/* ... (Same CSS content as before) ... */
:root {
    --primary-color: #3498db;
    --secondary-color: #2980b9;
    --success-color: #2ecc71;
    --danger-color: #e74c3c;
    --warning-color: #f39c12;
    --light-color: #f5f5f5;
    --dark-color: #333;
    --border-radius: 10px;
    --box-shadow: 0 6px 15px rgba(0, 0, 0, 0.1);
    --gradient: linear-gradient(135deg, #3498db, #8e44ad);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Poppins', sans-serif;
}

body {
    background: linear-gradient(135deg, #f5f7fa, #c3cfe2);
    color: var(--dark-color);
    line-height: 1.6;
    min-height: 100vh;
    padding: 20px;
}

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

header {
    background: var(--gradient);
    color: white;
    padding: 25px 0;
    text-align: center;
    border-radius: var(--border-radius);
    margin-bottom: 30px;
    box-shadow: var(--box-shadow);
    position: relative;
    overflow: hidden;
}

header::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="%23ffffff" fill-opacity="0.1" d="M0,96L48,112C96,128,192,160,288,186.7C384,213,480,235,576,213.3C672,192,768,128,864,128C960,128,1056,192,1152,192C1248,192,1344,128,1392,96L1440,64L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>');
    background-size: cover;
}

h1 {
    font-size: 2.8rem;
    margin-bottom: 5px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.developer {
    font-size: 1.2rem;
    opacity: 0.9;
    margin-bottom: 10px;
    font-weight: 500;
}

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

.dashboard {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.card {
    background-color: white;
    border-radius: var(--border-radius);
    padding: 25px;
    box-shadow: var(--box-shadow);
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
    border-top: 5px solid var(--primary-color);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
}

.card h3 {
    font-size: 2.2rem;
    margin-bottom: 10px;
    color: var(--primary-color);
}

.card p {
    color: #666;
    font-weight: 500;
}

.card i {
    font-size: 2.5rem;
    margin-bottom: 15px;
    color: var(--primary-color);
}

.tabs {
    display: flex;
    background-color: white;
    border-radius: var(--border-radius);
    overflow: hidden;
    margin-bottom: 20px;
    box-shadow: var(--box-shadow);
}

.tab {
    flex: 1;
    padding: 18px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 600;
    background: #f8f9fa;
    border-right: 1px solid #e9ecef;
}

.tab:last-child {
    border-right: none;
}

.tab:hover {
    background-color: #e9ecef;
}

.tab.active {
    background: var(--gradient);
    color: white;
}

.tab-content {
    display: none;
    background-color: white;
    border-radius: var(--border-radius);
    padding: 30px;
    box-shadow: var(--box-shadow);
    animation: fadeIn 0.5s ease;
}

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

.tab-content.active {
    display: block;
}

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

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #555;
}

input, select {
    width: 100%;
    padding: 14px;
    border: 1px solid #ddd;
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: border 0.3s;
}

input:focus, select:focus {
    border-color: var(--primary-color);
    outline: none;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
}

button {
    background: var(--gradient);
    color: white;
    border: none;
    padding: 14px 25px;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.3s;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

button:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 8px rgba(0, 0, 0, 0.15);
}

.btn-secondary {
    background: linear-gradient(135deg, #95a5a6, #7f8c8d);
}

.btn-success {
    background: linear-gradient(135deg, #2ecc71, #27ae60);
}

.btn-warning {
    background: linear-gradient(135deg, #f39c12, #e67e22);
}

.btn-danger {
    background: linear-gradient(135deg, #e74c3c, #c0392b);
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.05);
    border-radius: var(--border-radius);
    overflow: hidden;
}

th, td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid #e9ecef;
}

th {
    background-color: #f8f9fa;
    font-weight: 600;
    color: #495057;
}

tr:hover {
    background-color: #f8f9fa;
}

.present {
    color: var(--success-color);
    font-weight: 600;
}

.absent {
    color: var(--danger-color);
    font-weight: 600;
}

.action-btn {
    padding: 8px 15px;
    margin-right: 5px;
    border-radius: 6px;
    font-size: 0.9rem;
}

.attendance-controls {
    display: flex;
    justify-content: space-between;
    margin-bottom: 20px;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
}

.attendance-actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.attendance-table {
    overflow-x: auto;
}

.status-dot {
    display: inline-block;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    margin-right: 8px;
}

.present-dot {
    background-color: var(--success-color);
}

.absent-dot {
    background-color: var(--danger-color);
}

.attendance-date {
    font-weight: 600;
    margin-bottom: 15px;
    color: var(--primary-color);
    font-size: 1.2rem;
}

.alert {
    padding: 15px;
    border-radius: var(--border-radius);
    margin: 20px 0;
    display: flex;
    align-items: center;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(231, 76, 60, 0.4); }
    70% { box-shadow: 0 0 0 10px rgba(231, 76, 60, 0); }
    100% { box-shadow: 0 0 0 0 rgba(231, 76, 60, 0); }
}

.alert-warning {
    background-color: #fff3cd;
    border-left: 5px solid var(--warning-color);
    color: #856404;
}

.alert i {
    margin-right: 15px;
    font-size: 1.5rem;
}

footer {
    text-align: center;
    margin-top: 40px;
    padding: 20px;
    color: #666;
    border-top: 1px solid #ddd;
}

.student-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--gradient);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
    margin-right: 10px;
}

.student-info {
    display: flex;
    align-items: center;
}

@media (max-width: 768px) {
    .dashboard {
        grid-template-columns: 1fr;
    }
    
    .attendance-controls {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .tabs {
        flex-direction: column;
    }
    
    h1 {
        font-size: 2.2rem;
    }
}