/* ======= NỀN CHUNG ======= */
body {
    margin: 0;
    padding: 0;
    background: #eef7ee;
    font-family: Arial, sans-serif;
}

/* ======= HEADER NHỎ GỌN ======= */
.topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 12px;
    background: linear-gradient(90deg, #22c55e, #0ea5e9);
    color: #fff;
    position: sticky;
    top: 0;
    z-index: 10;
}

.topbar-left {
    display: flex;
    align-items: center;
    gap: 6px;
}

.logo-circle {

    background: transparent;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 30px;
}

.site-title {
    font-size: 30px;
    font-weight: 600;
    white-space: nowrap;
}

.home-btn {
    padding: 6px 12px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.15);
    color: #fff;
    text-decoration: none;
    font-size: 16px;
    font-weight: 600;
    border: 1px solid rgba(255, 255, 255, 0.4);
}

/* Khi bấm trên mobile cho dễ thấy */
.home-btn:active {
    background: rgba(255, 255, 255, 0.3);
}

/* ======= CONTAINER & CARD ======= */
.container {
    max-width: 750px;
    margin: 16px auto 24px;
    padding: 0 10px;
}

.card {
    background: #fff;
    padding: 16px;
    border-radius: 14px;
    margin-bottom: 16px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.08);
}

.hidden {
    display: none;
}

/* ======= FORM ======= */
label {
    display: block;
    margin-top: 10px;
    font-weight: bold;
    font-size: 14px;
}

input {
    width: 100%;
    padding: 9px;
    margin-top: 4px;
    border-radius: 8px;
    border: 1px solid #ccc;
    font-size: 14px;
    box-sizing: border-box;
}

.status {
    margin-top: 8px;
    font-weight: 600;
    color: #0ea5e9;
    font-size: 13px;
}

/* ======= NÚT ======= */
.btn-primary {
    margin-top: 14px;
    width: 100%;
    padding: 11px;
    border: none;
    background: linear-gradient(90deg, #22c55e, #0ea5e9);
    color: white;
    font-size: 16px;
    border-radius: 10px;
    font-weight: bold;
    cursor: pointer;
}

/* ======= ITEM SÁCH ======= */
.book-item {
    padding: 9px;
    border: 1px solid #cfcfcf;
    border-radius: 8px;
    background: #f9fafb;
    margin-bottom: 8px;
    font-size: 14px;
}

/* ======= QR BOX ======= */
.barcode-box {
    text-align: center;
    margin-bottom: 10px;
}

#ticket-qrcode > img,
#ticket-qrcode > canvas {
    width: 140px;
    height: 140px;
}

/* ======= RESPONSIVE MOBILE ======= */
@media (max-width: 600px) {
    .topbar {
        padding: 6px 10px;
    }

    .site-title {
        font-size: 14px;
    }

    .home-btn {
        padding: 4px 10px;
        font-size: 12px;
    }

    .card {
        padding: 14px;
        border-radius: 12px;
        margin-bottom: 14px;
    }

    h2 {
        font-size: 16px;
    }

    input {
        font-size: 13px;
        padding: 8px;
    }

    .btn-primary {
        font-size: 15px;
        padding: 10px;
    }
}