/* ===================================
   CSS Custom Properties (Variables)
   =================================== */
:root {
    /* Colors */
    --bg-primary: #000000;
    --bg-secondary: #0a0a0a;
    --accent: #d4af37;
    --text-primary: #c9a959;
    --text-secondary: #b89b4c;
    --text-body: whitesmoke;
    --text-muted: #888888;
    --border-dark: #222222;
    --border-light: #444444;
    
    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    
    /* Spacing */
    --header-height: 70px;
    --section-padding: 100px;
    --container-width: 1200px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* ===================================
   Reset & Base Styles
   =================================== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--header-height);
}

@media (max-width: 768px) {
    html {
        scroll-behavior: auto;
    }
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-primary);
    color: var(--text-body);
    line-height: 1.6;
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
}

/* ===================================
   Starfield Canvas
   =================================== */
#starfield {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    pointer-events: none;
}

/* ===================================
   Container
   =================================== */
.container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* ===================================
   Header & Navigation
   =================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: rgba(0, 0, 0, 0.9);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-dark);
    z-index: 1000;
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

.logo {
    font-size: 1.2rem; /* исправлено: было '1.2 rem' */
    font-weight: 500;
    color: var(--accent);
    letter-spacing: 1px;
    transition: color var(--transition-fast);
}

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

.nav-links {
    display: flex;
    gap: 30px;
}

.nav-links a {
    color: var(--text-body);
    font-size: 0.95rem;
    font-weight: 500;
    position: relative;
    transition: color var(--transition-fast);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: width var(--transition-normal);
}

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

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

.lang-toggle {
    background: transparent;
    border: 1px solid var(--accent);
    color: var(--accent);
    padding: 8px 16px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    border-radius: 4px;
}

.lang-toggle:hover {
    background: var(--accent);
    color: var(--bg-primary);
}

/* Mobile Menu Button */
.mobile-menu {
    display: none;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 10px;
    z-index: 1001;
    touch-action: manipulation; /* улучшает отклик на тач-устройствах */
    -webkit-tap-highlight-color: transparent;
}

.hamburger {
    display: block;
    width: 25px;
    height: 2px;
    background: var(--accent);
    position: relative;
    transition: all var(--transition-normal);
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    width: 25px;
    height: 2px;
    background: var(--accent);
    left: 0;
    transition: all var(--transition-normal);
}

.hamburger::before {
    top: -8px;
}

.hamburger::after {
    top: 8px;
}

/* Hamburger Animation */
.mobile-menu.active .hamburger {
    background: transparent;
}

.mobile-menu.active .hamburger::before {
    top: 0;
    transform: rotate(45deg);
}

.mobile-menu.active .hamburger::after {
    top: 0;
    transform: rotate(-45deg);
}

/* Mobile Navigation */
.mobile-nav {
    display: none;
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: rgba(0, 0, 0, 0.98);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-dark);
    padding: 20px;
    transform: translateY(-100%);
    opacity: 0;
    transition: all var(--transition-normal);
    z-index: 1002; /* увеличен, чтобы навигация была наверху и кликабельна */
    -webkit-overflow-scrolling: touch;
    pointer-events: auto;
}

.mobile-nav.active {
    transform: translateY(0);
    opacity: 1;
}

.mobile-nav-links {
    display: flex;
    flex-direction: column;
    gap: 20px;
    text-align: center;
}

.mobile-nav-links a {
    color: var(--text-body);
    font-size: 1.1rem;
    font-weight: 500;
    padding: 10px;
    transition: color var(--transition-fast);
    -webkit-tap-highlight-color: rgba(0,0,0,0.15);
    cursor: pointer;
}

.mobile-nav-links a:hover {
    color: var(--accent);
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .lang-toggle {
        margin-right: 10px;
    }
    
    .mobile-menu {
        display: block;
    }
    
    .mobile-nav {
        display: block;
    }
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: calc(var(--header-height) + 40px) 20px 40px;
    text-align: center;
}

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

.hero-greeting {
    font-size: 1.2rem;
    color: var(--text-secondary);
    margin-bottom: 10px;
    letter-spacing: 2px;
    text-transform: uppercase;
}

