/* ============================================================
   ООО «Матвеево-Курганский КСМ» — лендинг
   Промышленно-премиальная B2B-тема: графит + серебро
   ============================================================ */

:root {
    --bg: #14171b;
    --bg-alt: #1a1e24;
    --bg-card: #20252c;
    --bg-card-hover: #262c34;
    --line: rgba(255, 255, 255, 0.08);
    --line-strong: rgba(255, 255, 255, 0.14);

    --text: #e8eaed;
    --text-muted: #9aa3ad;
    --text-dim: #6f7883;

    --silver: #c7ccd3;
    --steel: #8d96a1;

    --accent: #d8b36a;          /* кремнезёмный янтарный акцент */
    --accent-strong: #e7c88b;
    --accent-dim: rgba(216, 179, 106, 0.14);
    --accent-line: rgba(216, 179, 106, 0.35);

    --ok: #7fb98a;
    --ok-dim: rgba(127, 185, 138, 0.12);

    --radius: 14px;
    --radius-sm: 9px;

    --font: 'Manrope', system-ui, -apple-system, 'Segoe UI', sans-serif;
    --mono: 'JetBrains Mono', 'SF Mono', Consolas, monospace;

    --header-h: 72px;
    --container: 1180px;
}

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

html { scroll-behavior: smooth; }

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }
sup { font-size: 0.6em; }

.container {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 24px;
}

/* ============ Buttons ============ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: var(--radius-sm);
    font-weight: 700;
    font-size: 15px;
    letter-spacing: 0.01em;
    border: 1px solid transparent;
    transition: transform 0.2s, box-shadow 0.2s, background 0.2s, border-color 0.2s;
    white-space: nowrap;
}
.btn--accent {
    background: linear-gradient(135deg, var(--accent-strong), var(--accent));
    color: #17130a;
    box-shadow: 0 6px 22px rgba(216, 179, 106, 0.22);
}
.btn--accent:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(216, 179, 106, 0.32);
}
.btn--ghost {
    border-color: var(--line-strong);
    color: var(--text);
    background: rgba(255, 255, 255, 0.03);
}
.btn--ghost:hover {
    border-color: var(--accent-line);
    color: var(--accent-strong);
    background: var(--accent-dim);
}
.btn--sm { padding: 10px 18px; font-size: 13.5px; }
.btn--full { width: 100%; }

/* ============ Header ============ */
.header {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 100;
    height: var(--header-h);
    background: rgba(20, 23, 27, 0.82);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--line);
    transition: background 0.3s, box-shadow 0.3s;
}
.header.is-scrolled {
    background: rgba(16, 18, 22, 0.95);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
}
.header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    height: var(--header-h);
}

.logo {
    display: flex;
    align-items: center;
    gap: 11px;
    flex-shrink: 0;
}
.logo__mark { display: flex; }
.logo__text { display: flex; flex-direction: column; line-height: 1.15; }
.logo__text strong {
    font-size: 19px;
    font-weight: 800;
    letter-spacing: 0.06em;
    color: var(--silver);
}
.logo__text small {
    font-size: 10.5px;
    color: var(--text-dim);
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.nav { display: flex; gap: 4px; }
.nav__link {
    padding: 8px 13px;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-muted);
    border-radius: 7px;
    transition: color 0.2s, background 0.2s;
}
.nav__link:hover, .nav__link.is-active {
    color: var(--accent-strong);
    background: var(--accent-dim);
}

.header__actions { display: flex; align-items: center; gap: 14px; }
.header__phone {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    font-weight: 700;
    font-size: 14.5px;
    color: var(--silver);
    transition: color 0.2s;
    white-space: nowrap;
}
.header__phone:hover { color: var(--accent-strong); }

