/* Material 3 Design Tokens - Light Mode */
:root {
  /* Primary Colors */
  --md-sys-color-primary: #1e88e5;
  --md-sys-color-on-primary: #ffffff;
  --md-sys-color-primary-container: #bbdefb;
  --md-sys-color-on-primary-container: #0d47a1;
  
  /* Secondary Colors */
  --md-sys-color-secondary: #64b5f6;
  --md-sys-color-on-secondary: #ffffff;
  --md-sys-color-secondary-container: #e3f2fd;
  --md-sys-color-on-secondary-container: #1976d2;
  
  /* Surface Colors */
  --md-sys-color-surface: #fef7ff;
  --md-sys-color-surface-dim: #ded8e1;
  --md-sys-color-surface-bright: #fef7ff;
  --md-sys-color-surface-container-lowest: #ffffff;
  --md-sys-color-surface-container-low: #f7f2fa;
  --md-sys-color-surface-container: #f3edf7;
  --md-sys-color-surface-container-high: #ece6f0;
  --md-sys-color-surface-container-highest: #e6e0e9;
  --md-sys-color-on-surface: #1d1b20;
  --md-sys-color-on-surface-variant: #49454f;
  
  /* Background Colors */
  --md-sys-color-background: #fef7ff;
  --md-sys-color-on-background: #1d1b20;
  
  /* Outline */
  --md-sys-color-outline: #79747e;
  --md-sys-color-outline-variant: #cac4d0;
  
  /* Error Colors */
  --md-sys-color-error: #ba1a1a;
  --md-sys-color-on-error: #ffffff;
  --md-sys-color-error-container: #ffdad6;
  --md-sys-color-on-error-container: #410002;
  
  /* Typography */
  --md-sys-typescale-font-family: "Google Sans", "Inter", "MiSans", "Noto Sans SC", "LINESeedJP", sans-serif;
  --md-sys-typescale-display-large-size: 57px;
  --md-sys-typescale-display-large-weight: 400;
  --md-sys-typescale-display-large-line-height: 64px;
  --md-sys-typescale-headline-large-size: 32px;
  --md-sys-typescale-headline-large-weight: 400;
  --md-sys-typescale-headline-large-line-height: 40px;
  --md-sys-typescale-headline-medium-size: 28px;
  --md-sys-typescale-headline-medium-weight: 400;
  --md-sys-typescale-headline-medium-line-height: 36px;
  --md-sys-typescale-title-large-size: 22px;
  --md-sys-typescale-title-large-weight: 400;
  --md-sys-typescale-title-large-line-height: 28px;
  --md-sys-typescale-body-large-size: 16px;
  --md-sys-typescale-body-large-weight: 400;
  --md-sys-typescale-body-large-line-height: 24px;
  --md-sys-typescale-body-medium-size: 14px;
  --md-sys-typescale-body-medium-weight: 400;
  --md-sys-typescale-body-medium-line-height: 20px;
  
  /* Shape - M3 Expressive */
  --md-sys-shape-corner-none: 0px;
  --md-sys-shape-corner-extra-small: 4px;
  --md-sys-shape-corner-small: 8px;
  --md-sys-shape-corner-medium: 12px;
  --md-sys-shape-corner-large: 16px;
  --md-sys-shape-corner-extra-large: 28px;
  --md-sys-shape-corner-full: 9999px;
  
  /* Spacing */
  --md-sys-spacing-xs: 4px;
  --md-sys-spacing-sm: 8px;
  --md-sys-spacing-md: 16px;
  --md-sys-spacing-lg: 24px;
  --md-sys-spacing-xl: 32px;
  --md-sys-spacing-xxl: 48px;
  
  /* Layout */
  --page-max-width: 1200px;
  --page-gutter: clamp(16px, 4.5vw, 28px);

  /* Motion */
  --motion-ease-standard: cubic-bezier(0.22, 1, 0.36, 1);
  --motion-ease-emphasized: cubic-bezier(0.2, 0, 0, 1);
  --motion-duration-fast: 180ms;
  --motion-duration-medium: 360ms;
  --motion-duration-slow: 560ms;
  
