:root {
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-color: #1e293b;
    --text-muted: #64748b;
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --border-color: #e2e8f0;
    --accent-bg: #f1f5f9;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Header */
.header {
    background-color: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    padding: 16px 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
}

/* Логотип */
.logo-group {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    width: 36px;
    height: 36px;
}

.logo-text {
    font-size: 24px;
    font-weight: 800;
    color: var(--primary-color);
    letter-spacing: -0.5px;
}

/* Навигация */
.nav {
    display: flex;
    gap: 24px;
}

.nav a {
    text-decoration: none;
    color: var(--text-muted);
    font-size: 14px;
    font-weight: 500;
    transition: color 0.2s ease;
}

.nav a:hover {
    color: var(--primary-color);
}

/* Контакты в шапке */
.header-contacts {
    display: flex;
    align-items: center;
    gap: 20px;
}

.header-phones {
    display: flex;
    flex-direction: row;
    gap: 4px;
    align-items: center;
}

.header-phones a,
.header-email {
    color: var(--text-color);
    text-decoration: none;
    font-size: 13px;
    font-weight: 600;
    transition: color 0.2s;
}

.header-phones a:hover,
.header-email:hover {
    color: var(--primary-color);
}

/* Кнопка "Бургер" меню (скрыта на ПК) */
.burger-btn {
    display: none;
    background: transparent;
    border: none;
    cursor: pointer;
    flex-direction: column;
    justify-content: space-around;
    width: 30px;
    height: 24px;
    padding: 0;
    z-index: 101;
}

.burger-line {
    width: 100%;
    height: 3px;
    background-color: var(--text-color);
    border-radius: 2px;
    transition: all 0.3s ease;
}

/* Анимация трансформации бургера в крестик */
.burger-btn.active .burger-line:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
}

.burger-btn.active .burger-line:nth-child(2) {
    opacity: 0;
}

.burger-btn.active .burger-line:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #eff6ff 0%, #f8fafc 100%);
    padding: 80px 0 70px;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-badge {
    display: inline-block;
    background-color: #dbeafe;
    color: var(--primary-color);
    font-weight: 600;
    font-size: 13px;
    padding: 6px 14px;
    border-radius: 30px;
    margin-bottom: 20px;
}

.hero h1 {
    font-size: 38px;
    margin-bottom: 20px;
    color: #0f172a;
    line-height: 1.25;
    letter-spacing: -0.5px;
}

.hero p {
    font-size: 17px;
    margin-bottom: 30px;
    color: var(--text-muted);
    line-height: 1.6;
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: 12px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.2s ease;
}

.btn-primary {
    background-color: var(--primary-color);
    color: #ffffff;
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
}

.btn-secondary {
    background-color: #ffffff;
    color: var(--text-color);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: var(--accent-bg);
    border-color: #cbd5e1;
}

/* Общие заголовки секций */
.section-header {
    text-align: center;
    max-width: 650px;
    margin: 0 auto 40px;
}

.section-header h2 {
    font-size: 30px;
    color: #0f172a;
    margin-bottom: 10px;
    letter-spacing: -0.5px;
}

.section-header p {
    color: var(--text-muted);
    font-size: 15px;
}

/* Services Section */
.services {
    padding: 70px 0;
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.service-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    transition: all 0.25s ease;
}

.service-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.04);
    border-color: #cbd5e1;
}

.service-icon {
    font-size: 28px;
    margin-bottom: 14px;
}

.service-card h3 {
    font-size: 17px;
    margin-bottom: 8px;
    color: #0f172a;
}

.service-card p {
    font-size: 14px;
    color: var(--text-muted);
    line-height: 1.5;
}

/* Advantages Section */
.advantages {
    background-color: var(--accent-bg);
    padding: 70px 0;
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.advantage-card {
    background-color: var(--card-bg);
    border-radius: 12px;
    padding: 30px 24px;
    border: 1px solid var(--border-color);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.01);
}

.advantage-badge {
    display: inline-block;
    background-color: #eff6ff;
    color: var(--primary-color);
    font-weight: 700;
    font-size: 12px;
    padding: 4px 12px;
    border-radius: 20px;
    margin-bottom: 14px;
    border: 1px solid #bfdbfe;
}

.advantage-card h3 {
    font-size: 18px;
    margin-bottom: 10px;
    color: #0f172a;
}

.advantage-card p {
    font-size: 14px;
    color: var(--text-muted);
    line-height: 1.6;
}

/* Clients Section */
.clients {
    padding: 70px 0;
    background-color: #ffffff;
}

