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

:root {
  --accent: #2563eb;
  --text: #1f2937;
  --text-muted: #6b7280;
  --bg: #ffffff;
  --border: #e5e7eb;
  --max-width: 720px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 1rem;
}

/* Nav */
nav {
  border-bottom: 1px solid var(--border);
  padding: 1rem 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

nav .logo {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text);
  text-decoration: none;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 2rem;
}

nav a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.15s;
}

nav a:hover,
nav a.active {
  color: var(--accent);
}

/* Layout */
main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 3rem 2rem;
}

/* Hero */
.hero {
  padding: 5rem 0 3rem;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 1.25rem;
}

.hero h1 span {
  color: var(--accent);
}

.hero p {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 520px;
  margin-bottom: 2rem;
}

.btn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  padding: 0.65rem 1.5rem;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  transition: opacity 0.15s;
}

.btn:hover {
  opacity: 0.88;
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--accent);
  color: var(--accent);
  margin-left: 0.75rem;
}

.btn-outline:hover {
  background: var(--accent);
  color: #fff;
  opacity: 1;
}

/* Section headings */
h2 {
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
}

p + p {
  margin-top: 0.85rem;
}

/* About */
.bio {
  margin-bottom: 3rem;
}

.interests ul {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 0.75rem;
  margin-top: 1rem;
}

.interests li {
  background: #f9fafb;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.75rem 1rem;
  font-size: 0.95rem;
  color: var(--text);
}

.interests li::before {
  content: "→ ";
  color: var(--accent);
  font-weight: 700;
}

/* Contact form */
form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  margin-top: 1.5rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text);
}

input,
textarea {
  padding: 0.65rem 0.85rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 1rem;
  font-family: inherit;
  color: var(--text);
  background: var(--bg);
  transition: border-color 0.15s;
}

input:focus,
textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

textarea {
  resize: vertical;
  min-height: 140px;
}

button[type="submit"] {
  align-self: flex-start;
  background: var(--accent);
  color: #fff;
  border: none;
  padding: 0.7rem 1.6rem;
  border-radius: 6px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: opacity 0.15s;
}

button[type="submit"]:hover {
  opacity: 0.88;
}

.success-msg {
  display: none;
  background: #ecfdf5;
  border: 1px solid #6ee7b7;
  color: #065f46;
  padding: 0.85rem 1rem;
  border-radius: 6px;
  font-size: 0.95rem;
}

/* Footer */
footer {
  border-top: 1px solid var(--border);
  text-align: center;
  padding: 2rem;
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* Responsive */
@media (max-width: 600px) {
  nav {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.75rem;
  }

  nav ul {
    gap: 1.25rem;
  }

  .hero {
    padding: 3rem 0 2rem;
  }

  .btn-outline {
    margin-left: 0;
    margin-top: 0.5rem;
  }
}