:root {
  --bg-color: #fdfdfd;
  --text-color: #1a1a1a;
  --link-color: #0366d6;
  --heading-font: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --body-font: 'STSong', 'PMingLiU', 'SimSun', serif; /* Emulate realistic physical reading */
  --border-color: #eaeaea;
}

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: var(--body-font);
  line-height: 1.8;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--heading-font);
  font-weight: 600;
  margin-top: 2rem;
}

a {
  color: var(--link-color);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

.site-header {
  border-bottom: 1px solid var(--border-color);
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--heading-font);
}

.site-nav a {
  margin-left: 1.5rem;
  color: var(--text-color);
}

.page-content {
  flex: 1;
  display: flex;
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
  gap: 3rem;
}

.main-content {
  flex: 3;
  max-width: 800px;
}

.sidebar {
  flex: 1;
  font-family: var(--heading-font);
  border-left: 1px solid var(--border-color);
  padding-left: 2rem;
}

.sidebar-widget {
  margin-bottom: 2rem;
}

.sidebar-widget h3 {
  font-size: 1.2rem;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
}

.site-footer {
  border-top: 1px solid var(--border-color);
  padding: 2rem;
  text-align: center;
  font-family: var(--heading-font);
  font-size: 0.9rem;
}

.post-meta {
  color: #666;
  font-size: 0.9rem;
  font-family: var(--heading-font);
}

.post-content {
  font-size: 1.15rem; /* readable size for serif */
}

/* Forms & Buttons */
input[type="text"], input[type="email"], textarea {
  width: 100%;
  padding: 0.75rem;
  margin-bottom: 1rem;
  border: 1px solid #ccc;
  border-radius: 4px;
  box-sizing: border-box;
  font-family: var(--heading-font);
}

button {
  background-color: var(--text-color);
  color: #fff;
  border: none;
  padding: 0.75rem 1.5rem;
  cursor: pointer;
  border-radius: 4px;
  font-family: var(--heading-font);
  transition: opacity 0.2s;
}
button:hover {
  opacity: 0.8;
}

.buy-coffee {
  display: block;
  text-align: center;
  margin-top: 3rem;
  padding: 1rem;
  background-color: #ffd814;
  color: #0f1111;
  border-radius: 8px;
  font-weight: bold;
  text-decoration: none !important;
  font-family: var(--heading-font);
}

.post-nav {
  display: flex;
  justify-content: space-between;
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  font-family: var(--heading-font);
}

.comments-section {
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
}