/* ===== CSS Variables ===== */
:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --success-color: #22c55e;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --background-color: #f1f5f9;
    --card-background: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

/* ===== Reset & Base ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: var(--background-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

a {
    color: var(--primary-color);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

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

/* ===== Card ===== */
.card {
    background: var(--card-background);
    border-radius: 12px;
    box-shadow: var(--shadow);
    padding: 32px;
}

/* ===== Buttons ===== */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    text-align: center;
    text-decoration: none;
}

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

.btn-primary:hover {
    background-color: var(--primary-hover);
    text-decoration: none;
}

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

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

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

.btn-block {
    display: block;
    width: 100%;
}

.btn-link {
    background: none;
    border: none;
    color: var(--primary-color);
    cursor: pointer;
    font-size: 14px;
}

.btn-logout {
    background-color: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    padding: 8px 16px;
    font-size: 14px;
}

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

/* ===== Forms ===== */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-primary);
}

.form-group input {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.2s ease;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.form-hint {
    display: block;
    margin-top: 6px;
    font-size: 13px;
    color: var(--text-secondary);
}

/* ===== Alerts ===== */
.alert {
    padding: 12px 16px;
    border-radius: 8px;
    margin-bottom: 20px;
    font-size: 14px;
}

.alert-error {
    background-color: #fef2f2;
    color: #dc2626;
    border: 1px solid #fecaca;
}

.alert-success {
    background-color: #f0fdf4;
    color: #16a34a;
    border: 1px solid #bbf7d0;
}

/* ===== Access Page ===== */
.access-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.access-container .card {
    max-width: 420px;
    width: 100%;
    text-align: center;
}

.logo h1 {
    font-size: 32px;
    margin-bottom: 8px;
}

.logo .subtitle {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 24px;
}

.access-container h2 {
    margin-bottom: 8px;
}

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

.footer-text {
    margin-top: 24px;
    padding-top: 16px;
    border-top: 1px solid var(--border-color);
    font-size: 13px;
    color: var(--text-secondary);
}

/* ===== Auth Pages (Signin/Signup) ===== */
.auth-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.auth-container .card {
    max-width: 420px;
    width: 100%;
}

.auth-container h2 {
    text-align: center;
    margin-bottom: 24px;
}

.auth-footer {
    margin-top: 24px;
    text-align: center;
    padding-top: 16px;
    border-top: 1px solid var(--border-color);
    font-size: 14px;
}

/* ===== MFA Page ===== */
.mfa-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.mfa-container .card {
    max-width: 480px;
    width: 100%;
    text-align: center;
}

.duo-logo {
    margin-bottom: 24px;
}

.duo-logo img {
    width: 80px;
    margin-bottom: 16px;
}

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

#duo-frame-container {
    min-height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.duo-loading, .duo-prompt {
    text-align: center;
    padding: 24px;
}

.duo-icon {
    font-size: 48px;
    margin-bottom: 16px;
}

.duo-prompt h3 {
    margin-bottom: 12px;
}

.duo-status {
    color: var(--text-secondary);
    margin: 16px 0;
}

.duo-alternatives {
    margin-top: 24px;
    padding-top: 16px;
    border-top: 1px solid var(--border-color);
}

.duo-alternatives p {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 12px;
}

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

.mfa-footer {
    margin-top: 24px;
    font-size: 14px;
}

.mfa-footer a {
    color: var(--text-secondary);
}

/* ===== Spinner ===== */
.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 16px auto;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ===== Navbar ===== */
.navbar {
    background: var(--card-background);
    box-shadow: var(--shadow);
    padding: 16px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-brand h1 {
    font-size: 20px;
    color: var(--text-primary);
}

.nav-menu {
    display: flex;
    gap: 8px;
}

.nav-link {
    padding: 8px 16px;
    border-radius: 6px;
    color: var(--text-secondary);
    font-weight: 500;
    transition: all 0.2s ease;
}

.nav-link:hover {
    background-color: var(--background-color);
    color: var(--text-primary);
    text-decoration: none;
}

.nav-link.active {
    background-color: var(--primary-color);
    color: white;
}

