:root {
    --bg: #F4F6F9;
    --bg-2: #E9EDF2;
    --bg-3: #D8DEE6;
    --text: #0F172A;
    --text-muted: #64748B;
    --accent: #2563EB;
    --accent-2: #1E40AF;
    --accent-3: #60A5FA;
    --border: rgba(15,23,42,0.10);
    --radius: 14px;
    --radius-lg: 20px;
    --font: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --shadow: 0 10px 40px rgba(15,23,42,0.08);
    --shadow-accent: 0 10px 40px rgba(37,99,235,0.25);
    --container: 1200px;
    --header-h: 72px;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}
body::before {
    content: '';
    position: fixed; inset: 0;
    background-image:
        linear-gradient(rgba(37,99,235,0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(37,99,235,0.03) 1px, transparent 1px);
    background-size: 60px 60px;
    pointer-events: none;
    z-index: 0;
}
main { position: relative; z-index: 1; }
.container { max-width: var(--container); margin: 0 auto; padding: 0 20px; }
a { color: inherit; text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--accent); }
h1, h2, h3, h4 { font-weight: 800; line-height: 1.15; letter-spacing: -0.02em; }
h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.6rem, 3.5vw, 2.5rem); }
h3 { font-size: clamp(1.2rem, 2vw, 1.5rem); }

/* Кнопки */
.btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 14px 28px; border-radius: 10px;
    font-weight: 600; font-size: 15px;
    border: none; cursor: pointer;
    transition: all 0.25s ease;
    text-align: center; justify-content: center;
}
.btn-primary {
    background: linear-gradient(135deg, var(--accent-3), var(--accent-2));
    color: #FFFFFF;
    box-shadow: var(--shadow-accent);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 50px rgba(37,99,235,0.4); color: #FFFFFF; }
.btn-outline { background: transparent; color: var(--text); border: 1.5px solid var(--border); }
.btn-outline:hover { border-color: var(--accent); color: var(--accent); }
.btn-sm { padding: 10px 18px; font-size: 14px; }
.btn-lg { padding: 18px 36px; font-size: 16px; }

/* Header */
.site-header {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    height: var(--header-h);
    background: rgba(244,246,249,0.85);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--border);
    transition: all 0.3s;
}
.site-header.scrolled { background: rgba(244,246,249,0.98); box-shadow: 0 4px 30px rgba(0,0,0,0.3); }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: var(--header-h); gap: 20px; }
.logo { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 18px; }
.logo-mark {
    width: 36px; height: 36px; border-radius: 9px;
    background: linear-gradient(135deg, var(--accent-3), var(--accent-2));
    color: #FFFFFF; display: flex; align-items: center; justify-content: center;
    font-size: 20px; font-weight: 900;
}
.main-nav { display: flex; gap: 28px; }
.main-nav a { font-size: 15px; font-weight: 500; color: var(--text-muted); }
.main-nav a:hover, .main-nav a.active { color: var(--accent); }
.header-actions { display: flex; align-items: center; gap: 16px; }
.header-phone { font-size: 14px; font-weight: 600; color: var(--text); white-space: nowrap; }
.header-phone i { color: var(--accent); margin-right: 4px; }
.burger { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 6px; }
.burger span { width: 24px; height: 2px; background: var(--text); border-radius: 2px; transition: 0.3s; }

/* Page hero */
.page-hero { padding: calc(var(--header-h) + 60px) 0 40px; }
.breadcrumbs { display: flex; align-items: center; gap: 10px; font-size: 13px; color: var(--text-muted); margin-bottom: 16px; }
.breadcrumbs i { font-size: 10px; opacity: 0.5; }
.page-title { margin-bottom: 8px; }
.page-content { max-width: 800px; font-size: 16px; line-height: 1.8; }
.page-content h2 { margin: 32px 0 16px; }
.page-content p { margin-bottom: 16px; color: var(--text-muted); }
.page-content ul { margin: 16px 0 16px 24px; color: var(--text-muted); }

