.trangchu {
    max-width: 800px;
    margin: 20px auto;
    padding: 20px;
    background: #f9f9f9;
    border-radius: 12px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    font-family: Arial, sans-serif;
    color: #333;
}

.trangchu h1 {
    text-align: center;
    color: #4CAF50;
    font-size: 28px;
    margin-bottom: 20px;
}

.trangchu form {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.trangchu form label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 500;
}

.trangchu form input[type="number"] {
    width: 100px;
    padding: 8px;
    border: 1px solid #ccc;
    border-radius: 6px;
    transition: border-color 0.3s;
}

.trangchu form input[type="number"]:focus {
    border-color: #4CAF50;
    outline: none;
}

.trangchu form button {
    background-color: #4CAF50;
    color: white;
    border: none;
    padding: 10px 20px;
    font-size: 16px;
    border-radius: 6px;
    cursor: pointer;
    align-self: center;
    transition: background-color 0.3s;
}

.trangchu form button:hover {
    background-color: #45a049;
}

#piechart {
    margin-top: 30px;
    border: 2px solid #4CAF50;
    border-radius: 12px;
    background: white;
    padding: 10px;
}

/* CONTACT FLOAT */
.contact-fixed {
    position: fixed;
    top: 50%;
    right: 20px;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    gap: 15px;
    z-index: 999999;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 10px;
    background: #fff;
    padding: 12px 20px;
    border-radius: 30px 0 0 30px;
    text-decoration: none;
    font-weight: bold;
    box-shadow: -5px 5px 20px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
    min-width: 190px;
}

/* Màu riêng từng nút */
.hotline {
    border-left: 5px solid #ff0000;
}

.messenger {
    border-left: 5px solid #0084ff;
}

.zalo {
    border-left: 5px solid #0068ff;
}

/* Hover trượt ra */
.contact-item:hover {
    transform: translateX(-12px);
    box-shadow: -8px 8px 25px rgba(0, 0, 0, 0.3);
}

/* Icon */
.contact-item i,
.contact-item img {
    font-size: 22px;
}

/* Hiệu ứng rung nhẹ liên tục */
@keyframes rung {
    0% {
        transform: translateX(0);
    }
    25% {
        transform: translateX(-3px);
    }
    50% {
        transform: translateX(3px);
    }
    75% {
        transform: translateX(-3px);
    }
    100% {
        transform: translateX(0);
    }
}

.hotline {
    animation: rung 1.5s infinite;
}