:root {
  --max-width: 960px;
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 160ms ease;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen,
    Ubuntu, Cantarell, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas,
    "Liberation Mono", "Courier New", monospace;

  /* Light theme (default) */
  --bg: #f7f8fa;
  --bg-alt: #ffffff;
  --surface: #ffffff;
  --border: #e3e6eb;
  --text: #0f172a;
  --text-muted: #475569;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-contrast: #ffffff;
  --shadow: 0 1px 2px rgba(15, 23, 42, 0.04),
            0 4px 12px rgba(15, 23, 42, 0.06);
}

[data-theme="dark"] {
  --bg: #0b1220;
  --bg-alt: #0f172a;
  --surface: #111c30;
  --border: #1f2a44;
  --text: #e5edf7;
  --text-muted: #94a3b8;
  --accent: #60a5fa;
  --accent-hover: #93c5fd;
  --accent-contrast: #0b1220;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.4),
            0 8px 24px rgba(0, 0, 0, 0.35);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0b1220;
    --bg-alt: #0f172a;
    --surface: #111c30;
    --border: #1f2a44;
    --text: #e5edf7;
    --text-muted: #94a3b8;
    --accent: #60a5fa;
    --accent-hover: #93c5fd;
    --accent-contrast: #0b1220;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.4),
              0 8px 24px rgba(0, 0, 0, 0.35);
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

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

h1, h2, h3 {
  line-height: 1.2;
  margin: 0 0 0.75rem;
  letter-spacing: -0.01em;
}
h1 { font-size: clamp(2rem, 5vw, 3rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2rem); margin-bottom: 1.25rem; }
h3 { font-size: 1.125rem; }

p { margin: 0 0 1rem; color: var(--text-muted); }
p strong, p em { color: var(--text); }

/* Skip link */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--accent);
  color: var(--accent-contrast);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  z-index: 100;
}
.skip-link:focus { left: 1rem; top: 1rem; }

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: saturate(180%) blur(10px);
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-top: 0.875rem;
  padding-bottom: 0.875rem;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text);
  font-weight: 700;
  letter-spacing: -0.01em;
}
.brand-mark { font-size: 1.25rem; }
.brand-name { font-size: 1.05rem; }

.nav-list {
  list-style: none;
  display: flex;
  gap: 1.25rem;
  margin: 0;
  padding: 0;
}
.nav-list a {
  color: var(--text-muted);
  font-size: 0.95rem;
  font-weight: 500;
}
.nav-list a:hover { color: var(--text); }

.theme-toggle {
  border: 1px solid var(--border);
  background: var(--surface);
  width: 38px;
  height: 38px;
  border-radius: 999px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  transition: background var(--transition), border-color var(--transition);
}
.theme-toggle:hover { border-color: var(--accent); }
.theme-icon-dark { display: none; }
[data-theme="dark"] .theme-icon-light { display: none; }
[data-theme="dark"] .theme-icon-dark { display: inline; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-icon-light { display: none; }
  :root:not([data-theme="light"]) .theme-icon-dark { display: inline; }
}

@media (max-width: 600px) {
  .nav-list { display: none; }
}

/* Hero */
.hero {
  padding: clamp(3rem, 8vw, 6rem) 0 clamp(2rem, 5vw, 4rem);
}
.hero-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  align-items: center;
}
@media (min-width: 720px) {
  .hero-inner {
    grid-template-columns: 1fr auto;
    gap: 3rem;
  }
}
.hero-avatar {
  display: block;
  justify-self: center;
  width: clamp(160px, 32vw, 240px);
  aspect-ratio: 1 / 1;
  border-radius: 50%;
  overflow: hidden;
  border: 3px solid var(--surface);
  box-shadow: var(--shadow), 0 0 0 1px var(--border);
}
.hero-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
@media (min-width: 720px) {
  .hero-avatar { order: 2; }
  .hero-text { order: 1; }
}
.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 0.8rem;
  color: var(--accent);
  margin-bottom: 0.5rem;
  font-weight: 600;
}
.tagline {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}
.lead {
  font-size: 1.125rem;
  max-width: 60ch;
  color: var(--text);
}
.cta-row {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: 1.5rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.1rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background var(--transition), color var(--transition),
              border-color var(--transition), transform var(--transition);
}
.btn-primary {
  background: var(--accent);
  color: var(--accent-contrast);
}
.btn-primary:hover {
  background: var(--accent-hover);
  color: var(--accent-contrast);
  transform: translateY(-1px);
}
.btn-ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--border);
}
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }

/* Sections */
.section {
  padding: clamp(2.5rem, 6vw, 4.5rem) 0;
}
.section-alt { background: var(--bg-alt); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }

/* Expertise cards */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
}
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  box-shadow: var(--shadow);
  transition: transform var(--transition), border-color var(--transition);
}
.card:hover { transform: translateY(-2px); border-color: var(--accent); }
.card h3 { margin-bottom: 0.5rem; }
.card p { margin: 0; font-size: 0.95rem; }

/* Links list */
.links-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 0.75rem;
}
.links-list a {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  padding: 1rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  transition: border-color var(--transition), transform var(--transition);
}
.links-list a:hover { border-color: var(--accent); transform: translateY(-1px); }
.link-icon { font-size: 1.4rem; }
.link-sub {
  display: block;
  font-size: 0.85rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

/* Contact form */
.contact-form {
  max-width: 560px;
  display: grid;
  gap: 1rem;
  margin-top: 1rem;
}
.form-row {
  display: grid;
  gap: 0.35rem;
}
.form-row label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text);
}
.form-row input,
.form-row textarea {
  font: inherit;
  color: var(--text);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.65rem 0.85rem;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.form-row input:focus,
.form-row textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 25%, transparent);
}
.form-row textarea { resize: vertical; min-height: 120px; }
.contact-form .btn { justify-self: start; }
.form-status {
  margin: 0;
  font-size: 0.9rem;
  min-height: 1.25em;
}
.form-status.success { color: #16a34a; }
.form-status.error { color: #dc2626; }
.form-note {
  font-size: 0.9rem;
  color: var(--text-muted);
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm);
  padding: 0.65rem 0.85rem;
  margin: 0.5rem 0 0.25rem;
  max-width: 560px;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  margin-top: 2rem;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.site-footer p { margin: 0; font-size: 0.9rem; }
.footer-sub a { color: var(--text-muted); }
.footer-sub a:hover { color: var(--accent); }

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition: none !important;
    animation: none !important;
    scroll-behavior: auto !important;
  }
}