:root {
    --primary: #2c3e50;
    --secondary: #3a7bd5;
    --accent: #00d2ff;
    --dark: #2c2c2c;
    --light: #f8f9fa;
    --success: #3CB371;
    --text: #1f1f1f;
    --text-light: #555555;
    --white: #ffffff;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 12px 30px rgba(0, 0, 0, 0.14);
    --transition: all 0.3s ease;
    --radius: 12px;
    --content-width: 1280px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Roboto', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text);
    background: linear-gradient(rgba(248, 249, 250, 0.65), rgba(248, 249, 250, 0.65)), url("../images/back-glonass.jpg") center center / cover fixed no-repeat;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: var(--content-width);
    margin: 0 auto;
    padding: 0 32px;
}

/* Header */

.main-header {
    background: var(--dark);
    color: var(--white);
    padding: 25px 0;
    text-align: center;
    box-shadow: var(--shadow);
    position: relative;
    z-index: 101;
}

.logo {
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--white);
    text-decoration: none;
    display: inline-block;
    margin-bottom: 8px;
    transition: var(--transition);
}

.logo:hover {
    color: var(--accent);
}

.tagline {
    font-size: 1.1rem;
    color: rgba(255,255,255,0.8);
}

.main-nav {
    background-color: var(--primary);
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.main-nav ul {
    display: flex;
    justify-content: center;
    align-items: center;
    list-style: none;
    gap: 30px;
    flex-wrap: wrap;
    margin: 0;
    padding: 0;
}

.main-nav a {
    color: var(--white);
    text-decoration: none;
    font-weight: 500;
    padding: 8px 15px;
    border-radius: 4px;
    transition: var(--transition);
    font-size: 1.05rem;
}

.main-nav a:hover,
.main-nav a.active {
    background-color: var(--accent);
    color: var(--dark);
}

.hero-section {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: var(--white);
    padding: 80px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero-section h1 {
    font-size: clamp(2rem, 4vw, 3.2rem);
    line-height: 1.2;
    margin-bottom: 20px;
    animation: fadeInDown 1s ease;
}

.hero-text {
    font-size: clamp(1.05rem, 1.8vw, 1.25rem);
    line-height: 1.65;
    max-width: 760px;
    margin: 0 auto 30px;
    animation: fadeIn 1.5s ease;
}

.main-content {
    position: relative;
    flex: 1;
    padding: 60px 0 80px;
}

.glonass-intro {
    margin-bottom: 80px;
}

.content-banner {
    width: 100%;
    margin: 0 auto 40px;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
}

.content-banner img {
    width: 100%;
    height: auto;
    display: block;
    max-height: 520px;
    object-fit: cover;
}

.intro-text {
    max-width: 950px;
    margin: 0 auto;
    text-align: center;
}

.intro-text h2 {
    color: var(--primary);
    font-size: clamp(1.8rem, 3vw, 2.4rem);
    line-height: 1.25;
    margin-bottom: 22px;
}

.intro-text p {
    color: var(--text-light);
    font-size: 1.08rem;
    line-height: 1.7;
    margin-bottom: 14px;
}

.glonass-section {
    margin-bottom: 90px;
}

.section-title {
    text-align: center;
    margin-bottom: 42px;
    font-size: clamp(1.8rem, 3vw, 2.35rem);
    line-height: 1.25;
    color: var(--primary);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 80px;
    height: 4px;
    background: linear-gradient(to right, var(--accent), var(--secondary));
    margin: 16px auto 0;
    border-radius: 10px;
}

.section-description {
    max-width: 950px;
    margin: -15px auto 42px;
    text-align: center;
    color: var(--text-light);
    font-size: 1.08rem;
    line-height: 1.7;
}

.glonass-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 28px;
}

.glonass-card {
    background-color: var(--white);
    border-radius: var(--radius);
    padding: 34px 30px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: var(--transition);
    border-top: 3px solid transparent;
    min-height: 260px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.glonass-card:hover {
    transform: translateY(-7px);
    border-top-color: var(--accent);
    box-shadow: var(--shadow-hover);
}

.glonass-card-icon {
    width: 68px;
    height: 68px;
    margin: 0 auto 20px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 210, 255, 0.1);
    color: var(--secondary);
    font-size: 1.7rem;
    flex-shrink: 0;
}

.glonass-card h3 {
    color: var(--primary);
    font-size: 1.3rem;
    line-height: 1.35;
    margin-bottom: 12px;
}

