* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: Arial, sans-serif;
}
body {
    min-height: 100vh;
    transition: 0.3s;
    padding: 20px;
}


body.dark {
    background: linear-gradient(135deg, #0f172a, #020617);
    color: white;
}
body.light {
    background: linear-gradient(135deg, #e0f2fe, #f8fafc);
    color: black;
}


#student-form {
    margin-bottom: 30px;
}
#student-form input {
    padding: 5px 10px;
    margin-top: 5px;
}


#bank-app {
    margin-bottom: 30px;
}
#b1 {
    background-color: blue;
    color: white;
    padding: 8px 15px;
    margin-right: 10px;
}
#b2 {
    background-color: red;
    color: white;
    padding: 8px 15px;
}


.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
}
.toggle-btn {
    padding: 10px 18px;
    border-radius: 12px;
    border: none;
    cursor: pointer;
    font-size: 14px;
    background: rgba(255,255,255,0.15);
    color: inherit;
    backdrop-filter: blur(10px);
}
.dashboard {
    display: grid;
    grid-template-columns: 260px 1fr;
    gap: 30px;
    padding: 20px 0;
}
.glass {
    background: rgba(255,255,255,0.08);
    border-radius: 18px;
    padding: 20px;
    backdrop-filter: blur(12px);
    border: 1px solid rgba(255,255,255,0.15);
}
body.light .glass {
    background: rgba(255,255,255,0.6);
    border: 1px solid rgba(0,0,0,0.1);
}
.sidebar {
    height: 150px;
    font-size: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.content {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}
.card {
    height: 100px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
}
@media(max-width: 900px) {
    .dashboard {
        grid-template-columns: 1fr;
    }
    .content {
        grid-template-columns: 1fr;
    }
}