/* ==========================================================================
   Firefly Hexo Theme - main.css
   Root CSS: custom properties, reset, utilities, and component classes.
   Ported from Firefly (Astro) — hand-written CSS with OKLCH color space.
   ========================================================================== */

/* --------------------------------------------------------------------------
   CSS Custom Properties (OKLCH Color Space)
   -------------------------------------------------------------------------- */

:root {
  /* --- Hue: rotate this single value to change the entire site color scheme --- */
  --hue: 165;

  /* --- Page background --- */
  --page-bg: oklch(0.98 0.01 var(--hue));

  /* --- Card background --- */
  --card-bg: oklch(0.99 0.005 var(--hue));
  --card-bg-transparent: oklch(0.99 0.005 var(--hue) / var(--card-transparent-opacity, 0.5));

  /* --- Primary accent color --- */
  --primary: oklch(0.65 0.18 var(--hue));
  --primary-hover: oklch(0.60 0.20 var(--hue));
  --primary-active: oklch(0.55 0.22 var(--hue));

  /* --- Text colors --- */
  --text-primary: oklch(0.15 0.01 var(--hue));
  --text-secondary: oklch(0.35 0.01 var(--hue));
  --text-tertiary: oklch(0.50 0.01 var(--hue));

  /* --- Line / divider --- */
  --line-divider: oklch(0.85 0.01 var(--hue));

  /* --- Button backgrounds --- */
  --btn-plain-bg-hover: oklch(0.95 0.02 var(--hue));
  --btn-plain-bg-active: oklch(0.90 0.03 var(--hue));
  --btn-regular-bg: oklch(0.92 0.02 var(--hue));
  --btn-regular-bg-hover: oklch(0.88 0.03 var(--hue));
  --btn-regular-bg-active: oklch(0.84 0.04 var(--hue));
  --btn-card-bg-hover: oklch(0.94 0.02 var(--hue));
  --btn-card-bg-active: oklch(0.90 0.03 var(--hue));
  --btn-content: var(--text-secondary);

  /* --- Link colors --- */
  --link-color: var(--primary);
  --link-hover: oklch(0.55 0.20 var(--hue));
  --link-underline: oklch(0.80 0.08 var(--hue));
  --link-active: oklch(0.50 0.22 var(--hue));

  /* --- Selection --- */
  --selection-bg: oklch(0.80 0.10 var(--hue) / 0.3);

  /* --- Meta divider --- */
  --meta-divider: oklch(0.60 0.02 var(--hue));

  /* --- Banner details --- */
  --banner-height: 67vh;
  --banner-height-home: 73vh;
  --banner-height-extend: 0px;

  /* --- Navbar --- */
  --navbar-height: 3.5rem;
  --navbar-glass-blur: 5px;

  /* --- Page width --- */
  --page-width: 100rem;

  /* --- Border radius --- */
  --radius-small: 0.375rem;
  --radius-medium: 0.5625rem;
  --radius-large: 0.875rem;
  --radius-xl: 1.125rem;

  /* --- Transitions --- */
  --duration-fast: 0.15s;
  --duration-medium: 0.3s;

  /* --- Font stack --- */
  --font-sans: 'Roboto', ui-sans-serif, system-ui, sans-serif;
  --font-mono: 'Fira Code', ui-monospace, monospace;

  /* ====================================================================
     Material You (Material 3) Design Tokens
     ==================================================================== */

  /* ---- Dynamic Color tokens (derived from --hue via OKLCH) ---- */
  --md-sys-color-primary-container: oklch(0.88 0.08 var(--hue));
  --md-sys-color-on-primary-container: oklch(0.25 0.06 var(--hue));
  --md-sys-color-surface-variant: oklch(0.93 0.02 var(--hue));
  --md-sys-color-on-surface-variant: oklch(0.40 0.02 var(--hue));
  --md-sys-color-surface-container-highest: oklch(0.90 0.01 var(--hue));

  /* ---- M3 Shape tokens ---- */
  --md-shape-corner-full: 12px;
  --md-shape-corner-large: 14px;
  --md-shape-corner-medium: 11px;
  --md-shape-corner-small: 9px;

  /* ---- M3 Motion tokens ---- */
  --md-motion-easing-emphasized: cubic-bezier(0.2, 0, 0, 1);
  --md-motion-easing-standard: cubic-bezier(0.2, 0, 0, 1);
  --md-motion-duration-medium: 300ms;
  --md-motion-duration-short: 200ms;
}

/* --------------------------------------------------------------------------
   Dark Mode
   -------------------------------------------------------------------------- */

