:root {
    --header-height: 500px;
    --background-black: rgb(39, 41, 47);
    --section-color: rgb(244, 247, 255);
}

.header {
    height: var(--header-height);
}

.header-image {
    background-image: url(../img/counter.webp);
    background-position: center center;
    background-repeat: no-repeat;
    background-size: cover;
    bottom: 0;
    left: 0;
    max-height: var(--header-height);
    overflow: hidden;
    position: absolute;
    right: 0;
    top: 0;
}

.header-image::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background: rgba(0, 0, 0, 0.5);
}

.header-text {
    color: #fff;
    font-size: xx-large;
}

@media (max-width: 768px) { /* До 768px (мобильные) */
    .first-row {
        padding-top: 50px;
    }
    .second-row {
        padding-top: 50px;
    }
    .third-row {
        padding-top: 50px;
    }
}

@media (min-width: 768px) { /* От 768px */
    .first-row {
        padding-top: 100px;
    }
    .second-row {
        padding-top: 50px;
    }
    .third-row {
        padding-top: 100px;
    }
}

.third-row {
    font-weight: bolder;
}

.easy-start-row {
    padding-bottom: 25px;
}

.easy-start-row .icon {
    width: 40px;
    display: inline-block;
}

.easy-start-row .text {
    display: inline;
    padding-left: 10px;
    font-size: 1.4em;
}

footer {
    background-color: var(--background-black);
    color: #fff;
    padding: 20px 0;
}

.required {
    color: red;
}

label {
    text-transform: uppercase;
    color: grey;
}

.submit-btn {
    width: 100%;
    background-color: var(--background-black);
    border-radius: 15px;
    border-color: var(--background-black);
    height: 50px;
    box-shadow: 0 5px 15px 0 rgba(39, 41, 47, 0.4);
}

.submit-btn:hover {
    background-color: #333;
    border-color: var(--background-black);
}

.submit-btn:active {
    box-shadow: none;
}

.section-color {
    background-color: var(--section-color);
    width: 100%;
    padding: 20px 0;
}

h2 {
    font-size: 2em;
    font-weight: 700;
    padding: 15px 0;
}

h4 {
    font-weight: bold;
    padding: 20px 0 10px;
}

.advantage-icon {
    width: 50px;
    display: inline-block;
    fill: rgb(31, 94, 255);
}

.advantage-text {
    font-size: 1.2em;
    line-height: 1.8;
}

.error-message {
    color: red;
    font-size: 0.8em;
}

.alert.alert-success {
    font-size: 1.4em;
}