:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --bg-color: #f3f4f6;
    --card-bg: #ffffff;
    --text-color: #1f2937;
    --text-muted: #6b7280;
    --border-color: #e5e7eb;
    --error-color: #ef4444;
    --radius: 12px;
}
* { box-sizing: border-box; margin: 0; padding: 0; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif; }
body { background-color: var(--bg-color); color: var(--text-color); display: flex; justify-content: center; align-items: center; min-height: 100vh; }
.app-container { width: 100%; max-width: 420px; background: var(--card-bg); min-height: 100vh; display: flex; flex-direction: column; box-shadow: 0 4px 20px rgba(0,0,0,0.08); }
.auth-header { padding: 32px 24px 16px; text-align: center; }
.auth-header h1 { font-size: 24px; color: var(--primary); font-weight: 700; }
.auth-header p { font-size: 14px; color: var(--text-muted); margin-top: 6px; }
.auth-form { padding: 24px; display: flex; flex-direction: column; gap: 16px; }
.form-group { display: flex; flex-direction: column; gap: 6px; }
.form-group label { font-size: 13px; font-weight: 600; }
.form-control { width: 100%; padding: 12px 14px; border: 1px solid var(--border-color); border-radius: var(--radius); font-size: 15px; outline: none; }
.form-control:focus { border-color: var(--primary); }
.btn-primary { background-color: var(--primary); color: #fff; border: none; padding: 14px; border-radius: var(--radius); font-size: 16px; font-weight: 600; cursor: pointer; }
.btn-primary:hover { background-color: var(--primary-hover); }
.alert { padding: 12px 14px; border-radius: var(--radius); font-size: 14px; background-color: #fee2e2; color: var(--error-color); border: 1px solid #fca5a5; }
.auth-footer { text-align: center; margin-top: auto; padding: 24px; font-size: 14px; color: var(--text-muted); }
.auth-footer a { color: var(--primary); text-decoration: none; font-weight: 600; }