-decoration-color var(--transition-fast);
}

.article-body a:hover {
  text-decoration-color: var(--md-sys-color-primary);
}

.article-body code:not(pre code) {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--md-sys-color-surface-variant);
  padding: 0.15em 0.45em;
  border-radius: 4px;
  color: var(--md-sys-color-secondary);
}

.article-body pre {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  background: var(--md-sys-color-surface-variant);
  border: 1px solid var(--md-sys-color-outline-variant);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  overflow-x: auto;
  line-height: 1.6;
}

.article-body blockquote {
  margin: var(--space-6) 0;
  padding: var(--space-4) var(--space-6);
  border-left: 4px solid var(--md-sys-color-primary);
  background: var(--md-sys-color-primary-container);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--md-sys-color-on-primary-container);
  font-style: italic;
}

.article-body img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  box-shadow: var(--glass-shadow);
}

/* ─── Comments Section ───────────────────────────────────────────────────────── */
.comments-section {
  margin-top: var(--space-12);
  padding-top: var(--space-8);
  border-top: 1px solid var(--md-sys-color-outline-variant);
}

.comments-title {
  font-size: 1.35rem;
  font-weight: 600;
  margin: 0 0 var(--space-6);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.comment-item {
  display: flex;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
  padding: var(--space-4);
  border-radius: var(--radius-md);
  background: var(--glass-bg-light);
  border: 1px solid var(--md-sys-color-outline-variant);
  transition: border-color var(--transition-fast);
}

.comment-item:hover {
  border-color: var(--md-sys-color-primary);
}

.comment-item.is-admin {
  border-color: var(--md-sys-color-primary);
  background: var(--md-sys-color-primary-container);
}

.comment-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  flex-shrink: 0;
  background: linear-gradient(135deg, var(--md-sys-color-primary), var(--md-sys-color-tertiary));
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 600;
  font-size: 1rem;
}

.comment-body {
  flex: 1;
  min-width: 0;
}

.comment-author {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--md-sys-color-on-surface);
  margin-bottom: var(--space-1);
}

.comment-time {
  font-size: 0.78rem;
  color: var(--md-sys-color-on-surface-variant);
  margin-left: var(--space-2);
}

.comment-content {
  font-size: 0.95rem;
  line-height: 1.65;
  color: var(--md-sys-color-on-surface);
  margin-top: var(--space-1);
  word-break: break-word;
}

/* Comment form */
.comment-form {
  margin-top: var(--space-8);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
}

.comment-form mdui-text-field {
  width: 100%;
}

.comment-form .comment-textarea {
  grid-column: 1 / -1;
}

.comment-form .comment-submit {
  grid-column: 1 / -1;
  display: flex;
  justify-content: flex-end;
}

/* ─── Archive Page ────────────────────────────────────────────────────────────── */
.archive-year {
  margin-bottom: var(--space-8);
}

.archive-year-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: var(--space-3);
  color: var(--md-sys-color-primary);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.archive-year-title::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--md-sys-color-outline-variant);
}

/* ─── Forum / Discussion Page ────────────────────────────────────────────────── */
.forum-header {
  background: linear-gradient(135deg, var(--md-sys-color-primary-container), var(--md-sys-color-surface-variant));
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  margin-bottom: var(--space-6);
  text-align: center;
}

.forum-item {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: var(--space-4);
  padding: var(--space-4) var(--space-6);
  border-radius: var(--radius-md);
  background: var(--glass-bg-light);
  border: 1px solid var(--md-sys-color-outline-variant);
  margin-bottom: var(--space-3);
  transition: all var(--transition-fast);
  cursor: pointer;
}

.forum-item:hover {
  border-color: var(--md-sys-color-primary);
  background: var(--md-sys-color-primary-container);
  transform: translateX(4px);
}

/* ─── Micro-animations ────────────────────────────────────────────────────────── */

/* Float animation for hero cards */
@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50%       { transform: translateY(-8px); }
}

/* Skeleton loading shimmer */
@keyframes shimmer {
  0%   { background-position: -200% center; }
  100% { background-position: 200% center; }
}

.skeleton {
  background: linear-gradient(
    90deg,
    var(--md-sys-color-surface-variant) 25%,
    rgba(255,255,255,0.2) 50%,
    var(--md-sys-color-surface-variant) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: var(--radius-sm);
}

/* Fade-in entrance for content */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in-up {
  animation: fadeInUp var(--transition-slow) both;
}

.fade-in-up:nth-child(1) { animation-delay: 0ms; }
.fade-in-up:nth-child(2) { animation-delay: 60ms; }
.fade-in-up:nth-child(3) { animation-delay: 120ms; }
.fade-in-up:nth-child(4) { animation-delay: 180ms; }
.fade-in-up:nth-child(5) { animation-delay: 240ms; }
.fade-in-up:nth-child(6) { animation-delay: 300ms; }

/* Pulse dot for live TG sync indicator */
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%       { opacity: 0.5; transform: scale(1.3); }
}

.live-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: hsl(130, 70%, 50%);
  animation: pulse 2s infinite;
}

/* ─── Scrollbar Styling ──────────────────────────────────────────────────────── */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: var(--md-sys-color-surface-variant);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb {
  background: var(--md-sys-color-outline);
  border-radius: 3px;
  transition: background var(--transition-fast);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--md-sys-color-primary);
}

/* ─── Selection ─────────────────────────────────────────────────────────────── */
::selection {
  background: hsla(250, 80%, 62%, 0.25);
  color: var(--md-sys-color-on-surface);
}

/* ─── Site Footer ───────────────────────────────────────────────────────────── */
.site-footer {
  text-align: center;
  padding: var(--space-8) var(--space-4);
  color: var(--md-sys-color-on-surface-variant);
  font-size: 0.875rem;
  border-top: 1px solid var(--md-sys-color-outline-variant);
}

.site-footer a {
  color: var(--md-sys-color-primary);
  text-decoration: none;
}

/* ─── FAB scroll-to-top ─────────────────────────────────────────────────────── */
#fab-scroll-top {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  z-index: 200;
  opacity: 0;
  transform: scale(0.8) translateY(10px);
  transition: opacity var(--transition-fast), transform var(--transition-fast);
  pointer-events: none;
}

#fab-scroll-top.visible {
  opacity: 1;
  transform: scale(1) translateY(0);
  pointer-events: auto;
}

/* ─── Responsive ─────────────────────────────────────────────────────────────── */
@media (max-width: 768px) {
  .posts-grid {
    grid-template-columns: 1fr;
    gap: var(--space-4);
  }

  .comment-form {
    grid-template-columns: 1fr;
  }

  .hero-section {
    padding: var(--space-12) 0 var(--space-8);
  }

  .article-wrapper {
    padding: 0 var(--space-3);
  }
}

@media (max-width: 480px) {
  .forum-item {
    grid-template-columns: 1fr;
  }
}