body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f0f2f5;
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
    padding: 40px 20px;
}
.card {
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    width: 100%;
    max-width: 500px;
    padding: 30px;
    text-align: center;
}
h1 {
    color: #1a73e8;
    margin-bottom: 30px;
    font-weight: 300;
}
.function-display {
    font-size: 2.5rem;
    margin: 40px 0;
    min-height: 4rem;
    display: flex;
    justify-content: center;
    align-items: center;
}
.button-container {
    margin-top: 20px;
    display: flex;
    gap: 12px;
    justify-content: center;
    align-items: center;
}
button {
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}
.random-btn {
    background-color: #1a73e8;
    color: white;
}
.random-btn:hover {
    background-color: #1557b0;
}
.copy-btn {
    background-color: #f8f9fa;
    color: #6c757d;
    border: 1px solid #dee2e6;
    padding: 11px 20px;
    font-weight: 500;
}
.copy-btn:hover {
    background-color: #e9ecef;
    border-color: #ced4da;
    color: #495057;
}
.icon-box {
    display: inline-flex;
    width: 24px;
    margin-right: 8px;
    justify-content: center;
}
/* Animation for icon swap */
.fade-scale-enter-active,
.fade-scale-leave-active {
    transition: all 0.2s ease;
}
.fade-scale-enter-from,
.fade-scale-leave-to {
    opacity: 0;
    transform: scale(0.5);
}

/* A selection buttons */
.a-selection-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    margin-bottom: 20px;
}
.a-btn {
    background-color: #f8f9fa;
    color: #6c757d;
    border: 1px solid #dee2e6;
    padding: 10px 5px;
    font-size: 0.9rem;
    cursor: pointer;
}
.a-btn:hover {
    background-color: #e9ecef;
    border-color: #ced4da;
}
.a-btn.active {
    background-color: #1a73e8;
    color: white;
    border-color: #1a73e8;
    font-weight: bold;
}