/* Footer */
.site-footer { background: var(--bg-2); border-top: 1px solid var(--border); padding: 60px 0 0; margin-top: 80px; position: relative; z-index: 1; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1.5fr; gap: 40px; padding-bottom: 40px; }
.footer-col h4 { font-size: 15px; margin-bottom: 16px; color: var(--text); }
.footer-col a, .footer-col p { display: block; font-size: 14px; color: var(--text-muted); margin-bottom: 10px; }
.footer-col a:hover { color: var(--accent); }
.footer-col i { color: var(--accent); margin-right: 6px; width: 16px; }
.footer-desc { font-size: 14px; color: var(--text-muted); margin-top: 12px; max-width: 300px; }
.footer-bottom { border-top: 1px solid var(--border); padding: 20px 0; }
.footer-bottom .container { display: flex; justify-content: space-between; font-size: 13px; color: var(--text-muted); flex-wrap: wrap; gap: 10px; }
.footer-bottom a { color: var(--accent); }

/* Mobile CTA */
.mobile-cta { display: none; position: fixed; bottom: 0; left: 0; right: 0; z-index: 90; background: var(--bg-2); border-top: 1px solid var(--border); padding: 10px; gap: 10px; }
.mobile-cta-btn { flex: 1; display: flex; align-items: center; justify-content: center; gap: 6px; padding: 12px; border-radius: 10px; font-size: 14px; font-weight: 600; background: var(--bg-3); color: var(--text); }
.mobile-cta-primary { background: linear-gradient(135deg, var(--accent-3), var(--accent-2)); color: #FFFFFF; }

/* Reveal animation */
.reveal { opacity: 0; transform: translateY(30px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.visible { opacity: 1; transform: none; }

/* Mobile */
@media (max-width: 900px) {
    .header-phone { display: none; }
    .main-nav { display: none; position: fixed; top: var(--header-h); left: 0; right: 0; background: var(--bg-2); flex-direction: column; padding: 20px; gap: 16px; border-bottom: 1px solid var(--border); }
    .main-nav.open { display: flex; }
    .burger { display: flex; }
    .footer-grid { grid-template-columns: 1fr 1fr; }
    .mobile-cta { display: flex; }
    body { padding-bottom: 70px; }
}
@media (max-width: 560px) {
    .footer-grid { grid-template-columns: 1fr; }
    .btn { width: 100%; }
    .header-actions .btn { display: none; }
}

/* ═══ СВЕТЛАЯ ТЕМА: точечные фиксы ═══ */
.portfolio-tag {
    background: rgba(15,23,42,0.82) !important;
    color: #FFFFFF !important;
    backdrop-filter: blur(6px);
}
.site-header {
    background: rgba(244,246,249,0.85) !important;
    border-bottom: 1px solid rgba(0,0,0,0.08);
}
.site-header.scrolled {
    background: rgba(244,246,249,0.98) !important;
    box-shadow: 0 4px 30px rgba(0,0,0,0.06);
}
body::before {
    background-image:
        linear-gradient(rgba(15,23,42,0.035) 1px, transparent 1px),
        linear-gradient(90deg, rgba(15,23,42,0.035) 1px, transparent 1px) !important;
}
.mobile-cta {
    background: var(--bg-2);
    border-top: 1px solid var(--border);
}
.mobile-cta-btn {
    background: var(--bg-3);
    color: var(--text);
}
.mobile-cta-primary {
    background: var(--accent);
    color: #FFFFFF;
}


/* ═══ ФИРМЕННЫЕ ЦВЕТА (v3) ═══ */
:root {
    --accent-sky: #0EA5E9;      /* небесный — иконки, ховеры */
    --accent-indigo: #4F46E5;   /* индиго — градиенты */
    --accent-glow: rgba(37,99,235,0.18);

