:root {
  --bg-body: #f5f5f7;
  --bg-card: #ffffff;
  --text-primary: #1d1d1f;
  --text-secondary: #86868b;
  --accent-blue: #0066cc;
  --btn-bg: #e8e8ed;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-hover: 0 12px 30px rgba(0, 0, 0, 0.12);
  --radius: 18px;
  --font-stack: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  background: var(--bg-body);
  color: var(--text-primary);
  font-family: var(--font-stack);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent-blue);
  text-decoration: none;
  transition: color 0.2s, background 0.2s, transform 0.2s, box-shadow 0.2s;
}

a:hover {
  color: #004499;
}

.container {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 50px;
  max-width: 1180px;
  margin: 0 auto;
  padding: 60px 30px;
}

.sidebar {
  position: sticky;
  top: 40px;
  height: fit-content;
}

.profile-card,
.news-card,
.paper-card,
.exp-card,
.simple-card {
  background: var(--bg-card);
  border: 1px solid rgba(0, 0, 0, 0.02);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.profile-card {
  padding: 30px 20px;
  text-align: center;
  box-shadow: var(--shadow-md);
}

.avatar {
  display: block;
  width: 140px;
  height: 140px;
  margin: 0 auto 15px;
  border: 1px solid rgba(0, 0, 0, 0.05);
  border-radius: 50%;
  background: #ffffff;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  object-fit: cover;
  object-position: center;
}

.name {
  margin-bottom: 4px;
  color: #000000;
  font-size: 22px;
  font-weight: 700;
  line-height: 1.25;
}

.name span {
  display: block;
  font-size: 18px;
  font-weight: 650;
}

.role {
  margin-bottom: 20px;
  color: var(--text-secondary);
  font-size: 14px;
}

.social-links {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-top: 15px;
}

.social-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--btn-bg);
  color: #333333;
}

.social-btn:hover {
  background: #333333;
  color: #ffffff;
  transform: scale(1.08);
}

.nav-menu {
  margin-top: 30px;
  text-align: left;
  list-style: none;
}

.nav-link {
  display: block;
  margin-left: 0;
  padding: 8px 12px;
  border-left: 3px solid transparent;
  border-radius: 8px;
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
}

.nav-link:hover,
.nav-link.active {
  background: rgba(0, 0, 0, 0.04);
  color: #000000;
}

.nav-link.active {
  padding-left: 9px;
  border-left-color: var(--accent-blue);
}

section {
  margin-bottom: 50px;
  scroll-margin-top: 50px;
}

#about {
  padding-top: 8px;
}

h2 {
  margin-bottom: 20px;
  padding-left: 14px;
  border-left: 4px solid var(--accent-blue);
  color: #000000;
  font-size: 26px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.about-text {
  font-size: 16px;
  line-height: 1.65;
}

.about-text p + p {
  margin-top: 14px;
}

.news-card,
.simple-card {
  padding: 24px;
}

.news-card:hover,
.paper-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}

.news-scroll-area {
  max-height: 180px;
  overflow-y: auto;
  padding-right: 10px;
}

.news-scroll-area::-webkit-scrollbar {
  width: 6px;
}

.news-scroll-area::-webkit-scrollbar-track {
  background: transparent;
}

.news-scroll-area::-webkit-scrollbar-thumb {
  border-radius: 10px;
  background: rgba(0, 0, 0, 0.1);
}

.news-item {
  display: grid;
  grid-template-columns: 90px 1fr;
  gap: 10px;
  margin-bottom: 12px;
  padding-bottom: 12px;
  border-bottom: 1px solid #f0f0f0;
  font-size: 14px;
}

.news-item:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
}

.news-date {
  color: var(--text-secondary);
  font-variant-numeric: tabular-nums;
  font-weight: 500;
}

.exp-card {
  padding: 10px 20px 10px 32px;
}

.exp-timeline {
  position: relative;
}

.exp-timeline::before {
  position: absolute;
  top: 18px;
  bottom: 18px;
  left: -18px;
  width: 2px;
  border-radius: 1px;
  background: var(--accent-blue);
  content: "";
  opacity: 0.35;
}

.exp-item {
  position: relative;
  display: flex;
  gap: 15px;
  padding: 15px 0;
  border-bottom: 1px solid #f0f0f0;
}

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

.exp-item::before {
  position: absolute;
  top: 22px;
  left: -24px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--accent-blue);
  content: "";
}

.exp-logo {
  display: flex;
  flex: 0 0 auto;
  align-items: center;
  justify-content: center;
  width: 45px;
  height: 45px;
  border: 1px solid #eeeeee;
  border-radius: 8px;
  background: #ffffff;
  color: var(--accent-blue);
  font-weight: 800;
}

.exp-logo img {
  max-width: 34px;
  max-height: 34px;
  object-fit: contain;
}

.exp-body {
  flex: 1;
  min-width: 0;
}

.exp-title {
  color: #000000;
  font-weight: 600;
}

.exp-desc {
  color: var(--text-secondary);
  font-size: 14px;
}

.exp-date {
  color: #999999;
  font-size: 12px;
}

.topic-title {
  margin: 30px 0 15px;
  padding-bottom: 8px;
  border-bottom: 1px solid #e5e5e5;
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.paper-card {
  margin-bottom: 20px;
  padding: 24px;
}

.paper-content {
  min-width: 0;
}

.paper-title {
  margin-bottom: 6px;
  color: #000000;
  font-size: 18px;
  font-weight: 600;
  line-height: 1.35;
}

.paper-authors {
  margin-bottom: 10px;
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.5;
}

.paper-venue {
  display: inline-block;
  margin-right: 10px;
  padding: 4px 10px;
  border-radius: 6px;
  background: #f2f2f7;
  color: #000000;
  font-size: 12px;
  font-weight: 600;
}

.paper-venue.highlight {
  background: rgba(0, 102, 204, 0.1);
  color: var(--accent-blue);
}

.edu-item {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 15px 0;
  border-bottom: 1px solid #f0f0f0;
}

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

.simple-card p + p,
.simple-card li + li {
  margin-top: 10px;
}

.simple-card ul {
  padding-left: 18px;
}

.site-footer {
  margin-top: 60px;
  padding-top: 24px;
  border-top: 1px solid rgba(0, 0, 0, 0.08);
  color: var(--text-secondary);
  font-size: 12px;
  text-align: center;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg-body: #1d1d1f;
    --bg-card: #2d2d2f;
    --text-primary: #f5f5f7;
    --text-secondary: #a1a1a6;
    --accent-blue: #5eb8ff;
    --btn-bg: #3a3a3c;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.25);
    --shadow-hover: 0 12px 30px rgba(0, 0, 0, 0.35);
  }

  .name,
  .paper-title,
  .exp-title,
  h2 {
    color: var(--text-primary);
  }

  .avatar,
  .exp-logo {
    background: #38383a;
    border-color: #48484a;
  }

  .nav-link:hover,
  .nav-link.active {
    color: var(--text-primary);
  }

  .paper-venue {
    background: #3a3a3c;
    color: var(--text-primary);
  }
}

@media (max-width: 800px) {
  .container {
    grid-template-columns: 1fr;
    gap: 30px;
    padding: 20px;
  }

  .sidebar {
    position: static;
    margin-bottom: 20px;
  }

  .nav-menu {
    display: none;
  }

  .exp-card {
    padding-left: 20px;
  }

  .exp-timeline::before,
  .exp-item::before {
    display: none;
  }

  .edu-item {
    flex-direction: column;
    gap: 4px;
  }
}