.burger {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 42px;
    height: 42px;
    background: transparent;
    border: 1px solid var(--line-strong);
    border-radius: 8px;
    padding: 0 10px;
}
.burger span {
    display: block;
    height: 2px;
    background: var(--silver);
    border-radius: 2px;
    transition: transform 0.25s, opacity 0.25s;
}
.burger.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.burger.is-open span:nth-child(2) { opacity: 0; }
.burger.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ============ Hero ============ */
.hero {
    position: relative;
    padding: calc(var(--header-h) + 84px) 0 90px;
    overflow: hidden;
}
.hero__bg {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(900px 480px at 78% 12%, rgba(216, 179, 106, 0.09), transparent 60%),
        radial-gradient(720px 520px at 8% 90%, rgba(141, 150, 161, 0.10), transparent 62%),
        linear-gradient(180deg, #191d23 0%, var(--bg) 100%);
}
.hero__bg::after {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(var(--line) 1px, transparent 1px),
        linear-gradient(90deg, var(--line) 1px, transparent 1px);
    background-size: 72px 72px;
    mask-image: radial-gradient(ellipse 80% 70% at 50% 30%, black 30%, transparent 75%);
    -webkit-mask-image: radial-gradient(ellipse 80% 70% at 50% 30%, black 30%, transparent 75%);
    opacity: 0.5;
}
.hero__inner {
    position: relative;
    display: flex;
    flex-direction: column;
    gap: 58px;
}
.hero__top {
    display: grid;
    grid-template-columns: 1.12fr 0.88fr;
    gap: 52px;
    align-items: center;
}
.hero__content { max-width: 640px; }

.hero__visual { position: relative; }
.hero__photo {
    margin: 0;
    position: relative;
    border-radius: var(--radius);
    overflow: hidden;
    border: 1px solid var(--line-strong);
    box-shadow: 0 34px 70px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(255, 255, 255, 0.03);
    transform: rotate(1.6deg);
    transition: transform 0.35s cubic-bezier(0.22, 1, 0.36, 1);
}
.hero__photo:hover { transform: rotate(0deg) scale(1.015); }
.hero__photo img {
    display: block;
    width: 100%;
    height: auto;
    aspect-ratio: 650 / 651;
    object-fit: cover;
}
.hero__photo::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, transparent 55%, rgba(10, 12, 15, 0.55) 100%);
    pointer-events: none;
}
.hero__photo-tag {
    position: absolute;
    left: 14px;
    bottom: 14px;
    z-index: 2;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 14px;
    border-radius: 100px;
    background: rgba(16, 18, 22, 0.78);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid var(--accent-line);
    color: var(--accent-strong);
    font-size: 12.5px;
    font-weight: 700;
    letter-spacing: 0.03em;
}
.hero__photo-dot {
    width: 7px; height: 7px;
    border-radius: 50%;
    background: var(--accent);
    box-shadow: 0 0 8px var(--accent);
}

.hero__badge {
    display: inline-flex;
    align-items: center;
    gap: 9px;
    padding: 8px 16px;
    border: 1px solid var(--accent-line);
    border-radius: 100px;
    background: var(--accent-dim);
    color: var(--accent-strong);
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 0.04em;
    margin-bottom: 26px;
    white-space: nowrap;
}
.dot {
    width: 7px; height: 7px;
    border-radius: 50%;
    background: var(--accent);
    box-shadow: 0 0 10px var(--accent);
    animation: pulse 2.2s infinite;
}
@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.35; }
}

.hero__title {
    font-size: clamp(34px, 5vw, 56px);
    font-weight: 800;
    line-height: 1.14;
    letter-spacing: -0.015em;
    margin-bottom: 22px;
}
.hero__title-main,
.hero__title-accent {
    display: block;
    hyphens: none;
    -webkit-hyphens: none;
    white-space: nowrap;
}
.hero__title-accent {
    background: linear-gradient(100deg, var(--silver) 0%, var(--accent-strong) 55%, var(--accent) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}
.hero__subtitle {
    font-size: 17.5px;
    color: var(--text-muted);
    max-width: 640px;
    margin-bottom: 36px;
}
.hero__cta { display: flex; gap: 14px; flex-wrap: wrap; }