  /* Elevation - Shadow */
  --md-sys-elevation-level0: none;
  --md-sys-elevation-level1: 0px 1px 2px rgba(0, 0, 0, 0.3), 0px 1px 3px 1px rgba(0, 0, 0, 0.15);
  --md-sys-elevation-level2: 0px 1px 2px rgba(0, 0, 0, 0.3), 0px 2px 6px 2px rgba(0, 0, 0, 0.15);
  --md-sys-elevation-level3: 0px 4px 8px 3px rgba(0, 0, 0, 0.15), 0px 1px 3px rgba(0, 0, 0, 0.3);
  
  /* State Layers */
  --md-sys-state-hover-opacity: 0.08;
  --md-sys-state-focus-opacity: 0.12;
  --md-sys-state-pressed-opacity: 0.12;
}

/* Material 3 Design Tokens - Dark Mode */
[data-theme="dark"] {
  /* Primary Colors */
  --md-sys-color-primary: #90caf9;
  --md-sys-color-on-primary: #003258;
  --md-sys-color-primary-container: #004a77;
  --md-sys-color-on-primary-container: #cce5ff;
  
  /* Secondary Colors */
  --md-sys-color-secondary: #64b5f6;
  --md-sys-color-on-secondary: #003258;
  --md-sys-color-secondary-container: #004a77;
  --md-sys-color-on-secondary-container: #cce5ff;
  
  /* Surface Colors */
  --md-sys-color-surface: #141218;
  --md-sys-color-surface-dim: #141218;
  --md-sys-color-surface-bright: #3b383e;
  --md-sys-color-surface-container-lowest: #0f0d13;
  --md-sys-color-surface-container-low: #1d1b20;
  --md-sys-color-surface-container: #211f26;
  --md-sys-color-surface-container-high: #2b2930;
  --md-sys-color-surface-container-highest: #36343b;
  --md-sys-color-on-surface: #e6e0e9;
  --md-sys-color-on-surface-variant: #cac4d0;
  
  /* Background Colors */
  --md-sys-color-background: #141218;
  --md-sys-color-on-background: #e6e0e9;
  
  /* Outline */
  --md-sys-color-outline: #938f99;
  --md-sys-color-outline-variant: #49454f;
  
  /* Error Colors */
  --md-sys-color-error: #ffb4ab;
  --md-sys-color-on-error: #690005;
  --md-sys-color-error-container: #93000a;
  --md-sys-color-on-error-container: #ffdad6;
}

/* Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  color-scheme: light;
}

html[data-theme="dark"] {
  color-scheme: dark;
}

body {
  font-family: var(--md-sys-typescale-font-family);
  font-size: var(--md-sys-typescale-body-large-size);
  font-weight: var(--md-sys-typescale-body-large-weight);
  line-height: var(--md-sys-typescale-body-large-line-height);
  color: var(--md-sys-color-on-background);
  background-color: var(--md-sys-color-background);
  margin: 0;
  max-width: none;
  transition: background-color 0.3s ease, color 0.3s ease;
  width: 100%;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* Container Utility Class */
.container {
  width: 100%;
  max-width: var(--page-max-width);
  margin-inline: auto;
  padding-inline: max(var(--page-gutter), env(safe-area-inset-left)) max(var(--page-gutter), env(safe-area-inset-right));
  box-sizing: border-box;
}

/* Typography */
h1 {
  font-size: var(--md-sys-typescale-headline-large-size);
  font-weight: var(--md-sys-typescale-headline-large-weight);
  line-height: var(--md-sys-typescale-headline-large-line-height);
  color: var(--md-sys-color-on-surface);
  margin-bottom: var(--md-sys-spacing-lg);
}

h2 {
  font-size: var(--md-sys-typescale-headline-medium-size);
  font-weight: var(--md-sys-typescale-headline-medium-weight);
  line-height: var(--md-sys-typescale-headline-medium-line-height);
  color: var(--md-sys-color-on-surface);
  margin-bottom: var(--md-sys-spacing-md);
}