    --grad-light: linear-gradient(180deg, #F4F6F9 0%, #EEF2F7 100%);
    --grad-light-2: linear-gradient(180deg, #E9EDF2 0%, #DDE5EE 100%);
    --grad-hero: linear-gradient(180deg, #F4F6F9 0%, #EEF2F7 60%, #E4ECF7 100%);
    --grad-cta: linear-gradient(135deg, #0F172A 0%, #1E3A8A 55%, #2563EB 100%);
}

/* ═══ ШАПКА — ГРАДИЕНТЫ И АКЦЕНТЫ (v2) ═══ */
.site-header {
    background: linear-gradient(135deg, rgba(244,246,249,0.94) 0%, rgba(238,242,247,0.88) 50%, rgba(228,236,247,0.90) 100%) !important;
    backdrop-filter: blur(18px) saturate(1.2) !important;
    -webkit-backdrop-filter: blur(18px) saturate(1.2) !important;
    border-bottom: 1px solid rgba(37,99,235,0.18) !important;
}
.site-header::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 3px;
    background: linear-gradient(90deg, #0EA5E9, #2563EB, #4F46E5, #60A5FA, #2563EB, #0EA5E9);
    background-size: 200% 100%;
    animation: headerGradient 8s linear infinite;
    z-index: 2;
}
@keyframes headerGradient {
    0%   { background-position: 0% 0; }
    100% { background-position: 200% 0; }
}
.site-header.scrolled {
    background: linear-gradient(135deg, rgba(244,246,249,0.97) 0%, rgba(238,242,247,0.95) 100%) !important;
    box-shadow: 0 8px 32px rgba(37,99,235,0.12), 0 1px 0 rgba(37,99,235,0.10) !important;
}

/* Логотип */
.site-header .logo-mark {
    background: linear-gradient(135deg, #0EA5E9, #4F46E5) !important;
    color: #FFFFFF !important;
    box-shadow: 0 4px 14px rgba(37,99,235,0.35);
    transition: transform 0.35s cubic-bezier(0.22,1,0.36,1), box-shadow 0.35s;
}
.site-header .logo:hover .logo-mark {
    transform: rotate(-8deg) scale(1.08);
    box-shadow: 0 8px 24px rgba(37,99,235,0.55);
}
.site-header .logo-text {
    background: linear-gradient(135deg, #0F172A 0%, #2563EB 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Меню */
.main-nav a {
    position: relative;
    padding: 8px 0;
    transition: color 0.25s;
}
.main-nav a::after {
    content: '';
    position: absolute;
    left: 0; right: 0; bottom: 0;
    height: 2px;
    background: linear-gradient(90deg, #0EA5E9, #4F46E5);
    border-radius: 2px;
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.35s cubic-bezier(0.22,1,0.36,1);
}
.main-nav a:hover::after,
.main-nav a.active::after {
    transform: scaleX(1);
}
.main-nav a:hover,
.main-nav a.active {
    color: var(--accent) !important;
}

/* Телефон */
.header-phone i {
    background: linear-gradient(135deg, #0EA5E9, #4F46E5);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Кнопка «Рассчитать» — блик */
.site-header .btn-primary {
    position: relative;
    overflow: hidden;
}
.site-header .btn-primary::before {
    content: '';
    position: absolute;
    top: 0; left: -100%;
    width: 100%; height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.35), transparent);
    transition: left 0.7s ease;
    pointer-events: none;
}
.site-header .btn-primary:hover::before {
    left: 100%;
}

/* Мобильное меню — с градиентным фоном */
@media (max-width: 900px) {
    .main-nav {
        background: linear-gradient(180deg, #F4F6F9 0%, #E9EDF2 100%) !important;
        box-shadow: 0 12px 32px rgba(37,99,235,0.15) !important;
    }
    .main-nav a { padding: 12px 0; }
    .main-nav a::after { bottom: 6px; }
}