.hero__metrics {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    list-style: none;
    border: 1px solid var(--line-strong);
    border-radius: var(--radius);
    background: rgba(255, 255, 255, 0.025);
    backdrop-filter: blur(6px);
}
.metric {
    padding: 28px 30px;
    display: flex;
    flex-direction: column;
    gap: 4px;
}
.metric--divider { border-left: 1px solid var(--line); }
.metric__value {
    font-family: var(--mono);
    font-size: clamp(28px, 3.2vw, 40px);
    font-weight: 600;
    color: var(--accent-strong);
    line-height: 1.1;
    white-space: nowrap;
}
.metric__unit {
    font-size: 15px;
    color: var(--text-muted);
    font-family: var(--font);
    font-weight: 700;
}
.metric__unit small {
    display: block;
    font-size: 12.5px;
    color: var(--text-dim);
    font-weight: 600;
}
.metric__label {
    font-size: 13.5px;
    color: var(--text-dim);
    margin-top: 8px;
    line-height: 1.45;
}

/* ============ Sections ============ */
.section { padding: 96px 0; }
.section--alt { background: var(--bg-alt); }

.section__head { margin-bottom: 52px; max-width: 820px; }
.section__eyebrow {
    font-family: var(--mono);
    font-size: 13px;
    font-weight: 600;
    color: var(--accent);
    letter-spacing: 0.14em;
    text-transform: uppercase;
    margin-bottom: 14px;
    white-space: nowrap;
}
.section__title {
    font-size: clamp(27px, 3.4vw, 38px);
    font-weight: 800;
    line-height: 1.2;
    letter-spacing: -0.01em;
    margin-bottom: 16px;
    white-space: nowrap;
}
.section__desc {
    color: var(--text-muted);
    font-size: 16.5px;
}

/* ============ Cards ============ */
.card {
    background: var(--bg-card);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 30px;
    transition: border-color 0.25s, background 0.25s, transform 0.25s;
}
.card:hover {
    border-color: var(--accent-line);
    background: var(--bg-card-hover);
    transform: translateY(-3px);
}
.card__icon {
    width: 52px; height: 52px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    background: var(--accent-dim);
    color: var(--accent-strong);
    margin-bottom: 18px;
}
.card__title { font-size: 18.5px; font-weight: 700; margin-bottom: 10px; }
.card__text { color: var(--text-muted); font-size: 15px; }
.card--row {
    display: flex;
    gap: 20px;
    align-items: flex-start;
}
.card--row .card__icon { margin-bottom: 0; flex-shrink: 0; }
.card--accent { border-color: var(--accent-line); }

/* ============ About / GOST ============ */
.about__gallery {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 40px;
}
.gallery__item {
    margin: 0;
    border-radius: var(--radius);
    overflow: hidden;
    border: 1px solid var(--line);
    background: var(--bg-card);
    transition: border-color 0.25s, transform 0.25s;
}
.gallery__item:hover {
    border-color: var(--accent-line);
    transform: translateY(-3px);
}
.gallery__item img {
    display: block;
    width: 100%;
    height: 300px;
    object-fit: cover;
}
.gallery__item figcaption {
    padding: 13px 20px;
    font-size: 13.5px;
    font-weight: 600;
    color: var(--text-muted);
    border-top: 1px solid var(--line);
}

