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

:root {
  --bg: #FAFAFA;
  --text: #1a1a1a;
  --text-muted: #6b7280;
  --accent: #1E40AF;
  --accent-hover: #1e3a8a;
  --border: #e5e7eb;
  --input-bg: #ffffff;
  --focus-ring: rgba(30, 64, 175, 0.25);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121212;
    --text: #f3f4f6;
    --text-muted: #9ca3af;
    --accent: #3B82F6;
    --accent-hover: #60a5fa;
    --border: #2a2a2a;
    --input-bg: #1e1e1e;
    --focus-ring: rgba(59, 130, 246, 0.35);
  }
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ===== Layout ===== */
main {
  flex: 1;
  width: 100%;
  max-width: 36rem;
  margin: 0 auto;
  padding: 3rem 1.25rem 4rem;
}

/* ===== Hero ===== */
.hero {
  text-align: center;
  padding: 4rem 0 5rem;
}

.hero h1 {
  font-size: 1.875rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: 0.75rem;
}

.subtitle {
  font-size: 0.9375rem;
  color: var(--text-muted);
  margin-bottom: 1.75rem;
}

.lead {
  font-size: 1.125rem;
  line-height: 1.65;
  margin-bottom: 0.75rem;
}

.extra {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 2.25rem;
}

/* ===== Buttons ===== */
.btn {
  display: inline-block;
  background-color: var(--accent);
  color: #ffffff;
  font-size: 0.9375rem;
  font-weight: 500;
  font-family: inherit;
  text-decoration: none;
  text-align: center;
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: 0.375rem;
  cursor: pointer;
  line-height: 1.4;
}

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

.btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.btn-full {
  width: 100%;
}

/* ===== Contact ===== */
.contact {
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

.contact h2 {
  font-size: 1.25rem;
  font-weight: 600;
  text-align: center;
  margin-bottom: 0.75rem;
}

.contact-intro {
  text-align: center;
  font-size: 1rem;
  margin-bottom: 0.25rem;
}

.contact-note {
  text-align: center;
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

/* ===== Form ===== */
.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 0.375rem;
}

.field label {
  font-size: 0.875rem;
  font-weight: 500;
}

.field input,
.field textarea {
  font-family: inherit;
  font-size: 1rem;
  color: var(--text);
  background-color: var(--input-bg);
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  padding: 0.75rem 0.875rem;
  width: 100%;
  line-height: 1.4;
}

.field input::placeholder,
.field textarea::placeholder {
  color: var(--text-muted);
  opacity: 0.7;
}

.field input:focus,
.field textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--focus-ring);
}

.field textarea {
  resize: vertical;
  min-height: 7.5rem;
}

/* ===== Footer ===== */
footer {
  text-align: center;
  padding: 1.5rem 1.25rem;
  border-top: 1px solid var(--border);
}

footer p {
  font-size: 0.8125rem;
  color: var(--text-muted);
  max-width: 36rem;
  margin: 0 auto;
}

/* ===== Desktop ===== */
@media (min-width: 640px) {
  main {
    padding: 4rem 1.5rem 5rem;
  }

  .hero {
    padding: 1rem 0 6rem;
  }

  .hero h1 {
    font-size: 2.25rem;
  }

  .lead {
    font-size: 1.1875rem;
  }
}