:root {
    --primary: #1dc5a3;
}
* {
    box-sizing: border-box;
}
body {
    margin: 0;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #f3f3f4;
    color: #333;
    font-family:
        -apple-system, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}
.card {
    background: #fff;
    width: 100%;
    max-width: 420px;
    margin: 16px;
    padding: 32px 28px;
    border-radius: 8px;
    text-align: center;
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.1);
}
.logo {
    margin-bottom: 24px;
}
.logo img {
    max-width: 180px;
    height: auto;
}
.alert {
    padding: 14px 16px;
    border-radius: 4px;
    margin: 0 0 20px;
}
.alert-success {
    background: #e6f9f4;
    color: #138a73;
    border: 1px solid #b8ecdf;
}
.alert-danger {
    background: #fdecea;
    color: #b23b32;
    border: 1px solid #f5c6c2;
}
.btn {
    display: block;
    width: 100%;
    padding: 11px 16px;
    border-radius: 4px;
    text-decoration: none;
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
    border: 1px solid transparent;
    margin-top: 10px;
}
.btn-primary {
    background: var(--primary);
    color: #fff;
}
.btn-white {
    background: #fff;
    color: #555;
    border-color: #ddd;
}
.spinner {
    width: 32px;
    height: 32px;
    margin: 8px auto 0;
    border: 3px solid #eee;
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}
@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}
.muted {
    font-size: 13px;
    color: #888;
}