/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #f74040;
    --primary-dark: #e63535;
    --primary-light: #ff6b6b;
    --secondary-color: #2c3e50;
    --text-dark: #2c3e50;
    --text-light: #7f8c8d;
    --text-white: #ffffff;
    --bg-light: #f8f9fa;
    --bg-white: #ffffff;
    --border-color: #e9ecef;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);
    --border-radius: 12px;
    --transition: all 0.3s ease;
    --student-color: #3498db;
    --teacher-color: #27ae60;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
    min-height: 100vh;
}

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

/* Navigation */
.navbar {
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo {
    height: 40px;
    width: 35px;
}

.logo-text {
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--text-dark);
}

.nav-link {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: var(--transition);
    padding: 8px 16px;
    border-radius: 6px;
}

.nav-link:hover {
    background-color: var(--bg-light);
    color: var(--primary-color);
}

/* Main Content */
.main-content {
    padding: 60px 0 80px;
    min-height: calc(100vh - 200px);
}

.header-section {
    text-align: center;
    margin-bottom: 60px;
}

.page-title {
    font-size: 3rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 1rem;
}

.page-description {
    font-size: 1.25rem;
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto;
}

/* Selection Container */
.selection-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(450px, 1fr));
    gap: 3rem;
    margin-bottom: 60px;
    max-width: 1000px;
    margin-left: auto;
    margin-right: auto;
}

.selection-card {
    background: var(--bg-white);
    border-radius: var(--border-radius);
    padding: 2.5rem;
    box-shadow: var(--shadow);
    border: 2px solid transparent;
    transition: var(--transition);
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.selection-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--primary-light));
    transform: scaleX(0);
    transition: var(--transition);
}

.selection-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.selection-card:hover::before {
    transform: scaleX(1);
}

.student-card:hover {
    border-color: var(--student-color);
}

.teacher-card:hover {
    border-color: var(--teacher-color);
}

.student-card:hover::before {
    background: linear-gradient(90deg, var(--student-color), #5dade2);
}

.teacher-card:hover::before {
    background: linear-gradient(90deg, var(--teacher-color), #58d68d);
}

.card-header {
    text-align: center;
    margin-bottom: 2rem;
}

.card-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.student-icon {
    background: linear-gradient(135deg, var(--student-color), #5dade2);
    color: var(--text-white);
}

.teacher-icon {
    background: linear-gradient(135deg, var(--teacher-color), #58d68d);
    color: var(--text-white);
}

.card-icon svg {
    width: 40px;
    height: 40px;
}

.card-title {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.card-content {
    margin-bottom: 2rem;
}

.card-description {
    font-size: 1.125rem;
    color: var(--text-light);
    margin-bottom: 1.5rem;
    text-align: center;
}

.feature-list {
    list-style: none;
    margin-bottom: 1.5rem;
}

.feature-list li {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 0;
    color: var(--text-dark);
}

.feature-icon {
    width: 20px;
    height: 20px;
    background: var(--primary-color);
    color: var(--text-white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: 600;
    flex-shrink: 0;
}

.student-card .feature-icon {
    background: var(--student-color);
}

.teacher-card .feature-icon {
    background: var(--teacher-color);
}

.card-note {
    background: var(--bg-light);
    border-radius: 8px;
    padding: 1rem;
    display: flex;
    align-items: flex-start;
    gap: 12px;
}

.note-icon {
    font-size: 1.25rem;
    flex-shrink: 0;
}

.card-note p {
    margin: 0;
    font-size: 0.9rem;
    color: var(--text-light);
}

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

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1.1rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.btn-student {
    background: linear-gradient(135deg, var(--student-color), #5dade2);
    color: var(--text-white);
}

.btn-teacher {
    background: linear-gradient(135deg, var(--teacher-color), #58d68d);
    color: var(--text-white);
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-arrow {
    transition: var(--transition);
}

.btn:hover .btn-arrow {
    transform: translateX(4px);
}

/* Additional Info */
.additional-info {
    text-align: center;
    margin-bottom: 40px;
}

.info-card {
    background: var(--bg-white);
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--shadow);
    max-width: 600px;
    margin: 0 auto;
    border-left: 4px solid var(--primary-color);
}

.info-card h3 {
    color: var(--text-dark);
    margin-bottom: 1rem;
    font-size: 1.25rem;
}

.info-card p {
    color: var(--text-light);
    margin: 0;
}

/* Footer */
.footer {
    background-color: var(--text-dark);
    color: var(--text-white);
    padding: 40px 0;
    margin-top: auto;
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.footer-logo .logo-text {
    color: var(--text-white);
}

.footer-text {
    color: #bdc3c7;
    margin: 0;
    text-align: center;
}

/* Loading Animation */
.selection-card.loading {
    pointer-events: none;
    opacity: 0.7;
}

.selection-card.loading .btn {
    background: #95a5a6;
    cursor: not-allowed;
}

.selection-card.loading .btn::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 20px;
    height: 20px;
    margin: -10px 0 0 -10px;
    border: 2px solid transparent;
    border-top: 2px solid var(--text-white);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .page-title {
        font-size: 2.5rem;
    }

    .page-description {
        font-size: 1.125rem;
    }

    .selection-container {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .selection-card {
        padding: 2rem;
    }

    .card-icon {
        width: 70px;
        height: 70px;
    }

    .card-icon svg {
        width: 35px;
        height: 35px;
    }

    .card-title {
        font-size: 1.5rem;
    }
}

@media (max-width: 480px) {
    .main-content {
        padding: 40px 0 60px;
    }

    .page-title {
        font-size: 2rem;
    }

    .selection-card {
        padding: 1.5rem;
    }

    .btn {
        padding: 12px 24px;
        font-size: 1rem;
    }

    .container {
        padding: 0 15px;
    }
}