:root {
    --primary-color: #2563eb;
    --text-color: #1f2937;
    --bg-color: #ffffff;
    --light-gray: #f3f4f6;
    --header-height: 90px;
}

html {
    scroll-behavior: smooth;
    scrollbar-gutter: stable;
    -webkit-text-size-adjust: 100%;
}

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

body {
    font-family: 'Inter', sans-serif;
    color: var(--text-color);
    line-height: 1.6;

    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

main {
    flex: 1;
}

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

ul {
    list-style: none;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

img,
picture,
video,
canvas,
svg {
    display: block;
    max-width: 100%;
}

input,
button,
textarea,
select {
    font: inherit;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

.header {
    height: var(--header-height);
    background: #fff;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

.logo-img {
    height: 55px;
}

.logo-text {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.desktop-nav {
    display: flex;
    align-items: center;
    gap: 40px;
}

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

.nav-item {
    font-weight: 600;
    font-size: 0.95rem;
    transition: color 0.3s;
}

.nav-item:hover {
    color: var(--primary-color);
}

.dropdown {
    position: relative;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: auto;
    right: 0;
    background: #fff;
    border: 1px solid #eee;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    min-width: 180px;
    display: none;
    border-radius: 6px;
    padding: 10px 0;
}

.dropdown:hover .dropdown-menu {
    display: block;
}

.dropdown-menu a {
    display: block;
    padding: 10px 20px;
    font-size: 0.9rem;
}

.dropdown-menu a:hover {
    background: var(--light-gray);
    color: var(--primary-color);
}

.lang-switch {
    display: flex;
    gap: 10px;
    border-left: 1px solid #ddd;
    padding-left: 20px;
}

.lang-btn {
    font-size: 0.85rem;
    color: #888;
}

.lang-btn.active {
    color: var(--text-color);
    font-weight: 700;
}

.lang-btn:hover {
    color: var(--primary-color);
}

.hamburger {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    flex-direction: column;
    gap: 5px;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: #333;
    display: block;
}

.mobile-menu {
    position: fixed;
    top: 0;
    right: -300px;
    width: 280px;
    height: 100%;
    background: #fff;
    box-shadow: -2px 0 10px rgba(0, 0, 0, 0.1);
    padding: 80px 30px;
    transition: right 0.3s ease;
    z-index: 1001;
    overflow-y: auto;
}

.mobile-menu.active {
    right: 0;
}

.close-menu {
    position: absolute;
    top: 20px;
    right: 20px;
    font-size: 2rem;
    background: none;
    border: none;
    cursor: pointer;
}

.mobile-links>li {
    margin-bottom: 20px;
    font-size: 1.1rem;
    font-weight: 600;
}

.mobile-sub-menu {
    padding-left: 15px;
    margin-top: 10px;
    font-size: 0.95rem;
    color: #555;
}

.mobile-lang {
    margin-top: 40px;
    border-top: 1px solid #eee;
    padding-top: 20px;
    display: flex;
    gap: 15px;
}

.mobile-menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: none;
    z-index: 1000;
}

.mobile-menu-overlay.active {
    display: block;
}

.hero-section {
    padding-top: 150px;
    padding-bottom: 100px;
    text-align: center;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 80vh;
}

.hero-section h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    color: #2d3748;
}

.hero-section p {
    font-size: 1.2rem;
    color: #4a5568;
    margin-bottom: 40px;
}

.cta-button {
    background: var(--primary-color);
    color: #fff;
    padding: 15px 30px;
    border-radius: 50px;
    font-weight: 600;
    transition: transform 0.2s;
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.footer {
    background: #1f2937;
    color: #9ca3af;
    padding: 40px 0;
    text-align: center;
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    .desktop-nav {
        display: none;
    }

    .hamburger {
        display: flex;
    }

    .hero-section h1 {
        font-size: 2rem;
    }
}

.certification-badge:hover {
    transform: translateY(-2px);
    background-color: #f3f4f6;
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.1);
}

#myBtn {
    position: fixed;
    bottom: 20px;
    right: 30px;
    z-index: 99;
    border: none;
    outline: none;
    background-color: #555;
    cursor: pointer;
    border-radius: 10px;
    width: 50px;
    height: 50px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.3s ease;
}

#myBtn.show {
    opacity: 0.7;
    visibility: visible;
    transform: translateY(0);
}

#myBtn:hover {
    background-color: #333;
    opacity: 1;
}

#myBtn .arrow-up {
    border: solid #fff;
    border-width: 0 4px 4px 0;
    display: inline-block;
    padding: 6px;
    transform: rotate(-135deg);
    margin-top: 16px;
}