/* ======================================================
// Universal
// ------------------------------------------------------ */
*,
::before,
::after {
  /* Ensure padding and borders are included within the dimensions of the element. */
  box-sizing: border-box;

  /* Prevent inline elements from extending beyond their container's bounds. */
  min-inline-size: 0;

  /* Remove any default borders. */
  border-width: 0;

  /* Set a default border style of solid for easy border additions. */
  border-style: solid;
}

@media (prefers-reduced-motion: reduce) {
  *,
  ::before,
  ::after,
  ::backdrop {
    /* Disable animations and transitions for users who prefer reduced motion. */
    background-attachment: scroll !important;
    scroll-behavior: auto !important;
    transition-delay: 0s !important;
    transition-duration: 1ms !important;
    animation-duration: 1ms !important;
    animation-delay: 0s !important;
    animation-iteration-count: 1 !important;
    view-transition-name: none !important;
  }
}

/* ======================================================
// Document
// ------------------------------------------------------ */
:where(:root) {
  /* This ensures that the vertical space is evenly distributed, improving the visual balance of text. (https: //www.tak-dcxi.com/article/use-line-height-trim-as-css-variable) */
  --is-support-lh: initial;
  --is-support-not-lh: ;
  --leading-trim: var(--is-support-lh, calc((1em - 1lh) / 2))
    var(--is-support-not-lh, 0px);

  /* Custom easing functions using cubic-bezier. */
  --ease-in-sine: cubic-bezier(0.47, 0, 0.745, 0.715);
  --ease-out-sine: cubic-bezier(0.39, 0.575, 0.565, 1);
  --ease-in-out-sine: cubic-bezier(0.445, 0.05, 0.55, 0.95);
  --ease-in-quad: cubic-bezier(0.55, 0.085, 0.68, 0.53);
  --ease-out-quad: cubic-bezier(0.25, 0.46, 0.45, 0.94);
  --ease-in-out-quad: cubic-bezier(0.455, 0.03, 0.515, 0.955);
  --ease-in-cubic: cubic-bezier(0.55, 0.055, 0.675, 0.19);
  --ease-out-cubic: cubic-bezier(0.215, 0.61, 0.355, 1);
  --ease-in-out-cubic: cubic-bezier(0.645, 0.045, 0.355, 1);
  --ease-in-quart: cubic-bezier(0.895, 0.03, 0.685, 0.22);
  --ease-out-quart: cubic-bezier(0.165, 0.84, 0.44, 1);
  --ease-in-out-quart: cubic-bezier(0.77, 0, 0.175, 1);
  --ease-in-quint: cubic-bezier(0.755, 0.05, 0.855, 0.06);
  --ease-out-quint: cubic-bezier(0.23, 1, 0.32, 1);
  --ease-in-out-quint: cubic-bezier(0.86, 0, 0.07, 1);
  --ease-in-expo: cubic-bezier(0.95, 0.05, 0.795, 0.035);
  --ease-out-expo: cubic-bezier(0.19, 1, 0.22, 1);
  --ease-in-out-expo: cubic-bezier(1, 0, 0, 1);
  --ease-in-circ: cubic-bezier(0.6, 0.04, 0.98, 0.335);
  --ease-out-circ: cubic-bezier(0.075, 0.82, 0.165, 1);
  --ease-in-out-circ: cubic-bezier(0.785, 0.135, 0.15, 0.86);
  --ease-in-back: cubic-bezier(0.6, -0.28, 0.735, 0.045);
  --ease-out-back: cubic-bezier(0.175, 0.885, 0.32, 1.275);
  --ease-in-out-back: cubic-bezier(0.68, -0.55, 0.265, 1.55);

  /* Use a common sans-serif font stack for better cross-platform compatibility. */
  font-family: "Helvetica Neue", arial, "Hiragino Kaku Gothic ProN",
    "Hiragino Sans", "BIZ UDPGothic", meiryo, sans-serif;

  /* Normalize font-style. */
  font-style: unset;

  /* Normalize font-weight. */
  font-weight: 400;

  /* From an accessibility perspective, the line spacing within a paragraph should be at least 1.5 times the text size. (https://waic.jp/translations/WCAG21/#visual-presentation) */
  line-height: 1.5;

  /* Align text to the start of the element, accommodating left-to-right and right-to-left languages. */
  text-align: start;

  /* Remove leading white space for a cleaner text alignment. */
  text-spacing-trim: trim-start;