:root.dark,
html.dark {
  --page-bg: oklch(0.15 0.01 var(--hue));
  --card-bg: oklch(0.20 0.01 var(--hue));
  --card-bg-transparent: oklch(0.20 0.01 var(--hue) / var(--card-transparent-opacity, 0.5));
  --primary: oklch(0.70 0.15 var(--hue));
  --primary-hover: oklch(0.65 0.17 var(--hue));
  --primary-active: oklch(0.60 0.19 var(--hue));
  --text-primary: oklch(0.92 0.01 var(--hue));
  --text-secondary: oklch(0.72 0.01 var(--hue));
  --text-tertiary: oklch(0.55 0.01 var(--hue));
  --line-divider: oklch(0.28 0.01 var(--hue));
  --btn-plain-bg-hover: oklch(0.25 0.02 var(--hue));
  --btn-plain-bg-active: oklch(0.30 0.03 var(--hue));
  --btn-regular-bg: oklch(0.25 0.02 var(--hue));
  --btn-regular-bg-hover: oklch(0.30 0.03 var(--hue));
  --btn-regular-bg-active: oklch(0.35 0.04 var(--hue));
  --btn-card-bg-hover: oklch(0.25 0.02 var(--hue));
  --btn-card-bg-active: oklch(0.30 0.03 var(--hue));
  --link-color: var(--primary);
  --link-hover: oklch(0.60 0.18 var(--hue));
  --link-underline: oklch(0.40 0.06 var(--hue));
  --link-active: oklch(0.55 0.20 var(--hue));
  --selection-bg: oklch(0.60 0.12 var(--hue) / 0.3);
  --meta-divider: oklch(0.45 0.02 var(--hue));

  /* ---- M3 Dark tokens ---- */
  --md-sys-color-primary-container: oklch(0.30 0.06 var(--hue));
  --md-sys-color-on-primary-container: oklch(0.88 0.05 var(--hue));
  --md-sys-color-surface-variant: oklch(0.28 0.02 var(--hue));
  --md-sys-color-on-surface-variant: oklch(0.65 0.02 var(--hue));
  --md-sys-color-surface-container-highest: oklch(0.25 0.01 var(--hue));
}

/* --------------------------------------------------------------------------
   Reset & Base
   -------------------------------------------------------------------------- */

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

html {
  scroll-behavior: smooth;
  font-size: 15px;
  -webkit-text-size-adjust: 100%;
}

@media (min-width: 768px) {
  html {
    font-size: 16px;
  }
}

@media (min-width: 1024px) {
  html {
    font-size: 17px;
  }
}

body.is-home {
  --banner-height: var(--banner-height-home, 55vh) !important;
}

body {
  font-family: var(--font-sans);
  background-color: var(--page-bg);
  color: var(--text-primary);
  line-height: 1.6;
  font-weight: 400;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--link-color);
  text-decoration: none;
  font-weight: 500;
  transition: color var(--duration-fast);
}

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

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

ul, ol {
  list-style: none;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.3;
  color: var(--text-primary);
}
h1 { font-weight: 800; }
h2 { font-weight: 700; }
h3 { font-weight: 600; }

p {
  margin-bottom: 1rem;
}

button {
  font-family: inherit;
  font-size: inherit;
}

input, textarea, select {
  font-family: inherit;
  font-size: inherit;
}

/* --------------------------------------------------------------------------
   Utility Classes (Tailwind conversions)
   -------------------------------------------------------------------------- */

/* ---- Display ---- */

.flex { display: flex; }
.inline-flex { display: inline-flex; }
.grid { display: grid; }
.block { display: block; }
.inline-block { display: inline-block; }
.hidden { display: none; }
.inline { display: inline; }

/* ---- Flex helpers ---- */

.flex-col { flex-direction: column; }
.flex-row { flex-direction: row; }
.flex-wrap { flex-wrap: wrap; }
.flex-nowrap { flex-wrap: nowrap; }
.flex-1 { flex: 1 1 0%; }
.flex-shrink-0 { flex-shrink: 0; }
.flex-grow { flex-grow: 1; }

/* ---- Grid helpers ---- */

.grid-cols-1 { grid-template-columns: repeat(1, 1fr); }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }

/* ---- Gap ---- */

.gap-0 { gap: 0; }
.gap-1 { gap: 0.25rem; }
.gap-2 { gap: 0.5rem; }
.gap-3 { gap: 0.75rem; }
.gap-4 { gap: 1rem; }
.gap-5 { gap: 1.25rem; }
.gap-6 { gap: 1.5rem; }
.gap-8 { gap: 2rem; }
.gap-10 { gap: 2.5rem; }
.gap-12 { gap: 3rem; }

/* ---- Alignment ---- */

.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.items-stretch { align-items: stretch; }
.items-baseline { align-items: baseline; }

.justify-center { justify-content: center; }
.justify-start { justify-content: flex-start; }
.justify-end { justify-content: flex-end; }
.justify-between { justify-content: space-between; }
.justify-around { justify-content: space-around; }
.justify-evenly { justify-content: space-evenly; }

