:root {
    --primary-color: #2c3e50;     
    --secondary-color: #34495e;
    --accent-color: #3498db;
    --text-color: #252525;
    --bg-color: #ffffff;
    --light-bg: #f4f6f7;
    --border-color: #bdc3c7;
}
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
}

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

header {
    background-color: rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid rgba(100, 255, 218, 0.1);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.2);
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 0;
}


.logo {
    text-align: left;
}

.logo img {
    filter: brightness(1.2);
}


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

.nav-links .dropdown {
    position: relative;
}

.nav-links a {
    color: var(--text-color);
    text-decoration: none;
    padding: 5px 15px;
    border-radius: 4px;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--accent-color);
    transition: width 0.3s ease;
}

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

.nav-links a:hover::after {
    width: 70%;
}

.nav-links a.active {
    background-color: rgba(5, 194, 201, 0.1);
    color: var(--accent-color);
}

.nav-links a.active::after {
    width: 70%;
}

.dropdown-content {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background-color: var(--light-bg);
    min-width: 160px;
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2);
    z-index: 1;
    border-radius: 4px;
    border: 1px solid rgba(100, 255, 218, 0.1);
    margin-top: 5px;
}

.dropdown-content a {
    color: var(--text-color);
    padding: 12px 16px;
    text-decoration: none;
    display: block;
    transition: all 0.3s ease;
}

.dropdown-content a:hover {
    background-color: rgba(5, 194, 201, 0.1);
    color: var(--accent-color);
}

.dropdown:hover .dropdown-content {
    display: block;
    animation: fadeIn 0.3s ease;
}


@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Animation */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* Tech Pattern Background */
.tech-pattern {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image:
            radial-gradient(rgba(5, 194, 201, 0.1) 1px, transparent 1px),
            radial-gradient(rgba(100, 255, 218, 0.05) 1px, transparent 1px);
    background-size: 40px 40px, 20px 20px;
    background-position: 0 0, 20px 20px;
    z-index: -1;
    opacity: 0.3;
}

/* Particle effect */
#particles-js {
    position: fixed;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    z-index: -1;
}