.about__grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-bottom: 40px;
}

.gost {
    border: 1px solid var(--accent-line);
    border-radius: var(--radius);
    padding: 34px;
    background:
        radial-gradient(600px 200px at 15% 0%, rgba(216, 179, 106, 0.08), transparent 65%),
        var(--bg-card);
}
.gost__title {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 19px;
    font-weight: 800;
    color: var(--accent-strong);
    margin-bottom: 24px;
}
.gost__cards {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 18px;
}
.gost__card {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--line);
    border-radius: var(--radius-sm);
    padding: 24px;
}
.gost__grade {
    display: inline-block;
    font-family: var(--mono);
    font-weight: 600;
    font-size: 15px;
    padding: 5px 14px;
    border-radius: 6px;
    margin-bottom: 14px;
}
.gost__card--shell .gost__grade {
    background: rgba(199, 204, 211, 0.12);
    color: var(--silver);
    border: 1px solid rgba(199, 204, 211, 0.3);
}
.gost__card--core .gost__grade {
    background: var(--accent-dim);
    color: var(--accent-strong);
    border: 1px solid var(--accent-line);
}
.gost__card h4 { font-size: 16.5px; font-weight: 700; margin-bottom: 8px; }
.gost__card p { color: var(--text-muted); font-size: 14.5px; }

/* ============ Chemistry ============ */
.chem__layout {
    display: grid;
    grid-template-columns: 1.55fr 1fr;
    gap: 28px;
    align-items: start;
}
.chem__table-wrap {
    background: var(--bg-card);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    overflow: hidden;
}
.chem__tabs {
    display: flex;
    gap: 6px;
    padding: 14px 14px 0;
    border-bottom: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.02);
}
.chem__tab {
    padding: 12px 20px;
    background: transparent;
    border: none;
    border-bottom: 2px solid transparent;
    color: var(--text-muted);
    font-size: 14.5px;
    font-weight: 700;
    transition: color 0.2s, border-color 0.2s;
    margin-bottom: -1px;
}
.chem__tab:hover { color: var(--silver); }
.chem__tab.is-active {
    color: var(--accent-strong);
    border-bottom-color: var(--accent);
}

.chem__table { width: 100%; border-collapse: collapse; }
.chem__table th, .chem__table td {
    padding: 12px 22px;
    font-size: 14.5px;
    text-align: left;
    border-bottom: 1px solid var(--line);
}
.chem__table thead th {
    font-family: var(--mono);
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.07em;
    color: var(--text-dim);
    background: rgba(255, 255, 255, 0.02);
    padding-top: 16px;
    padding-bottom: 16px;
}
.chem__table td:first-child { color: var(--text-muted); font-weight: 600; }
.chem__table td {
    font-family: var(--mono);
    font-size: 14px;
    color: var(--text);
}
.chem__table tr:hover td { background: rgba(255, 255, 255, 0.025); }
.chem__table .row-main td {
    color: var(--accent-strong);
    font-weight: 600;
}
.chem__table .row-main td:first-child { color: var(--text); }
.chem__table .row-last td { border-bottom: none; }

.chem__table .col-shell { display: none; }
.chem__table.show-shell .col-core { display: none; }
.chem__table.show-shell .col-shell { display: table-cell; }
.chem__table .col-core.is-active { display: table-cell; }
.chem__table.show-shell .col-core.is-active { display: none; }
.chem__table.show-shell .col-shell.is-active { display: table-cell; }

.chem__note {
    padding: 14px 22px;
    font-size: 12.5px;
    color: var(--text-dim);
    background: rgba(255, 255, 255, 0.02);
    font-family: var(--mono);
}

.chem__aside { display: flex; flex-direction: column; gap: 20px; }
.highlight {
    background: var(--bg-card);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 26px;
}
.highlight--key {
    border-color: var(--accent-line);
    background:
        radial-gradient(400px 160px at 90% 0%, rgba(216, 179, 106, 0.10), transparent 70%),
        var(--bg-card);
}
.highlight h3 { font-size: 16px; font-weight: 700; margin-bottom: 10px; color: var(--silver); }
.highlight__big {
    font-family: var(--mono);
    font-size: 42px;
    font-weight: 600;
    color: var(--accent-strong);
    line-height: 1.1;
    margin-bottom: 8px;
}
.highlight p { color: var(--text-muted); font-size: 14.5px; }