.self-center { align-self: center; }
.self-start { align-self: flex-start; }
.self-end { align-self: flex-end; }

/* ---- Text alignment ---- */

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

/* ---- Font sizes ---- */

.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-3xl { font-size: 1.875rem; line-height: 2.25rem; }
.text-4xl { font-size: 2.25rem; line-height: 2.5rem; }

/* ---- Font weight ---- */

.font-normal { font-weight: 400; }
.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }
.font-extrabold { font-weight: 800; }

/* ---- Padding ---- */

.p-0 { padding: 0; }
.p-1 { padding: 0.25rem; }
.p-2 { padding: 0.5rem; }
.p-3 { padding: 0.75rem; }
.p-4 { padding: 1rem; }
.p-5 { padding: 1.25rem; }
.p-6 { padding: 1.5rem; }
.p-8 { padding: 2rem; }
.p-10 { padding: 2.5rem; }

.px-1 { padding-left: 0.25rem; padding-right: 0.25rem; }
.px-2 { padding-left: 0.5rem; padding-right: 0.5rem; }
.px-3 { padding-left: 0.75rem; padding-right: 0.75rem; }
.px-4 { padding-left: 1rem; padding-right: 1rem; }
.px-5 { padding-left: 1.25rem; padding-right: 1.25rem; }
.px-6 { padding-left: 1.5rem; padding-right: 1.5rem; }
.px-8 { padding-left: 2rem; padding-right: 2rem; }

.py-1 { padding-top: 0.25rem; padding-bottom: 0.25rem; }
.py-2 { padding-top: 0.5rem; padding-bottom: 0.5rem; }
.py-3 { padding-top: 0.75rem; padding-bottom: 0.75rem; }
.py-4 { padding-top: 1rem; padding-bottom: 1rem; }
.py-5 { padding-top: 1.25rem; padding-bottom: 1.25rem; }
.py-6 { padding-top: 1.5rem; padding-bottom: 1.5rem; }
.py-8 { padding-top: 2rem; padding-bottom: 2rem; }

.pt-1 { padding-top: 0.25rem; }
.pt-2 { padding-top: 0.5rem; }
.pt-3 { padding-top: 0.75rem; }
.pt-4 { padding-top: 1rem; }
.pt-5 { padding-top: 1.25rem; }
.pt-6 { padding-top: 1.5rem; }
.pt-8 { padding-top: 2rem; }

.pb-1 { padding-bottom: 0.25rem; }
.pb-2 { padding-bottom: 0.5rem; }
.pb-3 { padding-bottom: 0.75rem; }
.pb-4 { padding-bottom: 1rem; }
.pb-5 { padding-bottom: 1.25rem; }
.pb-6 { padding-bottom: 1.5rem; }
.pb-8 { padding-bottom: 2rem; }

.pl-1 { padding-left: 0.25rem; }
.pl-2 { padding-left: 0.5rem; }
.pl-3 { padding-left: 0.75rem; }
.pl-4 { padding-left: 1rem; }

.pr-1 { padding-right: 0.25rem; }
.pr-2 { padding-right: 0.5rem; }
.pr-3 { padding-right: 0.75rem; }
.pr-4 { padding-right: 1rem; }

/* ---- Margin ---- */

.m-0 { margin: 0; }
.m-1 { margin: 0.25rem; }
.m-2 { margin: 0.5rem; }
.m-3 { margin: 0.75rem; }
.m-4 { margin: 1rem; }
.m-5 { margin: 1.25rem; }
.m-6 { margin: 1.5rem; }
.m-8 { margin: 2rem; }

.mx-auto { margin-left: auto; margin-right: auto; }
.mx-1 { margin-left: 0.25rem; margin-right: 0.25rem; }
.mx-2 { margin-left: 0.5rem; margin-right: 0.5rem; }
.mx-3 { margin-left: 0.75rem; margin-right: 0.75rem; }
.mx-4 { margin-left: 1rem; margin-right: 1rem; }

.my-1 { margin-top: 0.25rem; margin-bottom: 0.25rem; }
.my-2 { margin-top: 0.5rem; margin-bottom: 0.5rem; }
.my-3 { margin-top: 0.75rem; margin-bottom: 0.75rem; }
.my-4 { margin-top: 1rem; margin-bottom: 1rem; }
.my-6 { margin-top: 1.5rem; margin-bottom: 1.5rem; }
.my-8 { margin-top: 2rem; margin-bottom: 2rem; }

.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 0.75rem; }
.mt-4 { margin-top: 1rem; }
.mt-6 { margin-top: 1.5rem; }
.mt-8 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 0.75rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-6 { margin-bottom: 1.5rem; }
.mb-8 { margin-bottom: 2rem; }

