/* ===== Custom Properties / Theming ===== */
:root {
  --bg: #fafafa;
  --bg-alt: #f0f0f0;
  --text: #1a1a1a;
  --text-muted: #555;
  --accent: #0d9488;
  --accent-hover: #0f766e;
  --card-bg: #fff;
  --card-border: #e5e5e5;
  --nav-bg: rgba(250, 250, 250, 0.92);
  --nav-border: #e5e5e5;
  --timeline-line: #d4d4d4;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.1);
  --font: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

[data-theme="dark"] {
  --bg: #111;
  --bg-alt: #1a1a1a;
  --text: #e5e5e5;
  --text-muted: #a3a3a3;
  --accent: #2dd4bf;
  --accent-hover: #5eead4;
  --card-bg: #1e1e1e;
  --card-border: #333;
  --nav-bg: rgba(17, 17, 17, 0.92);
  --nav-border: #333;
  --timeline-line: #444;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.4);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 4rem;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  transition: background 0.3s, color 0.3s;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s;
}

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

img {
  max-width: 100%;
  height: auto;
  display: block;
}

ul {
  list-style: none;
}

/* ===== Container ===== */
.container {
  max-width: 52rem;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ===== Navbar ===== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--nav-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--nav-border);
  transition: background 0.3s, border-color 0.3s;
}

.nav-inner {
  max-width: 52rem;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 3.5rem;
}

.nav-name {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text);
  text-decoration: none;
}

.nav-name:hover {
  color: var(--accent);
  text-decoration: none;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-links a {
  color: var(--text-muted);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  position: relative;
  padding-bottom: 2px;
}

.nav-links a::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--accent);
  text-decoration: none;
}

.nav-links a.active::after,
.nav-links a:hover::after {
  width: 100%;
}

/* Theme Toggle */
.theme-toggle {
  background: none;
  border: 1px solid var(--card-border);
  border-radius: 6px;
  cursor: pointer;
  padding: 0.35rem 0.55rem;
  color: var(--text-muted);
  font-size: 0.95rem;
  display: flex;
  align-items: center;
  transition: color 0.2s, border-color 0.2s;
}

.theme-toggle:hover {
  color: var(--accent);
  border-color: var(--accent);
}

/* Show moon in light mode, sun in dark mode */
.theme-toggle .fa-sun {
  display: none;
}

[data-theme="dark"] .theme-toggle .fa-moon {
  display: none;
}

[data-theme="dark"] .theme-toggle .fa-sun {
  display: inline;
}

/* Hamburger (mobile) */
.nav-hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  flex-direction: column;
  gap: 4px;
  padding: 0.5rem;
}

.nav-hamburger span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text);
  border-radius: 1px;
  transition: transform 0.2s, opacity 0.2s;
}

/* ===== Hero ===== */
.hero {
  text-align: center;
  padding: 5rem 1.5rem 3.5rem;
}

.hero h1 {
  font-size: 2.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 0.3rem;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.hero-links {
  display: flex;
  gap: 1.2rem;
}

.hero-links a {
  color: var(--text-muted);
  font-size: 1.4rem;
  transition: color 0.2s, transform 0.2s;
}

.hero-links a:hover {
  color: var(--accent);
  transform: translateY(-2px);
  text-decoration: none;
}

.hero-inner {
  display: flex;
  align-items: center;
  gap: 2rem;
  justify-content: center;
}

.hero-photo {
  width: 130px;
  height: 130px;
  border-radius: 50%;
  object-fit: cover;
  flex-shrink: 0;
  box-shadow: var(--shadow);
}

.hero-text {
  text-align: left;
}

/* ===== Sections ===== */
.section {
  padding: 4rem 0;
}

.section-alt {
  background: var(--bg-alt);
  transition: background 0.3s;
}

.section h2 {
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 1.8rem;
  position: relative;
  display: inline-block;
}

.section h2::after {
  content: "";
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 2.5rem;
  height: 3px;
  background: var(--accent);
  border-radius: 2px;
}

.section h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin: 2rem 0 1rem;
  color: var(--text);
}

