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

:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --error-color: #ef4444;
    --warning-color: #f59e0b;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --background: #ffffff;
    --background-secondary: #f8fafc;
    --border-color: #e2e8f0;
    --border-radius: 8px;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--background-secondary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.site-header {
    background: var(--background);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.site-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
}

.header-nav {
    display: flex;
    gap: 2rem;
}

.header-nav a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    transition: all 0.2s ease;
}

.header-nav a:hover,
.header-nav a.active {
    color: var(--primary-color);
    background-color: rgba(37, 99, 235, 0.1);
}

/* Main Content */
.main-content {
    flex: 1;
    padding: 2rem 0;
}

.page-header {
    text-align: center;
    margin-bottom: 3rem;
}

.page-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.page-description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* Content Grid */
.content-grid {
    display: grid;
    gap: 2rem;
    max-width: 800px;
    margin: 0 auto;
}

/* Cards */
.card {
    background: var(--background);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    overflow: hidden;
}

.card-content {
    padding: 2rem;
}

.card h2,
.card h3 {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.card h2 {
    font-size: 1.5rem;
    font-weight: 600;
}

.card h3 {
    font-size: 1.25rem;
    font-weight: 600;
}

/* Auth Section */
.auth-section {
    text-align: center;
}

.auth-section p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

/* User Info */
.info-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-color);
}

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

.orcid-id {
    font-family: Monaco, 'Cascadia Code', 'Roboto Mono', monospace;
    font-size: 0.9rem;
    background: var(--background-secondary);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    color: var(--text-primary);
}

/* Forms */
.profile-form {
    display: grid;
    gap: 1.5rem;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.form-group input {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: all 0.2s ease;
    background: var(--background);
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group input::placeholder {
    color: var(--text-muted);
}

.form-actions {
    display: flex;
    justify-content: flex-end;
    margin-top: 1rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.2s ease;
    min-width: 120px;
}

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

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

/* Alerts */
.alert {
    padding: 1rem;
    border-radius: var(--border-radius);
    margin-bottom: 1rem;
    display: none;
    border-left: 4px solid;
}

.alert-success {
    background-color: rgba(16, 185, 129, 0.1);
    color: #065f46;
    border-left-color: var(--success-color);
}

.alert-error {
    background-color: rgba(239, 68, 68, 0.1);
    color: #991b1b;
    border-left-color: var(--error-color);
}

/* Loading */
.loading-section {
    display: none;
    text-align: center;
    padding: 3rem;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--border-color);
    border-top: 3px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Footer */
.site-footer {
    background: var(--text-primary);
    color: white;
    margin-top: auto;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    padding: 2rem 0;
}

.footer-section h4 {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    color: white;
}

.footer-section p {
    color: var(--text-muted);
    line-height: 1.6;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    border-top: 1px solid #374151;
    padding: 1rem 0;
    text-align: center;
}

.footer-bottom p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 15px;
    }
    
    .header-content {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .page-header h1 {
        font-size: 2rem;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .card-content {
        padding: 1.5rem;
    }
}

@media (max-width: 480px) {
    .header-nav {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .btn {
        width: 100%;
    }
    
    .form-actions {
        justify-content: stretch;
    }
}