:root {
  color-scheme: dark;

  --color-bg: #0d1117;
  --color-bg-soft: #0d1117;
  --color-surface: #0d1117;
  --color-surface-strong: #111827;
  --color-surface-muted: #161b22;
  --color-border: transparent;
  --color-border-strong: transparent;
  --color-text: #d0d7de;
  --color-text-muted: #8b949e;
  --color-text-strong: #f0f6fc;
  --color-link: #58a6ff;
  --color-link-hover: #79c0ff;
  --color-accent: #58a6ff;
  --color-accent-strong: #79c0ff;
  --color-focus-ring: rgba(88, 166, 255, 0.55);
  --color-success: #3fb950;
  --color-success-bg: rgba(63, 185, 80, 0.14);
  --color-danger: #f85149;
  --color-danger-bg: rgba(248, 81, 73, 0.14);

  --space-1: 0.25rem;
  --space-2: 0.375rem;
  --space-3: 0.5rem;
  --space-4: 0.75rem;
  --space-5: 1rem;
  --space-6: 1.25rem;
  --space-7: 1.5rem;
  --space-8: 2rem;
  --space-9: 2.5rem;

  --radius-sm: 0;
  --radius-md: 0;
  --radius-lg: 0;

  --shadow-soft: none;
  --shadow-card: none;

  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "SFMono-Regular", Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  --font-weight-regular: 400;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  --text-xs: 0.78rem;
  --text-sm: 0.875rem;
  --text-md: 1rem;
  --text-lg: 1.18rem;
  --text-xl: clamp(1.35rem, 1.2vw + 1rem, 1.75rem);
  --text-2xl: clamp(1.85rem, 1.8vw + 1.1rem, 2.55rem);

  --line-height-body: 1.65;
  --line-height-heading: 1.18;
  --transition-fast: 120ms ease;
  --sidebar-width: 18rem;
  --content-max-width: 1280px;
}
* {
  box-sizing: border-box;
}

html,
body {
  min-height: 100%;
  background: var(--color-bg);
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--text-md);
  font-weight: var(--font-weight-regular);
  line-height: var(--line-height-body);
  color: var(--color-text);
}

button,
input,
textarea {
  font: inherit;
  color: inherit;
}

button {
  appearance: none;
}

img {
  max-width: 100%;
}

::selection {
  background: rgba(88, 166, 255, 0.35);
  color: var(--color-text-strong);
}

.app-shell__inner {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.container {
  width: min(100%, var(--content-max-width));
  margin-inline: auto;
  padding-inline: var(--space-7);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  width: 100%;
  margin-bottom: var(--space-7);
  background: var(--color-surface-strong);
}

.site-header__inner {
  width: 100%;
  min-height: 3.75rem;
  margin: 0 auto;
  padding: var(--space-2) var(--space-7);
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.site-header__brand,
.site-header__actions,
.header-actions,
.header-auth {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.site-header__brand {
  margin-right: auto;
}

.site-header__actions {
  justify-content: flex-end;
  flex-wrap: wrap;
}

.site-header__home,
.site-header .sidebar-toggle {
  width: 2.25rem;
  height: 2.25rem;
  padding: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.site-header__home {
  color: var(--color-text);
  text-decoration: none;
  border: 1px solid rgba(139, 148, 158, 0.35);
  background: var(--color-surface);
}

.site-header__home:hover,
.site-header .sidebar-toggle:hover,
.header-link:hover,
.btn--ghost:hover {
  border-color: var(--color-accent);
  background: var(--color-surface-muted);
  text-decoration: none;
}

.site-header__home:focus-visible,
.header-link:focus-visible,
.btn:focus-visible,
.form-control:focus-visible,
.file-tree__link:focus-visible,
.file-tree__dir > summary:focus-visible {
  outline: 2px solid var(--color-focus-ring);
  outline-offset: 1px;
  box-shadow: none;
}

.site-header__home-icon,
.sidebar-toggle__icon {
  width: 1.18rem;
  height: 1.18rem;
  display: block;
}

.site-header__home-icon {
  fill: currentColor;
}

.sidebar-toggle__icon {
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
}

.site-main {
  width: 100%;
  padding-bottom: var(--space-9);
}

.page-grid {
  display: grid;
  grid-template-columns: minmax(0, var(--sidebar-width)) minmax(0, 1fr);
  gap: var(--space-7);
  align-items: flex-start;
}