/* ===== About ===== */
#about p {
  margin-bottom: 1rem;
}

/* ===== Timeline (Resume) ===== */
.timeline {
  position: relative;
  padding-left: 1.2rem;
  border-left: 2px solid var(--timeline-line);
}

.timeline-item {
  position: relative;
  padding: 0 0 1.5rem 1.2rem;
}

.timeline-item:last-child {
  padding-bottom: 0;
}

.timeline-item::before {
  content: "";
  position: absolute;
  left: -1.2rem;
  top: 0.5rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg-alt, var(--bg));
  transform: translateX(-50%);
  margin-left: -1px;
}

.timeline-date {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 0.15rem;
  letter-spacing: 0.01em;
}

.timeline-content strong {
  display: block;
  font-size: 0.95rem;
}

.timeline-place {
  display: block;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Languages */
.languages-list {
  padding-left: 1.2rem;
  list-style: disc;
}

.languages-list li {
  list-style: disc;
  margin-bottom: 0.4rem;
}

/* ===== News ===== */
.news-list {
  padding: 0;
}

.news-list li {
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--card-border);
  font-size: 0.92rem;
  line-height: 1.55;
  transition: border-color 0.3s;
}

.news-list li:last-child {
  border-bottom: none;
}

.news-date {
  display: inline;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--accent);
  margin-right: 0.6rem;
}

/* ===== Publications ===== */
.pub-compact {
  padding-left: 1.8rem;
  counter-reset: none;
}

.pub-compact li {
  margin-bottom: 1rem;
  font-size: 0.9rem;
  line-height: 1.6;
}

.pub-compact .pub-authors {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.pub-links {
  display: inline;
  font-size: 0.82rem;
  margin-left: 0.2rem;
}

.pub-links a {
  display: inline-flex;
  align-items: center;
  gap: 0.2rem;
  margin-right: 0.6rem;
  white-space: nowrap;
}

/* National pubs - simpler list */
.national-pubs {
  padding-left: 1.2rem;
}

.national-pubs li {
  list-style: disc;
  margin-bottom: 0.6rem;
  font-size: 0.9rem;
  line-height: 1.6;
}

.national-pubs .pub-authors {
  display: inline;
  font-size: inherit;
  color: var(--text-muted);
}

/* ===== Teaching ===== */
.teaching-note {
  font-size: 0.88rem;
  color: var(--text-muted);
  font-style: italic;
  margin-bottom: 1rem;
}

.teaching-group {
  margin-bottom: 1.5rem;
}

.teaching-group h3 {
  margin-top: 0;
  margin-bottom: 0.6rem;
  color: var(--accent);
  font-size: 1.05rem;
}

.teaching-group ul {
  padding-left: 1.2rem;
}

.teaching-group li {
  list-style: disc;
  margin-bottom: 0.35rem;
  font-size: 0.92rem;
}

.level {
  color: var(--text-muted);
  font-size: 0.82rem;
}

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--card-border);
  padding: 2rem 0;
  text-align: center;
  font-size: 0.82rem;
  color: var(--text-muted);
  transition: border-color 0.3s;
}

/* ===== Responsive ===== */
@media (max-width: 640px) {
  .hero {
    padding: 4rem 1.5rem 2.5rem;
  }

  .hero h1 {
    font-size: 1.8rem;
  }

  .hero-inner {
    flex-direction: column;
    text-align: center;
  }

  .hero-text {
    text-align: center;
  }

  .hero-photo {
    width: 100px;
    height: 100px;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 3.5rem;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--nav-bg);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--nav-border);
    padding: 1rem 1.5rem;
    gap: 0.8rem;
    align-items: flex-start;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-hamburger {
    display: flex;
  }

  .nav-hamburger.open span:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
  }

  .nav-hamburger.open span:nth-child(2) {
    opacity: 0;
  }

  .nav-hamburger.open span:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
  }

  .timeline-item {
    padding-left: 0.8rem;
  }

  .section {
    padding: 2.5rem 0;
  }
}