html, body {
    background-color: #f4f4f4;
    margin: 0;
    padding: 0;
    height: 100%;
    font-family: 'Roboto', sans-serif;
}
body {
    display: flex;
    flex-direction: column;
}
.page {
    display: none;
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    padding-top: 150px;
}
.page.active {
    display: block;
}

.navbar-bottom {
    position: fixed;
    top: 0;
    width: 100%;
    background: #fff;
    display: flex;
    justify-content: center;
    gap: 150px;
    padding: 40px 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    z-index: 1000;
}
.navbar-bottom div {
    cursor: pointer;
    text-align: center;
    font-size: 14px;
    color: #757575;
    transition: color 0.3s, filter 0.3s;
}
.navbar-bottom div.active {
    color: #429bf5;
}
.navbar-bottom div img {
    width: 24px;
    height: 24px;
    display: block;
    margin: 0 auto 5px;
    filter: grayscale(100%) brightness(50%);
    transition: filter 0.3s;
}
.navbar-bottom div.active img {
    filter: none;
}

.recados-container,
.calc-container,
.qr-container {
    background: #fff;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.08);
    max-width: 500px;
    margin: auto;
    text-align: center;
}
.recados-container input,
.recados-container textarea,
.calc-container input,
.calc-container select,
.qr-section input {
    border: 2px solid #ddd;
    border-radius: 10px;
    margin-bottom: 15px;
    font-size: 1rem;
    padding: 14px;
    width: 100%;
    box-sizing: border-box;
    color: #333;
}
.qr-section input {
    padding: 12px;
    margin-bottom: 10px;
}
button {
    font-size: 14px;
    cursor: pointer;
}
.recados-container button,
.calc-container button,
.qr-section button {
    background: #429bf5;
    color: #fff;
    border: none;
    border-radius: 8px;
    width: 100%;
    padding: 14px 20px;
    margin-bottom: 20px;
}
.qr-section button {
    padding: 12px 20px;
    margin: 5px 0;
}
.recados-container button:hover,
.calc-container button:hover,
.qr-section button:hover {
    background: #1b5288;
}
.recados-container textarea::placeholder {
    font-family: 'Roboto', sans-serif;
}
.recado {
    border: 2px solid #ddd;
    padding: 14px;
    margin-bottom: 15px;
    border-radius: 10px;
    background: #fafafa;
    box-shadow: 0 2px 5px rgba(0,0,0,0.03);
}
.recado strong {
    color: #429bf5;
}
#resultado {
    margin-top: 15px;
    padding: 10px;
    background: #f9f9f9;
    border-radius: 5px;
}
.smaller {
    font-size: 11px;
}
.qr-menu {
    display: flex;
    margin-bottom: 20px;
}
.qr-menu button {
    flex: 1;
    padding: 10px;
    border: 1px solid #ddd;
}
.qr-menu button.active {
    background: #429bf5;
    color: #fff;
}
.qr-menu #btn-gen { border-radius: 10px 0 0 10px; }
.qr-menu #btn-read { border-radius: 0 10px 10px 0; }
.qr-section {
    display: none;
}
.qr-section.active {
    display: block;
}
@media (max-width: 768px) {
    .navbar-bottom {
        top: auto;
        bottom: 0;
        justify-content: space-around;
        gap: 0px;
        box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
    }
    .page{
        padding: 20px;
    }
    .navbar-bottom div{
        flex: 1;
    }
}