/* ==========================================================================
   Chansaki site — calm, editorial, low-noise UI
   ========================================================================== */

:root{
  /* Color */
  --bg: #f2fbf7;
  --bg-2: #f2fbf7;
  --surface: rgba(255, 255, 255, 0.86);
  --surface-strong: #ffffff;
  --text: #1f3a34;
  --muted: #5f7a72;
  --border: rgba(120, 170, 156, 0.24);

  --accent: #9edbc8;
  --accent-soft: rgba(158, 219, 200, 0.26);
  --accent-ink: #3f8a75;
  --accent-warm: #9edbc8;

  --shadow: 0 18px 42px rgba(76, 86, 110, 0.12);
  --shadow-soft: 0 8px 18px rgba(76, 86, 110, 0.10);

  /* Typography */
  --font-sans: "Avenir Next", "Avenir", "Segoe UI", "Noto Sans JP", "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
  --font-display: "Iowan Old Style", "Hiragino Mincho ProN", "Yu Mincho", "Noto Serif JP", Georgia, serif;
  --font-heading: var(--font-sans);

  /* Layout */
  --container: 48rem;
  --radius: 16px;

  /* Spacing */
  --s-1: .25rem;
  --s-2: .5rem;
  --s-3: .75rem;
  --s-4: 1rem;
  --s-5: 1.5rem;
  --s-6: 2rem;
  --s-7: 3rem;
}

@media (prefers-color-scheme: dark){
  :root{
    --bg: #111a17;
    --bg-2: #111a17;
    --surface: rgba(24, 38, 33, 0.88);
    --surface-strong: #1d312b;
    --text: #e9f6f1;
    --muted: rgba(233, 246, 241, 0.72);
    --border: rgba(233, 246, 241, 0.17);

    --accent: #82c9b1;
    --accent-soft: rgba(130, 201, 177, 0.23);
    --accent-ink: #a8decf;
    --accent-warm: #82c9b1;

    --shadow: 0 18px 44px rgba(0, 0, 0, 0.35);
    --shadow-soft: 0 8px 20px rgba(0, 0, 0, 0.28);
  }
}

*{ box-sizing: border-box; }

html{
  color-scheme: light dark;
  text-rendering: optimizeLegibility;
  -webkit-text-size-adjust: 100%;
}

body{
  margin: 0;
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.88;
  letter-spacing: 0.01em;
  position: relative;
}

body::before{
  content: none;
}

/* A11y */
.skip-link{
  position: absolute;
  left: -9999px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
}
.skip-link:focus{
  left: var(--s-4);
  top: var(--s-4);
  width: auto;
  height: auto;
  padding: .5rem .75rem;
  background: var(--surface-strong);
  border: 1px solid var(--border);
  border-radius: 10px;
  box-shadow: var(--shadow-soft);
  z-index: 9999;
}

/* Layout */
.container{
  max-width: var(--container);
  padding: 0 var(--s-4);
  margin: 0 auto;
}

.site-header{
  position: sticky;
  top: 0;
  z-index: 30;
  padding: .9rem 0;
  border-bottom: 1px solid var(--border);
  background: var(--surface);
  backdrop-filter: blur(10px);
}

.site-header .container{
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s-4);
  flex-wrap: wrap;
}

.site-title{
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: clamp(1.06rem, 2.4vw, 1.28rem);
  letter-spacing: 0.01em;
  text-decoration: none;
  color: var(--text);
}

.site-nav{
  display: flex;
  gap: .4rem;
  flex-wrap: wrap;
}

.site-nav a{
  color: var(--accent-ink);
  text-decoration: none;
  padding: .3rem .58rem;
  border-radius: 999px;
  border: 1px solid transparent;
  transition: background-color .22s ease, border-color .22s ease, transform .22s ease;
}

.site-nav a:hover{
  background: var(--accent-soft);
  border-color: var(--border);
  transform: translateY(-1px);
}

.site-nav a:focus-visible{
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

main.container{
  padding-top: 1.15rem;
}

.site-footer{
  padding: var(--s-6) 0 var(--s-6);
  margin-top: var(--s-7);
  border-top: 1px solid var(--border);
}

/* Typographic helpers */
.small{ font-size: .92rem; }
.muted{ color: var(--muted); }

/* Prose */
.prose{
  margin-top: .6rem;
  padding: clamp(1.1rem, 3.2vw, 2rem);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: calc(var(--radius) + 2px);
  box-shadow: var(--shadow);
}

