/* ==========================================================================
   MINIMALIST MONOCHROME DESIGN SYSTEM
   Developer-focused, fast-loading, clean typography
   ========================================================================== */

:root {
  --bg: #ffffff;
  --bg-subtle: #f6f8fa;
  --bg-hover: #f1f3f5;
  --bg-card: #ffffff;
  --text: #1f2328;
  --text-muted: #656d76;
  --text-faint: #8c959f;
  --border: #d0d7de;
  --border-subtle: #e1e4e8;
  --border-focus: #1f2328;
  --accent: #111111;
  --code-bg: #161b22;
  --code-text: #e6edf3;
  --badge-bg: #f3f4f6;
  --badge-text: #374151;
  --tag-bg: #f6f8fa;
  --tag-border: #d0d7de;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans", Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --font-home-header: 'Mountains of Christmas', cursive, sans-serif;
  --font-home-content: 'LXGW WenKai TC', -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-handwritten: 'Mountains of Christmas', cursive, sans-serif;
  --max-w: 740px;
  --radius-sm: 3px;
  --radius: 5px;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-modal: 0 8px 24px rgba(0, 0, 0, 0.12);
}

[data-theme="dark"] {
  --bg: #0d1117;
  --bg-subtle: #161b22;
  --bg-hover: #21262d;
  --bg-card: #161b22;
  --text: #e6edf3;
  --text-muted: #8b949e;
  --text-faint: #6e7681;
  --border: #30363d;
  --border-subtle: #21262d;
  --border-focus: #f0f6fc;
  --accent: #f0f6fc;
  --code-bg: #090d13;
  --code-text: #e6edf3;
  --badge-bg: #21262d;
  --badge-text: #c9d1d9;
  --tag-bg: #161b22;
  --tag-border: #30363d;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-modal: 0 8px 24px rgba(0, 0, 0, 0.6);
}

/* Base reset */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.7;
  transition: background-color 0.15s ease, color 0.15s ease, border-color 0.15s ease;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Layout container */
.container {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
}

main.content {
  flex: 1 0 auto;
  padding: 2.5rem 0 4rem;
}

/* Header */
.site-header {
  border-bottom: 1px solid var(--border-subtle);
  padding: 1.25rem 0;
  background-color: var(--bg);
  position: sticky;
  top: 0;
  z-index: 50;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.site-brand {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.02em;
  font-family: var(--font-mono);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.site-brand:hover {
  opacity: 0.85;
}

.brand-cursor {
  display: inline-block;
  width: 7px;
  height: 15px;
  background-color: var(--accent);
  vertical-align: middle;
  animation: blink 1.2s step-end infinite;
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 1.25rem;
  align-items: center;
}

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.15s;
}

.nav-link:hover,
.nav-link.active {
  color: var(--text);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-left: 0.5rem;
  border-left: 1px solid var(--border-subtle);
  padding-left: 0.75rem;
}

/* Icon Buttons */
.btn-icon {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-muted);
  width: 34px;
  height: 34px;
  border-radius: var(--radius);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.15s;
}

.btn-icon:hover {
  background-color: var(--bg-hover);
  color: var(--text);
  border-color: var(--border-subtle);
}

.btn-icon svg {
  width: 17px;
  height: 17px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* Search trigger in nav */
.search-trigger-badge {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 0.15rem 0.4rem;
  border-radius: var(--radius-sm);
  background: var(--bg-subtle);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  margin-left: 0.25rem;
}

/* Hero / Profile */
.hero {
  margin-bottom: 3rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border-subtle);
}

.hero-title {
  font-size: 1.85rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 0.75rem;
  color: var(--text);
}

.hero-bio {
  color: var(--text-muted);
  font-size: 1.05rem;
  line-height: 1.6;
}

/* Section Headings */
.section-title {
  font-size: 0.85rem;
  font-family: var(--font-mono);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.section-title::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--border-subtle);
}

/* Post list */
.post-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.post-item {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  transition: transform 0.1s ease;
}

.post-meta-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.post-item-title {
  font-size: 1.2rem;
  font-weight: 600;
  line-height: 1.4;
  letter-spacing: -0.01em;
}

.post-item-title a {
  color: var(--text);
  text-decoration: none;
}

.post-item-title a:hover {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.post-item-summary {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.55;
  margin-top: 0.2rem;
}

.post-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 0.35rem;
}

.tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 0.15rem 0.5rem;
  background: var(--tag-bg);
  border: 1px solid var(--tag-border);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  text-decoration: none;
  transition: all 0.15s;
}

.tag:hover {
  background: var(--bg-hover);
  color: var(--text);
  border-color: var(--text-muted);
}

.badge-draft {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  padding: 0.1rem 0.4rem;
  background-color: var(--bg-subtle);
  border: 1px dashed var(--text-faint);
  color: var(--text-muted);
  border-radius: var(--radius-sm);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* Post single reading page */
.post-header {
  margin-bottom: 2.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-subtle);
}