  /* Use the browser's default method to determine word breaking. */
  word-break: initial;

  /* Apply strict line breaking rules to enhance readability in languages that require it. */
  line-break: strict;

  /* Allow long words to be broken and wrapped at any point to prevent overflow. */
  overflow-wrap: anywhere;

  /* Automatically insert hyphens where appropriate for better text flow and alignment. */
  hyphens: auto;

  /* Prevent mobile browsers from scaling text sizes automatically. */
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;

  /* Eliminate the tap highlight color on mobile devices for a cleaner interface. */
  -webkit-tap-highlight-color: transparent;
}

:where(:lang(en)) {
  /* This ensures that the vertical space is evenly distributed, improving the visual balance of text. (https: //www.tak-dcxi.com/article/use-line-height-trim-as-css-variable) */
  --leading-trim: var(--is-support-lh, calc((1cap - 1lh) / 2))
    var(--is-support-not-lh, 0px);
}

@supports not (top: 1lh) {
  /* this CSS code sets the --leading-trim variable to 0px in browsers that do not support the 1lh unit for the top property,
    ensuring fallback compatibility. */
  :where(:root) {
    --is-support-lh: ;
    --is-support-not-lh: initial;
  }
}

/* ======================================================
// Sections
// ------------------------------------------------------ */
:where(body) {
  /* Ensures the body element occupies at least 100% of the viewport's block size. */
  min-block-size: 100svb;

  /* Reset default margin. */
  margin: unset;
}

:where(h1, h2, h3, h4, h5, h6) {
  /* Reset default margin. */
  margin-block: unset;

  /* Reset default font-size. */
  font-size: unset;
}

:where(search) {
  /* Render the `search` element consistently. */
  display: block flow;
}

/* ======================================================
// Grouping content
// ------------------------------------------------------ */
:where(p, blockquote, figure, pre, address, ul, ol, dl) {
  /* Reset default margin-block. */
  margin-block: unset;
}

:where(blockquote, figure) {
  /* Reset default margin-inline. */
  margin-inline: unset;
}

:where(address):where(:lang(ja)) {
  /* Reset font style for specific Japanese language elements. */
  font-style: unset;
}

:where(ul, ol) {
  /* Remove default padding-inline-start. */
  padding-inline-start: unset;

  /* In Safari, using 'list-style: none' causes the list not to be announced by screen readers, so use 'list-style-type: ""' to hide markers without affecting accessibility. */
  list-style-type: "";
}

:where(dt) {
  /* Make definition terms bolder. */
  font-weight: 700;
}

:where(dd) {
  /* Remove default indentation. */
  margin-inline-start: unset;
}

:where(hr) {
  /* Sets the thickness of the top border of the <hr> element to 1px. */
  border-block-start-width: 1px;
}

:where(pre) {
  /* Sets the tab character width to 2 spaces for better readability in preformatted text. */
  tab-size: 2;
}

/* ======================================================
// Text-level semantics
// ------------------------------------------------------ */
:where(b, strong) {
  /* Enhance the weight of bold elements for emphasis. */
  font-weight: 700;
}

:where(em):where(:lang(ja)) {
  /* Enhance the weight of bold elements for emphasis. */
  font-weight: 700;
}

:where(i, cite, em, dfn, var):where(:lang(ja)) {
  /* Reset font style for specific Japanese language elements. */
  font-style: unset;
}

:where(code, kbd, samp) {
  /* Set the monospace font using Tailwind as a reference. (https: //tailwindcss.com/docs/font-family) */
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas,
    "Liberation Mono", "Courier New", monospace;

  /* Reset font size to ensure consistent appearance across different devices. */
  font-size: unset;
}

:where(cite, dfn)::before {
  /* Inserts an opening quotation mark before the content of <cite> and <dfn> elements, defaulting to a double quote unless overridden. */
  content: var(--_quotation-start, "“");
}

:where(cite, dfn)::after {
  /* Inserts a closing quotation mark after the content of <cite> and <dfn> elements, defaulting to a double quote unless overridden. */
  content: var(--_quotation-end, "”");
}

:where(cite, dfn):where(:lang(ja)) {
  /* Overrides the default opening quotation mark with the Japanese opening quote for <cite> and <dfn> elements in Japanese. */
  --_quotation-start: "「";
  --_quotation-end: "」";
}

:where(var) {
  /* Sets the font family to serif for <var> elements, enhancing the typographic distinction of variable names in technical content. */
  font-family: serif;
}