.clients-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 30px;
}

.flip-card {
    background-color: transparent;
    height: 250px;
    perspective: 1000px;
    cursor: pointer;
}

.flip-card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: center;
    transition: transform 0.6s cubic-bezier(0.4, 0.2, 0.2, 1);
    transform-style: preserve-3d;
}

.flip-card:hover .flip-card-inner,
.flip-card-inner.is-flipped {
    transform: rotateY(180deg);
}

.flip-card-front,
.flip-card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    border-radius: 10px;
    border: 1px solid var(--border-color);
    padding: 14px 10px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.flip-card-front {
    background-color: var(--accent-bg);
    color: #0f172a;
}

.flip-card-front h3 {
    font-size: 14px;
    margin-top: 8px;
    margin-bottom: 6px;
    color: #0f172a;
    line-height: 1.25;
}

.client-cat-icon {
    font-size: 30px;
}

.flip-hint {
    font-size: 10px;
    color: var(--primary-color);
    font-weight: 600;
    margin-top: 6px;
}

.flip-card-back {
    background-color: var(--primary-color);
    color: #ffffff;
    transform: rotateY(180deg);
    justify-content: flex-start;
    overflow-y: auto;
    padding: 12px 8px;
}

.flip-card-back h3 {
    font-size: 13px;
    margin-bottom: 6px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
    padding-bottom: 4px;
    width: 100%;
}

.flip-card-back ul {
    list-style: none;
    padding: 0;
    margin: 0;
    width: 100%;
    text-align: left;
}

.flip-card-back li {
    font-size: 11px;
    line-height: 1.35;
    padding: 2px 0;
    border-bottom: 1px dashed rgba(255, 255, 255, 0.15);
}

.flip-card-back li:last-child {
    border-bottom: none;
}

/* Кастомный скроллбар */
.flip-card-back::-webkit-scrollbar {
    width: 3px;
}

.flip-card-back::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.4);
    border-radius: 3px;
}

/* Footer (Стиль точь-в-точь как на скриншоте) */
.footer {
    background-color: #0b132a;
    color: #ffffff;
    padding: 60px 0 25px;
    text-align: center;
}

.footer h2 {
    font-size: 32px;
    font-weight: 700;
    color: #ffffff;
    margin-bottom: 12px;
    letter-spacing: -0.5px;
}

.footer-desc {
    color: #94a3b8;
    font-size: 15px;
    margin-bottom: 25px;
}

.footer-contacts-block {
    margin-bottom: 40px;
}

.footer-contacts-block p {
    color: #cbd5e1;
    font-size: 15px;
    margin-bottom: 8px;
}

.footer-contacts-block a {
    color: #3b82f6;
    text-decoration: none;
    font-weight: 600;
    transition: opacity 0.2s;
}

.footer-contacts-block a:hover {
    text-decoration: underline;
    opacity: 0.9;
}

.footer-bottom-row {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 20px;
    margin-top: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.copyright {
    font-size: 13px;
    color: #64748b;
}

.key-btn-footer {
    background: transparent;
    border: none;
    color: #334155;
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    border-radius: 4px;
    transition: color 0.2s;
}

.key-btn-footer:hover {
    color: #64748b;
}

.key-icon {
    width: 16px;
    height: 16px;
}

/* Адаптивность для мобильных устройств */
@media (max-width: 1150px) {
    .clients-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 768px) {
    /* Отображаем бургер-кнопку */
    .burger-btn {
        display: flex;
    }

    /* Мобильное выпадающее меню */
    .nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: #ffffff;
        flex-direction: column;
        padding: 20px 24px;
        gap: 16px;
        box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
        border-bottom: 1px solid var(--border-color);
    }

    .nav.active {
        display: flex;
    }

    .nav a {
        font-size: 16px;
        font-weight: 600;
        padding: 6px 0;
        border-bottom: 1px solid #f1f5f9;
    }

    .header-contacts {
        flex-direction: column;
        align-items: flex-end;
        gap: 4px;
    }

    .header-phones {
        flex-direction: column;
        align-items: flex-end;
        gap: 2px;
    }

    .hero h1 {
        font-size: 26px;
    }

    .hero-actions {
        flex-direction: column;
    }

    .clients-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .footer-bottom-row {
        flex-direction: column;
        gap: 15px;
    }
}

@media (max-width: 480px) {
    .header-contacts {
        display: none; /* Скрываем громоздкие контакты из шапки на очень маленьких экранах (они доступны в меню и подвале) */
    }
}