.glonass-card p {
    color: var(--text-light);
    font-size: 1.02rem;
    line-height: 1.65;
    max-width: 340px;
}

.benefits-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 25px;
    margin-top: 30px;
}

.benefit-card {
    background-color: var(--white);
    padding: 32px 25px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    text-align: center;
    transition: var(--transition);
    min-height: 250px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.benefit-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
}

.benefit-icon {
    font-size: 2.8rem;
    color: var(--accent);
    margin-bottom: 20px;
}

.benefit-card h3 {
    margin-bottom: 14px;
    color: var(--primary);
    font-size: 1.25rem;
    line-height: 1.35;
}

.benefit-card p {
    color: var(--text-light);
    font-size: 1.02rem;
    line-height: 1.65;
}

.fuel-saving {
    margin-top: 30px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: var(--white);
    border-radius: var(--radius);
    padding: 35px 45px;
    display: flex;
    align-items: center;
    gap: 25px;
    box-shadow: var(--shadow);
}

.fuel-saving-icon {
    width: 75px;
    height: 75px;
    min-width: 75px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.15);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
}

.fuel-saving-value {
    font-size: 2.6rem;
    font-weight: 700;
    line-height: 1;
    margin-bottom: 7px;
}

.fuel-saving h3 {
    font-size: 1.35rem;
    margin-bottom: 8px;
}

.fuel-saving p {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.02rem;
    line-height: 1.6;
}

.process-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 22px;
}

.process-card {
    background-color: var(--white);
    padding: 32px 27px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    position: relative;
    min-height: 230px;
}

.process-number {
    color: var(--accent);
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 15px;
}

.process-card h3 {
    color: var(--primary);
    margin-bottom: 12px;
    font-size: 1.2rem;
    line-height: 1.35;
}

.process-card p {
    color: var(--text-light);
    font-size: 1.02rem;
    line-height: 1.65;
}

.system-flow {
    margin-top: 35px;
    background-color: var(--white);
    border-radius: var(--radius);
    padding: 35px 30px;
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 18px;
}

.flow-item {
    min-width: 150px;
    text-align: center;
    color: var(--primary);
}

.flow-item i {
    display: block;
    font-size: 2rem;
    color: var(--secondary);
    margin-bottom: 10px;
}

.flow-item span {
    font-weight: 500;
    font-size: 1rem;
}

.flow-arrow {
    font-size: 2rem;
    color: var(--accent);
    flex-shrink: 0;
}

.transport-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 25px;
}

.transport-card {
    background-color: var(--white);
    padding: 32px 28px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
    min-height: 220px;
}

.transport-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
}

.transport-icon {
    font-size: 2.5rem;
    color: var(--secondary);
    margin-bottom: 20px;
}

.transport-card h3 {
    color: var(--primary);
    margin-bottom: 12px;
    font-size: 1.25rem;
}

.transport-card p {
    color: var(--text-light);
    font-size: 1.02rem;
    line-height: 1.65;
}

.installation-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 22px;
}

.installation-card {
    background-color: var(--white);
    padding: 32px 27px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    min-height: 220px;
}

.installation-number {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background-color: var(--secondary);
    color: var(--white);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.2rem;
    margin-bottom: 20px;
}

.installation-card h3 {
    color: var(--primary);
    margin-bottom: 10px;
    font-size: 1.25rem;
}

.installation-card p {
    color: var(--text-light);
    font-size: 1.02rem;
    line-height: 1.65;
}

.fleet-section {
    margin-bottom: 90px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: var(--radius);
    padding: 50px;
    color: var(--white);
    box-shadow: var(--shadow);
}

.fleet-content {
    display: grid;
    grid-template-columns: 100px minmax(0, 1fr);
    gap: 30px;
    align-items: start;
}

.fleet-icon {
    width: 85px;
    height: 85px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.15);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.3rem;
}

.fleet-content h2 {
    font-size: clamp(1.8rem, 3vw, 2.3rem);
    margin-bottom: 15px;
}

.fleet-content p {
    color: rgba(255, 255, 255, 0.9);
    max-width: 850px;
    margin-bottom: 25px;
    font-size: 1.05rem;
    line-height: 1.7;
}

.fleet-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 12px 25px;
    margin-bottom: 30px;
}

