@layer base {
  /* --------------------------------------------------------------------------
   ROOT CONFIGURATION
   -------------------------------------------------------------------------- */

  :root {
    /* Fluid spacing scale */
    --spacing-xs: clamp(0.5rem, 0.375rem + 0.625vw, 0.75rem);
    --spacing-sm: clamp(0.75rem, 0.5625rem + 0.9375vw, 1.25rem);
    --spacing-md: clamp(1rem, 0.75rem + 1.25vw, 1.5rem);
    --spacing-lg: clamp(1.5rem, 1.125rem + 1.875vw, 2.5rem);
    --spacing-xl: clamp(2rem, 1.5rem + 2.5vw, 3rem);

    /* Utility variables */
    --scroll-offset: 5rem;

    /* System font stacks - optimal performance & consistency */
    --font-family-base: system-ui, -apple-system, 'Segoe UI', Roboto,
      'Helvetica Neue', Arial, 'Noto Sans', sans-serif;
    --font-family-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas,
      'Liberation Mono', 'Courier New', monospace;
  }

  /* --------------------------------------------------------------------------
   BODY - Global Typography Settings
   -------------------------------------------------------------------------- */

  body {
    font-family: var(--font-family-base);
    font-size: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
    line-height: 1.75;

    /* Rendering optimizations */
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;

    /* Progressive enhancement - better line breaks (Chrome 117+, Safari 16.4+) */
    text-wrap: pretty;
  }

  /* --------------------------------------------------------------------------
   HEADINGS (H1-H6) - Structural Hierarchy
   -------------------------------------------------------------------------- */

  :where(h1, h2, h3, h4, h5, h6) {
    font-weight: 600;
    scroll-margin-top: var(--scroll-offset);
  }

  h1 {
    font-size: clamp(2.25rem, 1.95rem + 1.5vw, 3rem);
    line-height: 1.1111;
    font-weight: 800;
    margin-top: 0;
    margin-bottom: var(--spacing-xl);
  }

  h2 {
    font-size: clamp(1.5rem, 1.35rem + 0.75vw, 1.875rem);
    line-height: 1.3333;
    font-weight: 700;
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
  }

  h3 {
    font-size: clamp(1.25rem, 1.15rem + 0.5vw, 1.5rem);
    line-height: 1.5;
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-sm);
  }

  h4 {
    font-size: clamp(1rem, 0.975rem + 0.125vw, 1.125rem);
    line-height: 1.5;
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-sm);
  }

  h5 {
    font-size: 1rem;
    line-height: 1.5;
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-xs);
  }

  h6 {
    font-size: 0.875rem;
    line-height: 1.5;
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-xs);
  }

  :is(h1, h2, h3, h4, h5, h6):first-child {
    margin-top: 0;
  }

  /* --------------------------------------------------------------------------
   LINKS - Clickable Text (Structural Indicators)
   -------------------------------------------------------------------------- */

  a {
    text-decoration-line: underline;
    text-decoration-thickness: 0.0625em;
    text-underline-offset: 0.15em;
    cursor: pointer;
  }

  /* Remove underline from heading links */
  :where(h1, h2, h3, h4, h5, h6) a {
    text-decoration: none;
  }

  /* --------------------------------------------------------------------------
   MENU - Interactive Lists (Toolbars, Navigation)
   -------------------------------------------------------------------------- */

  menu {
    list-style: none;
    margin-bottom: var(--spacing-md);
    padding-left: 0;
  }

  /* Remove custom markers from menu items */
  menu > li::before {
    display: none;
  }

  /* --------------------------------------------------------------------------
   HGROUP - Heading Groups (Title + Subtitle)
   -------------------------------------------------------------------------- */

  hgroup {
    margin-bottom: var(--spacing-lg);
  }

  /* Reduce spacing between heading and subtitle */
  hgroup :where(h1, h2, h3, h4, h5, h6) {
    margin-bottom: var(--spacing-xs);
  }

  /* Subtitle/tagline styling (typically <p>) */
  hgroup :where(p) {
    margin-top: 0;
    margin-bottom: 0;
    font-size: 0.875em;
    font-weight: 400;
    line-height: 1.5;
  }

  /* --------------------------------------------------------------------------
   TEXT CONTENT - Paragraphs & Inline Elements
   -------------------------------------------------------------------------- */

  /* Paragraphs */
  p {
    line-height: 1.75;
    margin-bottom: var(--spacing-md);
  }

