:root {
  --bg: #f4f5f7;
  --surface: #ffffff;
  --border: #e2e4e9;
  --fg: #1d1d20;
  --muted: #5c5c66;
  --accent: #2f5bd3;
  --accent-fg: #ffffff;
  --shadow: 0 1px 2px rgb(0 0 0 / 0.04), 0 4px 16px rgb(0 0 0 / 0.06);
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #131316;
    --surface: #1c1c21;
    --border: #2c2c33;
    --fg: #ececf0;
    --muted: #a4a4ae;
    --accent: #6d8ff0;
    --accent-fg: #0d0d10;
    --shadow: none;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--fg);
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  line-height: 1.5;
}

.site-header {
  padding: 1rem;
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}

.brand {
  display: block;
  max-width: 32rem;
  margin: 0 auto;
  color: var(--fg);
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: 0.01em;
  text-decoration: none;
}

main {
  max-width: 32rem;
  margin: 0 auto;
  padding: 2.5rem 1rem;
}

.card {
  padding: 2rem 1.5rem;
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  background: var(--surface);
  box-shadow: var(--shadow);
}

h1 { font-size: 1.6rem; line-height: 1.25; margin: 0 0 0.75rem; }
p { color: var(--muted); margin: 0 0 1rem; }
a { color: var(--accent); }

.providers {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.75rem;
}

form { margin: 1.5rem 0 0; }

.button {
  display: block;
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid transparent;
  border-radius: 0.5rem;
  background: var(--accent);
  color: var(--accent-fg);
  font: inherit;
  font-weight: 600;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: filter 0.15s ease;
}

.button:hover { filter: brightness(0.95); }
.button:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }

.button-google {
  background: #ffffff;
  color: #1f1f1f;
  border-color: #dadce0;
}

.button-discord {
  background: #5865f2;
  color: #ffffff;
}

.button-secondary {
  background: transparent;
  color: var(--fg);
  border-color: var(--border);
}