@supports (text-decoration-color: color-mix(in sRGB, Mark, transparent)) {
  :where(mark) {
    /* Remove any default background colors. */
    background-color: unset;

    /* Reset text color to default or inherited value. */
    color: unset;

    /* Applies an underline to the text to highlight it. */
    text-decoration-line: underline;

    /* Sets the color of the underline using a mix of the 'Mark' color and transparency. */
    text-decoration-color: color-mix(in sRGB, Mark, transparent 50%);

    /* Specifies the thickness of the underline. */
    text-decoration-thickness: 0.4em;

    /* Adjusts the position of the underline closer to the text. */
    text-underline-offset: -0.2em;

    /* Ensures the underline is not broken by descenders in characters like g, j, p, q, and y. */
    text-decoration-skip-ink: none;
  }
}

/* ======================================================
// Links
// ------------------------------------------------------ */
:where(:any-link) {
  /* Remove any default background colors. */
  background-color: unset;

  /* Reset text color to default or inherited value. */
  color: unset;

  /* Remove underline from links. */
  text-decoration-line: none;

  /* Set the thickness of the text decoration based on the font metrics. */
  text-decoration-thickness: from-font;

  /* Position the underline slightly away from the text for enhanced legibility. */
  text-underline-offset: 0.25em;
}

/* ======================================================
// Edits
// ------------------------------------------------------ */
:where(ins) {
  /* Use a dashed line for underlining inserted content, making it distinctly visible. */
  text-decoration-style: dashed;

  /* Position the underline slightly away from the text for enhanced legibility. */
  text-underline-offset: 0.4em;
}

:where(del) {
  /* Apply a double line through the text for deleted content, enhancing visibility. */
  text-decoration-style: double;
}

/* ======================================================
// Embedded content
// ------------------------------------------------------ */
:where(img, video, canvas, audio, iframe, embed, object) {
  /* Set elements to display as block-level flow containers, suitable for complex layouts. */
  display: block flow;

  /* Align these elements vertically to the middle of their containing line. */
  vertical-align: middle;
}

:where(img, svg, video) {
  /* Automatically adjusts the block size based on content. */
  block-size: auto;

  /* Limits the maximum size inline to prevent overflow. */
  max-inline-size: 100%;
}

:where(svg) {
  /* Align these elements vertically to the middle of their containing line. */
  vertical-align: middle;
}

/* ======================================================
// Tabular data
// ------------------------------------------------------ */
:where(table) {
  /* Collapses border for a more compact table design. */
  border-collapse: collapse;
}

:where(caption) {
  /* Aligns the caption text to the start of the element. */
  text-align: start;
}

:where(td, th) {
  /* Removes default padding from table cells and headers. */
  padding: unset;

  /* Aligns content of table cells to the top. */
  vertical-align: top;
}

:where(th) {
  /* Makes table header text bold. */
  font-weight: 700;

  /* Aligns header text to the start of the cell. */
  text-align: start;
}

/* ======================================================
// Forms
// ------------------------------------------------------ */
:where(button, input, select, textarea),
::file-selector-button {
  /* Remove default padding. */
  padding: unset;

  /* Apply a transparent border for forced colors mode. */
  border-width: 1px;
  border-color: transparent;

  /* Resets border-radius to default. */
  border-radius: unset;

  /* Removes default background color. */
  background-color: unset;

  /* Removes default text color. */
  color: unset;

  /* Resets font settings to inherit from parent. */
  font: unset;

  /* Centers the element vertically within its line box. */
  vertical-align: middle;

  /* Resets letter-spacing to default. */
  letter-spacing: unset;

  /* Resets text alignment to default. */
  text-align: unset;

  /* Resets text transformation to default. */
  text-transform: unset;
}

:where([type="radio" i], [type="checkbox" i]) {
  /* Remove default margin. */
  margin: unset;
}

:where([type="file" i]) {
  /* Default cursor for file input fields. */
  cursor: unset;
}

:where(textarea) {
  /* Remove default margin in Firefox. */
  margin-block: unset;

  /* Allows resizing of textarea vertically only. */
  resize: block;
}

:where(button),
::file-selector-button {
  /* Set the inline-size of the button to match the content's inline-size exactly. */
  inline-size: fit-content;

  /* Optimizes touch interaction for buttons. */
  touch-action: manipulation;
}

:where(button)::-moz-focus-inner {
  /* Remove the inner padding in Firefox. */
  padding: unset;
}