  /* Text modifiers - semantic emphasis */
  :where(strong, b) {
    font-weight: 700;
  }

  :where(em, i, cite, var) {
    font-style: italic;
  }

  /* Definition term - semantic emphasis with italic */
  dfn {
    font-style: italic;
    font-weight: 600;
  }

  /* Contextual sizing - uses 'em' to scale with parent */
  small {
    font-size: 0.875em;
    line-height: 1.5;
  }

  /* Keyboard input - typically user actions */
  kbd {
    font-family: var(--font-family-mono);
    font-size: 0.875em;
    font-weight: 600;
  }

  /* Sample output - typically program/system output */
  samp {
    font-family: var(--font-family-mono);
    font-size: 0.875em;
  }

  /* Data element - machine-readable values */
  data {
    font-variant-numeric: tabular-nums;
  }

  /* Superscript & subscript - essential for scientific notation */
  :where(sub, sup) {
    font-size: 0.75em;
    line-height: 0;
    position: relative;
    vertical-align: baseline;
  }
  sup {
    top: -0.5em;
  }
  sub {
    bottom: -0.25em;
  }

  /* Abbreviations with titles */
  abbr[title] {
    text-decoration: underline dotted;
    cursor: help;
  }

  del {
    text-decoration: line-through;
  }

  ins {
    text-decoration: underline;
  }

  /* Strikethrough */
  s {
    text-decoration: line-through;
  }

  /* Underline */
  u {
    text-decoration: underline;
  }

  /* Mark/Highlight element */
  mark {
    font-style: normal;
    font-weight: inherit;
  }

  /* Address element */
  address {
    font-style: italic;
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-md);
  }

  /* Time element */
  time {
    font-style: normal;
    font-variant-numeric: tabular-nums; /* Monospace numbers for alignment */
  }

  /* --------------------------------------------------------------------------
   BLOCKQUOTES - Structural Spacing Only
   -------------------------------------------------------------------------- */

  blockquote {
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    padding-left: var(--spacing-md);
  }

  /* Nested blockquotes - reduced spacing for hierarchy */
  blockquote blockquote {
    margin-top: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
    padding-left: var(--spacing-sm);
  }

  /* Inline quotes */
  q {
    font-style: inherit;
    /* Browser adds quotation marks automatically */
  }

  /* --------------------------------------------------------------------------
   LISTS - Custom Structured Markers (Prose-like)
   -------------------------------------------------------------------------- */

  /* Reset default list styles to build custom ones */
  :where(ul, ol) {
    list-style: none;
    margin-bottom: var(--spacing-md);
    padding-left: clamp(1.5rem, 1.25rem + 1.25vw, 2rem);
  }

  li {
    position: relative;
    padding-left: 0.375em; /* Space between marker and text */
  }

  /* Spacing between list items */
  li + li {
    margin-top: var(--spacing-xs);
  }

  /* Spacing for nested lists - proper separation from parent text */
  li > ul,
  li > ol {
    margin-top: var(--spacing-xs);
    margin-bottom: var(--spacing-sm);
    padding-left: var(--spacing-md);
  }

  /* Perfectly centered dot relative to the first line of text */
  ul > li::before {
    content: '';
    position: absolute;
    left: -1.125em;
    top: calc(
      0.875em - 0.1875em
    ); /* Aligns with center of first line (assuming 1.5 line-height) */
    width: 0.375em;
    height: 0.375em;
    background-color: currentColor;
    border-radius: 50%;
  }

  /* Right-aligned numbers for professional look (e.g. "9." aligns with "10.") */
  ol {
    counter-reset: list-counter;
  }

  ol > li {
    counter-increment: list-counter;
  }

  ol > li::before {
    content: counter(list-counter) '.';
    position: absolute;
    left: -2.5em;
    width: 1.75em;
    text-align: right;
    font-weight: 600;
    color: currentColor;
  }
  /* --------------------------------------------------------------------------
   DEFINITION LISTS - Glossaries & Key-Value Pairs
   -------------------------------------------------------------------------- */

  dl {
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-md);
  }

  dt {
    font-weight: 600;
    margin-top: var(--spacing-sm);
  }

  /* First dt shouldn't have top margin */
  dt:first-child {
    margin-top: 0;
  }

  dd {
    margin-left: var(--spacing-md);
  }

  /* Spacing between term and definition (consistent with lists) */
  dt + dd {
    margin-top: var(--spacing-xs);
  }