.hero-name {
    font-size: clamp(2.5rem, 8vw, 5rem);
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent) 0%, var(--text-primary) 50%, var(--accent) 100%);
    background-size: 200% auto;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: shimmer 3s linear infinite;
    margin-bottom: 15px;
}

@keyframes shimmer {
    0% { background-position: 0% center; }
    100% { background-position: 200% center; }
}

.hero-title {
    font-size: clamp(1.2rem, 3vw, 1.8rem);
    color: var(--text-muted);
    font-weight: 400;
    margin-bottom: 30px;
    letter-spacing: 1px;
}

.hero-intro {
    font-size: 1.1rem;
    color: var(--text-body);
    line-height: 1.8;
    margin-bottom: 40px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    justify-content: center;
}

/* ===================================
   Buttons
   =================================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 6px;
    cursor: pointer;
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s ease;
}

.btn:hover::before {
    left: 100%;
}

.btn-primary {
    background: var(--accent);
    color: var(--bg-primary);
    border: 2px solid var(--accent);
}

.btn-primary:hover {
    background: transparent;
    color: var(--accent);
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(212, 175, 55, 0.3);
}

.btn-secondary {
    background: transparent;
    color: var(--accent);
    border: 2px solid var(--border-light);
}

.btn-secondary:hover {
    border-color: var(--accent);
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(212, 175, 55, 0.1);
}

/* ===================================
   Sections
   =================================== */
/* Добавлено: корректный отступ при прокрутке к якорю (фиксированный хедер) */
.section {
    padding: var(--section-padding) 0;
    scroll-margin-top: calc(var(--header-height) + 20px);
}

.section-title {
    font-size: clamp(2rem, 5vw, 2.5rem);
    color: var(--accent);
    text-align: center;
    margin-bottom: 60px;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, transparent, var(--accent), transparent);
}

/* ===================================
   About Section
   =================================== */
.about {
    background: var(--bg-secondary);
}

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

.about-content p {
    font-size: 1.1rem;
    line-height: 1.9;
    margin-bottom: 25px;
    color: var(--text-body);
}

.about-content p:last-child {
    margin-bottom: 0;
}

/* ===================================
   Skills Section
   =================================== */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
}

.skill-group {
    background: var(--bg-secondary);
    border: 1px solid var(--border-dark);
    border-radius: 12px;
    padding: 25px;
    transition: all var(--transition-normal);
}

.skill-group:hover {
    border-color: var(--accent);
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(212, 175, 55, 0.1);
}

.skill-group-title {
    color: var(--text-primary);
    font-size: 1.2rem;
    margin-bottom: 15px;
    font-weight: 600;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.skill-tag {
    background: rgba(212, 175, 55, 0.1);
    color: var(--text-secondary);
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 0.85rem;
    border: 1px solid var(--border-dark);
    transition: all var(--transition-fast);
}

.skill-group:hover .skill-tag {
    border-color: rgba(212, 175, 55, 0.3);
}

/* ===================================
   Projects Section
   =================================== */
.projects {
    background: var(--bg-secondary);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
}

@media (max-width: 400px) {
    .projects-grid {
        grid-template-columns: 1fr;
    }
}

.project-card {
    background: var(--bg-primary);
    border: 1px solid var(--border-dark);
    border-radius: 12px;
    padding: 30px;
    transition: all var(--transition-normal);
}

.project-card:hover {
    border-color: var(--accent);
    transform: translateY(-5px);
    box-shadow: 0 20px 50px rgba(212, 175, 55, 0.15);
}

.project-title {
    color: var(--accent);
    font-size: 1.4rem;
    margin-bottom: 15px;
}

.project-description {
    color: var(--text-body);
    font-size: 1rem;
    line-height: 1.7;
    margin-bottom: 20px;
}

.project-stack {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 25px;
}

.stack-tag {
    background: rgba(212, 175, 55, 0.15);
    color: var(--text-primary);
    padding: 5px 12px;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 500;
}

.project-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--accent);
    font-weight: 600;
    transition: all var(--transition-fast);
}

.project-link:hover {
    color: var(--text-primary);
    gap: 12px;
}

.project-link svg {
    transition: transform var(--transition-fast);
}

.project-link:hover svg {
    transform: translate(3px, -3px);
}

/* ===================================
   Certificates Section
   =================================== */
.certificates-list {
    max-width: 700px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.certificate-item {
    display: flex;
    align-items: center;
    gap: 20px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-dark);
    border-radius: 12px;
    padding: 25px;
    transition: all var(--transition-normal);
}