h3 {
  font-size: var(--md-sys-typescale-title-large-size);
  font-weight: var(--md-sys-typescale-title-large-weight);
  line-height: var(--md-sys-typescale-title-large-line-height);
  color: var(--md-sys-color-on-surface);
  margin-bottom: var(--md-sys-spacing-md);
}

p {
  margin-bottom: var(--md-sys-spacing-md);
  color: var(--md-sys-color-on-surface-variant);
}

a {
  color: var(--md-sys-color-primary);
  text-decoration: none;
  transition: color var(--motion-duration-fast) var(--motion-ease-standard),
    opacity var(--motion-duration-fast) var(--motion-ease-standard),
    transform var(--motion-duration-fast) var(--motion-ease-standard);
}

a:hover {
  color: var(--md-sys-color-on-primary-container);
}

a:active {
  transform: translateY(0.5px) scale(0.995);
}

/* Surface Components */
.surface {
  background-color: var(--md-sys-color-surface-container);
  border-radius: var(--md-sys-shape-corner-extra-large);
  padding: var(--md-sys-spacing-lg);
  margin-bottom: var(--md-sys-spacing-lg);
  transition: background-color 0.3s ease;
}

.surface-elevated {
  background-color: var(--md-sys-color-surface-container-high);
  box-shadow: var(--md-sys-elevation-level2);
}

/* Header Styles */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--md-sys-color-outline-variant);
  transition: background-color var(--motion-duration-medium) var(--motion-ease-standard),
    border-color var(--motion-duration-medium) var(--motion-ease-standard),
    box-shadow var(--motion-duration-medium) var(--motion-ease-standard);
}

header.header-scrolled {
  box-shadow: 0 10px 32px rgba(0, 0, 0, 0.12);
}

[data-theme="dark"] header {
  background-color: rgba(20, 18, 24, 0.8);
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-block: var(--md-sys-spacing-md);
}

.site-title {
  font-size: var(--md-sys-typescale-title-large-size);
  font-weight: 500;
  color: var(--md-sys-color-on-surface);
  margin: 0;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--md-sys-spacing-sm);
}

.header-actions-desktop {
  display: flex;
}

.icon-button.mobile-menu-toggle {
  display: none;
}

/* Navigation */
nav ul {
  display: flex;
  list-style: none;
  gap: var(--md-sys-spacing-sm);
  margin: 0;
  padding: 0;
}

nav a {
  padding: var(--md-sys-spacing-sm) var(--md-sys-spacing-md);
  border-radius: var(--md-sys-shape-corner-full);
  color: var(--md-sys-color-on-surface);
  transition: background-color var(--motion-duration-fast) var(--motion-ease-standard),
    transform var(--motion-duration-fast) var(--motion-ease-standard);
  display: block;
}

nav a:hover {
  background-color: rgba(0, 0, 0, var(--md-sys-state-hover-opacity));
}

[data-theme="dark"] nav a:hover {
  background-color: rgba(255, 255, 255, var(--md-sys-state-hover-opacity));
}

nav a.active {
  background-color: var(--md-sys-color-secondary-container);
  color: var(--md-sys-color-on-secondary-container);
}

nav a:active {
  transform: scale(0.98);
}

/* Icon Button */
.icon-button {
  width: 40px;
  height: 40px;
  border: none;
  border-radius: var(--md-sys-shape-corner-full);
  background-color: transparent;
  color: var(--md-sys-color-on-surface);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color var(--motion-duration-fast) var(--motion-ease-standard),
    transform var(--motion-duration-fast) var(--motion-ease-standard),
    opacity var(--motion-duration-fast) var(--motion-ease-standard);
}

.icon-button:hover {
  background-color: rgba(0, 0, 0, var(--md-sys-state-hover-opacity));
}

[data-theme="dark"] .icon-button:hover {
  background-color: rgba(255, 255, 255, var(--md-sys-state-hover-opacity));
}

.icon-button .material-symbols-rounded {
  font-size: 24px;
  font-variation-settings: 'FILL' 0, 'wght' 400, 'GRAD' 0, 'opsz' 24;
}