.page-grid--sidebar-hidden {
  grid-template-columns: minmax(0, 1fr);
}

.article {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(22rem, 0.85fr);
  gap: var(--space-6);
  align-items: flex-start;
}

.article--single {
  grid-template-columns: minmax(0, 1fr);
}

.article--single .article__editor,
.article__preview,
.not-found,
.form-card {
  background: var(--color-surface);
  box-shadow: none;
}

.article--single .article__editor {
  padding: var(--space-8);
}

.article__preview {
  padding: var(--space-7);
}

.sidebar {
  width: var(--sidebar-width);
  padding: var(--space-5);
  position: sticky;
  top: 4.75rem;
  max-height: calc(100vh - 5.75rem);
  overflow-y: auto;
  background: transparent;
}

.sidebar.sidebar--hidden {
  display: none;
}

.sidebar__header {
  margin-bottom: var(--space-4);
  color: var(--color-text-strong);
  font-size: var(--text-sm);
  font-weight: var(--font-weight-bold);
}

.sidebar-toggle {
  display: inline-flex;
}

.file-tree {
  margin: 0;
  padding-left: 0;
  display: grid;
  gap: 0.08rem;
  list-style: none;
}

.file-tree .file-tree {
  margin-top: 0.12rem;
  padding-left: var(--space-4);
  border-left: 0;
}

.file-tree__item {
  margin: 0;
}

.file-tree__dir > summary {
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0.22rem 0.35rem;
  border: 1px solid transparent;
  transition: background var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast);
}

.file-tree__dir > summary::marker,
.file-tree__dir > summary::-webkit-details-marker {
  content: "";
  display: none;
}

.file-tree__dir > summary::before {
  content: "›";
  width: 1rem;
  height: 1rem;
  flex: 0 0 1rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  font-size: 1.05rem;
  line-height: 1;
  transform-origin: center;
  transition: transform var(--transition-fast), color var(--transition-fast);
}

.file-tree__dir[open] > summary::before {
  transform: rotate(90deg);
  color: var(--color-accent);
}

.file-tree__dir[open] > summary,
.file-tree__dir > summary:hover,
.file-tree__link:hover,
.file-tree__link.active,
.file-tree__summary.active {
  border-color: transparent;
  background: var(--color-surface-muted);
}

.file-tree__link {
  min-width: 0;
  display: block;
  padding: 0.22rem 0.35rem;
  border: 1px solid transparent;
  color: var(--color-link);
  line-height: 1.35;
  transition: background var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast);
}

.file-tree__link--summary {
  flex: 1;
  display: inline;
  padding: 0;
  border: 0;
}

.file-tree__link--summary:hover {
  background: transparent;
}

.file-tree__link.active {
  color: var(--color-text-strong);
  font-weight: var(--font-weight-semibold);
}

.header-actions__form {
  margin: 0;
}

.header-identity {
  padding: 0.4rem 0.65rem;
  background: var(--color-surface);
  color: var(--color-text-muted);
  font-size: var(--text-sm);
}

.header-link,
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-height: 2.25rem;
  padding: 0.45rem 0.75rem;
  border: 1px solid transparent;
  background: transparent;
  color: var(--color-text);
  cursor: pointer;
  font-size: var(--text-sm);
  font-weight: var(--font-weight-semibold);
  line-height: 1;
  text-decoration: none;
  transition: background var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast);
}

.btn--primary,
.header-link--primary {
  border-color: var(--color-accent);
  background: var(--color-accent);
  color: #0d1117;
}

.btn--primary:hover,
.header-link--primary:hover {
  border-color: var(--color-accent-strong);
  background: var(--color-accent-strong);
  color: #0d1117;
}

.btn--ghost,
.header-link:not(.header-link--primary) {
  border-color: rgba(139, 148, 158, 0.35);
  background: var(--color-surface);
}

.btn--small {
  min-height: 2.15rem;
  padding: 0.4rem 0.65rem;
}

.form-card {
  width: min(100%, 32rem);
  padding: var(--space-8);
}

.auth-layout {
  min-height: calc(100vh - 10rem);
  display: flex;
  align-items: center;
  justify-content: center;
}

.form-grid,
.new-file {
  display: grid;
  gap: var(--space-4);
}

.new-file {
  margin-top: var(--space-5);
  padding-top: var(--space-5);
  border-top: 0;
}

.form-label {
  display: grid;
  gap: var(--space-2);
  color: var(--color-text-strong);
  font-size: var(--text-sm);
  font-weight: var(--font-weight-semibold);
}

