/* 
  Academic Theme CSS
  Goal: Minimalist, readable, paper-like UI.
*/

:root {
  /* Typography */
  --font-sans: "Roboto", "Segoe UI", "Helvetica Neue", Arial, "Noto Sans", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-serif: var(--font-sans); /* Overriding serif to match Project Zero style everywhere */
  --font-mono: "Roboto Mono", ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  
  --line-height: 1.7;
  --max-width: 70ch;
  
  /* Colors - Light Mode */
  --bg-color: #ffffff;
  --text-color: #222222;
  --text-light: #555555;
  --text-lighter: #888888;
  --link-color: #0366d6;
  --link-hover: #004098;
  --border-color: #e1e4e8;
  --code-bg: #f6f8fa;
  --blockquote-border: #dfe2e5;
  --blockquote-text: #6a737d;
}

@media (prefers-color-scheme: dark) {
  :root {
    /* Colors - Dark Mode */
    --bg-color: #0d1117;
    --text-color: #c9d1d9;
    --text-light: #8b949e;
    --text-lighter: #6e7681;
    --link-color: #58a6ff;
    --link-hover: #79c0ff;
    --border-color: #30363d;
    --code-bg: #161b22;
    --blockquote-border: #3b434b;
    --blockquote-text: #8b949e;
  }
}

/* Global Reset */
* {
  box-sizing: border-box;
}

body {
  font-family: var(--font-sans); /* Use modern sans-serif for Project Zero feel */
  font-size: 18px;
  line-height: var(--line-height);
  color: var(--text-color);
  background-color: var(--bg-color);
  margin: 0;
  padding: 0;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  transition: background-color 0.3s, color 0.3s;
}

/* Layout container */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1rem;
}

/* Typography Hierarchy */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-sans);
  font-weight: 700;
  color: var(--text-color);
  margin-top: 2.5em;
  margin-bottom: 1em;
  line-height: 1.3;
  letter-spacing: -0.5px;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 1.75rem; border-bottom: 1px solid var(--border-color); padding-bottom: 0.3em; margin-top: 3rem; }
h3 { font-size: 1.5rem; margin-top: 2rem; }
h4 { font-size: 1.25rem; }

p {
  margin-top: 0;
  margin-bottom: 1.8em;
  text-align: justify; /* Justify text for paper-like appearance */
}

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

a:hover {
  color: var(--link-hover);
  border-bottom: 1px solid var(--link-hover);
}

/* Header */
.header {
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 1.5rem;
  margin-bottom: 3rem;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  font-family: var(--font-sans);
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  width: 100%;
}

.site-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-color);
  border: none;
  letter-spacing: -0.5px;
}
.site-title:hover {
  border: none;
}

.site-nav {
  margin-top: 1rem;
}

.site-nav a {
  margin-right: 1.5rem;
  margin-left: 0;
  font-size: 1.05rem;
  color: var(--text-light);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  font-weight: 500;
}

.site-nav a.active {
  color: var(--text-color);
  font-weight: 600;
}

/* Home */
.home .profile {
  text-align: center;
  margin-bottom: 4rem;
  padding-bottom: 3rem;
  border-bottom: 1px dashed var(--border-color);
  position: relative;
}
.home .profile::after {
  content: "§";
  position: absolute;
  bottom: -0.8rem;
  left: 50%;
  transform: translateX(-50%);
  background-color: var(--bg-color);
  padding: 0 1rem;
  color: var(--text-lighter);
  font-family: var(--font-sans);
  font-size: 1.2rem;
}
.avatar {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  margin-bottom: 1rem;
}
.author-name {
  font-size: 2rem;
  margin: 0.5rem 0;
  font-family: var(--font-sans);
}
.bio {
  color: var(--text-light);
  font-size: 1.1rem;
  text-align: center;
}

.recent-posts h2 {
  border: none;
  font-size: 1rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--text-lighter);
  margin-bottom: 2.5rem;
  margin-top: 2rem;
}

