/* ---------- Base ---------- */
:root {
  --color-bg: #ffffff;
  --color-bg-alt: #f4f6fa;
  --color-text: #1f2937;
  --color-muted: #6b7280;
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-border: #e5e7eb;
  --radius: 10px;
  --max-width: 960px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
}

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

a:hover {
  text-decoration: underline;
}

h1, h2, h3 {
  line-height: 1.2;
  margin: 0 0 0.5em;
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* ---------- Header / Nav ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.95);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(6px);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding-top: 0.9rem;
  padding-bottom: 0.9rem;
}

.logo {
  font-weight: 800;
  font-size: 1.25rem;
  color: var(--color-text);
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  color: var(--color-muted);
  font-weight: 500;
}

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

/* ---------- Hero ---------- */
.hero {
  padding: 6rem 0 5rem;
  text-align: center;
  background: linear-gradient(135deg, #eff6ff 0%, #ffffff 100%);
}

.eyebrow {
  margin: 0;
  color: var(--color-primary);
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  margin: 0.25em 0;
}

.tagline {
  font-size: 1.15rem;
  color: var(--color-muted);
  margin: 0 0 2rem;
}

.hero-actions {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.75rem;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  padding: 0.7rem 1.4rem;
  border-radius: var(--radius);
  font-weight: 600;
  border: 2px solid var(--color-primary);
  transition: background 0.2s, color 0.2s;
}

.btn:hover {
  text-decoration: none;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
}

.btn-outline {
  background: transparent;
  color: var(--color-primary);
}

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

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

.section-alt {
  background: var(--color-bg-alt);
}

.section h2 {
  font-size: 1.9rem;
  margin-bottom: 1.5rem;
  position: relative;
  padding-bottom: 0.5rem;
}

.section h2::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 48px;
  height: 4px;
  border-radius: 2px;
  background: var(--color-primary);
}

/* ---------- Cards ---------- */
.card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1.25rem;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
}

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

.card h3 {
  font-size: 1.2rem;
  margin: 0;
}

.date {
  color: var(--color-muted);
  font-size: 0.95rem;
}

.org {
  color: var(--color-muted);
  margin: 0.25rem 0 0.75rem;
}

.card ul {
  margin: 0;
  padding-left: 1.25rem;
}

.card p:last-child {
  margin-bottom: 0;
}

/* ---------- Skills ---------- */
.skills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.skills li {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  padding: 0.4rem 1rem;
  font-weight: 500;
}

/* ---------- Contact ---------- */
.contact .contact-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  list-style: none;
  padding: 0;
  margin: 1.5rem 0 0;
}

.contact-links a {
  display: inline-block;
  padding: 0.6rem 1.2rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-weight: 600;
}

.contact-links a:hover {
  border-color: var(--color-primary);
  text-decoration: none;
}

/* ---------- Footer ---------- */
.site-footer {
  padding: 2rem 0;
  text-align: center;
  color: var(--color-muted);
  border-top: 1px solid var(--color-border);
  font-size: 0.9rem;
}

/* ---------- Responsive ---------- */
@media (max-width: 600px) {
  .nav {
    justify-content: center;
  }

  .nav-links {
    justify-content: center;
    gap: 0.9rem;
    font-size: 0.95rem;
  }

  .hero {
    padding: 4rem 0 3.5rem;
  }

  .section {
    padding: 3rem 0;
  }
}