:root {
    color-scheme: light;
    --color-background: #ffffff;
    --color-text: #202124;
    --color-muted: #6b7280;
    --color-border: #e5e7eb;

    --color-accent: #01d8f7;
    --color-accent-hover: #5342a5;

    --container-width: 1100px;

    --space-sm: 1rem;
    --space-md: 2rem;
    --space-lg: 4rem;
    --space-xl: 7rem;

    --shadow-sm: 0 2px 10px rgba(0, 0, 0, 0.05);
}


/* =========================================================
   Base
   ========================================================= */

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 90px;
}

body {
    margin: 0;

    font-family:
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        Roboto,
        Helvetica,
        Arial,
        sans-serif;

    font-size: 16px;
    line-height: 1.6;

    color: var(--color-text);
    background: var(--color-background);
}


/* =========================================================
   Typography
   ========================================================= */

h1,
h2,
p {
    margin-top: 0;
}

h1,
h2 {
    line-height: 1.15;
}

h1 {
    margin-bottom: var(--space-md);

    font-size: clamp(2.5rem, 7vw, 5rem);
    font-weight: 700;
    letter-spacing: -0.03em;
}

h2 {
    margin-bottom: var(--space-sm);

    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 650;
    letter-spacing: -0.02em;
}

p {
    max-width: 65ch;
    color: var(--color-muted);
}


/* =========================================================
   Links
   ========================================================= */

a {
    color: inherit;
    text-decoration: none;
}

a:focus-visible {
    outline: 3px solid var(--color-accent);
    outline-offset: 4px;
}


/* =========================================================
   Header
   ========================================================= */

header {
    position: sticky;
    top: 0;
    z-index: 100;

    background: #161936ff; 
    border-bottom: 1px solid rgba(1, 216, 247, 0.2);

    backdrop-filter: blur(10px);
}

.site-nav {
    width: min(100% - 1rem, var(--container-width));
    min-height: 72px;
    margin: 0 auto;

    display: flex;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    flex-shrink: 0;
    margin-left: -0.5rem;
}

.logo img {
    display: block;
    width: auto;
    max-width: 160px;
    max-height: 72px;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 2rem;
    margin-left: auto;
}

.navigation {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.navigation a,
.languages a {
    color: #01d8f7;
    font-size: 0.95rem;
    font-weight: 500;

    transition: color 0.2s ease;
}

.navigation a:hover,
.languages a:hover {
    color: #5342a5;
}

.languages {
    display: flex;
    align-items: center;
    gap: 0.5rem;

    padding-left: 1.5rem;
    border-left: 1px solid rgba(1, 216, 247, 0.2);
}

.languages a {
    font-size: 0.8rem;
    font-weight: 700;
}

.languages a.current {
    color: #5342a5;
}


/* =========================================================
   Mobile menu button
   ========================================================= */

.menu-toggle {
    display: none;

    position: relative;

    width: 32px;
    height: 32px;
    padding: 0;

    border: 0;
    background: transparent;

    cursor: pointer;
    flex-shrink: 0;
}

.menu-toggle span {
    position: absolute;
    left: 5px;

    width: 22px;
    height: 2px;

    background: #01d8f7;

    transition:
        transform 0.2s ease,
        opacity 0.2s ease;
}

.menu-toggle span:nth-child(1) {
    top: 10px;
}

.menu-toggle span:nth-child(2) {
    top: 15px;
}

.menu-toggle span:nth-child(3) {
    top: 20px;
}


/* =========================================================
   Open state
   ========================================================= */

.menu-toggle[aria-expanded="true"] span:nth-child(1) {
    top: 15px;
    transform: rotate(45deg);
}

.menu-toggle[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
}

.menu-toggle[aria-expanded="true"] span:nth-child(3) {
    top: 15px;
    transform: rotate(-45deg);
}


/* =========================================================
   Main
   ========================================================= */

main {
    width: min(100% - 2rem, var(--container-width));
    margin: 0 auto;
}

section {
    padding: var(--space-xl) 0;
    border-bottom: 1px solid var(--color-border);
}


/* =========================================================
   Hero
   ========================================================= */

.hero {
    min-height: min(720px, calc(100vh - 72px));

    display: flex;
    flex-direction: column;
    justify-content: center;
}

.hero p {
    max-width: 650px;
    font-size: clamp(1.1rem, 2vw, 1.35rem);
}


/* =========================================================
   Sections
   ========================================================= */

#about,
#services,
#advantages,
#contacts {
    min-height: 400px;
}

.contacts {
  padding: 64px 20px;
  text-align: center;
  background: #f8fafc;
  color: #1e293b;
}

.contacts h2 {
  margin-bottom: 12px;
  font-size: 32px;
}

.contacts p {
  line-height: 1.6;
}

.contacts-button {
  display: inline-block;
  margin-top: 16px;
  padding: 14px 28px;
  background: #161936ff;
  color: #ffffff;
  text-decoration: none;
  font-weight: 600;
  border-radius: 8px;
  transition: background 0.2s ease;
}

.contacts-button:hover {
  background: #5342a5;
}

.contacts-button:focus-visible {
  outline: 3px solid #93c5fd;
  outline-offset: 4px;
}

.contacts-email {
  margin-top: 20px;
  color: #64748b;
  font-size: 14px;
}

/* =========================================================
   Footer
   ========================================================= */

footer {
    width: min(100% - 2rem, var(--container-width));
    margin: 0 auto;

    padding: var(--space-md) 0;

    color: var(--color-muted);
    font-size: 0.9rem;
}


/* =========================================================
   Mobile
   ========================================================= */

@media (max-width: 700px) {

    .site-nav {
        min-height: 64px;
        position: relative;
    }

    .menu-toggle {
        display: block;
        margin-left: auto;
    }

    .nav-menu {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;

        display: flex;

        padding: 1rem;

        flex-direction: column;
        align-items: stretch;
        gap: 1rem;

        background: #131732;
        border-bottom: 1px solid rgba(1, 216, 247, 0.2);
        box-shadow: var(--shadow-sm);
    }

    .js .nav-menu {
        display: none;
    }

    .js .nav-menu.is-open {
        display: flex;
    }

    .navigation {
        flex-direction: column;
        align-items: stretch;
        gap: 0;
    }

    .navigation a {
        padding: 0.75rem 0;
    }

    .languages {
        padding: 1rem 0 0;
        border-left: 0;
        border-top: 1px solid rgba(1, 216, 247, 0.2);
    }

    section {
        padding: var(--space-lg) 0;
    }

    .hero {
        min-height: calc(100vh - 130px);
    }

    #about,
    #services,
    #advantages,
    #contacts {
        min-height: 300px;
    }
}


/* =========================================================
   Reduced motion
   ========================================================= */

@media (prefers-reduced-motion: reduce) {

    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        transition-duration: 0.01ms !important;
        animation-duration: 0.01ms !important;
    }
}