/* ========================================
   Jianbo Lin's Blog - Minimal Style
   Inspired by kevinlu.ai
   ======================================== */

:root {
  /* Colors */
  --color-bg: #ffffff;
  --color-text: #1a1a1a;
  --color-text-secondary: #666666;
  --color-accent: #8b88e6;
  --color-accent-hover: #6b68d6;
  --color-border: #e5e5e5;

  /* Fonts */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;

  /* Font Sizes - 修改这里统一调整全站字体 */
  --font-size-nav: 0.95rem;       /* 导航栏 */
  --font-size-h1: 2rem;           /* 标题 h1 */
  --font-size-h2: 1.5rem;         /* 标题 h2 */
  --font-size-h3: 1.25rem;        /* 标题 h3 */
  --font-size-body: 1.15rem;      /* 正文 */
  --font-size-caption: 0.85rem;   /* 注释/日期/小字 */

  /* Layout */
  --max-width: 720px;
  --nav-height: 60px;
}

/* Reset */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  min-height: 100vh;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.3;
  margin-bottom: 0.5em;
}

h1 { font-size: var(--font-size-h1); }
h2 { font-size: var(--font-size-h2); }
h3 { font-size: var(--font-size-h3); }

p {
  margin-bottom: 1em;
}

a {
  color: var(--color-text);
  text-decoration: underline;
  text-decoration-color: var(--color-accent);
  text-underline-offset: 3px;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--color-accent);
}

/* Navigation */
nav {
  position: sticky;
  top: 0;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
}

.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-weight: 600;
  font-size: 1.1rem;
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  text-decoration: none;
  color: var(--color-text-secondary);
  font-size: var(--font-size-nav);
  transition: color 0.2s ease;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-accent);
}

/* Mobile menu */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  margin: 5px 0;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.menu-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.menu-toggle.active span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

@media (max-width: 700px) {
  .menu-toggle {
    display: block;
  }

  .nav-links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-bg);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2rem;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
  }

  .nav-links.active {
    opacity: 1;
    visibility: visible;
  }

  .nav-links a {
    font-size: 1.25rem;
  }
}

/* Main content */
main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 3rem 1.5rem;
}

/* Hero section */
.hero {
  margin-bottom: 3rem;
}

.hero h1 {
  margin-bottom: 0.25em;
}

.hero .tagline {
  color: var(--color-text-secondary);
  font-size: var(--font-size-body);
  margin-bottom: 1rem;
}

.hero .intro {
  font-size: var(--font-size-body);
}

/* Blog list */
.blog-list {
  list-style: none;
}

.blog-item {
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--color-border);
}

.blog-item:last-child {
  border-bottom: none;
}

.blog-item-date {
  font-size: var(--font-size-caption);
  color: var(--color-text-secondary);
  margin-bottom: 0.25rem;
}

.blog-item-title {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.blog-item-title a {
  text-decoration: none;
}

.blog-item-title a:hover {
  text-decoration: underline;
  text-decoration-color: var(--color-accent);
}

.blog-item-excerpt {
  color: var(--color-text-secondary);
  font-size: var(--font-size-body);
}

/* Article content */
.article-header {
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--color-border);
}

.article-date {
  font-size: var(--font-size-caption);
  color: var(--color-text-secondary);
  margin-bottom: 0.5rem;
}

.article-title {
  font-size: var(--font-size-h1);
  margin-bottom: 0;
}

.article-content {
  font-size: var(--font-size-body);
}

.article-content h2 {
  margin-top: 2rem;
}

.article-content h3 {
  margin-top: 1.5rem;
}

.article-content img {
  max-width: 100%;
  height: auto;
  border-radius: 4px;
  margin: 1.5rem 0;
}

.article-content blockquote {
  border-left: 3px solid var(--color-accent);
  padding-left: 1rem;
  margin: 1.5rem 0;
  color: var(--color-text-secondary);
  font-style: italic;
}

.article-content ul,
.article-content ol {
  margin: 1rem 0;
  padding-left: 1.5rem;
}

.article-content li {
  margin-bottom: 0.5rem;
}

/* Code blocks */
.article-content code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: #f5f5f5;
  padding: 0.2em 0.4em;
  border-radius: 3px;
}

.article-content pre {
  background: #f5f5f5;
  padding: 1rem;
  border-radius: 6px;
  overflow-x: auto;
  margin: 1.5rem 0;
}

.article-content pre code {
  background: none;
  padding: 0;
}

/* About page */
.about-section {
  margin-bottom: 2rem;
}

.about-section p {
  font-size: var(--font-size-body);
}

.cv-download {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  background: var(--color-accent);
  color: white;
  text-decoration: none;
  border-radius: 6px;
  font-weight: 500;
  transition: background 0.2s ease;
}

.cv-download:hover {
  background: var(--color-accent-hover);
  color: white;
}

/* Footer */
footer {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1.5rem;
  border-top: 1px solid var(--color-border);
  text-align: center;
  color: var(--color-text-secondary);
  font-size: var(--font-size-caption);
}

/* Utilities */
.section-title {
  font-size: var(--font-size-h3);
  margin-bottom: 1.5rem;
  color: var(--color-text);
}

/* Loading state for markdown */
.loading {
  color: var(--color-text-secondary);
  font-style: italic;
}

/* KaTeX overrides */
.katex-display {
  margin: 1.5rem 0;
  overflow-x: auto;
  overflow-y: hidden;
}