/* Калькулятор монтажа котлов: оформление по стилям сайта. */
.bi-calc {
    margin: 0 0 140px;
    padding: 0 24px;
    background: #FFFFFF;
    color: #1F2937;
    font-family: 'Inter', sans-serif;
    font-size: 18px;
    line-height: 1.5;
    box-sizing: border-box;
}
.bi-calc * { box-sizing: border-box; }
.bi-calc [hidden] { display: none !important; }
.bi-calc h2 { margin: 0 0 24px; font-size: 40px; font-weight: 600; line-height: 1.1; }
.bi-calc > p { max-width: 792px; margin: 0 0 32px; color: #5E708B; }
.bi-calc p { line-height: 1.5; }
.bi-calc a { color: #2563EB; }
.bi-calc__layout { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(280px, .9fr); gap: 40px; align-items: start; }
.bi-calc__form, .bi-calc__result { min-width: 0; }
.bi-calc__field { min-width: 0; margin: 0 0 24px; }
.bi-calc__field > label { display: block; margin: 0 0 8px; color: #1F2937; font-size: 16px; font-weight: 500; }
.bi-calc input[type=number], .bi-calc select {
    display: block; width: 100%; max-width: 100%; min-width: 0; height: 50px;
    padding: 0 16px; border: 1px solid #C4C6C9; border-radius: 24px;
    background: #FFFFFF; color: #1F2937; font-family: inherit; font-size: 16px;
    transition: border-color .2s, box-shadow .2s;
}
.bi-calc select {
    padding-right: 42px; appearance: none; white-space: nowrap; text-overflow: ellipsis;
    background-image: linear-gradient(45deg, transparent 50%, #1F2937 50%), linear-gradient(135deg, #1F2937 50%, transparent 50%);
    background-position: calc(100% - 22px) 22px, calc(100% - 16px) 22px;
    background-size: 6px 6px, 6px 6px; background-repeat: no-repeat;
}
.bi-calc input[type=number]:hover, .bi-calc select:hover { border-color: #2563EB; }
.bi-calc input:focus-visible, .bi-calc select:focus-visible { border-color: #2563EB; box-shadow: 0 0 0 3px rgb(37 99 235 / 12%); }
.bi-calc input[aria-invalid=true] { border-color: #B42318; }
.bi-calc small { display: block; margin-top: 8px; color: #5E708B; font-size: 13px; line-height: 1.5; }
.bi-calc__extras { margin: 8px 0 24px; padding: 20px 0 0; border-top: 1px solid #DDE4EE; }
.bi-calc__extras summary { margin-bottom: 16px; color: #1F2937; font-size: 16px; font-weight: 500; cursor: pointer; }
.bi-calc__extras > p { margin: 0 0 20px; color: #5E708B; font-size: 14px; }
.bi-calc__extra { display: grid; grid-template-columns: 24px minmax(0, 1fr) 88px; gap: 12px; align-items: start; margin: 0 0 20px; }
.bi-calc__extra input[type=checkbox] { width: 18px; height: 18px; margin: 4px 0; accent-color: #2563EB; cursor: pointer; }
.bi-calc__extra label { min-width: 0; color: #1F2937; font-size: 16px; line-height: 1.4; cursor: pointer; }
.bi-calc__extra input[type=number] { height: 44px; padding: 0 12px; }
.bi-calc__extra small { margin-top: 4px; }
.bi-calc__link { display: inline-block; margin: 8px 0 0; padding: 4px 0; border: 0; background: transparent; color: #2563EB; font-family: inherit; font-size: 14px; line-height: 1.5; text-align: left; text-decoration: underline; cursor: pointer; }
.bi-calc__link:hover { color: #1F2937; text-decoration: none; }
.bi-calc__fixed { margin: 0 0 24px; font-size: 18px; font-weight: 500; }
.bi-calc__result { position: sticky; top: 24px; padding: 24px; border: 0; border-radius: 24px; background: #F5F7FA; }
.bi-calc__result h3 { margin: 0 0 20px; color: #1F2937; font-size: 24px; font-weight: 600; line-height: 1.25; }
.bi-calc__result ul { list-style: none; margin: 0; padding: 0; }
.bi-calc__result li { display: flex; justify-content: space-between; align-items: flex-start; gap: 16px; padding: 12px 0; border-bottom: 1px solid #DDE4EE; color: #1F2937; font-size: 14px; line-height: 1.5; }
.bi-calc__result li span:first-child { min-width: 0; overflow-wrap: anywhere; }
.bi-calc__result li span:last-child { flex: 0 0 auto; font-weight: 600; white-space: nowrap; text-align: right; }
.bi-calc__total { margin: 0; padding: 20px 0; }
.bi-calc__total strong { display: block; color: #2563EB; font-size: 32px; font-weight: 600; line-height: 1.25; }
.bi-calc__total p { margin: 10px 0 0; color: #5E708B; font-size: 14px; }
.bi-calc .bi-calc__notice { margin: 0 0 20px; padding: 14px; border-radius: 12px; background: #FFFFFF; color: #5E708B; font-size: 13px; }
.bi-calc .bi-calc__cta { display: block; padding: 15px 20px; border: 1px solid #2563EB; border-radius: 48px; background: #2563EB; color: #FFFFFF; font-size: 16px; font-weight: 400; line-height: 1.3; text-align: center; text-decoration: none; transition: background .3s, border-color .3s; }
.bi-calc .bi-calc__cta:hover { border-color: #2C41CC; background: #2C41CC; color: #FFFFFF; text-decoration: none; }
.bi-calc .bi-calc__cta:focus-visible { border-color: #1D76FE; background: #1D76FE; color: #FFFFFF; }
.bi-calc .bi-calc__cta[aria-disabled=true] { opacity: .55; cursor: not-allowed; }
.bi-calc :focus-visible { outline: 3px solid rgb(37 99 235 / 25%); outline-offset: 3px; }
@media (max-width: 980px) {
    .bi-calc { margin-bottom: 100px; }
    .bi-calc h2 { font-size: 32px; }
    .bi-calc__layout { grid-template-columns: 1fr; gap: 32px; }
    .bi-calc__result { position: static; }
}
@media (max-width: 600px) {
    .bi-calc { margin-bottom: 80px; padding: 0 12px; font-size: 16px; }
    .bi-calc h2 { margin-bottom: 20px; font-size: 28px; line-height: 1.15; }
    .bi-calc > p { margin-bottom: 24px; }
    .bi-calc__layout { gap: 24px; }
    .bi-calc__field { margin-bottom: 20px; }
    .bi-calc__field > label, .bi-calc__extra label { font-size: 14px; }
    .bi-calc__extra { grid-template-columns: 20px minmax(0, 1fr) 72px; gap: 8px; }
    .bi-calc__result { padding: 20px; border-radius: 24px; }
    .bi-calc__result h3 { font-size: 22px; }
    .bi-calc__result li { gap: 10px; }
    .bi-calc__total strong { font-size: 28px; }
}
@media (max-width: 360px) {
    .bi-calc__result { padding: 16px; }
    .bi-calc__result li { flex-direction: column; gap: 4px; }
    .bi-calc__result li span:last-child { text-align: left; }
}