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

:root {
  --color-primary: #1a3a5c;
  --color-primary-light: #2a5a8c;
  --color-accent: #c0392b;
  --color-bg: #ffffff;
  --color-bg-alt: #f5f6f8;
  --color-text: #333333;
  --color-text-light: #666666;
  --color-border: #dce1e8;
  --font-serif: Georgia, "Palatino Linotype", "Book Antiqua", Palatino, serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --max-width: 860px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
}

/* === Header === */
.site-header {
  background: var(--color-primary);
  color: #ffffff;
  padding: 3rem 1.5rem 2.5rem;
  text-align: center;
}

.site-header h1 {
  font-family: var(--font-serif);
  font-size: 2.4rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  margin-bottom: 0.4rem;
}

.site-header .subtitle {
  font-size: 1.1rem;
  font-weight: 300;
  opacity: 0.9;
  margin-bottom: 0.3rem;
}

.site-header .affiliation {
  font-size: 0.95rem;
  opacity: 0.75;
}

/* === Navigation === */
.site-nav {
  background: var(--color-primary-light);
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.site-nav ul {
  list-style: none;
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0;
}

.site-nav a {
  display: block;
  padding: 0.75rem 1.2rem;
  color: #ffffff;
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  transition: background 0.2s;
}

.site-nav a:hover {
  background: rgba(255, 255, 255, 0.12);
}

/* === Main Content === */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* === Section === */
.section {
  padding: 2.5rem 0 2rem;
  border-bottom: 1px solid var(--color-border);
}

.section:last-of-type {
  border-bottom: none;
}

.section-title {
  font-family: var(--font-serif);
  font-size: 1.6rem;
  color: var(--color-primary);
  margin-bottom: 1.5rem;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid var(--color-primary);
  display: inline-block;
}

/* === About === */
.about-text {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--color-text);
}

.highlight-box {
  background: var(--color-bg-alt);
  border-left: 3px solid var(--color-primary);
  padding: 1rem 1.2rem;
  margin-top: 1rem;
  font-size: 0.95rem;
  color: var(--color-text-light);
}

/* === Education Entry === */
.edu-entry {
  margin-bottom: 1.5rem;
}

.edu-entry:last-child {
  margin-bottom: 0;
}

.edu-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.edu-school {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--color-text);
}

.edu-date {
  font-size: 0.9rem;
  color: var(--color-text-light);
  white-space: nowrap;
}

.edu-degree {
  font-style: italic;
  font-size: 0.95rem;
  color: var(--color-text-light);
  margin-top: 0.15rem;
}

.edu-location {
  font-size: 0.9rem;
  color: var(--color-text-light);
}

/* === Research Entry === */
.research-entry {
  margin-bottom: 2rem;
}

.research-entry:last-child {
  margin-bottom: 0;
}

.research-title {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--color-text);
}

.research-meta {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 0.3rem;
}

.research-advisor {
  font-size: 0.9rem;
  color: var(--color-text-light);
  font-style: italic;
}

.research-items {
  list-style: disc;
  padding-left: 1.4rem;
  margin-top: 0.5rem;
}

.research-items li {
  font-size: 0.93rem;
  margin-bottom: 0.4rem;
  line-height: 1.6;
}

/* === Publications & Patents === */
.pub-list {
  list-style: none;
  counter-reset: pub-counter;
  padding-left: 0;
}

.pub-list li {
  counter-increment: pub-counter;
  position: relative;
  padding-left: 2.2rem;
  margin-bottom: 1rem;
  font-size: 0.93rem;
  line-height: 1.65;
}

.pub-list li::before {
  content: "[" counter(pub-counter) "]";
  position: absolute;
  left: 0;
  font-weight: 600;
  color: var(--color-primary);
}

.pub-list .author-self {
  font-weight: 700;
}

.pub-list .pub-venue {
  font-style: italic;
}

/* === Skills === */
.skills-grid {
  display: grid;
  gap: 1rem;
}

.skill-row {
  display: flex;
  gap: 0.8rem;
  align-items: baseline;
}

.skill-label {
  font-weight: 700;
  font-size: 0.93rem;
  color: var(--color-primary);
  min-width: 180px;
  flex-shrink: 0;
}

.skill-value {
  font-size: 0.93rem;
  color: var(--color-text);
}

/* === Footer === */
.site-footer {
  background: var(--color-bg-alt);
  border-top: 1px solid var(--color-border);
  text-align: center;
  padding: 1.5rem;
  font-size: 0.85rem;
  color: var(--color-text-light);
}

.site-footer a {
  color: var(--color-primary);
  text-decoration: none;
}

.site-footer a:hover {
  text-decoration: underline;
}

/* === Responsive === */
@media (max-width: 768px) {
  .site-header {
    padding: 2rem 1rem 1.5rem;
  }

  .site-header h1 {
    font-size: 1.8rem;
  }

  .site-nav a {
    padding: 0.6rem 0.8rem;
    font-size: 0.82rem;
  }

  .container {
    padding: 0 1rem;
  }

  .section {
    padding: 2rem 0 1.5rem;
  }

  .section-title {
    font-size: 1.35rem;
  }

  .edu-header,
  .research-meta {
    flex-direction: column;
    gap: 0.1rem;
  }

  .skill-row {
    flex-direction: column;
    gap: 0.2rem;
  }

  .skill-label {
    min-width: unset;
  }

  .pub-list li {
    padding-left: 1.8rem;
  }
}

@media (max-width: 480px) {
  .site-header h1 {
    font-size: 1.5rem;
  }

  .site-nav ul {
    justify-content: center;
  }

  .site-nav a {
    padding: 0.5rem 0.6rem;
    font-size: 0.78rem;
  }

  body {
    font-size: 15px;
  }
}