  /* Spacing between multiple definitions (consistent with list items) */
  dd + dd {
    margin-top: var(--spacing-xs);
  }

  /* Remove bottom margin from last dd */
  dd:last-child {
    margin-bottom: 0;
  }

  /* --------------------------------------------------------------------------
   CODE BLOCKS - Monospace Typography
   -------------------------------------------------------------------------- */

  pre {
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    font-family: var(--font-family-mono);
    line-height: 1.6;
    overflow-x: auto;
  }

  /* Code inside pre blocks */
  pre code {
    font-size: inherit;
    padding: 0;
    background: none;
    border-radius: 0;
  }

  /* --------------------------------------------------------------------------
   FORMS - Basic Structure
   -------------------------------------------------------------------------- */

  fieldset {
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    padding: var(--spacing-md);
    border: 0;
  }

  legend {
    font-weight: 600;
    padding: 0 var(--spacing-xs);
  }

  /* Form labels - structural emphasis for accessibility */
  label {
    display: inline-block;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
  }

  /* Form output element - typically displays calculation results */
  output {
    display: inline-block;
    font-variant-numeric: tabular-nums;
  }

  /* Visual indicator elements - structural spacing only */
  :where(meter, progress) {
    display: inline-block;
    vertical-align: middle;
  }

  /* --------------------------------------------------------------------------
   FORM CONTROLS - Typography Inheritance
   -------------------------------------------------------------------------- */

  input,
  button,
  textarea,
  select,
  optgroup {
    font-family: inherit;
    font-size: 100%;
    line-height: inherit;
  }

  /* Textarea - proper line height for multi-line input */
  textarea {
    line-height: 1.5;
  }

  /* Button cursor - indicates interactivity */
  button,
  [type='button'],
  [type='reset'],
  [type='submit'] {
    cursor: pointer;
  }

  /* --------------------------------------------------------------------------
   MEDIA - Images, Videos, Figures
   -------------------------------------------------------------------------- */

  :where(img, video, canvas, audio, iframe, svg) {
    max-width: 100%;
    height: auto;
    vertical-align: middle;
  }

  figure {
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
  }

  figcaption {
    margin-top: 0.375rem;
    font-size: 0.875em;
    line-height: 1.5;
  }

  /* --------------------------------------------------------------------------
   TABLES - Structural Layout
   -------------------------------------------------------------------------- */

  table {
    width: 100%;
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    border-collapse: collapse;
    font-size: 1em;
    line-height: 1.6;
  }

  caption {
    margin-bottom: var(--spacing-xs);
    font-size: 0.875em;
    font-weight: 600;
    text-align: left;
  }

  th,
  td {
    padding: var(--spacing-xs) var(--spacing-sm);
    text-align: left;
  }

  th {
    font-weight: 600;
  }

  /* Table sections - structural differentiation */
  thead th {
    vertical-align: bottom;
  }

  tbody th,
  tbody td {
    vertical-align: top;
  }

  tfoot th,
  tfoot td {
    vertical-align: top;
  }

  /* Add spacing between tbody sections if multiple exist */
  tbody + tbody {
    border-top-width: 2px;
  }

  /* --------------------------------------------------------------------------
   SEPARATORS - Spacing Only
   -------------------------------------------------------------------------- */

  hr {
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
    border: 0;
    border-top: 1px solid;
  }

  /* --------------------------------------------------------------------------
   INTERACTIVE ELEMENTS - Accessibility
   -------------------------------------------------------------------------- */

  :where(:focus, :focus-visible) {
    outline-offset: 2px;
  }

  details {
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-md);
  }

  summary {
    cursor: pointer;
    font-weight: 600;
  }

  details[open] > summary {
    margin-bottom: var(--spacing-xs);
  }

  dialog {
    font-size: inherit;
    line-height: inherit;
  }

  /* --------------------------------------------------------------------------
   UTILITIES - Margin Cleanup
   -------------------------------------------------------------------------- */

  :where(h1, h2, h3, h4, h5, h6, p, ul:not(li > ul, li > ol), ol:not(li > ul, li
        > ol), dl, blockquote, figure, table, pre):first-child {
    margin-top: 0;
  }

  :where(p, ul, ol, dl, blockquote, figure, table, pre):last-child {
    margin-bottom: 0;
  }
}