.certificate-item:hover {
    border-color: var(--accent);
    transform: translateX(10px);
}

.certificate-icon {
    flex-shrink: 0;
    width: 50px;
    height: 50px;
    background: rgba(212, 175, 55, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent);
}

.certificate-content {
    flex-grow: 1;
}

.certificate-name {
    color: var(--text-primary);
    font-size: 1.1rem;
    margin-bottom: 5px;
}

.certificate-desc {
    color: var(--text-body);
    font-size: 0.95rem;
    margin-bottom: 5px;
}

.certificate-year {
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* ===================================
   Contacts Section
   =================================== */
.contacts {
    background: var(--bg-secondary);
}

.contacts-intro {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-body);
    max-width: 600px;
    margin: 0 auto 50px;
}

.contacts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    max-width: 900px;
    margin: 0 auto;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 15px;
    background: var(--bg-primary);
    border: 1px solid var(--border-dark);
    border-radius: 12px;
    padding: 20px;
    transition: all var(--transition-normal);
}

.contact-item:hover {
    border-color: var(--accent);
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(212, 175, 55, 0.1);
}

.contact-icon {
    flex-shrink: 0;
    width: 45px;
    height: 45px;
    background: rgba(212, 175, 55, 0.1);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--accent);
    transition: all var(--transition-normal);
}

.contact-item:hover .contact-icon {
    background: var(--accent);
    color: var(--bg-primary);
}

.contact-info {
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.contact-label {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 3px;
}

.contact-value {
    color: var(--text-body);
    font-size: 0.95rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* ===================================
   Footer
   =================================== */
.footer {
    padding: 40px 20px;
    border-top: 1px solid var(--border-dark);
    text-align: center;
}

.footer p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* ===================================
   Animations
   =================================== */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Section Highlight Animation */
@keyframes highlight {
    0% { opacity: 1; }
    50% { opacity: 0.5; }
    100% { opacity: 1; }
}

.section-highlight {
    animation: highlight 0.6s ease;
}

/* Disable animations on mobile for performance */
@media (max-width: 768px) {
    .fade-in {
        opacity: 1;
        transform: none;
    }
}

/* ===================================
   Responsive Adjustments
   =================================== */
@media (max-width: 1024px) {
    :root {
        --section-padding: 80px;
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 60px;
        --header-height: 60px;
    }
    
    .hero {
        padding-top: calc(var(--header-height) + 30px);
    }
    
    .hero-intro {
        font-size: 1rem;
    }
    
    .btn {
        padding: 12px 24px;
        font-size: 0.95rem;
    }
    
    .section-title {
        margin-bottom: 40px;
    }
    
    .skills-grid {
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
        gap: 15px;
    }
    
    .skill-group {
        padding: 20px;
    }
    
    .certificate-item {
        padding: 20px;
    }
    
    .certificate-item:hover {
        transform: none;
    }
}

@media (max-width: 640px) {
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 250px;
        justify-content: center;
    }
    
    .skills-grid {
        grid-template-columns: 1fr;
    }
    
    .contacts-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-item:hover {
        transform: none;
    }
}

/* ===================================
   Focus States (Accessibility)
   =================================== */
a:focus,
button:focus {
    outline: 2px solid var(--accent);
    outline-offset: 3px;
}

a:focus:not(:focus-visible),
button:focus:not(:focus-visible) {
    outline: none;
}

a:focus-visible,
button:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 3px;
}

/* ===================================
   Selection Color
   =================================== */
::selection {
    background: var(--accent);
    color: var(--bg-primary);
}

::-moz-selection {
    background: var(--accent);
    color: var(--bg-primary);
}

``` 

Если после этой правки всё ещё наблюдаются:
- при нажатии на "ru" переход на блок сертификатов — пришлите разметку навигации (HTML-фрагмент с кнопкой ru и секциями, укажите href/id), чтобы я проверил соответствие href → id;
- гамбургер не открывает меню — пришлите JS, который отвечает за переключение классов .mobile-menu.active / .mobile-nav.active (или скажите, используете ли вы нативные ссылки). Я помогу подправить мелкий скрипт, если нужно.