:where(button, label[for], select, [role="tab"], [role="button"]),
::file-selector-button {
  /* Indicate clickable elements with a pointer cursor. */
  cursor: pointer;
}

:where(select:disabled) {
  /* Keep the opacity of disabled selects consistent with other disabled elements. */
  opacity: inherit;
}

:where(fieldset) {
  /* Remove default margin-inline. */
  margin-inline: unset;

  /* Remove default padding. */
  padding: unset;
}

:where(legend) {
  /* Remove default padding-inline. */
  padding-inline: unset;
}

:where(optgroup) {
  /* Resets font settings to inherit from parent. */
  font: unset;
}

::placeholder {
  /* Normalize the opacity of placeholder text to fully opaque in Firefox, where it might be set to less by default. */
  opacity: unset;
}

/* ======================================================
// Interactive elements
// ------------------------------------------------------ */
:where(summary) {
  /* Eliminate the default marker from details summary for a cleaner disclosure widget. */
  display: block flow;

  /* Indicate clickable elements with a pointer cursor. */
  cursor: pointer;
}

::-webkit-details-marker {
  /* Hide the default disclosure marker to allow for custom styling. */
  display: none;
}

:where(dialog) {
  /* Resets overflow property. */
  overflow: unset;

  /* Resets the inline size property. */
  inline-size: unset;

  /* Resets the block size property. */
  block-size: unset;

  /* Resets the max inline size limit. */
  max-inline-size: unset;

  /* Resets the max block size limit. */
  max-block-size: unset;

  /* Removes default padding. */
  padding: unset;

  /* Removes default background color. */
  background-color: unset;

  /* Resets color to default. */
  color: unset;
}

:where([popover]) {
  /* Resets overflow property. */
  overflow: unset;

  /* Resets the inline size property. */
  inline-size: unset;

  /* Resets the block size property. */
  block-size: unset;

  /* Removes default padding. */
  padding: unset;

  /* Removes default background color. */
  background-color: unset;

  /* Resets color to default. */
  color: unset;
}

::backdrop {
  /* Remove default backdrop color for a clearer view of the underlying content. */
  background-color: unset;
}

/* ======================================================
// Focus styles
// ------------------------------------------------------ */
:where(:-moz-focusring) {
  /* Improve outlines for Firefox and unify style with input elements and buttons. */
  outline: auto;
}

:where(:focus-visible) {
  /* Slightly offset focus outline for better visibility without overlapping text. */
  outline-offset: 2px;
}

:where(:focus:not(:focus-visible)) {
  /* Hide focus outline unless element is explicitly focus-visible to reduce visual clutter. */
  outline: none;
}

[tabindex="-1"]:focus-visible {
  /* Ensure that programmatically focused elements do not show an outline unless they are naturally focusable. */
  outline: none !important;
}

/* ======================================================
// Misc
// ------------------------------------------------------ */
:where(:disabled) {
  /* Show default cursor for disabled elements to reflect their non-interactive state. */
  cursor: default;
}

[hidden]:not([hidden="until-found"]) {
  /* Ensure elements intended to be hidden are not displayed, enhancing clarity and layout control. */
  display: none !important;
}

/* Fallback trick for hover states. */
:where(:any-link, :enabled, summary) {
  --is-hover-true: ;
  --is-hover-false: initial;
}

:where(:where(:any-link, :enabled, summary):focus-visible) {
  --is-hover-true: initial;
  --is-hover-false: ;
}

@media (any-hover: hover) {
  :where(:where(:any-link, :enabled, summary):hover) {
    --is-hover-true: initial;
    --is-hover-false: ;
  }
}

/* ======================================================
// Utility Classes
// ------------------------------------------------------ */
/* Create a pseudo-element to adjust the vertical space above and below an element. */
.leading-trim::before,
.leading-trim::after {
  content: "";
  display: block flow;
  inline-size: 0;
  block-size: 1px;
}

.leading-trim::before {
  margin-block-end: var(--leading-trim);
}

.leading-trim::after {
  margin-block-start: var(--leading-trim);
}

/* Hide content visually but keep it accessible to screen readers. */
.visually-hidden {
  position: fixed !important;
  inset: 0 !important;
  contain: strict !important;
  display: block flow !important;
  visibility: visible !important;
  inline-size: 4px !important;
  block-size: 4px !important;
  margin: 0 !important;
  padding: 0 !important;
  border: none !important;
  opacity: 0 !important;
  pointer-events: none !important;
}

ol,
ul {
  list-style-type: none;
}