.ml-1 { margin-left: 0.25rem; }
.ml-2 { margin-left: 0.5rem; }
.ml-3 { margin-left: 0.75rem; }
.ml-4 { margin-left: 1rem; }
.ml-auto { margin-left: auto; }

.mr-1 { margin-right: 0.25rem; }
.mr-2 { margin-right: 0.5rem; }
.mr-3 { margin-right: 0.75rem; }
.mr-4 { margin-right: 1rem; }

/* ---- Width & Height ---- */

.w-full { width: 100%; }
.w-auto { width: auto; }
.w-screen { width: 100vw; }
.w-1\/2 { width: 50%; }
.w-1\/3 { width: 33.333333%; }
.w-2\/3 { width: 66.666667%; }
.w-1\/4 { width: 25%; }

.h-full { height: 100%; }
.h-auto { height: auto; }
.h-screen { height: 100vh; }

.min-w-0 { min-width: 0; }
.min-h-screen { min-height: 100vh; }

.max-w-full { max-width: 100%; }
.max-w-screen { max-width: 100vw; }

/* ---- Border radius ---- */

.rounded-none { border-radius: 0; }
.rounded { border-radius: var(--radius-small); }
.rounded-md { border-radius: var(--radius-medium); }
.rounded-lg { border-radius: var(--radius-large); }
.rounded-full { border-radius: 9999px; }

/* ---- Shadows ---- */

.shadow-none { box-shadow: none; }
.shadow-sm { box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05); }
.shadow { box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1); }
.shadow-md { box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1); }
.shadow-lg { box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1); }
.shadow-xl { box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1); }

/* ---- Borders ---- */

.border { border: 1px solid var(--line-divider); }
.border-0 { border: none; }
.border-b { border-bottom: 1px solid var(--line-divider); }
.border-t { border-top: 1px solid var(--line-divider); }
.border-l { border-left: 1px solid var(--line-divider); }
.border-r { border-right: 1px solid var(--line-divider); }

/* ---- Overflow ---- */

.overflow-hidden { overflow: hidden; }
.overflow-auto { overflow: auto; }
.overflow-scroll { overflow: scroll; }
.overflow-x-auto { overflow-x: auto; }
.overflow-y-auto { overflow-y: auto; }
.overflow-x-hidden { overflow-x: hidden; }
.overflow-y-hidden { overflow-y: hidden; }

/* ---- Positioning ---- */

.relative { position: relative; }
.absolute { position: absolute; }
.fixed { position: fixed; }
.sticky { position: sticky; }

.top-0 { top: 0; }
.top-2 { top: 0.5rem; }
.top-4 { top: 1rem; }
.top-full { top: 100%; }

.left-0 { left: 0; }
.left-2 { left: 0.5rem; }
.left-4 { left: 1rem; }

.right-0 { right: 0; }
.right-2 { right: 0.5rem; }
.right-4 { right: 1rem; }

.bottom-0 { bottom: 0; }
.bottom-2 { bottom: 0.5rem; }
.bottom-4 { bottom: 1rem; }

.inset-0 { top: 0; right: 0; bottom: 0; left: 0; }
.inset-x-0 { left: 0; right: 0; }
.inset-y-0 { top: 0; bottom: 0; }

/* ---- Z-index ---- */

.z-0 { z-index: 0; }
.z-10 { z-index: 10; }
.z-20 { z-index: 20; }
.z-30 { z-index: 30; }
.z-40 { z-index: 40; }
.z-50 { z-index: 50; }

/* ---- Opacity ---- */

.opacity-0 { opacity: 0; }
.opacity-25 { opacity: 0.25; }
.opacity-50 { opacity: 0.5; }
.opacity-75 { opacity: 0.75; }
.opacity-100 { opacity: 1; }

/* ---- Pointer events ---- */

.pointer-events-none { pointer-events: none; }
.pointer-events-auto { pointer-events: auto; }

/* ---- Transitions ---- */

.transition { transition-property: color, background-color, border-color, text-decoration-color, fill, stroke; transition-timing-function: ease; transition-duration: var(--duration-fast); }
.transition-colors { transition-property: color, background-color, border-color, text-decoration-color, fill, stroke; transition-timing-function: ease; transition-duration: var(--duration-fast); }
.transition-all { transition-property: all; transition-timing-function: ease; transition-duration: var(--duration-fast); }
.transition-opacity { transition-property: opacity; transition-timing-function: ease; transition-duration: var(--duration-fast); }
.transition-transform { transition-property: transform; transition-timing-function: ease; transition-duration: var(--duration-fast); }

.duration-75 { transition-duration: 75ms; }
.duration-150 { transition-duration: 150ms; }
.duration-300 { transition-duration: 300ms; }
.duration-500 { transition-duration: 500ms; }