/* ============ Properties ============ */
.props__grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}
.prop {
    background: var(--bg-card);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 28px;
    transition: border-color 0.25s, transform 0.25s, background 0.25s;
}
.prop:hover {
    border-color: var(--accent-line);
    background: var(--bg-card-hover);
    transform: translateY(-3px);
}
.prop__value {
    display: block;
    font-family: var(--mono);
    font-size: 32px;
    font-weight: 600;
    color: var(--accent-strong);
    margin-bottom: 12px;
    line-height: 1.15;
    white-space: nowrap;
}
.prop__value small {
    font-size: 15px;
    color: var(--text-muted);
    font-weight: 600;
}
.prop__name { font-size: 16.5px; font-weight: 700; margin-bottom: 8px; }
.prop__text { color: var(--text-muted); font-size: 14px; }

/* ============ Safety ============ */
.safety__grid {
    display: grid;
    grid-template-columns: 1.6fr 1fr;
    gap: 28px;
    align-items: start;
}
.safety__table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-card);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    overflow: hidden;
}
.safety__table th, .safety__table td {
    padding: 13px 20px;
    font-size: 14.5px;
    text-align: left;
    border-bottom: 1px solid var(--line);
}
.safety__table thead th {
    font-family: var(--mono);
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.07em;
    color: var(--text-dim);
    background: rgba(255, 255, 255, 0.02);
}
.safety__table tr:last-child td { border-bottom: none; }
.safety__table td:first-child { font-weight: 700; }
.safety__table td:nth-child(2) { font-family: var(--mono); color: var(--silver); }

.tag {
    display: inline-block;
    font-size: 11.5px;
    font-weight: 700;
    padding: 4px 11px;
    border-radius: 100px;
    letter-spacing: 0.02em;
}
.tag--ok {
    background: var(--ok-dim);
    color: var(--ok);
    border: 1px solid rgba(127, 185, 138, 0.3);
}
.tag--best {
    background: var(--accent-dim);
    color: var(--accent-strong);
    border: 1px solid var(--accent-line);
}

.safety__aside {
    display: flex;
    flex-direction: column;
    gap: 22px;
}
.safety__badge {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 8px;
    padding: 38px 26px;
    background: var(--bg-card);
    border: 1px solid var(--accent-line);
    border-radius: var(--radius);
    color: var(--accent-strong);
}
.safety__class {
    font-size: 30px;
    font-weight: 800;
}
.safety__class-label {
    font-size: 13.5px;
    color: var(--text-muted);
}
.safety__text {
    color: var(--text-muted);
    font-size: 14.5px;
    padding: 0 6px;
}

/* ============ Terms ============ */
.terms__grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

/* ============ FAQ ============ */
.faq { max-width: 860px; }
.faq__item {
    background: var(--bg-card);
    border: 1px solid var(--line);
    border-radius: var(--radius-sm);
    margin-bottom: 12px;
    overflow: hidden;
    transition: border-color 0.25s;
}
.faq__item[open] { border-color: var(--accent-line); }
.faq__q {
    padding: 19px 56px 19px 24px;
    font-size: 16px;
    font-weight: 700;
    color: var(--text);
    cursor: pointer;
    list-style: none;
    position: relative;
    transition: color 0.2s;
}
.faq__q::-webkit-details-marker { display: none; }
.faq__q:hover { color: var(--accent-strong); }
.faq__q::after {
    content: '+';
    position: absolute;
    right: 22px;
    top: 50%;
    transform: translateY(-50%);
    width: 26px; height: 26px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: var(--accent-dim);
    color: var(--accent-strong);
    font-size: 18px;
    font-weight: 600;
    transition: transform 0.25s;
}
.faq__item[open] .faq__q::after {
    content: '−';
    transform: translateY(-50%) rotate(180deg);
}
.faq__a {
    padding: 0 24px 20px;
    color: var(--text-muted);
    font-size: 15px;
    line-height: 1.65;
}
.faq__a a { color: var(--accent-strong); font-weight: 600; }
.faq__a a:hover { text-decoration: underline; }

