/* ========================================
   Base element overrides (post-reset)
   ======================================== */

strong, b { font-weight: bold; }

/* ========================================
   CSS Custom Properties (Theme Colors)
   ======================================== */

:root {
  /* Background */
  --color-bg: #ffffff;
  --color-bg-muted: #f3f4f6;
  --color-bg-hover: #f9fafb;

  /* Text */
  --color-text: #374151;
  --color-heading: #111827;
  --color-muted: #6b7280;
  --color-light: #9ca3af;

  /* Accent (emerald) */
  --color-accent: #047857;
  --color-accent-hover: #059669;

  /* Borders */
  --color-border: #e5e7eb;
  --color-border-strong: #d1d5db;

  /* Alerts */
  --color-warning-bg: #fef3c7;
  --color-warning-border: #f59e0b;
  --color-warning-text: #78350f;

  --color-info-bg: #dbeafe;
  --color-info-border: #3b82f6;
  --color-info-text: #1e3a8a;

  --color-success-bg: #d1fae5;
  --color-success-border: #10b981;
  --color-success-text: #065f46;

  --color-error-bg: #fee2e2;
  --color-error-border: #ef4444;
  --color-error-text: #991b1b;
}

.dark {
  --color-bg: #111827;
  --color-bg-muted: #1f2937;
  --color-bg-hover: #1f2937;

  --color-text: #d1d5db;
  --color-heading: #d1d5db;
  --color-muted: #9ca3af;
  --color-light: #9ca3af;

  --color-accent: #6ee7b7;
  --color-accent-hover: #a7f3d0;

  --color-border: #374151;
  --color-border-strong: #374151;
}

/* ========================================
   Base Styles
   ======================================== */

* {
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-size: 1.125rem;
  line-height: 1.75;
  font-family: 'System UI', -apple-system, BlinkMacSystemFont, 'Avenir Next', Avenir, 'Segoe UI', 'Helvetica Neue', Helvetica, Cantarell, Ubuntu, Roboto, Noto, Arial, sans-serif;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  color: var(--color-heading);
  margin-bottom: 1.25rem;
  padding-top: 0.5rem;
}

h1 { font-size: 2.25rem; line-height: 2.5rem; }
h2 { font-size: 1.875rem; line-height: 2.5rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

hr {
  border-color: var(--color-border);
}

p, hr, pre, dl, details {
  margin-bottom: 1.25rem;
}

article > h1, article > h2 {
  margin-bottom: 0.25rem;
}

code {
  background-color: var(--color-bg-muted);
  border-radius: 0.5rem;
  font-size: 0.875rem;
  border: 1px solid var(--color-border);
  padding: 0.25rem 0.5rem;
  font-family: ui-monospace, SFMono-Regular, 'SF Mono', Menlo, Consolas, 'Liberation Mono', monospace;
}

pre {
  border-radius: 0.5rem;
  border: 1px solid var(--color-border);
  padding: 1.25rem;
  overflow: auto;
  font-size: 1rem;
}

pre code {
  background-color: transparent;
  border: 0;
  padding: 0;
}

pre.mermaid {
  background: transparent;
  border: none;
  padding: 0;
  text-align: center;
}

figure {
  margin-bottom: 1.25rem;
}

figcaption {
  font-size: 1rem;
  color: var(--color-muted);
  margin-top: 0.5rem;
}

blockquote {
  font-size: 1.25rem;
  color: var(--color-muted);
  font-style: italic;
  border-left: 4px solid var(--color-border-strong);
  padding-left: 1rem;
  margin-bottom: 1.25rem;
}

ul, ol {
  margin-bottom: 1.25rem;
  margin-left: 1.5rem;
}

ol { list-style-type: decimal; }
ul { list-style-type: disc; }

nav ul, footer ul {
  list-style: none;
  margin-left: 0;
}

header h1 {
  margin-bottom: 0;
}

/* Tables */
.table-wrapper {
  display: block;
  overflow-x: auto;
  margin-bottom: 1.25rem;
}

table {
  width: 100%;
  border: 1px solid var(--color-border);
  border-radius: 0.375rem;
  border-collapse: separate;
  border-spacing: 0;
  display: table;
}

thead th {
  border-bottom: 2px solid var(--color-border);
  border-right: 1px solid var(--color-border);
  padding: 0.5rem 0.75rem;
  white-space: nowrap;
}

thead th:last-child { border-right: 0; }

tbody td {
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid var(--color-border);
  font-size: 1rem;
  border-right: 1px solid var(--color-border);
  white-space: nowrap;
}

tbody td:last-child { border-right: 0; }
tbody tr:last-child td { border-bottom: 0; }