.ease-in { transition-timing-function: ease-in; }
.ease-out { transition-timing-function: ease-out; }
.ease-in-out { transition-timing-function: ease-in-out; }

/* ---- Screen reader only ---- */

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

/* ---- Text truncate ---- */

.truncate {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* ---- Whitespace ---- */

.whitespace-nowrap { white-space: nowrap; }
.whitespace-pre-wrap { white-space: pre-wrap; }
.break-all { word-break: break-all; }
.break-words { overflow-wrap: break-word; }

/* ---- Cursor ---- */

.cursor-pointer { cursor: pointer; }
.cursor-default { cursor: default; }
.cursor-not-allowed { cursor: not-allowed; }

/* ---- Responsive visibility ---- */

@media (max-width: 768px) {
  .max-sm\:hidden { display: none; }
  .max-sm\:block { display: block; }
  .max-sm\:flex { display: flex; }
  .max-sm\:flex-col { flex-direction: column; }
  .max-sm\:w-full { width: 100%; }
}

@media (min-width: 769px) {
  .sm\:hidden { display: none; }
  .sm\:block { display: block; }
  .sm\:flex { display: flex; }
}

/* --------------------------------------------------------------------------
   Component Classes (ported from Firefly @layer components)
   -------------------------------------------------------------------------- */

/* ---- Card base ---- */

.card-base {
  border-radius: var(--radius-large);
  overflow: hidden;
  background: var(--card-bg);
  transition: background-color var(--duration-fast);
}

.card-base-transparent {
  border-radius: var(--radius-large);
  overflow: hidden;
  background: var(--card-bg-transparent);
  transition: background-color var(--duration-fast);
}

/* Card border effect */
.enable-card-border .card-base,
.enable-card-border .card-base-transparent {
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}

/* Wallpaper transparent mode — card overrides */
.wallpaper-transparent .card-base {
  background: var(--card-bg-transparent) !important;
}

.wallpaper-transparent #navbar > div {
  background: var(--card-bg-transparent) !important;
}

/* ---- Text opacity classes (OKLCH-based) ---- */

.text-90 { color: oklch(0.10 0.01 var(--hue)); }
.text-75 { color: oklch(0.25 0.01 var(--hue)); }
.text-50 { color: oklch(0.50 0.01 var(--hue)); }
.text-30 { color: oklch(0.70 0.01 var(--hue)); }

.dark .text-90,
:root.dark .text-90,
html.dark .text-90 {
  color: oklch(0.90 0.01 var(--hue));
}

.dark .text-75,
:root.dark .text-75,
html.dark .text-75 {
  color: oklch(0.75 0.01 var(--hue));
}

.dark .text-50,
:root.dark .text-50,
html.dark .text-50 {
  color: oklch(0.50 0.01 var(--hue));
}

.dark .text-30,
:root.dark .text-30,
html.dark .text-30 {
  color: oklch(0.30 0.01 var(--hue));
}

/* ---- Button: plain (icon / text-only, no background) ---- */

.btn-plain {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  color: var(--text-secondary);
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.25rem;
  border-radius: var(--radius-medium);
  transition: all var(--duration-fast);
  font-size: inherit;
  line-height: 1;
}

.btn-plain:hover {
  background: var(--btn-plain-bg-hover);
  color: var(--primary);
}

.btn-plain:active {
  background: var(--btn-plain-bg-active);
}

.btn-plain svg,
.btn-plain i {
  pointer-events: none;
  flex-shrink: 0;
}

/* ---- Button: regular (with background) ---- */

.btn-regular {
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--btn-regular-bg);
  color: var(--text-secondary);
  border: none;
  cursor: pointer;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-medium);
  transition: all var(--duration-fast);
  font-size: inherit;
  line-height: 1.5;
}

.btn-regular:hover {
  background: var(--btn-regular-bg-hover);
}

.btn-regular:active {
  background: var(--btn-regular-bg-active);
}

/* ---- Button: card ---- */

.btn-card {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  color: var(--text-secondary);
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.375rem;
  border-radius: var(--radius-medium);
  transition: all var(--duration-fast);
}

.btn-card:hover {
  background: var(--btn-card-bg-hover);
}

.btn-card:active {
  background: var(--btn-card-bg-active);
}

/* ---- Dropdown ---- */

.dropdown-container {
  position: relative;
}

.dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  padding-top: 0.5rem;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-0.5rem);
  transition: all 0.2s ease-out;
  z-index: 50;
}

.dropdown-menu-right {
  left: auto;
  right: 0;
}

.dropdown-container:hover .dropdown-menu,
.dropdown-container:focus-within .dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.dropdown-content {
  background: var(--card-bg);
  border-radius: var(--md-shape-corner-large);
  padding: 0.5rem 0;
  min-width: 12rem;
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  width: 100%;
  cursor: pointer;
  border: none;
  background: none;
  color: var(--text-secondary);
  font-size: 0.875rem;
  transition: all var(--duration-fast);
  text-align: left;
}

