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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 480px;
    margin: 0 auto;
}

.card {
    background: white;
    border-radius: 16px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.15);
    padding: 32px;
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

h2 {
    font-size: 28px;
    font-weight: 700;
    color: #1a202c;
    margin-bottom: 8px;
    text-align: center;
}

.subtitle {
    color: #718096;
    font-size: 14px;
    text-align: center;
    margin-bottom: 24px;
}

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

label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    color: #4a5568;
    margin-bottom: 6px;
}

input {
    width: 100%;
    padding: 12px 16px;
    font-size: 16px;
    border: 1.5px solid #e2e8f0;
    border-radius: 10px;
    transition: all 0.2s;
    background: #fafafa;
}

input:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
    background: white;
}

button, .btn {
    display: inline-block;
    width: 100%;
    padding: 14px 20px;
    font-size: 16px;
    font-weight: 600;
    color: white;
    background: #667eea;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: background 0.2s, transform 0.1s;
}

button:hover {
    background: #5a67d8;
}

button:active {
    transform: scale(0.98);
}

.btn-secondary {
    background: #edf2f7;
    color: #4a5568;
    margin-top: 12px;
}

.btn-secondary:hover {
    background: #e2e8f0;
}

.alert {
    padding: 12px 16px;
    border-radius: 10px;
    margin-bottom: 20px;
    font-size: 14px;
}

.alert-error {
    background: #fed7d7;
    color: #c53030;
    border-left: 4px solid #fc8181;
}

.alert-success {
    background: #c6f6d5;
    color: #276749;
    border-left: 4px solid #68d391;
}

.otp-input {
    letter-spacing: 8px;
    font-size: 24px;
    text-align: center;
    font-weight: 600;
}

.qr-container {
    text-align: center;
    margin: 24px 0;
}

.qr-container img {
    max-width: 200px;
    border-radius: 12px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.secret-key {
    background: #f7fafc;
    padding: 12px;
    border-radius: 8px;
    font-family: monospace;
    font-size: 18px;
    text-align: center;
    letter-spacing: 2px;
    margin: 16px 0;
    word-break: break-all;
    border: 1px dashed #cbd5e0;
}

.link {
    text-align: center;
    margin-top: 20px;
    font-size: 14px;
    color: #718096;
}

.link a {
    color: #667eea;
    text-decoration: none;
    font-weight: 500;
}

.link a:hover {
    text-decoration: underline;
}

.tabs {
    display: flex;
    margin-bottom: 24px;
    border-bottom: 1px solid #e2e8f0;
}

.tab {
    flex: 1;
    text-align: center;
    padding: 12px;
    font-weight: 500;
    color: #718096;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: all 0.2s;
}

.tab.active {
    color: #667eea;
    border-bottom-color: #667eea;
}

.hidden {
    display: none;
}

.user-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 1px solid #e2e8f0;
}

.welcome {
    font-size: 18px;
    font-weight: 600;
    color: #1a202c;
}

.logout {
    color: #e53e3e;
    text-decoration: none;
    font-weight: 500;
}

@media (max-width: 480px) {
    .card { padding: 24px; }
    h2 { font-size: 24px; }
}