:root {
  --bg: #f4f6f8;
  --bg-dark: #12161b;
  --text: #1c1c1c;
  --text-dark: #eee;
  --accent: #3498db;
  --panel: #ffffff;
  --panel-dark: #1f2a32;
  --btn-gradient: linear-gradient(135deg, #3498db, #9b59b6);
  --font: 'Segoe UI', sans-serif;
}

html, body {
  height: 100%;
  margin: 0;
  display: flex;
  flex-direction: column;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  transition: background 0.3s, color 0.3s;
}

body.dark-mode {
  background: var(--bg-dark);
  color: var(--text-dark);
}

.navbar {
  background: var(--panel);
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  position: sticky;
  top: 0;
  z-index: 100;
}

body.dark-mode .navbar {
  background: var(--panel-dark);
}

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

.site-title {
  display: flex;
  align-items: center;
}

.logo {
  height: 40px;
  margin-right: 10px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-left: auto;
}

.nav-links a {
  text-decoration: none;
  color: var(--accent);
  font-weight: 500;
  position: relative;
  padding: 0.3rem 0.5rem;
}

.nav-links a::after {
  content: '';
  position: absolute;
  width: 0%;
  height: 2px;
  bottom: 0;
  left: 0;
  background-color: var(--accent);
  transition: width 0.3s ease-in-out;
}

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

.theme-toggle {
  margin-left: 1rem;
  padding: 0.4rem 1rem;
  background: transparent;
  border: 1px solid var(--accent);
  color: var(--accent);
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.2s;
}

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

main, .content {
  flex: 1;
  padding: 2rem;
}

.hero {
  padding: 6rem 2rem;
  background: var(--btn-gradient);
  color: white;
  text-align: center;
}

.hero-buttons {
  margin-top: 1.5rem;
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  font-weight: bold;
  border-radius: 30px;
  text-decoration: none;
  font-size: 1rem;
  margin: 0.5rem;
  transition: background 0.3s, color 0.3s;
}

.btn.gradient {
  background: var(--btn-gradient);
  color: white;
}

.btn.outline {
  background: transparent;
  border: 2px solid white;
  color: white;
}

.btn.outline:hover {
  background: white;
  color: var(--accent);
}

.section {
  padding: 4rem 2rem;
  text-align: center;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

.feature-card, .bio-card {
  background: var(--panel);
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 3px 12px rgba(0, 0, 0, 0.05);
  transition: transform 0.2s, box-shadow 0.2s;
}

.feature-card:hover, .bio-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.1);
}

body.dark-mode .feature-card,
body.dark-mode .bio-card {
  background: var(--panel-dark);
}

.bio-card h3 {
  margin-bottom: 0.25rem;
}

.bio-card small {
  display: block;
  color: #888;
  margin-bottom: 0.75rem;
}

.bio-card img {
  border-radius: 12px;
  margin-bottom: 1rem;
  box-shadow: 0 5px 12px rgba(0,0,0,0.1);
  width: 150px;
  height: 150px;
  object-fit: cover;
}

.bio-avatar {
  width: 150px;
  height: 150px;
  border-radius: 12px;
  margin-bottom: 1rem;
  box-shadow: 0 4px 10px rgba(0,0,0,0.2);
}

.footer {
  padding: 1.5rem;
  text-align: center;
  background: var(--panel);
  color: #888;
  margin-top: auto;
}

body.dark-mode .footer {
  background: var(--panel-dark);
  color: #bbb;
}

.footer-links {
  margin: 10px 0;
  font-size: 0.9em;
}

.footer-links a {
  color: var(--accent-color, #00ffff);
  text-decoration: none;
  margin: 0 5px;
}

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