.icon-button:active {
  transform: scale(0.94);
}

.search-field {
  display: flex;
  align-items: center;
  gap: var(--md-sys-spacing-xs);
  background-color: var(--md-sys-color-surface-container-high);
  border: 1px solid var(--md-sys-color-outline-variant);
  border-radius: var(--md-sys-shape-corner-full);
  padding-inline: var(--md-sys-spacing-sm);
  height: 40px;
  transition: border-color var(--motion-duration-fast) var(--motion-ease-standard),
    box-shadow var(--motion-duration-fast) var(--motion-ease-standard),
    background-color var(--motion-duration-fast) var(--motion-ease-standard);
}

.search-field:focus-within {
  border-color: var(--md-sys-color-primary);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--md-sys-color-primary) 22%, transparent);
}

.search-field .material-symbols-rounded {
  font-size: 20px;
  color: var(--md-sys-color-on-surface-variant);
}

.search-field input {
  border: none;
  outline: none;
  background: transparent;
  color: var(--md-sys-color-on-surface);
  width: 160px;
  font: inherit;
}

.search-field input::placeholder {
  color: var(--md-sys-color-on-surface-variant);
}

.mobile-menu-overlay {
  position: fixed;
  inset: 0;
  background-color: rgba(12, 10, 18, 0.62);
  z-index: 220;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--motion-duration-medium) var(--motion-ease-standard);
}

@supports ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
  .mobile-menu-overlay {
    background-color: rgba(12, 10, 18, 0.36);
    backdrop-filter: blur(20px) saturate(145%);
    -webkit-backdrop-filter: blur(20px) saturate(145%);
  }
}

.mobile-menu-overlay[hidden] {
  display: none !important;
}

.mobile-menu-overlay.is-open {
  opacity: 1;
  pointer-events: auto;
}

.mobile-menu-panel {
  position: relative;
  z-index: 1;
  min-height: 100dvh;
  background-color: var(--md-sys-color-surface);
  padding-top: var(--md-sys-spacing-lg);
  padding-bottom: var(--md-sys-spacing-lg);
  display: flex;
  flex-direction: column;
  gap: var(--md-sys-spacing-lg);
  transform: translateY(20px) scale(0.99);
  opacity: 0;
  transition: transform var(--motion-duration-medium) var(--motion-ease-emphasized),
    opacity var(--motion-duration-medium) var(--motion-ease-standard);
}

.mobile-menu-overlay.is-open .mobile-menu-panel {
  transform: translateY(0) scale(1);
  opacity: 1;
}

.mobile-menu-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.mobile-menu-top h2 {
  margin: 0;
}

.search-field-mobile {
  width: 100%;
}

.search-field-mobile input {
  width: 100%;
}

.mobile-nav nav ul {
  flex-direction: column;
  align-items: stretch;
  gap: var(--md-sys-spacing-sm);
}

.mobile-nav nav a {
  border-radius: var(--md-sys-shape-corner-large);
  padding: var(--md-sys-spacing-md);
  font-size: 20px;
  line-height: 28px;
}

.mobile-theme-toggle {
  width: 100%;
  border: 1px solid var(--md-sys-color-outline-variant);
  border-radius: var(--md-sys-shape-corner-large);
  background: var(--md-sys-color-surface-container-high);
  color: var(--md-sys-color-on-surface);
  min-height: 48px;
  padding: var(--md-sys-spacing-sm) var(--md-sys-spacing-md);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--md-sys-spacing-sm);
  cursor: pointer;
  transition: transform var(--motion-duration-fast) var(--motion-ease-standard),
    background-color var(--motion-duration-fast) var(--motion-ease-standard),
    border-color var(--motion-duration-fast) var(--motion-ease-standard);
}

.mobile-theme-toggle:active {
  transform: scale(0.98);
}

body.menu-open {
  overflow: hidden;
}

/* Main Content */
main {
  padding-block: var(--md-sys-spacing-xl);
  min-height: calc(100vh - 200px);
}