.nav-user {
    display: flex;
    align-items: center;
    gap: 16px;
}

.user-name {
    font-weight: 600;
    color: var(--text-primary);
}

/* ===== Main Content ===== */
.main-content {
    padding: 32px 0;
    min-height: calc(100vh - 140px);
}

.page-title {
    font-size: 28px;
    margin-bottom: 24px;
}

/* ===== Dashboard ===== */
.welcome-card {
    background: linear-gradient(135deg, var(--primary-color) 0%, #7c3aed 100%);
    color: white;
    border-radius: 12px;
    padding: 40px;
    margin-bottom: 32px;
    text-align: center;
}

.welcome-card h1 {
    font-size: 36px;
    margin-bottom: 8px;
}

.welcome-message {
    font-size: 18px;
    opacity: 0.9;
}

.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.dashboard-card {
    text-align: center;
}

.card-icon {
    font-size: 48px;
    margin-bottom: 16px;
}

.dashboard-card h3 {
    margin-bottom: 8px;
}

.dashboard-card p {
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.grade-display {
    font-size: 48px !important;
    font-weight: 700;
    color: var(--success-color) !important;
}

/* ===== Grades Page ===== */
.grades-container {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 24px;
}

@media (max-width: 768px) {
    .grades-container {
        grid-template-columns: 1fr;
    }
}

.grades-card h2 {
    margin-bottom: 24px;
}

.grades-table {
    width: 100%;
    border-collapse: collapse;
}

.grades-table th,
.grades-table td {
    padding: 16px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.grades-table th {
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 14px;
    text-transform: uppercase;
}

.category-icon {
    margin-right: 8px;
}

.score {
    font-weight: 600;
    font-size: 18px;
}

.badge {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
}

.badge-success {
    background-color: #dcfce7;
    color: #16a34a;
}

.badge-good {
    background-color: #dbeafe;
    color: #2563eb;
}

.badge-warning {
    background-color: #fef3c7;
    color: #d97706;
}

.final-grade-card {
    text-align: center;
}

.final-grade-card h2 {
    margin-bottom: 24px;
}

.final-grade-display {
    margin-bottom: 16px;
}

.grade-letter {
    font-size: 72px;
    font-weight: 700;
    color: var(--success-color);
}

.grade-message {
    color: var(--text-secondary);
    font-size: 14px;
}

/* ===== Account Page ===== */
.account-container {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 24px;
}

@media (max-width: 768px) {
    .account-container {
        grid-template-columns: 1fr;
    }
}

.account-header {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-bottom: 32px;
    padding-bottom: 24px;
    border-bottom: 1px solid var(--border-color);
}

.avatar {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color) 0%, #7c3aed 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 32px;
    font-weight: 700;
}

.account-name h2 {
    margin-bottom: 4px;
}

.account-name p {
    color: var(--text-secondary);
    font-size: 14px;
}

.account-details {
    margin-bottom: 32px;
}

.detail-row {
    display: flex;
    justify-content: space-between;
    padding: 16px 0;
    border-bottom: 1px solid var(--border-color);
}

.detail-label {
    color: var(--text-secondary);
}

.detail-value {
    font-weight: 600;
}

.security-card h3 {
    margin-bottom: 20px;
}

.security-item {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px 0;
    border-bottom: 1px solid var(--border-color);
}

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

.security-icon {
    font-size: 24px;
}

.security-info strong {
    display: block;
    margin-bottom: 4px;
}

.security-info p {
    color: var(--text-secondary);
    font-size: 13px;
}

/* ===== Error Page ===== */
.error-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.error-card {
    max-width: 480px;
    width: 100%;
    text-align: center;
}

.error-icon {
    font-size: 64px;
    margin-bottom: 24px;
}

.error-card h1 {
    margin-bottom: 16px;
}

.error-message {
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.error-code {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 24px;
}

/* ===== Footer ===== */
.footer {
    background: var(--card-background);
    padding: 20px;
    text-align: center;
    color: var(--text-secondary);
    font-size: 14px;
    border-top: 1px solid var(--border-color);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .navbar {
        flex-wrap: wrap;
        gap: 16px;
    }
    
    .nav-menu {
        order: 3;
        width: 100%;
        justify-content: center;
    }
    
    .welcome-card h1 {
        font-size: 28px;
    }
    
    .dashboard-grid {
        grid-template-columns: 1fr;
    }
}