.fleet-list li {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1rem;
}

.fleet-list i {
    color: var(--accent);
    margin-right: 8px;
}

.faq-section {
    margin-bottom: 90px;
}

.faq-list {
    max-width: 950px;
    margin: 0 auto;
}

.faq-item {
    background-color: var(--white);
    border-radius: var(--radius);
    margin-bottom: 14px;
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: var(--transition);
}

.faq-item:hover {
    box-shadow: var(--shadow-hover);
}

.faq-item summary {
    cursor: pointer;
    padding: 22px 60px 22px 25px;
    font-weight: 600;
    color: var(--primary);
    list-style: none;
    position: relative;
    font-size: 1.05rem;
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-item summary::after {
    content: '+';
    position: absolute;
    right: 25px;
    top: 14px;
    font-size: 1.8rem;
    font-weight: 400;
    color: var(--secondary);
}

.faq-item[open] summary::after {
    content: '−';
}

.faq-item p {
    padding: 0 25px 22px;
    color: var(--text-light);
    font-size: 1.02rem;
    line-height: 1.7;
}


.cta-button {
    display: inline-block;
    padding: 13px 30px;
    border: 0;
    border-radius: 50px;
    background-color: var(--accent);
    color: var(--white);
    font-family: inherit;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0,210,255,0.3);
    transition: var(--transition);
}

.cta-button:hover {
    background-color: #00b8e6;
    transform: translateY(-3px);
    box-shadow: 0 7px 20px rgba(0,210,255,0.4);
}

.contact-section {
    max-width: 900px;
    margin: 0 auto;
}

.contact-header {
    text-align: center;
    margin-bottom: 35px;
}


.contact-header .section-title {
    margin-bottom: 18px;
}

.contact-header p {
    max-width: 650px;
    margin: 15px auto 0;
    color: var(--text-light);
    font-size: 1.05rem;
}

.contact-form {
    max-width: 800px;
    margin: 0 auto;
    padding: 40px;
    border-radius: 12px;
    background-color: var(--white);
    box-shadow: var(--shadow-hover);
    text-align: left;
}

.form-group {
    margin-bottom: 22px;
    text-align: left;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--primary);
    font-weight: 500;
    text-align: left;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 13px 15px;
    border: 1px solid #ddd;
    border-radius: 5px;
    background: var(--white);
    color: var(--text);
    font-family: inherit;
    font-size: 16px;
    transition: var(--transition);
    text-align: left;
}

.form-group textarea {
    min-height: 120px;
    resize: vertical;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: var(--accent);
    outline: none;
    box-shadow: 0 0 0 3px rgba(0,210,255,0.16);
}

.contact-form .cta-button {
    border: 0;
}

.hp-field {
    position: absolute;
    height: 0;
    opacity: 0;
    overflow: hidden;
    pointer-events: none;
}

.hp-field label {
    display: none !important;
}



.main-footer {
    background-color: var(--dark);
    color: var(--white);
    padding: 60px 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-column h3 {
    font-size: 1.3rem;
    margin-bottom: 20px;
    color: var(--white);
    position: relative;
    padding-bottom: 10px;
}

.footer-column h3::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 50px;
    height: 2px;
    background-color: var(--accent);
}

.contact-list,
.social-list,
.nav-list {
    list-style: none;
}

.contact-list li,
.social-list li,
.nav-list li {
    margin-bottom: 12px;
}

.contact-list a,
.social-list a,
.nav-list a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition);
}

.contact-list a:hover,
.social-list a:hover,
.nav-list a:hover {
    color: var(--accent);
}

.contact-list i,
.social-list i {
    margin-right: 10px;
    width: 20px;
    text-align: center;
    color: var(--accent);
}

.footer-bottom {
    text-align: center;
    padding: 20px 0;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 14px;
    color: rgba(255, 255, 255, 0.6);
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes fadeInDown {
    from { opacity: 0; transform: translateY(-20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* большие экраны */
@media (min-width: 1600px) {
    .container { max-width: 1440px; }
    .main-content { padding-top: 75px; }
    .glonass-grid { gap: 32px; }
    .glonass-card { padding: 40px 35px; min-height: 280px; }
    .benefit-card { padding: 38px 30px; min-height: 270px; }
    .process-card, .installation-card { padding: 38px 30px; }
    .transport-card { padding: 38px 32px; }
    .intro-text p, .section-description { font-size: 1.12rem; }
    .glonass-card p, .benefit-card p, .process-card p, .transport-card p, .installation-card p { font-size: 1.05rem; }
}