.post-title {
  font-size: 2.25rem;
  font-weight: 700;
  letter-spacing: -0.035em;
  line-height: 1.25;
  margin-bottom: 1rem;
}

.post-meta-detailed {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-muted);
}

.post-cover-image {
  margin: 1.5rem 0 2rem;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border-subtle);
}

.post-cover-image img {
  width: 100%;
  height: auto;
  display: block;
}

/* Typography & Prose */
.prose {
  color: var(--text);
  font-size: 1.05rem;
  line-height: 1.75;
}

.prose > * + * {
  margin-top: 1.4rem;
}

.prose h1, .prose h2, .prose h3, .prose h4 {
  color: var(--text);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.35;
  margin-top: 2.2rem;
  margin-bottom: 0.8rem;
}

.prose h1 { font-size: 1.75rem; }
.prose h2 { font-size: 1.45rem; border-bottom: 1px solid var(--border-subtle); padding-bottom: 0.3rem; }
.prose h3 { font-size: 1.2rem; }
.prose h4 { font-size: 1.05rem; }

.prose p {
  margin-bottom: 1.2rem;
}

.prose a {
  color: var(--text);
  text-decoration: underline;
  text-underline-offset: 3px;
  font-weight: 500;
}

.prose a:hover {
  opacity: 0.75;
}

.prose strong {
  color: var(--text);
  font-weight: 600;
}

.prose ul, .prose ol {
  padding-left: 1.5rem;
  margin-bottom: 1.2rem;
}

.prose li {
  margin-bottom: 0.4rem;
}

.prose li::marker {
  color: var(--text-faint);
}

.prose blockquote {
  border-left: 3px solid var(--border);
  padding: 0.5rem 0 0.5rem 1.25rem;
  color: var(--text-muted);
  font-style: italic;
  margin: 1.5rem 0;
}

.prose hr {
  border: none;
  border-top: 1px solid var(--border-subtle);
  margin: 2.5rem 0;
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.95rem;
}

.prose th, .prose td {
  padding: 0.65rem 0.85rem;
  border: 1px solid var(--border-subtle);
  text-align: left;
}

.prose th {
  background: var(--bg-subtle);
  font-weight: 600;
}

/* Inline code */
.prose code:not(pre code) {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--bg-subtle);
  padding: 0.15rem 0.35rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
  color: var(--text);
}

/* Pre / Code Blocks */
.highlight, pre {
  margin: 1.5rem 0;
  background-color: var(--code-bg) !important;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  position: relative;
  overflow: hidden;
}

pre {
  padding: 1.15rem 1.25rem;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  line-height: 1.55;
  color: var(--code-text);
}

pre code {
  font-family: inherit;
  font-size: inherit;
  background: transparent !important;
  padding: 0;
  border: none;
  color: inherit;
}

/* Code block copy button */
.code-copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  padding: 0.25rem 0.55rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  background: rgba(255, 255, 255, 0.1);
  color: #c9d1d9;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-sm);
  cursor: pointer;
  opacity: 0;
  transition: all 0.15s ease;
  z-index: 5;
}

.highlight:hover .code-copy-btn,
pre:hover .code-copy-btn {
  opacity: 1;
}

.code-copy-btn:hover {
  background: rgba(255, 255, 255, 0.2);
  color: #ffffff;
}

/* Search Modal */
.search-modal-backdrop {
  position: fixed;
  inset: 0;
  background-color: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(2px);
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding-top: 12vh;
  z-index: 100;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s ease;
}

.search-modal-backdrop.open {
  opacity: 1;
  pointer-events: auto;
}

.search-dialog {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-modal);
  width: 100%;
  max-width: 580px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  max-height: 70vh;
}

.search-input-wrapper {
  display: flex;
  align-items: center;
  padding: 0.85rem 1rem;
  border-bottom: 1px solid var(--border-subtle);
  gap: 0.75rem;
}

.search-input-wrapper svg {
  width: 18px;
  height: 18px;
  color: var(--text-muted);
}

.search-input {
  flex: 1;
  background: transparent;
  border: none;
  outline: none;
  font-size: 1rem;
  font-family: var(--font-sans);
  color: var(--text);
}

.search-results {
  list-style: none;
  overflow-y: auto;
  padding: 0.5rem 0;
  margin: 0;
}

.search-result-item {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--border-subtle);
  cursor: pointer;
  transition: background-color 0.1s;
}

.search-result-item:last-child {
  border-bottom: none;
}

.search-result-item:hover,
.search-result-item.selected {
  background: var(--bg-hover);
}

.search-result-title {
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.2rem;
}

.search-result-summary {
  font-size: 0.84rem;
  color: var(--text-muted);
  line-height: 1.4;
}

.search-footer {
  padding: 0.6rem 1rem;
  font-size: 0.78rem;
  font-family: var(--font-mono);
  color: var(--text-faint);
  border-top: 1px solid var(--border-subtle);
  background: var(--bg-subtle);
  display: flex;
  justify-content: space-between;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border-subtle);
  padding: 2rem 0;
  font-size: 0.88rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.site-footer .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