.form-help {
  margin: 0;
  color: var(--color-text-muted);
  font-size: var(--text-sm);
}

.form-control {
  width: 100%;
  padding: 0.65rem 0.75rem;
  border: 1px solid transparent;
  background: var(--color-surface-muted);
  color: var(--color-text);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-fast);
}

.form-control:hover,
.form-control:focus-visible {
  border-color: var(--color-accent);
}

.form-control--textarea {
  min-height: 12rem;
  resize: vertical;
}

.form-control--mono {
  font-family: var(--font-mono);
  font-size: 0.92rem;
}

.alert,
.status {
  font-size: var(--text-sm);
}

.alert {
  padding: var(--space-4) var(--space-5);
  background: var(--color-surface-strong);
}

.alert--info,
.status--saving {
  border-color: var(--color-accent);
  background: rgba(88, 166, 255, 0.14);
}

.alert--success,
.status--success {
  border-color: var(--color-success);
  background: var(--color-success-bg);
}

.alert--error,
.status--error {
  border-color: var(--color-danger);
  background: var(--color-danger-bg);
}

.status {
  min-height: 2rem;
  padding: 0.35rem 0.65rem;
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}

.status--idle {
  border-color: transparent;
  background: transparent;
  color: var(--color-text-muted);
}

.article__status {
  margin-top: var(--space-3);
}

h1,
h2,
h3,
h4,
h5,
h6 {
  margin: 0 0 var(--space-5);
  color: var(--color-text-strong);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-heading);
}

h1 {
  padding-bottom: var(--space-2);
  font-size: var(--text-2xl);
}

h2 {
  margin-top: var(--space-8);
  padding-bottom: var(--space-2);
  font-size: var(--text-xl);
}

h3 {
  margin-top: var(--space-7);
  font-size: var(--text-lg);
}

p,
ul,
ol,
blockquote,
pre,
table {
  margin-top: 0;
  margin-bottom: var(--space-5);
}

p {
  max-width: 78ch;
}

ul,
ol {
  padding-left: var(--space-7);
}

li + li {
  margin-top: 0.25rem;
}

a {
  color: var(--color-link);
  text-decoration: none;
  text-underline-offset: 0.18em;
}

a:hover {
  color: var(--color-link-hover);
  text-decoration: underline;
}

strong {
  color: var(--color-text-strong);
  font-weight: var(--font-weight-bold);
}

hr {
  border: 0;
  border-top: 0;
  margin: var(--space-8) 0;
}

blockquote {
  padding: var(--space-3) var(--space-5);
  background: var(--color-surface-strong);
  color: var(--color-text-muted);
}

code {
  padding: 0.12rem 0.28rem;
  background: var(--color-surface-strong);
  font-family: var(--font-mono);
  font-size: 0.88em;
}

pre {
  overflow-x: auto;
  padding: var(--space-5);
  background: var(--color-surface-strong);
}

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

.article__editor .form-control {
  width: 100%;
  min-height: 70vh;
  padding: var(--space-5);
}

.article img {
  display: block;
  width: auto;
  max-width: 100%;
  height: auto;
}

.article__preview {
  position: sticky;
  top: 4.75rem;
  max-height: calc(100vh - 5.75rem);
  overflow-y: auto;
}

.not-found {
  max-width: 42rem;
  margin: var(--space-9) auto;
  padding: var(--space-9);
  text-align: center;
}

.not-found h1 {
  margin-top: 0;
}

.not-found p {
  margin-inline: auto;
  margin-bottom: var(--space-7);
  color: var(--color-text-muted);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 900px) {
  .container {
    padding-inline: var(--space-4);
  }

  .site-header__inner {
    min-height: auto;
    padding: var(--space-2) var(--space-4);
    flex-wrap: wrap;
  }

  .site-header__actions {
    width: 100%;
    justify-content: flex-start;
  }

  .page-grid,
  .article {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--space-4);
  }

  .sidebar {
    display: none;
    position: relative;
    top: 0;
    width: 100%;
    max-height: none;
  }

  .sidebar.sidebar--open {
    display: block;
  }

  .article--single .article__editor,
  .article__preview,
  .not-found,
  .form-card {
    padding: var(--space-5);
  }

  .article__preview {
    position: static;
    max-height: none;
  }

  .article__editor .form-control {
    min-height: 45vh;
    max-height: 65vh;
  }
}