/* ============ Contacts ============ */
.contacts__grid {
    display: grid;
    grid-template-columns: 1fr 1.25fr;
    gap: 44px;
    align-items: start;
}
.contacts__info {
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.contact-item {
    display: flex;
    gap: 16px;
    align-items: flex-start;
    padding: 18px;
    border-radius: var(--radius-sm);
    transition: background 0.2s;
}
.contact-item:hover { background: rgba(255, 255, 255, 0.03); }
.contact-item__icon {
    width: 44px; height: 44px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 11px;
    background: var(--accent-dim);
    color: var(--accent-strong);
}
.contact-item h3 {
    font-size: 12.5px;
    text-transform: uppercase;
    letter-spacing: 0.09em;
    color: var(--text-dim);
    margin-bottom: 5px;
    font-weight: 700;
}
.contact-item p { color: var(--text); font-size: 15.5px; line-height: 1.55; }
.contact-item a { color: var(--silver); font-weight: 600; transition: color 0.2s; }
.contact-item a:hover { color: var(--accent-strong); }

.form {
    background: var(--bg-card);
    border: 1px solid var(--line-strong);
    border-radius: var(--radius);
    padding: 34px;
}
.form__title {
    font-size: 20px;
    font-weight: 800;
    margin-bottom: 24px;
}
.form__row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}
.form__field { margin-bottom: 16px; }
.form__field label {
    display: block;
    font-size: 13px;
    font-weight: 700;
    color: var(--text-muted);
    margin-bottom: 7px;
}
.req { color: var(--accent); }
.form__field input,
.form__field textarea {
    width: 100%;
    padding: 13px 15px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--line-strong);
    border-radius: var(--radius-sm);
    color: var(--text);
    font-family: inherit;
    font-size: 15px;
    transition: border-color 0.2s, background 0.2s;
    resize: vertical;
}
.form__field input:focus,
.form__field textarea:focus {
    outline: none;
    border-color: var(--accent);
    background: rgba(255, 255, 255, 0.06);
}
.form__field input::placeholder,
.form__field textarea::placeholder { color: var(--text-dim); }
.form__field.has-error input,
.form__field.has-error textarea {
    border-color: #d16a6a;
}
.form__error {
    display: none;
    font-size: 12.5px;
    color: #e08a8a;
    margin-top: 5px;
}
.form__field.has-error .form__error { display: block; }
.form__hint {
    margin-top: 14px;
    font-size: 13px;
    color: var(--text-dim);
    text-align: center;
}
.form__hint a { color: var(--accent-strong); }

/* ============ Footer ============ */
.footer {
    border-top: 1px solid var(--line);
    background: #101317;
    padding: 46px 0 34px;
}
.footer__inner {
    display: flex;
    flex-direction: column;
    gap: 22px;
    align-items: center;
    text-align: center;
}
.footer__brand p { color: var(--text-dim); font-size: 14px; max-width: 480px; margin-top: 8px; }
.logo__text--footer strong { font-size: 16.5px; letter-spacing: 0.03em; }
.footer__contacts {
    display: flex;
    gap: 26px;
    flex-wrap: wrap;
    justify-content: center;
}
.footer__contacts a {
    color: var(--text-muted);
    font-weight: 600;
    font-size: 14.5px;
    transition: color 0.2s;
}
.footer__contacts a:hover { color: var(--accent-strong); }
.footer__copy { color: var(--text-dim); font-size: 13px; }

/* ============ Call FAB (mobile) ============ */
.call-fab {
    display: none;
    position: fixed;
    right: 18px;
    bottom: 18px;
    z-index: 90;
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent-strong), var(--accent));
    color: #17130a;
    align-items: center;
    justify-content: center;
    box-shadow: 0 8px 26px rgba(216, 179, 106, 0.4);
    animation: pulse 2.4s infinite;
}

