* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 64px;
}

body {
    font-family: "Segoe UI", Tahoma, sans-serif;
    color: #1f3668;
    background: #f5f6fa;
}

a {
    text-decoration: none;
    color: inherit;
}

img {
    max-width: 100%;
    display: block;
}

button {
    font: inherit;
}

.container {
    width: min(92%, 1140px);
    margin: 0 auto;
}

.section {
    padding: 34px 0;
}

.section-title {
    font-size: 42px;
    line-height: 1.1;
    margin-bottom: 14px;
    color: #1d3f86;
}

.btn {
    border: 1px solid transparent;
    border-radius: 4px;
    padding: 11px 26px;
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
}

.btn-primary {
    color: #fff;
    background: linear-gradient(180deg, #3aa0ea, #228bd9);
    border-color: #1f7fc7;
    box-shadow: 0 3px 10px rgba(34, 139, 217, 0.35);
}

.grid {
    display: grid;
}

.back-to-top {
    position: fixed;
    right: 20px;
    bottom: 20px;
    width: 42px;
    height: 42px;
    border: 0;
    border-radius: 50%;
    background: #2452ab;
    color: #fff;
    font-size: 22px;
    line-height: 1;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 8px 20px rgba(24, 58, 125, 0.35);
    opacity: 0;
    visibility: hidden;
    transform: translateY(8px);
    transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease;
    z-index: 9999;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}