:root {
  /* Theme colors */
  --bg: #0b1020;
  --ink: #e6edf3;
  --muted: #9fb0c4;
  --panel: #0f162e;
  --line: #1f2a44;
  --accent: #22d3ee;
  /* Article section palette */
  --article-primary: #007bff;
  --article-light: #f4f4f4;
  --article-text-light: #e0e0e0;
  --article-text-muted: #aaaaaa;
  --article-bg-card: #1e1e1e;
  --article-code-bg: #2a2a2a;
}

/* Ensure predictable box sizing across the page */
* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial;
  background: var(--bg);
  color: var(--ink);
}

header {
  padding: 18px 16px;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.03), rgba(255, 255, 255, 0));
}

header h1 {
  margin: 0 0 4px;
  font-size: 22px;
}

header .muted {
  color: var(--muted);
  font-size: 13px;
}

.shell {
  max-width: 1000px;
  margin: 24px auto 40px;
  padding: 0 20px 40px;
}

/* Main article card */
.content {
  background: var(--article-bg-card);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 8px;
  padding: 30px;
  margin-top: 30px;
  color: var(--article-text-light);
  box-shadow: 0 15px 40px rgba(0, 0, 0, 0.35);
}

.content p {
  line-height: 1.7;
  margin: 0 0 16px;
  color: var(--article-text-light);
}

.content h2 {
  border-bottom: 2px solid var(--article-primary);
  padding-bottom: 10px;
  margin: 40px 0 20px;
  font-size: 1.9rem;
  color: var(--ink);
}

.content h3,
.content h6 {
  margin: 30px 0 14px;
  font-size: 1.35rem;
  color: var(--article-text-light);
  border-left: 4px solid var(--article-text-muted);
  padding-left: 12px;
  letter-spacing: 0.02em;
}

.content h2:first-of-type {
  margin-top: 0;
}

.content strong {
  color: var(--article-light, #f4f4f4);
}

.math-formula,
.pre-code,
.content pre {
  background-color: var(--article-code-bg);
  padding: 15px;
  border-left: 5px solid #ffaa00;
  margin: 20px 0;
  overflow-x: auto;
  border-radius: 6px;
  color: #dcdcdc;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.95rem;
}

.content code {
  background-color: var(--article-code-bg);
  padding: 4px 6px;
  border-radius: 4px;
  color: #ffd479;
}

.page-actions {
  display: flex;
  justify-content: flex-start;
  margin-bottom: 12px;
}

.back-home {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 16px;
  border-radius: 999px;
  border: 1px solid rgba(34, 211, 238, 0.4);
  color: #22d3ee;
  background: transparent;
  text-decoration: none;
  font-weight: 600;
  font-size: 14px;
  transition: background-color 0.2s, transform 0.2s;
}

.back-home:hover {
  background: rgba(34, 211, 238, 0.16);
  transform: translateY(-1px);
}

.content figure {
  margin: 30px 0;
  text-align: center;
}

.content figure img {
  max-width: 100%;
  height: auto;
  border-radius: 6px;
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.content figure figcaption {
  font-style: italic;
  font-size: 0.9rem;
  color: var(--article-text-muted);
  margin-top: 10px;
}

.mini-panorama {
  width: 100%;
  height: 400px;
  margin: 20px 0;
  border-radius: 6px;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.mini-panorama > div {
  width: 100%;
  height: 100%;
}

ul {
  list-style: disc;
  margin-left: 20px;
  color: var(--article-text-light);
}

li {
  margin-bottom: 8px;
}

footer {
  color: var(--muted);
  font-size: 12px;
  text-align: center;
  padding: 28px 16px;
}