:root {
    --bg-main: #0a1a2f;
    --bg-alt: #f5f7fb;
    --bg-card: #111c2b;
    --text-main: #ffffff;
    --text-dark: #0a1a2f;
    --accent: #4da3ff;
    --accent-soft: rgba(77, 163, 255, 0.15);
    --border-soft: rgba(255, 255, 255, 0.08);
    --radius: 10px;
    --shadow-soft: 0 18px 40px rgba(0, 0, 0, 0.25);
    --transition: 0.25s ease;
    --font-main: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

html, body {
    margin: 0;
    padding: 0;
    font-family: var(--font-main);
    color: var(--text-main);
    background: var(--bg-main);
}

body {
    line-height: 1.6;
}

/* Layout */

.container {
    width: 100%;
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 16px;
}

/* Header */

.header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(10, 26, 47, 0.96);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.logo {
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    font-size: 18px;
}

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

.nav {
    display: flex;
    gap: 20px;
}

.nav a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    font-size: 14px;
    position: relative;
    padding-bottom: 2px;
    transition: color var(--transition);
}

.nav a::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width var(--transition);
}

.nav a:hover {
    color: #ffffff;
}

.nav a:hover::after {
    width: 100%;
}

.lang-switch {
    display: flex;
    gap: 6px;
    margin-left: 16px;
}

.lang-btn {
    border: 1px solid rgba(255, 255, 255, 0.25);
    background: transparent;
    color: rgba(255, 255, 255, 0.8);
    font-size: 11px;
    padding: 4px 8px;
    border-radius: 999px;
    cursor: pointer;
    transition: background var(--transition), color var(--transition), border-color var(--transition);
}

.lang-btn.active,
.lang-btn:hover {
    background: var(--accent-soft);
    color: #ffffff;
    border-color: var(--accent);
}

/* Burger (mobile) */

.burger {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    margin-left: 12px;
}

.burger span {
    width: 20px;
    height: 2px;
    background: #ffffff;
}

/* Hero */

.hero {
    padding: 72px 0 64px;
    background: radial-gradient(circle at top right, #1b3558 0, #0a1a2f 55%);
}

.hero-inner {
    display: grid;
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    gap: 40px;
    align-items: center;
}

.hero-text h1 {
    font-size: 32px;
    margin: 0 0 12px;
}

.hero-sub {
    font-size: 18px;
    color: rgba(255, 255, 255, 0.85);
    margin: 0 0 8px;
}

.hero-desc {
    color: rgba(255, 255, 255, 0.7);
    max-width: 520px;
    margin-bottom: 24px;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 18px;
    border-radius: 999px;
    font-size: 14px;
    border: 1px solid transparent;
    cursor: pointer;
    text-decoration: none;
    transition: background var(--transition), color var(--transition), border-color var(--transition), transform var(--transition);
}

.btn.primary {
    background: var(--accent);
    color: #0a1a2f;
    font-weight: 600;
}

.btn.primary:hover {
    background: #6bb3ff;
    transform: translateY(-1px);
}

.btn.ghost {
    background: transparent;
    color: #ffffff;
    border-color: rgba(255, 255, 255, 0.4);
}

.btn.ghost:hover {
    background: rgba(255, 255, 255, 0.06);
}

.hero-visual {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-card {
    position: relative;
    z-index: 2;
    background: linear-gradient(135deg, #111c2b, #18263a);
    border-radius: 16px;
    padding: 18px 20px;
    box-shadow: var(--shadow-soft);
    border: 1px solid rgba(255, 255, 255, 0.06);
    max-width: 260px;
}

.hero-card-title {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--accent);
}

.hero-card-text {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.8);
}

.hero-bg-circle {
    position: absolute;
    width: 260px;
    height: 260px;
    border-radius: 50%;
    background: radial-gradient(circle, var(--accent-soft), transparent 60%);
    filter: blur(2px);
}

/* Sections */

.section {
    padding: 64px 0;
    background: var(--bg-main);
}

.section-alt {
    background: var(--bg-alt);
    color: var(--text-dark);
}

.section-alt .card {
    background: #ffffff;
    border-color: rgba(10, 26, 47, 0.06);
}