/* Responsive */
@media (max-width: 640px) {
  .site-header .container {
    flex-direction: column;
    align-items: flex-start;
  }
  .site-nav {
    width: 100%;
    justify-content: space-between;
  }
  .post-title {
    font-size: 1.8rem;
  }
  .search-modal-backdrop {
    padding-top: 2rem;
    padding-left: 1rem;
    padding-right: 1rem;
  }
}

/* ==========================================================================
   HOMEPAGE TYPOGRAPHY
   Header: Mountains of Christmas (Bold)
   Content: LXGW WenKai TC (Regular)
   ========================================================================== */

.homepage-container {
  padding-top: 0.5rem;
  font-family: var(--font-home-content);
  font-weight: 400;
}

/* Header Elements: Mountains of Christmas Bold */
.home-greeting,
.homepage-container h1,
.homepage-container h2,
.homepage-container h3,
.homepage-container .section-title,
.homepage-container .post-item-title,
.homepage-container .home-pillar-title,
.homepage-container .home-note-signature {
  font-family: var(--font-home-header);
  font-weight: 700;
}

.home-greeting {
  font-family: var(--font-home-header);
  font-weight: 700;
  font-size: 3.2rem;
  line-height: 1.25;
  letter-spacing: 0.01em;
  color: var(--text);
  margin-bottom: 0.85rem;
}

.homepage-container .section-title {
  font-family: var(--font-home-header);
  font-weight: 700;
  font-size: 1.45rem;
  letter-spacing: 0.03em;
  text-transform: none;
}

.homepage-container .post-item-title {
  font-family: var(--font-home-header);
  font-weight: 700;
  font-size: 1.4rem;
  letter-spacing: 0.01em;
}

.home-pillar-title {
  font-family: var(--font-home-header);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text);
  margin-bottom: 0.35rem;
  display: flex;
  align-items: center;
  gap: 0.45rem;
}

.home-note-signature {
  font-family: var(--font-home-header);
  font-weight: 700;
  font-size: 1.95rem;
  color: var(--text);
  margin-top: 1.25rem;
  text-align: right;
  letter-spacing: 0.02em;
}

/* Content Elements: LXGW WenKai TC Regular */
.home-lead,
.home-note-text,
.home-pillar-desc,
.homepage-container .post-item-summary,
.homepage-container .post-meta-row,
.homepage-container p {
  font-family: var(--font-home-content);
  font-weight: 400;
}

.home-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font-home-content);
  font-size: 0.88rem;
  padding: 0.25rem 0.75rem;
  border-radius: 99px;
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.home-lead {
  font-size: 1.2rem;
  color: var(--text-muted);
  line-height: 1.8;
  margin-bottom: 2rem;
  max-width: 640px;
}

/* Note Box */
.home-note-card {
  position: relative;
  background: var(--bg-subtle);
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  padding: 2rem 2.25rem;
  margin: 2.25rem 0 3rem;
  transition: border-color 0.15s ease;
}

.home-note-card::before {
  content: "✦";
  position: absolute;
  top: -10px;
  left: 24px;
  background: var(--bg);
  padding: 0 0.4rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.home-note-text {
  font-size: 1.25rem;
  line-height: 1.85;
  color: var(--text);
}

/* Introduction Pillars Grid */
.home-pillars {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.25rem;
  margin-bottom: 3rem;
}

.home-pillar-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius);
  padding: 1.25rem 1.35rem;
  transition: border-color 0.15s ease;
}

.home-pillar-item:hover {
  border-color: var(--border);
}

.home-pillar-desc {
  font-size: 0.96rem;
  color: var(--text-muted);
  line-height: 1.65;
}

.homepage-container .post-item-summary {
  font-size: 1.02rem;
  line-height: 1.65;
}

.homepage-container .post-meta-row {
  font-size: 0.92rem;
}

/* Call to action & button */
.home-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
  margin-top: 2rem;
}

.btn-primary-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--text);
  color: var(--bg);
  padding: 0.6rem 1.25rem;
  border-radius: var(--radius);
  font-family: var(--font-home-content);
  font-size: 0.95rem;
  font-weight: 400;
  text-decoration: none;
  transition: opacity 0.15s ease;
}

.btn-primary-link:hover {
  opacity: 0.88;
}

.btn-secondary-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--text);
  padding: 0.6rem 1rem;
  font-family: var(--font-home-content);
  font-size: 0.95rem;
  font-weight: 400;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.btn-secondary-link:hover {
  opacity: 0.8;
}

/* Mobile adjustments */
@media (max-width: 640px) {
  .home-greeting {
    font-size: 2.4rem;
  }
  .home-note-text {
    font-size: 1.15rem;
  }
  .home-note-card {
    padding: 1.5rem 1.25rem;
  }
}