/* ═══ ШАПКА — ТЁМНЫЙ ГРАДИЕНТ (v3) ═══ */
.site-header {
    background: linear-gradient(135deg, #0F172A 0%, #1E293B 50%, #1E3A8A 100%) !important;
    backdrop-filter: blur(18px) saturate(1.2) !important;
    -webkit-backdrop-filter: blur(18px) saturate(1.2) !important;
    border-bottom: 1px solid rgba(96,165,250,0.25) !important;
    box-shadow: 0 4px 24px rgba(15,23,42,0.25);
}
.site-header.scrolled {
    background: linear-gradient(135deg, #0A0F1F 0%, #151E2E 50%, #1E3A8A 100%) !important;
    box-shadow: 0 8px 32px rgba(15,23,42,0.45), 0 1px 0 rgba(96,165,250,0.15) !important;
}

/* Полоса сверху — на тёмном фоне ярче */
.site-header::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 3px;
    background: linear-gradient(90deg, #0EA5E9, #60A5FA, #4F46E5, #0EA5E9, #2563EB, #60A5FA);
    background-size: 200% 100%;
    animation: headerGradient 8s linear infinite;
    z-index: 2;
    box-shadow: 0 0 18px rgba(96,165,250,0.5);
}

/* Логотип */
.site-header .logo-mark {
    background: linear-gradient(135deg, #60A5FA, #4F46E5) !important;
    color: #FFFFFF !important;
    box-shadow: 0 4px 18px rgba(96,165,250,0.5);
    transition: transform 0.35s cubic-bezier(0.22,1,0.36,1), box-shadow 0.35s;
}
.site-header .logo:hover .logo-mark {
    transform: rotate(-8deg) scale(1.08);
    box-shadow: 0 8px 28px rgba(96,165,250,0.75);
}
.site-header .logo-text {
    background: linear-gradient(135deg, #FFFFFF 0%, #93C5FD 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Меню — светлое на тёмном */
.site-header .main-nav a {
    color: #CBD5E1 !important;
    position: relative;
    padding: 8px 0;
    transition: color 0.25s;
}
.site-header .main-nav a:hover,
.site-header .main-nav a.active {
    color: #60A5FA !important;
}
.site-header .main-nav a::after {
    content: '';
    position: absolute;
    left: 0; right: 0; bottom: 0;
    height: 2px;
    background: linear-gradient(90deg, #0EA5E9, #4F46E5);
    border-radius: 2px;
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.35s cubic-bezier(0.22,1,0.36,1);
}
.site-header .main-nav a:hover::after,
.site-header .main-nav a.active::after {
    transform: scaleX(1);
}

/* Телефон */
.site-header .header-phone {
    color: #E2E8F0 !important;
}
.site-header .header-phone i {
    background: linear-gradient(135deg, #60A5FA, #0EA5E9);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Кнопка «Рассчитать» — блик */
.site-header .btn-primary {
    position: relative;
    overflow: hidden;
}
.site-header .btn-primary::before {
    content: '';
    position: absolute;
    top: 0; left: -100%;
    width: 100%; height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.35), transparent);
    transition: left 0.7s ease;
    pointer-events: none;
}
.site-header .btn-primary:hover::before {
    left: 100%;
}

/* Бургер — светлый */
.site-header .burger span {
    background: #E2E8F0 !important;
}

/* Мобильное меню — тёмное */
@media (max-width: 900px) {
    .site-header .main-nav {
        background: linear-gradient(180deg, #0F172A 0%, #1E293B 100%) !important;
        box-shadow: 0 12px 32px rgba(15,23,42,0.5) !important;
        border-top: 1px solid rgba(96,165,250,0.2) !important;
    }
    .site-header .main-nav a {
        color: #E2E8F0 !important;
        padding: 12px 0;
    }
    .site-header .main-nav a::after { bottom: 6px; }
}