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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

.screen {
    display: none;
}

.screen.active {
    display: block;
}

/* Contenedor de dos columnas */
.split-container {
    display: flex;
    min-height: 100vh;
    width: 100%;
}

.left-column {
    flex: 1;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px;
}

.hero-section {
    text-align: center;
    color: white;
    max-width: 400px;
}

.hero-icon {
    font-size: 80px;
    margin-bottom: 20px;
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

.hero-section h1 {
    font-size: 2.5rem;
    margin-bottom: 20px;
}

.hero-section p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    opacity: 0.9;
}

.features {
    text-align: left;
    display: inline-block;
    margin-top: 20px;
}

.features div {
    margin: 10px 0;
    font-size: 1rem;
}

.right-column {
    flex: 1;
    background: white;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px;
}

.form-wrapper {
    max-width: 450px;
    width: 100%;
    padding: 40px;
}

.form-wrapper h2 {
    text-align: center;
    color: #333;
    margin-bottom: 30px;
    font-size: 1.8rem;
}

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

.input-group label {
    display: block;
    margin-bottom: 8px;
    color: #555;
    font-weight: 500;
    font-size: 0.9rem;
}

.input-group input,
.input-group select {
    width: 100%;
    padding: 12px;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-size: 1rem;
    transition: all 0.3s;
}

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

.password-field {
    position: relative;
    display: flex;
    align-items: center;
}

.password-field input {
    flex: 1;
    padding-right: 45px;
}

.toggle-eye {
    position: absolute;
    right: 10px;
    background: none;
    border: none;
    font-size: 1.2rem;
    cursor: pointer;
    padding: 5px;
    color: #999;
}

.toggle-eye:hover {
    color: #667eea;
}

.password-strength {
    font-size: 12px;
    margin-top: -5px;
    margin-bottom: 10px;
}

.btn-login {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.3s, box-shadow 0.3s;
    margin-top: 10px;
}

.btn-login:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    width: 100%;
    padding: 12px;
    background: #dc3545;
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    margin-top: 20px;
}

.btn-secondary:hover {
    background: #c82333;
}

.register-link {
    text-align: center;
    margin-top: 25px;
    color: #666;
}

.register-link a {
    color: #667eea;
    text-decoration: none;
    font-weight: 600;
    cursor: pointer;
}

.message {
    margin-top: 20px;
    padding: 12px;
    border-radius: 10px;
    text-align: center;
    font-size: 0.9rem;
}

.message.error {
    background: #fee;
    color: #c33;
    border-left: 4px solid #c33;
}

.message.success {
    background: #efe;
    color: #3c3;
    border-left: 4px solid #3c3;
}

/* Dashboard */
.dashboard-container {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 25px;
    max-width: 1400px;
    margin: 30px auto;
    padding: 20px;
}

.form-card, .table-card {
    background: white;
    border-radius: 16px;
    padding: 25px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.form-card h2, .table-card h2 {
    font-size: 1.5rem;
    margin-bottom: 20px;
    color: #333;
    border-left: 4px solid #667eea;
    padding-left: 15px;
}

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

.estudiantes-table th,
.estudiantes-table td {
    padding: 12px 15px;
    text-align: left;
}

.estudiantes-table th {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    font-weight: 600;
}

.estudiantes-table td {
    border-bottom: 1px solid #e0e0e0;
    color: #333;
}

.estudiantes-table tr:hover td {
    background-color: #f5f5f5;
}

.delete-btn {
    background: #dc3545;
    color: white;
    border: none;
    padding: 5px 10px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.8rem;
}

.delete-btn:hover {
    background: #c82333;
}

@media (max-width: 768px) {
    .split-container {
        flex-direction: column;
    }
    
    .left-column {
        min-height: 300px;
    }
    
    .dashboard-container {
        grid-template-columns: 1fr;
        margin: 15px;
        padding: 10px;
    }
    
    .hero-icon {
        font-size: 50px;
    }
    
    .hero-section h1 {
        font-size: 1.5rem;
    }
    
    .estudiantes-table {
        display: block;
        overflow-x: auto;
        white-space: nowrap;
    }
}