:root {
  --bg: #f4f7fb;
  --surface: #ffffff;
  --text: #1f2a37;
  --muted: #52606d;
  --brand: #1f6feb;
  --brand-dark: #174ea6;
  --shadow: 0 10px 25px rgba(15, 23, 42, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Inter", "Segoe UI", Roboto, Arial, sans-serif;
  color: var(--text);
  background: linear-gradient(180deg, #f8fbff 0%, var(--bg) 100%);
  min-height: 100vh;
}

.top-nav {
  background: var(--surface);
  border-bottom: 1px solid #e5e7eb;
  position: sticky;
  top: 0;
  z-index: 10;
}

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0.9rem 1rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.site-title {
  font-weight: 700;
  text-decoration: none;
  color: var(--text);
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 1rem;
  margin: 0;
  padding: 0;
}

.nav-links a {
  text-decoration: none;
  color: var(--muted);
  font-weight: 600;
  padding: 0.35rem 0.5rem;
  border-radius: 6px;
}

.nav-links a:hover,
.nav-links a:focus-visible,
.nav-links a.active {
  color: var(--brand-dark);
  background: #eaf1ff;
}

main {
  max-width: 1100px;
  margin: 2.5rem auto;
  padding: 0 1rem;
}

.hero,
.card {
  background: var(--surface);
  border-radius: 14px;
  box-shadow: var(--shadow);
  padding: 2rem;
}

.hero h1,
.card h1 {
  margin-top: 0;
}

.grid {
  margin-top: 1.5rem;
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
}

.tile {
  background: #f8fafc;
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  padding: 1rem;
}

.about-layout {
  display: grid;
  grid-template-columns: minmax(220px, 320px) 1fr;
  gap: 2rem;
  align-items: start;
}

.profile-image {
  width: 100%;
  border-radius: 12px;
  border: 1px solid #d1d5db;
  box-shadow: var(--shadow);
  object-fit: cover;
}

.placeholder-note {
  font-size: 0.85rem;
  color: var(--muted);
}

@media (max-width: 760px) {
  .nav-inner {
    flex-direction: column;
    gap: 0.8rem;
  }

  .about-layout {
    grid-template-columns: 1fr;
  }
}