:root {
  --bg-color: #fafafa;
  --text-color: #2c3e50;
  /* Softer dark blue-gray instead of near-black */
  --link-color: #3498db;
  --heading-color: #1a252f;
  --code-bg: #eceff1;
  --border-color: #e0e0e0;
  --max-width: 720px;
  --spacing: 1.5rem;
  color-scheme: light;
}



html {
  font-size: 17px;
  /* Increased from 16px for better legibility */
  -webkit-font-smoothing: auto;
  /* Remove forced antialiasing which can make thin fonts too thin */
  -moz-osx-font-smoothing: auto;
}

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  margin: 0;
  padding: 0;
  line-height: 1.8;
  font-weight: 450;
  /* Slightly heavier than regular 400 for better rendering of Noto Sans */
  letter-spacing: 0.01em;
  /* Slight positive spacing for clearer glyph separation */
  font-feature-settings: "palt";
  /* Proportional metrics for Japanese */
}

/* Layout container */
main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1.5rem;
  background-color: transparent;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
  color: var(--heading-color);
  margin-top: 2.5em;
  margin-bottom: 1em;
  line-height: 1.3;
  font-weight: 700;
}

h1 {
  font-size: 2.5rem;
  margin-top: 1em;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.5em;
}

h2 {
  font-size: 1.75rem;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.3em;
}

p {
  margin-bottom: 1.5em;
  text-align: justify;
}

a {
  color: var(--link-color);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s;
}

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

/* Code blocks */
pre {
  background-color: var(--code-bg);
  padding: 1rem;
  border-radius: 8px;
  overflow-x: auto;
  margin: 1.5em 0;
  border: 1px solid var(--border-color);
}

code {
  font-family: Menlo, Monaco, Consolas, "Courier New", monospace;
  font-size: 0.9em;
  background-color: var(--code-bg);
  padding: 0.2em 0.4em;
  border-radius: 4px;
}

pre code {
  background-color: transparent;
  padding: 0;
}

/* Lists */
ul,
ol {
  margin-bottom: 1.5em;
  padding-left: 2em;
}

li {
  margin-bottom: 0.5em;
}

/* Blockquote */
blockquote {
  margin: 1.5em 0;
  padding: 0.5em 1em 0.5em 1.5em;
  border-left: 4px solid var(--link-color);
  background-color: var(--code-bg);
  font-style: italic;
  color: var(--text-color);
}

/* Mermaid / Centering */
.mermaid {
  display: flex;
  justify-content: center;
  margin: 2em 0;
  background: white;
  /* Graphs often look better on white */
  padding: 1rem;
  border-radius: 8px;
}