@media (min-width: 768px) {
  table { width: auto; min-width: 500px; }
  thead th, tbody td { white-space: normal; }
}

/* Definition lists */
dt { font-weight: 700; font-style: italic; }
dd { padding-left: 2.5rem; }

/* Navigation */
header nav > ul {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  text-transform: uppercase;
  font-size: 0.75rem;
  font-weight: 600;
  gap: 1.75rem;
}

nav a, footer a {
  color: var(--color-muted);
  font-weight: 600;
}

nav a:hover, footer a:hover {
  color: var(--color-heading);
}

nav a.active {
  color: var(--color-heading);
}

footer {
  font-size: 0.75rem;
}

/* ========================================
   Component Classes
   ======================================== */

/* Site title */
#site-title {
  text-align: center;
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--color-heading);
}

/* Header links (title, avatar) should not be underlined */
header a {
  text-decoration: none;
  color: inherit;
}

@media (min-width: 640px) {
  #site-title { text-align: left; }
}

/* Theme toggle button */
button {
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
  color: var(--color-text);
}

/* Avatar */
.avatar {
  flex: none;
  width: 5rem;
  height: 5rem;
  border-radius: 9999px;
  overflow: hidden;
}

.avatar a {
  display: block;
  width: 100%;
  height: 100%;
}

.avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 9999px;
}

/* Title variants */
.title-large {
  font-size: 1.75rem;
  line-height: 1.4;
  font-weight: 700;
  color: var(--color-heading);
  text-wrap: balance;
}

@media (min-width: 640px) {
  .title-large {
    font-size: 2.25rem;
  }
}

.title-small {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--color-heading);
}

/* Content area */
#content {
  line-height: 1.625;
}

#content img {
  max-width: 100%;
  height: auto;
  display: block;
  margin-left: auto;
  margin-right: auto;
}

#content a {
  text-decoration: underline;
  font-weight: 700;
  color: var(--color-accent);
}

#content a:hover {
  color: var(--color-accent-hover);
}

#content .date {
  padding: 0.5rem 0;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-light);
}

#content article > h2 {
  line-height: 1.75rem;
}

#content h2 > a {
  text-decoration: none;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-heading);
}

#content h2 > a:hover {
  text-decoration: underline;
  color: var(--color-heading);
}

#content .meta {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-muted);
  display: flex;
  gap: 0.75rem;
  margin-top: 0.5rem;
}

#content .meta a {
  text-decoration: none;
}

#content .description {
  color: var(--color-text);
  font-size: 1rem;
}

#content .read-more {
  text-decoration: none;
  display: inline-flex;
  gap: 0.5rem;
  font-size: 0.875rem;
  font-weight: 600;
  align-items: center;
  color: var(--color-accent);
}

#content .read-more:hover {
  color: var(--color-accent-hover);
}

/* Footnotes */
#content .footnotes {
  font-size: 0.875rem;
}

#content .footnotes p {
  display: inline-block;
  margin-bottom: 0;
}

#content .footnotes ol {
  display: block;
}

#content .footnotes li {
  margin-bottom: 0.75rem;
}

/* Alert boxes */
#content .alert-box {
  padding: 1rem 1rem 0.25rem 1rem;
  margin-bottom: 1.25rem;
  border-top: 4px solid;
}

#content .alert-box .alert-title {
  color: inherit;
  font-weight: 600;
  font-size: 1.125rem;
  padding: 0;
  margin-bottom: 0.5rem;
}

#content .alert-box a {
  color: inherit;
}

#content .alert-box a:hover {
  color: inherit;
}

#content .alert-box .alert-icon {
  width: 1.75rem;
  height: 1.75rem;
  margin-right: 0.5rem;
  flex-shrink: 0;
}

#content .alert-box p {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 0.5rem;
}

#content .alert-box.warning {
  background-color: var(--color-warning-bg);
  border-color: var(--color-warning-border);
  color: var(--color-warning-text);
}

#content .alert-box.info {
  background-color: var(--color-info-bg);
  border-color: var(--color-info-border);
  color: var(--color-info-text);
}

#content .alert-box.success {
  background-color: var(--color-success-bg);
  border-color: var(--color-success-border);
  color: var(--color-success-text);
}

#content .alert-box.error {
  background-color: var(--color-error-bg);
  border-color: var(--color-error-border);
  color: var(--color-error-text);
}

/* Table of contents */
#content .table-of-contents {
  background-color: var(--color-bg-muted);
  color: var(--color-text);
  padding: 1rem;
  border: 1px solid var(--color-border);
  border-radius: 0.5rem;
}

#content .table-of-contents #TableOfContents ul {
  list-style-type: decimal;
  list-style-position: inside;
  margin-left: 1rem;
}