.section h2 {
    font-size: 24px;
    margin-bottom: 16px;
}

.section p {
    max-width: 720px;
    color: rgba(255, 255, 255, 0.78);
}

.section-alt p {
    color: rgba(10, 26, 47, 0.78);
}

/* Cards & grids */

.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
    margin-top: 24px;
}

.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
    margin-top: 24px;
}

.card {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 18px 18px 16px;
    border: 1px solid var(--border-soft);
    box-shadow: 0 10px 26px rgba(0, 0, 0, 0.25);
}

.card h3 {
    margin-top: 0;
    margin-bottom: 8px;
    font-size: 16px;
}

.card p {
    margin: 0;
    font-size: 14px;
}

.card ul {
    margin: 0;
    padding-left: 18px;
    font-size: 14px;
}

.card li {
    margin-bottom: 4px;
}

/* Tech grid */

.tech-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 20px;
}

.tech-grid span {
    font-size: 13px;
    padding: 6px 10px;
    border-radius: 999px;
    border: 1px solid rgba(10, 26, 47, 0.12);
    background: rgba(255, 255, 255, 0.9);
}

/* Contact */

.contact-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 1.2fr);
    gap: 32px;
    align-items: flex-start;
}

.contact-list {
    list-style: none;
    padding: 0;
    margin-top: 16px;
    font-size: 14px;
}

.contact-list li {
    margin-bottom: 6px;
}

.contact-form {
    background: #111c2b;
    border-radius: var(--radius);
    padding: 20px 18px;
    border: 1px solid var(--border-soft);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.3);
}

.section-alt .contact-form {
    background: #ffffff;
    border-color: rgba(10, 26, 47, 0.08);
}

.form-group {
    margin-bottom: 12px;
}

.form-group label {
    display: block;
    font-size: 13px;
    margin-bottom: 4px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 8px 10px;
    border-radius: 6px;
    border: 1px solid rgba(255, 255, 255, 0.18);
    background: rgba(5, 12, 24, 0.9);
    color: #ffffff;
    font-size: 13px;
    outline: none;
    transition: border-color var(--transition), box-shadow var(--transition), background var(--transition);
}

.section-alt .form-group input,
.section-alt .form-group textarea {
    background: #f5f7fb;
    border-color: rgba(10, 26, 47, 0.18);
    color: #0a1a2f;
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 1px var(--accent-soft);
}

.form-group textarea {
    resize: vertical;
}

.form-group.checkbox {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    font-size: 12px;
}

.form-group.checkbox input {
    width: auto;
    margin-top: 3px;
}

/* Footer */

.footer {
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    padding: 16px 0;
    background: #050a14;
    font-size: 12px;
}

.footer-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: rgba(255, 255, 255, 0.6);
}

/* Responsive */

@media (max-width: 900px) {
    .hero-inner {
        grid-template-columns: minmax(0, 1fr);
    }

    .hero-visual {
        order: -1;
        margin-bottom: 12px;
    }

    .grid-3 {
        grid-template-columns: minmax(0, 1fr);
    }

    .grid-2 {
        grid-template-columns: minmax(0, 1fr);
    }

    .contact-grid {
        grid-template-columns: minmax(0, 1fr);
    }
}

@media (max-width: 768px) {
    .nav {
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: #050a14;
        flex-direction: column;
        padding: 10px 16px 12px;
        gap: 10px;
        border-bottom: 1px solid rgba(255, 255, 255, 0.08);
        transform: translateY(-120%);
        opacity: 0;
        pointer-events: none;
        transition: transform var(--transition), opacity var(--transition);
    }

    .nav.open {
        transform: translateY(0);
        opacity: 1;
        pointer-events: auto;
    }

    .burger {
        display: flex;
    }

    .lang-switch {
        display: none;
    }
}

@media (max-width: 480px) {
    .hero-text h1 {
        font-size: 26px;
    }

    .hero-sub {
        font-size: 16px;
    }

    .header-inner {
        gap: 8px;
    }
}