@import url('https://fonts.googleapis.com/css2?family=SF+Pro+Text:wght@400;600&display=swap');

:root {
  --color-primary: #0071e3;
  --color-accent: #1d1d1f;
  --color-background: #f8f8f8;
  --color-text-primary: #1d1d1f;
  --color-text-secondary: #3c3c43;
  --color-on-primary: #ffffff;

  --font-base: 'SF Pro Text', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-size-base: 1rem;
  --font-size-title: 2.75rem;
  --font-size-subtitle: 1.75rem;
}

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

body {
  font-family: var(--font-base);
  font-size: var(--font-size-base);
  background-color: var(--color-background);
  color: var(--color-text-primary);
  line-height: 1.6;
  padding: 2rem;
  min-height: 100vh;
}

body.preload {
  opacity: 0;
  transition: opacity 0.3s ease-out;
}

h1,
h2 {
  font-weight: 600;
  color: #000;
}

h1 {
  font-size: var(--font-size-title);
  margin-bottom: 2rem;
  text-align: center;
}

h2 {
  font-size: var(--font-size-subtitle);
  margin-bottom: 1rem;
}

p {
  color: var(--color-text-secondary);
  margin-bottom: 1.5rem;
}

.system-centered {
  text-align: center;
  margin: 4rem 0;
}

.system-centered p {
  max-width: 600px;
  margin: 0 auto 1.5rem;
}

.system-header {
  text-align: center;
  margin-bottom: 4rem;
}

.system-nav ul {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  list-style: none;
  gap: 1rem;
  padding: 0;
  margin-top: 1rem;
}

.system-nav a {
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 600;
  padding: 0.5rem 1rem;
  border-radius: 8px;
  transition: background-color 0.3s ease, color 0.3s ease;
  text-align: center;
}

.system-nav a:hover {
  background-color: rgba(0, 113, 227, 0.1);
  color: var(--color-accent);
}

.btn-primary {
  background-color: var(--color-primary);
  color: var(--color-on-primary);
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: 12px;
  text-transform: uppercase;
  font-weight: 600;
  font-size: 0.875rem;
  letter-spacing: 0.5px;
  cursor: pointer;
  transition: background-color 0.3s ease, transform 0.3s ease;
}

.btn-primary:hover {
  background-color: #005bb5;
  transform: translateY(-2px);
}

.system-footer {
  text-align: center;
  color: var(--color-text-secondary);
  margin-top: 4rem;
  font-size: 0.875rem;
}

@media (max-width: 480px) {
  .system-nav a {
    padding: 0.4rem 0.75rem;
    font-size: 0.95rem;
  }

  body {
    padding: 1.5rem;
  }

  h1 {
    font-size: 2rem;
  }

  h2 {
    font-size: 1.25rem;
  }
}