#content .table-of-contents #TableOfContents ul li {
  margin: 0.5rem 0;
  font-size: 1rem;
}

#content .table-of-contents #TableOfContents ul li a {
  font-weight: 400;
  text-decoration: none;
  color: var(--color-text);
}

#content .table-of-contents #TableOfContents ul li a:hover {
  text-decoration: underline;
  color: var(--color-accent-hover);
}

/* Pagination button */
#content .pagination-button {
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--color-border-strong);
  font-size: 0.875rem;
  border-radius: 0.375rem;
  color: var(--color-text);
  background-color: var(--color-bg);
}

#content .pagination-button:hover {
  background-color: var(--color-bg-hover);
  color: var(--color-heading);
}

/* Taxonomy list (tags/categories) */
#content .taxonomy-list {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  gap: 0.5rem 0.5rem;
  list-style: none;
  margin-left: 0;
}

#content .taxonomy-list a {
  font-weight: 400;
  text-decoration: none;
  font-size: 1rem;
  color: var(--color-heading);
  background-color: var(--color-bg-muted);
  padding: 0.5rem 0.75rem;
  border-radius: 0.5rem;
}

#content .taxonomy-list a:hover {
  background-color: var(--color-border);
}

#content .tags-list {
  gap: 0.5rem;
}

/* Task lists */
#content span.task-list + ul {
  list-style: none;
}

/* Category link (used in list/categories.html) */
.category-link {
  background-color: var(--color-bg-muted);
  padding: 0.5rem 0.75rem;
  border-radius: 0.5rem;
  transition: background-color 0.5s;
}

.category-link:hover {
  background-color: var(--color-border);
}

/* ========================================
   Layout Utilities
   ======================================== */

/* Container */
.container {
  max-width: 768px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 0.625rem;
  padding-right: 0.625rem;
}

/* Flexbox */
.flex { display: flex; }
.flex-col { display: flex; flex-direction: column; }
.flex-row { display: flex; flex-direction: row; }
.flex-wrap { flex-wrap: wrap; }
.flex-none { flex: none; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-end { justify-content: flex-end; }

/* Grid */
.grid { display: grid; }
.grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }

/* Gap */
.gap-1 { gap: 0.25rem; }
.gap-2 { gap: 0.5rem; }
.gap-3 { gap: 0.75rem; }
.gap-5 { gap: 1.25rem; }
.gap-7 { gap: 1.75rem; }
.gap-10 { gap: 2.5rem; }

/* Padding */
.py-2 { padding-top: 0.5rem; padding-bottom: 0.5rem; }
.py-4 { padding-top: 1rem; padding-bottom: 1rem; }
.py-10 { padding-top: 2.5rem; padding-bottom: 2.5rem; }
.px-2 { padding-left: 0.5rem; padding-right: 0.5rem; }
.px-3 { padding-left: 0.75rem; padding-right: 0.75rem; }
.pb-10 { padding-bottom: 2.5rem; }
.pb-14 { padding-bottom: 3.5rem; }
.pt-5 { padding-top: 1.25rem; }

/* Margin */
.mt-2 { margin-top: 0.5rem; }
.mb-5 { margin-bottom: 1.25rem; }

/* Width/Height */
.w-4 { width: 1rem; }
.w-8 { width: 2rem; }
.w-20 { width: 5rem; }
.h-4 { height: 1rem; }
.h-8 { height: 2rem; }
.h-20 { height: 5rem; }

/* Border radius */
.rounded-full { border-radius: 9999px; }
.rounded-lg { border-radius: 0.5rem; }
.rounded-md { border-radius: 0.375rem; }

/* Overflow */
.overflow-hidden { overflow: hidden; }

/* Typography */
.font-bold { font-weight: 700; }
.font-extrabold { font-weight: 800; }
.font-semibold { font-weight: 600; }

.text-xs { font-size: 0.75rem; line-height: 1rem; }
.text-sm { font-size: 0.875rem; line-height: 1.25rem; }
.text-base { font-size: 1rem; line-height: 1.5rem; }
.text-lg { font-size: 1.125rem; line-height: 1.75rem; }
.text-xl { font-size: 1.25rem; line-height: 1.75rem; }
.text-2xl { font-size: 1.5rem; line-height: 2rem; }
.text-4xl { font-size: 2.25rem; line-height: 2.5rem; }

.text-center { text-align: center; }

.leading-snug { line-height: 1.4; }

.stroke-2 { stroke-width: 2; }

/* ========================================
   Responsive (sm: 640px+)
   ======================================== */

@media (min-width: 640px) {
  .sm\:flex-row { flex-direction: row; }
  .sm\:gap-10 { gap: 2.5rem; }
  .sm\:grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .sm\:text-left { text-align: left; }
}