:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --bg: #f8fafc;
    --card-bg: #ffffff;
    --text: #0f172a;
    --text-muted: #64748b;
    --border: #e2e8f0;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #0f172a;
        --card-bg: #1e293b;
        --text: #f8fafc;
        --text-muted: #94a3b8;
        --border: #334155;
    }
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg);
    color: var(--text);
    line-height: 1.6;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 40px 20px;
    flex: 1;
}

header {
    text-align: center;
    margin-bottom: 40px;
}

.logo {
    font-size: 32px;
    font-weight: 900;
    color: var(--primary);
    text-decoration: none;
    letter-spacing: -1px;
}

.card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 24px;
    padding: 40px;
    box-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1);
}

h1 { font-size: 28px; font-weight: 800; margin-bottom: 24px; }
h2 { font-size: 20px; font-weight: 700; margin-top: 32px; margin-bottom: 16px; border-bottom: 1px solid var(--border); padding-bottom: 8px; }

p { margin-bottom: 16px; }

.footer {
    text-align: center;
    padding: 40px;
    color: var(--text-muted);
    font-size: 14px;
}

.btn {
    display: inline-block;
    background: var(--primary);
    color: white;
    padding: 12px 24px;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 700;
    margin-top: 20px;
    transition: background 0.2s;
}

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

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