.prose h1, .prose h2, .prose h3{
  font-family: var(--font-heading);
  line-height: 1.35;
  letter-spacing: 0.005em;
  font-weight: 700;
  scroll-margin-top: 6.3rem;
}

.prose h1{
  font-size: clamp(1.6rem, 4vw, 2.15rem);
  margin: 0 0 .7rem;
}

.prose h2{
  font-size: clamp(1.14rem, 2.2vw, 1.45rem);
  margin: 2.2rem 0 .95rem;
  padding: .22rem 0 .22rem .9rem;
  border-left: 4px solid var(--accent);
  border-radius: 8px;
  background: var(--accent-soft);
}

.prose h2:first-of-type{
  margin-top: 1.35rem;
}

.prose h3{
  font-size: 1.06rem;
  margin: 1.4rem 0 .5rem;
}

.prose p{
  margin: .92rem 0;
}

.prose img{
  display: block;
  max-width: 100%;
  height: auto;
  margin: 1rem auto;
  border-radius: 10px;
}

.prose .image-row{
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.9rem;
  margin: 1rem 0;
}

.prose .image-row img{
  width: 100%;
  margin: 0;
}

.prose iframe{
  display: block;
  width: 100%;
  max-width: 100%;
  aspect-ratio: 16 / 9;
  height: auto;
  margin: 1rem auto;
  border: 0;
  border-radius: 10px;
}

.prose ul, .prose ol{
  margin: .78rem 0 1.1rem;
  padding-left: 1.42rem;
}

.prose li{
  margin: .52rem 0;
}

.prose li::marker{
  color: var(--accent-ink);
}

.prose li > ul, .prose li > ol{
  margin: .28rem 0 .52rem;
}

.prose hr{
  border: 0;
  border-top: 1px solid var(--border);
  margin: var(--s-6) 0;
}

.prose a{
  color: var(--accent-ink);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: .2em;
  overflow-wrap: anywhere;
  word-break: break-word;
  transition: color .22s ease, text-decoration-thickness .22s ease;
}

.prose a:hover{
  color: var(--accent);
  text-decoration-thickness: 2px;
}

.prose a:focus-visible{
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 8px;
}

/* In-page citation links: [[1]](#ref-1) */
.prose a[href^="#ref-"]{
  font-size: .76em;
  vertical-align: super;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 1.5em;
  height: 1.5em;
  text-decoration: none;
  padding: 0 .3em;
  margin-left: .08em;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-ink);
  background-image: none;
}

.prose a[href^="#ref-"]:hover{
  background: var(--accent-soft);
  background: color-mix(in srgb, var(--accent-soft) 70%, var(--accent) 30%);
  color: var(--accent-ink);
}

.refs-list li[id^="ref-"]{
  scroll-margin-top: 6.2rem;
}

.prose blockquote{
  margin: 1.2rem 0;
  padding: .95rem 1rem .95rem 1.2rem;
  background: var(--accent-soft);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: var(--radius);
  box-shadow: var(--shadow-soft);
  position: relative;
}

.prose blockquote::before{
  content: "“";
  position: absolute;
  left: .58rem;
  top: -.52rem;
  font-family: var(--font-display);
  font-size: 1.65rem;
  color: var(--accent);
  color: color-mix(in srgb, var(--accent) 68%, var(--text));
}

.prose blockquote p{
  margin: 0;
}

.prose code{
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: .92em;
  background: var(--accent-soft);
  background: color-mix(in srgb, var(--accent-soft) 70%, transparent);
  padding: .08em .34em;
  border-radius: 6px;
}

.prose pre{
  background: var(--accent-soft);
  background: color-mix(in srgb, var(--accent-soft) 40%, transparent);
  padding: var(--s-4);
  border-radius: var(--radius);
  overflow-x: auto;
  border: 1px solid var(--border);
}

.prose pre code{
  background: transparent;
  padding: 0;
}

.prose mjx-container{
  overflow-x: auto;
  overflow-y: hidden;
  max-width: 100%;
}

.prose .note{
  margin: var(--s-4) 0;
  padding: var(--s-3) var(--s-4);
  background: var(--surface-strong);
  background: color-mix(in srgb, var(--surface-strong) 86%, transparent);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-soft);
}

/* Post list */
.post-list{
  list-style: none;
  padding-left: 0;
  margin-top: 1rem;
}