.dropdown-item:hover {
  background: var(--btn-plain-bg-hover);
  color: var(--text-primary);
}

.dropdown-divider {
  height: 1px;
  background: var(--line-divider);
  margin: 0.25rem 0;
}

/* ---- Float panel ---- */

.float-panel {
  border-radius: var(--md-shape-corner-large);
  overflow: hidden;
  background: var(--card-bg);
  transition: all var(--md-motion-duration-medium) var(--md-motion-easing-standard);
}

.float-panel-closed {
  transform: translateY(-0.25rem);
  opacity: 0;
  pointer-events: none;
}

/* ---- Selection ---- */

::selection {
  background: var(--selection-bg);
}

::-moz-selection {
  background: var(--selection-bg);
}

/* ---- LQIP placeholder ---- */

.lqip-placeholder {
  position: absolute;
  inset: 0;
  z-index: 0;
  transition: opacity 0.5s ease-out;
}

.lqip-placeholder.loaded {
  opacity: 0;
}

/* ---- Hide scrollbar ---- */

.hide-scrollbar {
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.hide-scrollbar::-webkit-scrollbar {
  display: none;
}

/* ---- Top gradient highlight ---- */

.top-gradient-highlight {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 180px;
  background: linear-gradient(
    to bottom,
    rgba(255, 255, 255, 0.5) 0%,
    rgba(255, 255, 255, 0.3) 30%,
    transparent 100%
  );
  pointer-events: none;
  z-index: 20;
}

.dark .top-gradient-highlight,
:root.dark .top-gradient-highlight,
html.dark .top-gradient-highlight {
  background: linear-gradient(
    to bottom,
    rgba(0, 0, 0, 0.5) 0%,
    rgba(0, 0, 0, 0.3) 30%,
    transparent 100%
  );
}

/* ---- Skeleton loading ---- */

.skeleton {
  background: linear-gradient(
    90deg,
    var(--line-divider) 25%,
    transparent 50%,
    var(--line-divider) 75%
  );
  background-size: 200% 100%;
  animation: skeleton-shimmer 1.5s ease-in-out infinite;
  border-radius: var(--radius-small);
}

@keyframes skeleton-shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* ---- Backdrop blur utility ---- */

.backdrop-blur {
  backdrop-filter: blur(var(--navbar-glass-blur));
  -webkit-backdrop-filter: blur(var(--navbar-glass-blur));
}

/* ---- Material Symbols Outlined ---- */

@font-face {
  font-family: 'Material Symbols Outlined';
  font-style: normal;
  font-weight: 100 700;
  font-display: swap;
  src: url('/fonts/MaterialSymbolsOutlined.woff2') format('woff2');
}

.material-symbols-outlined {
  font-family: 'Material Symbols Outlined';
  font-weight: normal;
  font-style: normal;
  font-size: 1.25rem;
  line-height: 1;
  letter-spacing: normal;
  text-transform: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  vertical-align: middle;
  flex-shrink: 0;
  white-space: nowrap;
  word-wrap: normal;
  direction: ltr;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  font-feature-settings: 'liga';
  font-variation-settings: 'FILL' 0, 'wght' 400, 'GRAD' 0, 'opsz' 24;
  transition: font-variation-settings var(--md-motion-duration-short) var(--md-motion-easing-standard),
              color var(--md-motion-duration-short) var(--md-motion-easing-standard);
  color: inherit;
}

/* Size variants */
.material-symbols-outlined.md-18 { font-size: 1.125rem; }
.material-symbols-outlined.md-20 { font-size: 1.25rem; }
.material-symbols-outlined.md-24 { font-size: 1.5rem; }
.material-symbols-outlined.md-28 { font-size: 1.75rem; }

/* Unknown icon fallback */
.icon-unknown {
  opacity: 0.4;
}

/* ==========================================================================
   Material You Icon Components
   ========================================================================== */

/* ---- Icon Container (pill-shaped, for navigation items) ---- */
.md-icon-container {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.375rem;
  padding: 0.375rem 0.75rem;
  height: 2.25rem;
  border-radius: var(--md-shape-corner-full);
  background-color: transparent;
  color: var(--md-sys-color-on-surface-variant);
  cursor: pointer;
  text-decoration: none;
  border: none;
  font-family: inherit;
  font-size: 0.9375rem;
  font-weight: 500;
  white-space: nowrap;
  transition:
    background-color var(--md-motion-duration-medium) var(--md-motion-easing-emphasized),
    color var(--md-motion-duration-medium) var(--md-motion-easing-emphasized),
    box-shadow var(--md-motion-duration-medium) var(--md-motion-easing-emphasized);
}
.md-icon-container:hover {
  background-color: oklch(0.65 0.18 var(--hue) / 0.08);
  color: var(--primary);
}
.md-icon-container:active {
  background-color: oklch(0.65 0.18 var(--hue) / 0.12);
}

