/* --- Global Styles & Variables --- */
:root {
    --bg-color: #ffffff;
    --bg-light: #f0f9ff; /* Очень светлый голубой */
    --text-color: #334155;
    --heading-color: #0f172a;
    --primary-color: #0ea5e9; /* Яркий голубой */
    --primary-hover: #0284c7;
    --border-color: #e2e8f0;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
@keyframes fadeInUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }

body {
    font-family: 'Manrope', sans-serif;
    line-height: 1.7;
    background-color: var(--bg-color);
    color: var(--text-color);
}

.container { max-width: 1100px; margin: 0 auto; padding: 0 20px; }
h1, h2, h3, h4 { line-height: 1.3; color: var(--heading-color); font-weight: 800; }
h1 { font-size: 3.5rem; letter-spacing: -1.5px; }
h2 { font-size: 2.5rem; text-align: center; }
.subtitle { max-width: 600px; margin: 1rem auto 0 auto; font-size: 1.15rem; color: #475569; text-align: center; }
.section-subtitle { max-width: 700px; margin: 1rem auto 3.5rem auto; text-align: center; font-size: 1.1rem; }
.section-tag { display: block; font-weight: 700; color: var(--primary-color); margin-bottom: 1rem; }
section { padding: 80px 0; }
section:nth-of-type(even) { background-color: var(--bg-light); }

/* --- Buttons & Links --- */
.btn { display: inline-block; padding: 12px 28px; border-radius: 8px; text-decoration: none; font-weight: 600; transition: all 0.2s; cursor: pointer; border: 1px solid transparent; }
.btn-primary { background-color: var(--primary-color); color: white; }
.btn-primary:hover { background-color: var(--primary-hover); transform: translateY(-3px); box-shadow: 0 10px 20px rgba(14, 165, 233, 0.2); }
.nav-btn { font-size: 0.9rem; padding: 8px 18px; }
.btn-large { padding: 16px 36px; font-size: 1.1rem; font-weight: 700; margin-top: 2.5rem; }
.cta-button { display: block; width: fit-content; margin-left: auto; margin-right: auto; }

/* --- Header --- */
.header { border-bottom: 1px solid var(--border-color); padding: 15px 0; background-color: rgba(255, 255, 255, 0.85); position: sticky; top: 0; z-index: 1000; backdrop-filter: blur(10px); }
.main-nav { display: flex; justify-content: space-between; align-items: center; }
.logo span { font-size: 1.5rem; font-weight: 800; color: var(--heading-color); }

/* --- Hero Section --- */
.hero { padding: 80px 0 40px; text-align: center; }
.hero-image { max-width: 100%; height: auto; margin-top: 3.5rem; border-radius: 12px; }

/* --- Features Section --- */
.features { background-color: var(--bg-color); }
.features-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; align-items: center; }
.feature-text ul { list-style: none; margin-top: 2rem; }
.feature-text li { margin-bottom: 1rem; position: relative; padding-left: 30px; }
.feature-text li::before { content: '✓'; color: var(--primary-color); position: absolute; left: 0; font-weight: bold; }
.speed-icon { font-size: 6rem; text-align: center; opacity: 0.5; }

/* --- Solution Section --- */
.solution-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 20px; margin-top: 4rem; }
.solution-card { background: white; padding: 25px; border-radius: 12px; border: 1px solid var(--border-color); }
.solution-card h4 { margin-bottom: 0.5rem; }

/* --- FAQ Section --- */
.faq { background-color: var(--bg-color); }
.faq-accordion { max-width: 800px; margin: 3.5rem auto 0 auto; }
details { background: var(--bg-light); border: 1px solid transparent; border-radius: 12px; margin-bottom: 10px; padding: 20px; }
summary { font-weight: 600; cursor: pointer; list-style: none; display: flex; justify-content: space-between; align-items: center; color: var(--heading-color); }
summary::-webkit-details-marker { display: none; }
summary::after { content: '+'; font-size: 1.5rem; color: var(--primary-color); transition: transform 0.2s; }
details[open] summary::after { transform: rotate(45deg); }
details[open] { border-color: var(--border-color); }
details[open] p { padding-top: 15px; margin-top: 15px; border-top: 1px solid var(--border-color); }

/* --- Footer --- */
.footer { background-color: var(--bg-light); padding: 30px 0; text-align: center; font-size: 0.9rem; color: #64748b; border-top: 1px solid var(--border-color); }

/* --- Responsive --- */
@media (max-width: 992px) {
    .features-grid { grid-template-columns: 1fr; }
    .feature-visual { display: none; }
}
@media (max-width: 768px) {
    h1 { font-size: 2.8rem; }
    h2 { font-size: 2.2rem; }
}