.post-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.post-item {
  margin-bottom: 3rem;
}

.post-meta {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-light);
  margin-bottom: 0.5rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.post-title {
  font-size: 1.6rem;
  font-weight: 700;
  font-family: var(--font-sans);
  color: var(--text-color);
  display: inline-block;
  margin-bottom: 0.8rem;
  border: none;
  line-height: 1.3;
  letter-spacing: -0.5px;
}
.post-title:hover {
  color: var(--link-color);
  border: none;
}

.post-summary {
  color: var(--text-light);
  font-size: 1.05rem;
  text-align: left;
  line-height: 1.6;
}

.read-more {
  margin-top: 3rem;
  font-family: var(--font-sans);
  font-weight: 600;
}

/* Single Post */
.post-header {
  margin-bottom: 2rem;
}

.post-header .post-title {
  font-size: 2.5rem;
  margin-top: 0;
  margin-bottom: 0.5rem;
}

.post-tags {
  margin-left: 0.5rem;
}
.tag {
  color: var(--text-light);
  font-size: 0.9rem;
}

.toc {
  background: var(--code-bg);
  padding: 1.5rem;
  border: 1px solid var(--border-color);
  margin-bottom: 2rem;
  font-family: var(--font-sans);
  font-size: 0.95rem;
}
.toc-title {
  margin-top: 0;
  margin-bottom: 1rem;
  font-size: 1.1rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-light);
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.5rem;
}
.toc ul {
  list-style: none;
  padding-left: 1.5rem;
  margin: 0;
}
.toc > nav > ul {
  padding-left: 0;
}
.toc a {
  color: var(--text-light);
  border: none;
}
.toc a:hover {
  color: var(--link-color);
}

.post-content img {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 2rem auto;
}

.post-content ul, .post-content ol {
  margin-bottom: 1.5rem;
  padding-left: 2rem;
}
.post-content li {
  margin-bottom: 0.5rem;
}

/* Blockquote - Paper Style */
blockquote {
  margin: 2rem 0;
  padding: 1rem 1.5rem;
  border-left: 4px solid var(--blockquote-border);
  color: var(--blockquote-text);
  background: var(--code-bg);
  font-style: italic;
}
blockquote p:last-child {
  margin-bottom: 0;
}

/* Code */
code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background-color: var(--code-bg);
  padding: 0.2em 0.4em;
  border-radius: 3px;
}

pre {
  background-color: var(--code-bg);
  padding: 1.5rem;
  overflow: auto;
  border-radius: 4px;
  margin: 2rem 0;
  border: 1px solid var(--border-color);
}

pre code {
  background-color: transparent;
  padding: 0;
  border-radius: 0;
  font-size: 0.9em;
  white-space: pre;
}

/* Tables */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 2rem 0;
  font-family: var(--font-sans);
  font-size: 0.95em;
}
th, td {
  border: 1px solid var(--border-color);
  padding: 0.75rem 1rem;
  text-align: left;
}
th {
  background-color: var(--code-bg);
  font-weight: 600;
}

/* Tags Cloud */
.tags-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 2rem;
}
.tag-cloud-item {
  font-family: var(--font-sans);
  background: var(--code-bg);
  padding: 0.5rem 1rem;
  border-radius: 4px;
  border: 1px solid var(--border-color);
  color: var(--text-color);
  font-size: 1rem;
}
.tag-cloud-item:hover {
  border-color: var(--link-color);
}
.tag-count {
  color: var(--text-light);
  font-size: 0.85em;
  margin-left: 0.25rem;
}

/* Footnotes */
.footnotes {
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border-color);
  font-size: 0.9em;
  color: var(--text-light);
}

.footnotes hr {
  display: none;
}

/* Footer */
.footer {
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  text-align: center;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  color: var(--text-lighter);
}
.theme-info {
  margin-top: 0.5rem;
}