/* Footer */
footer {
  background-color: var(--md-sys-color-surface-container);
  border-top: 1px solid var(--md-sys-color-outline-variant);
}

.footer-content {
  padding-block: var(--md-sys-spacing-lg);
  text-align: center;
  color: var(--md-sys-color-on-surface-variant);
}

.footer-content p {
  margin-bottom: var(--md-sys-spacing-xs);
}

/* Post List */
section {
  margin-bottom: var(--md-sys-spacing-xl);
  padding: var(--md-sys-spacing-lg);
  background-color: var(--md-sys-color-surface-container);
  border-radius: var(--md-sys-shape-corner-extra-large);
  transition: box-shadow var(--motion-duration-medium) var(--motion-ease-standard),
    transform var(--motion-duration-medium) var(--motion-ease-standard),
    opacity var(--motion-duration-medium) var(--motion-ease-standard);
  will-change: transform, opacity;
}

section:hover {
  box-shadow: var(--md-sys-elevation-level2);
  transform: translateY(-2px);
}

.motion-reveal {
  opacity: 0;
  transform: translateY(18px) scale(0.995);
  transition: opacity var(--motion-duration-slow) var(--motion-ease-standard),
    transform var(--motion-duration-slow) var(--motion-ease-emphasized);
}

.motion-reveal.is-visible {
  opacity: 1;
  transform: translateY(0) scale(1);
}

.motion-reveal-delay-1 {
  transition-delay: 50ms;
}

.motion-reveal-delay-2 {
  transition-delay: 100ms;
}

.motion-reveal-delay-3 {
  transition-delay: 150ms;
}

/* Tags */
.tags {
  display: flex;
  gap: var(--md-sys-spacing-sm);
  flex-wrap: wrap;
  margin-top: var(--md-sys-spacing-md);
}

.tags ul {
  display: flex;
  gap: var(--md-sys-spacing-sm);
  list-style: none;
  flex-wrap: wrap;
}

.tags li {
  background-color: var(--md-sys-color-secondary-container);
  color: var(--md-sys-color-on-secondary-container);
  padding: var(--md-sys-spacing-xs) var(--md-sys-spacing-md);
  border-radius: var(--md-sys-shape-corner-small);
  font-size: var(--md-sys-typescale-body-medium-size);
}

/* Images */
img {
  max-width: 100%;
  height: auto;
  border-radius: var(--md-sys-shape-corner-large);
  margin: var(--md-sys-spacing-lg) 0;
}

/* Time */
time {
  color: var(--md-sys-color-on-surface-variant);
  font-size: var(--md-sys-typescale-body-medium-size);
  display: block;
  margin-bottom: var(--md-sys-spacing-md);
}

/* Responsive */
@media (max-width: 768px) {
  :root {
    --page-gutter: clamp(18px, 5.2vw, 30px);
  }
  
  .header-content {
    padding-block: var(--md-sys-spacing-sm);
  }
  
  nav ul {
    gap: var(--md-sys-spacing-xs);
  }
  
  nav a {
    padding: var(--md-sys-spacing-xs) var(--md-sys-spacing-sm);
    font-size: var(--md-sys-typescale-body-medium-size);
  }
  
  main {
    padding-block: var(--md-sys-spacing-lg);
  }
  
  h1 {
    font-size: 24px;
    line-height: 32px;
  }
  
  h2 {
    font-size: 22px;
    line-height: 28px;
  }

  section {
    padding: var(--md-sys-spacing-md);
  }
}

@media (max-width: 480px) {
  :root {
    --page-gutter: clamp(16px, 5.6vw, 24px);
  }

  .site-title {
    font-size: 18px;
  }
  
  h1 {
    font-size: 22px;
    line-height: 28px;
  }

  section {
    padding: 14px;
  }
}

@media (max-width: 768px) {
  .header-actions-desktop {
    display: none;
  }

  .icon-button.mobile-menu-toggle {
    display: inline-flex;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition-duration: 1ms !important;
    scroll-behavior: auto !important;
  }

  .motion-reveal,
  .motion-reveal.is-visible {
    opacity: 1;
    transform: none;
  }
}