:root {
    --primary: #3b82f6;
    --primary-hover: #2563eb;
    --secondary: #6b7280;
    --danger: #ef4444;
    --success: #10b981;
    --warning: #f59e0b;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --border: #e5e7eb;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    color: var(--text-primary);
}

.container {
    width: 100%;
    max-width: 600px;
}

.header {
    text-align: center;
    margin-bottom: 30px;
    color: white;
}

.header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 5px;
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
}

.page {
    display: block;
}

.page.hidden {
    display: none;
}

.card {
    background: var(--bg-primary);
    border-radius: 12px;
    padding: 32px;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

.card h2 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: var(--text-primary);
}

.info-text {
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.user-info {
    background: var(--bg-secondary);
    padding: 16px;
    border-radius: 8px;
    margin-bottom: 24px;
}

.info-item {
    display: flex;
    justify-content: space-between;
    padding: 8px 0;
    border-bottom: 1px solid var(--border);
}

.info-item:last-child {
    border-bottom: none;
}

.info-item .label {
    font-weight: 600;
    color: var(--text-secondary);
}

.info-item .value {
    color: var(--text-primary);
}

.section {
    margin-top: 32px;
    padding-top: 32px;
    border-top: 2px solid var(--border);
}

.section h3 {
    font-size: 1.25rem;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: 6px;
    color: var(--text-primary);
}

.form-group input {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 14px;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.hint {
    display: block;
    margin-top: 4px;
    font-size: 12px;
    color: var(--text-secondary);
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-block;
}

.btn-primary {
    background: var(--primary);
    color: white;
}

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

.btn-secondary {
    background: var(--secondary);
    color: white;
}

.btn-secondary:hover {
    background: #4b5563;
}

.btn-danger {
    background: var(--danger);
    color: white;
}

.btn-danger:hover {
    background: #dc2626;
}

.button-group {
    display: flex;
    gap: 12px;
    margin-top: 16px;
}

.profile-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.status-box {
    background: var(--bg-secondary);
    padding: 12px 16px;
    border-radius: 6px;
    margin-bottom: 16px;
}

.qr-container {
    text-align: center;
    margin: 20px 0;
    padding: 20px;
    background: white;
    border-radius: 8px;
    border: 1px solid var(--border);
}

.qr-container img {
    max-width: 250px;
    border: 1px solid var(--border);
}

.warning-text {
    color: var(--danger);
    margin-bottom: 12px;
}

.hidden {
    display: none !important;
}

/* Alert Messages */
#alert-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    max-width: 400px;
}

.alert {
    background: white;
    padding: 16px 20px;
    border-radius: 8px;
    margin-bottom: 12px;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    border-left: 4px solid var(--primary);
    animation: slideIn 0.3s ease-out;
}

.alert.success {
    border-left-color: var(--success);
}

.alert.error {
    border-left-color: var(--danger);
}

.alert.warning {
    border-left-color: var(--warning);
}

@keyframes slideIn {
    from {
        transform: translateX(400px);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

/* Responsive */
@media (max-width: 640px) {
    .card {
        padding: 24px;
    }

    .header h1 {
        font-size: 2rem;
    }

    .profile-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 16px;
    }

    .button-group {
        flex-direction: column;
    }

    .button-group .btn {
        width: 100%;
    }
}