.post-list li{
  margin: .72rem 0;
  display: flex;
  flex-wrap: wrap;
  gap: .38rem .8rem;
  align-items: baseline;
  padding: .74rem .88rem;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--surface-strong);
  background: color-mix(in srgb, var(--surface-strong) 85%, transparent);
  box-shadow: var(--shadow-soft);
}

.post-list a{
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: .18em;
}

.post-list a:hover{
  color: var(--accent);
  text-decoration-thickness: 2px;
}

/* Reference list */
.refs-list{
  margin: .95rem 0 .4rem;
  padding-left: 1.55rem;
  overflow-wrap: anywhere;
}

.refs-list li{
  margin: .68rem 0;
  padding: .36rem .32rem;
  line-height: 1.75;
}

/* Tags */
.tag{
  display: inline-block;
  padding: .08rem .48rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--accent-soft);
}

/* Knowledge graph (Cytoscape.js) */
.kg-shell{
  position: relative;
  display: block;
}

.kg-stage{
  min-width: 0;
}

.kg{
  height: min(83vh, 900px);
  width: 100%;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface-strong);
  box-shadow: var(--shadow-soft);
  overflow: hidden;
}

.kg-panel{
  position: absolute;
  top: 12px;
  right: 12px;
  width: min(320px, calc(100% - 24px));
  z-index: 20;
}

.kg-panel__inner{
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--surface-strong) 88%, transparent);
  box-shadow: var(--shadow-soft);
  padding: var(--s-4);
}

.kg-panel__header{
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s-3);
  margin-bottom: var(--s-3);
}

.kg-panel__kicker{
  margin: 0;
}

.kg-panel__title{
  font-family: var(--font-heading);
  font-size: 1.08rem;
  line-height: 1.4;
  margin: 0 0 .4rem;
}

.kg-panel__meta{
  margin: 0 0 var(--s-4);
}

.kg-panel__actions{
  display: flex;
  gap: .5rem;
  flex-wrap: wrap;
}

.kg-panel__open{
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: .36rem .7rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--accent-soft);
  color: var(--accent-ink);
  text-decoration: none;
  font-weight: 700;
  transition: transform .18s ease, background-color .18s ease, border-color .18s ease;
}

.kg-panel__open:hover{
  transform: translateY(-1px);
  border-color: var(--accent);
}

.kg-panel__open[aria-disabled="true"]{
  opacity: .55;
  pointer-events: none;
}

.kg-panel__clear{
  border: 1px solid var(--border);
  background: transparent;
  color: var(--muted);
  padding: .26rem .56rem;
  border-radius: 999px;
  cursor: pointer;
}

.kg-panel__clear:hover{
  border-color: var(--accent);
  color: var(--accent-ink);
}

.kg-hint{
  margin: 0 0 .75rem;
}

/* Murmur pages feel slightly more essay-like */
.prose-murmur{
  font-family: var(--font-heading);
}

.prose-murmur p{
  font-size: 1.04rem;
}

/* Comments (giscus) */
.comments{
  margin-top: var(--s-6);
}

.comments h2{
  font-size: 1.1rem;
  margin: 0 0 .6rem;
}

.giscus-wrap{
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: var(--s-3);
  background: color-mix(in srgb, var(--surface-strong) 70%, transparent);
  box-shadow: var(--shadow-soft);
}

.giscus,
.giscus-frame{
  width: 100%;
}

@media (max-width: 640px){
  .kg-panel{
    top: auto;
    bottom: 12px;
    left: 12px;
    right: 12px;
    width: auto;
  }

  .site-header{
    padding: .72rem 0;
  }

  .site-nav a{
    padding: .24rem .5rem;
  }

  .prose{
    padding: 1rem .92rem 1.15rem;
  }

  .prose h2{
    padding-left: .72rem;
  }

  .prose .image-row{
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: no-preference){
  .prose{
    animation: prose-enter .52s cubic-bezier(.22, .61, .36, 1) both;
  }

  .post-list li{
    animation: prose-enter .42s cubic-bezier(.22, .61, .36, 1) both;
  }
}

@keyframes prose-enter{
  from{
    opacity: 0;
    transform: translateY(8px);
  }
  to{
    opacity: 1;
    transform: translateY(0);
  }
}

/* Reduce motion */
@media (prefers-reduced-motion: reduce){
  *{ scroll-behavior: auto !important; transition: none !important; animation: none !important; }
}