/* Active state: filled primary container */
.md-icon-container.active {
  background-color: var(--md-sys-color-primary-container);
  color: var(--md-sys-color-on-primary-container);
}
.md-icon-container.active:hover {
  background-color: oklch(0.82 0.10 var(--hue));
}
.md-icon-container.active .material-symbols-outlined {
  font-variation-settings: 'FILL' 1, 'wght' 600, 'GRAD' 0, 'opsz' 24;
}

/* ---- Icon Button (square rounded, for action buttons) ---- */
.md-icon-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--md-shape-corner-full);
  background-color: transparent;
  color: var(--md-sys-color-on-surface-variant);
  cursor: pointer;
  border: none;
  padding: 0;
  font-size: inherit;
  line-height: 1;
  transition:
    background-color var(--md-motion-duration-medium) var(--md-motion-easing-emphasized),
    color var(--md-motion-duration-medium) var(--md-motion-easing-emphasized);
}
.md-icon-button:hover {
  background-color: oklch(0.65 0.18 var(--hue) / 0.08);
  color: var(--primary);
}
.md-icon-button:active {
  background-color: oklch(0.65 0.18 var(--hue) / 0.12);
}

/* Tonal icon button (with surface-variant background) */
.md-icon-button.md-icon-tonal {
  background-color: var(--md-sys-color-surface-variant);
}
.md-icon-button.md-icon-tonal:hover {
  background-color: oklch(0.65 0.18 var(--hue) / 0.16);
  color: var(--md-sys-color-on-primary-container);
}

/* Filled icon button (with primary container background) */
.md-icon-button.md-icon-filled {
  background-color: var(--md-sys-color-primary-container);
  color: var(--md-sys-color-on-primary-container);
}
.md-icon-button.md-icon-filled:hover {
  filter: brightness(0.92);
}

/* ---- Icon Stat (small rounded-square for stats widget) ---- */
.md-icon-stat {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  border-radius: var(--md-shape-corner-medium);
  background-color: var(--md-sys-color-primary-container);
  color: var(--md-sys-color-on-primary-container);
  flex-shrink: 0;
}
.md-icon-stat .material-symbols-outlined {
  font-size: 1.125rem;
}

/* ---- Social Link (M3 tonal button) ---- */
.md-social-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--md-shape-corner-full);
  background-color: var(--md-sys-color-surface-variant);
  color: var(--md-sys-color-on-surface-variant);
  text-decoration: none;
  cursor: pointer;
  transition:
    background-color var(--md-motion-duration-medium) var(--md-motion-easing-emphasized),
    color var(--md-motion-duration-medium) var(--md-motion-easing-emphasized),
    box-shadow var(--md-motion-duration-medium) var(--md-motion-easing-emphasized);
}
.md-social-link:hover {
  background-color: var(--md-sys-color-primary-container);
  color: var(--md-sys-color-on-primary-container);
  box-shadow: 0 1px 3px 1px rgba(0,0,0,0.08);
}

/* ---- Tag Chip (M3 assist chip style) ---- */
.md-chip {
  display: inline-flex;
  align-items: center;
  padding: 0.3rem 0.75rem;
  border-radius: var(--md-shape-corner-full);
  background-color: var(--md-sys-color-surface-variant);
  color: var(--md-sys-color-on-surface-variant);
  font-size: 0.8125rem;
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  transition:
    background-color var(--md-motion-duration-short) var(--md-motion-easing-standard),
    color var(--md-motion-duration-short) var(--md-motion-easing-standard);
}
.md-chip:hover {
  background-color: var(--md-sys-color-primary-container);
  color: var(--md-sys-color-on-primary-container);
}
.md-chip .material-symbols-outlined {
  font-size: 1rem;
  margin-right: 0.375rem;
}

/* ---- Focus visible ---- */

:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
  border-radius: var(--radius-small);
}

/* ---- Reduced motion ---- */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* --------------------------------------------------------------------------
   Tags Cloud Page
   -------------------------------------------------------------------------- */

.tags-container {
  padding: 2rem 0;
  max-width: 820px;
  margin: 0 auto;
}

.tags-header {
  text-align: center;
  margin-bottom: 2.5rem;
}

.tags-title {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.tags-description {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.tags-count {
  font-size: 0.875rem;
  color: var(--text-tertiary);
}

.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem;
  padding: 1.5rem;
  background: var(--card-bg);
  border-radius: var(--radius-large);
}