/* ============ Reveal animations ============ */
.reveal {
    opacity: 0;
    transform: translateY(26px);
    transition: opacity 0.7s cubic-bezier(0.22, 1, 0.36, 1), transform 0.7s cubic-bezier(0.22, 1, 0.36, 1);
}
.reveal.is-visible {
    opacity: 1;
    transform: none;
}
@media (prefers-reduced-motion: reduce) {
    .reveal { opacity: 1; transform: none; transition: none; }
    html { scroll-behavior: auto; }
}

/* ============ Responsive ============ */
@media (max-width: 1024px) {
    .nav { display: none; }
    .header__phone { display: none; }
    .burger { display: flex; }

    .nav.is-open {
        display: flex;
        flex-direction: column;
        position: fixed;
        top: var(--header-h);
        left: 0; right: 0;
        background: rgba(16, 18, 22, 0.98);
        backdrop-filter: blur(16px);
        border-bottom: 1px solid var(--line-strong);
        padding: 18px 24px 26px;
        gap: 4px;
        animation: navDrop 0.25s ease;
    }
    @keyframes navDrop {
        from { opacity: 0; transform: translateY(-10px); }
        to { opacity: 1; transform: none; }
    }
    .nav.is-open .nav__link {
        padding: 13px 14px;
        font-size: 16px;
        border-radius: 9px;
    }

    .hero__metrics { grid-template-columns: 1fr 1fr; }
    .metric--divider:nth-child(3) { border-left: none; }
    .metric:nth-child(n+3) { border-top: 1px solid var(--line); }

    .hero__top { grid-template-columns: 1fr; gap: 40px; }
    .hero__visual { max-width: 460px; }
    .hero__content { max-width: none; }
    .about__gallery { grid-template-columns: 1fr 1fr; }
    .about__grid { grid-template-columns: 1fr 1fr; }
    .props__grid { grid-template-columns: 1fr 1fr; }
    .chem__layout { grid-template-columns: 1fr; }
    .safety__grid { grid-template-columns: 1fr; }
    .contacts__grid { grid-template-columns: 1fr; gap: 30px; }
}

@media (max-width: 640px) {
    .section { padding: 68px 0; }
    .hero { padding: calc(var(--header-h) + 56px) 0 60px; }
    .hero__badge {
        font-size: 11px;
        padding: 7px 12px;
        letter-spacing: 0.02em;
    }
    .hero__title-main { word-break: normal; }
    .hero__title { letter-spacing: -0.01em; }
    .hero__metrics { grid-template-columns: 1fr; }
    .metric--divider { border-left: none; }
    .metric:nth-child(n+2) { border-top: 1px solid var(--line); }

    .hero__photo { transform: none; }
    .hero__photo-tag { font-size: 11.5px; padding: 7px 12px; }
    .about__gallery { grid-template-columns: 1fr; }
    .gallery__item img { height: 240px; }
    .about__grid { grid-template-columns: 1fr; }
    .props__grid { grid-template-columns: 1fr; }
    .terms__grid { grid-template-columns: 1fr; }
    .gost { padding: 24px; }
    .gost__cards { grid-template-columns: 1fr; }

    .faq__q { padding: 16px 50px 16px 18px; font-size: 15px; }
    .faq__a { padding: 0 18px 16px; font-size: 14px; }
    .form { padding: 24px 20px; }
    .form__row { grid-template-columns: 1fr; gap: 0; }

    .chem__tabs { flex-direction: column; gap: 0; padding: 8px 8px 0; }
    .chem__tab { text-align: left; margin-bottom: 0; }

    .chem__table th, .chem__table td { padding: 10px 14px; font-size: 13px; }
    .safety__table th, .safety__table td { padding: 10px 12px; font-size: 13px; }
    .safety__table thead th:nth-child(3),
    .safety__table td:nth-child(3) { display: none; }

    .card--row { flex-direction: column; gap: 14px; }
    .btn { width: 100%; }
    .hero__cta { flex-direction: column; }
    .header__actions .btn--sm { display: none; }
    .call-fab { display: flex; }
}