/* ноутбуки */
@media (max-width: 1100px) {
    .container { padding: 0 28px; }
    .glonass-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .benefits-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .process-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .transport-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .installation-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .fleet-list { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .system-flow { flex-wrap: wrap; }
}

/* планшеты */
@media (max-width: 800px) {
    .container { padding: 0 22px; }
    .hero-section { padding: 65px 0; }
    .main-content { padding: 45px 0 60px; }
    .glonass-section, .faq-section, .fleet-section { margin-bottom: 65px; }
    .content-banner { margin-bottom: 30px; }
    .content-banner img { max-height: 420px; }
    .system-flow { display: grid; grid-template-columns: repeat(2, 1fr); gap: 25px; }
    .flow-arrow { display: none; }
    .fleet-section { padding: 38px 30px; }
    .fleet-content { grid-template-columns: 75px minmax(0, 1fr); gap: 22px; }
    .fleet-icon { width: 65px; height: 65px; font-size: 1.8rem; }
    .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .footer-column:last-child { grid-column: 1 / -1; }
}

/* телефоны */
@media (max-width: 600px) {
    .container { padding: 0 18px; }
    .logo { font-size: 1.7rem; }
    .tagline { font-size: 0.95rem; }
    .main-nav { position: relative; padding: 10px 0; }
    .main-nav ul { gap: 5px; }
    .main-nav a { display: block; padding: 7px 10px; font-size: 0.95rem; }
    .hero-section { padding: 55px 0; }
    .hero-section h1 { font-size: 1.9rem; }
    .hero-text { font-size: 1rem; margin-bottom: 25px; }
    .main-content { padding: 35px 0 50px; }
    .glonass-intro { margin-bottom: 55px; }
    .content-banner { margin-bottom: 25px; border-radius: 9px; }
    .content-banner img { max-height: 300px; }
    .intro-text h2 { font-size: 1.7rem; }
    .intro-text p { font-size: 1rem; }
    .glonass-section { margin-bottom: 60px; }
    .section-title { font-size: 1.7rem; margin-bottom: 32px; }
    .section-description { font-size: 1rem; margin-bottom: 30px; }
    .glonass-grid, .benefits-grid, .process-grid, .transport-grid, .installation-grid { grid-template-columns: 1fr; gap: 18px; }
    .glonass-card { min-height: auto; padding: 28px 22px; }
    .benefit-card { min-height: auto; padding: 28px 22px; }
    .process-card, .transport-card, .installation-card { min-height: auto; padding: 28px 22px; }
    .fuel-saving { padding: 28px 22px; gap: 18px; }
    .fuel-saving-icon { width: 60px; height: 60px; min-width: 60px; font-size: 1.5rem; }
    .fuel-saving-value { font-size: 2.1rem; }
    .fuel-saving h3 { font-size: 1.15rem; }
    .fuel-saving p { font-size: 0.95rem; }
    .system-flow { grid-template-columns: 1fr; padding: 25px 20px; }
    .flow-item { min-width: auto; }
    .fleet-section { padding: 32px 22px; }
    .fleet-content { grid-template-columns: 1fr; gap: 20px; }
    .fleet-icon { width: 65px; height: 65px; }
    .fleet-content h2 { font-size: 1.7rem; }
    .fleet-list { grid-template-columns: 1fr; gap: 9px; }
    .faq-item summary { padding: 18px 50px 18px 18px; font-size: 0.98rem; }
    .faq-item summary::after { right: 18px; }
    .faq-item p { padding: 0 18px 18px; font-size: 0.95rem; }
    .contact-form { padding: 28px 20px; }
    .footer-grid { grid-template-columns: 1fr; gap: 30px; }
    .footer-column:last-child { grid-column: auto; }
}

@media (max-width: 400px) {
    .container { padding: 0 14px; }
    .logo { font-size: 1.45rem; }
    .tagline { font-size: 0.88rem; }
    .main-nav a { font-size: 0.88rem; padding: 6px 8px; }
    .hero-section { padding: 45px 0; }
    .hero-section h1 { font-size: 1.65rem; }
    .hero-text { font-size: 0.95rem; }
    .cta-button { padding: 11px 25px; font-size: 0.95rem; }
    .content-banner img { max-height: 230px; }
    .section-title { font-size: 1.5rem; }
    .fuel-saving { flex-direction: column; align-items: flex-start; }
    .contact-form { padding: 22px 16px; }
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        scroll-behavior: auto !important;
        transition-duration: 0.01ms !important;
    }
}