.tag-cloud-item {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.4rem 0.875rem;
  background: var(--md-sys-color-surface-variant);
  color: var(--md-sys-color-on-surface-variant);
  border-radius: var(--md-shape-corner-full);
  font-weight: 500;
  text-decoration: none;
  transition:
    background-color var(--md-motion-duration-short) var(--md-motion-easing-standard),
    color var(--md-motion-duration-short) var(--md-motion-easing-standard);
}

.tag-cloud-item:hover {
  background: var(--md-sys-color-primary-container);
  color: var(--md-sys-color-on-primary-container);
}

.tag-cloud-count {
  font-size: 0.7em;
  opacity: 0.7;
  font-weight: 600;
}

.tag-cloud-empty {
  width: 100%;
  text-align: center;
  color: var(--text-tertiary);
  padding: 2rem 0;
}

/* Single tag page */
.tag-container,
.category-container {
  padding: 2rem 0;
}

.tag-header,
.category-header {
  text-align: center;
  margin-bottom: 2rem;
}

.tag-title,
.category-title {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}
.tag-title i,
.category-title i {
  margin-right: 0.5rem;
  color: var(--primary);
}

.tag-count,
.category-count {
  font-size: 0.9375rem;
  color: var(--text-tertiary);
}

/* Post meta-top meta items — M3 chip style */
.post-meta-item {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.25rem 0.65rem;
  background: var(--md-sys-color-surface-variant);
  border-radius: var(--md-shape-corner-full);
  font-size: 0.8125rem;
  color: var(--md-sys-color-on-surface-variant);
  transition:
    background-color var(--md-motion-duration-short) var(--md-motion-easing-standard),
    color var(--md-motion-duration-short) var(--md-motion-easing-standard);
}
.post-meta-item:hover {
  background: var(--md-sys-color-primary-container);
  color: var(--md-sys-color-on-primary-container);
}

/* Navbar action button — M3 standard icon button */
.navbar-action-btn {
  transition:
    background-color var(--md-motion-duration-medium) var(--md-motion-easing-emphasized),
    color var(--md-motion-duration-medium) var(--md-motion-easing-emphasized) !important;
}
.navbar-action-btn:hover {
  transform: none;
  box-shadow: none;
  background-color: oklch(0.65 0.18 var(--hue) / 0.08);
}
.navbar-links a {
  transition:
    background-color var(--md-motion-duration-medium) var(--md-motion-easing-emphasized),
    color var(--md-motion-duration-medium) var(--md-motion-easing-emphasized);
}
.navbar-links a:hover {
  transform: none;
}

/* --------------------------------------------------------------------------
   Categories Page
   -------------------------------------------------------------------------- */

.categories-container {
  padding: 2rem 0;
  max-width: 900px;
  margin: 0 auto;
}

.categories-header {
  text-align: center;
  margin-bottom: 2.5rem;
}

.categories-title {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.categories-description {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.categories-count {
  font-size: 0.875rem;
  color: var(--text-tertiary);
}

.categories-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.25rem;
}

.category-card {
  background: var(--card-bg);
  border-radius: var(--md-shape-corner-large);
  padding: 1.5rem;
  transition:
    background-color var(--md-motion-duration-short) var(--md-motion-easing-standard);
  display: flex;
  flex-direction: column;
}

.category-card:hover {
  background: var(--md-sys-color-surface-variant);
}

.category-card-link {
  text-decoration: none;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.category-card-icon {
  width: 3.5rem;
  height: 3.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--md-shape-corner-large);
  background: var(--md-sys-color-primary-container);
  color: var(--md-sys-color-on-primary-container);
  font-size: 1.5rem;
  transition:
    background-color var(--md-motion-duration-short) var(--md-motion-easing-standard),
    color var(--md-motion-duration-short) var(--md-motion-easing-standard);
}

.category-card:hover .category-card-icon {
  filter: brightness(0.92);
}

.category-card-name {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0;
}

.category-card-count {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  margin: 0;
}

.category-card-subcategories {
  display: flex;
  flex-wrap: wrap;
  gap: 0.375rem;
  margin-top: 0.75rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--line-divider);
}

.category-card-subitem {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.2rem 0.6rem;
  background: var(--md-sys-color-surface-variant);
  color: var(--md-sys-color-on-surface-variant);
  border-radius: var(--md-shape-corner-full);
  font-size: 0.75rem;
  font-weight: 500;
  text-decoration: none;
  transition:
    background-color var(--md-motion-duration-short) var(--md-motion-easing-standard),
    color var(--md-motion-duration-short) var(--md-motion-easing-standard);
}

.category-card-subitem:hover {
  background: var(--md-sys-color-primary-container);
  color: var(--md-sys-color-on-primary-container);
}

.subitem-count {
  opacity: 0.6;
}

.categories-empty {
  text-align: center;
  padding: 3rem 0;
  color: var(--text-tertiary);
}