:root {
    --net-bg: #f0f2f5;
    --net-text: #2c3e50;
    --net-primary: #3498db; /* Network Blue */
    --net-secondary: #2ecc71; /* Connection Green */
    --net-card: #ffffff;
    --net-border: #bdc3c7;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    background-color: var(--net-bg); color: var(--net-text);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    background-image: linear-gradient(var(--net-border) 1px, transparent 1px),
                      linear-gradient(90deg, var(--net-border) 1px, transparent 1px);
    background-size: 50px 50px;
    background-attachment: fixed;
}

.net-container { max-width: 1000px; margin: 0 auto; padding: 0 30px; background: rgba(255,255,255,0.9); box-shadow: 0 0 20px rgba(0,0,0,0.05); min-height: 100vh;}

/* Header */
.net-header {
    display: flex; justify-content: space-between; align-items: center;
    padding: 30px 0; border-bottom: 2px solid var(--net-primary);
    margin-bottom: 50px;
}
.net-brand {
    font-size: 24px; font-weight: bold; color: var(--net-primary);
    display: flex; align-items: center; gap: 10px;
}
.net-brand::before { content: '🌐'; font-size: 26px; }
.net-nav { display: flex; gap: 20px; }
.net-nav a {
    color: #555; text-decoration: none; font-weight: 600;
    padding: 5px 15px; border-radius: 20px; transition: all 0.3s;
}
.net-nav a:hover, .net-nav a.active {
    background: var(--net-primary); color: #fff;
}

/* Hero */
.net-hero {
    text-align: center; margin-bottom: 60px; padding: 40px 20px;
    background: var(--net-card); border: 1px solid var(--net-border);
    border-radius: 10px; position: relative; overflow: hidden;
}
.net-hero::before {
    content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 5px;
    background: linear-gradient(90deg, var(--net-primary), var(--net-secondary));
}
.net-hero h1 { font-size: 36px; color: #2c3e50; margin-bottom: 20px; }
.net-hero p { font-size: 16px; color: #7f8c8d; max-width: 700px; margin: 0 auto 30px;}

.btn-net {
    display: inline-block; padding: 12px 30px; font-size: 16px; font-weight: bold;
    color: #fff; background: var(--net-primary); border-radius: 5px;
    text-decoration: none; transition: background 0.3s;
    box-shadow: 0 4px 6px rgba(52, 152, 219, 0.3);
}
.btn-net:hover { background: #2980b9; }

/* Diagnostic Tools */
.net-tools { margin-bottom: 80px; }
.t-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 30px; }
.t-card {
    background: var(--net-card); padding: 30px; border-radius: 8px;
    border: 1px solid var(--net-border); display: flex; gap: 20px;
    align-items: flex-start; transition: transform 0.2s;
}
.t-card:hover { transform: translateY(-5px); box-shadow: 0 10px 20px rgba(0,0,0,0.05); }
.t-icon {
    font-size: 30px; color: var(--net-secondary); background: rgba(46, 204, 113, 0.1);
    width: 60px; height: 60px; display: flex; align-items: center; justify-content: center;
    border-radius: 50%; flex-shrink: 0;
}
.t-content h3 { font-size: 18px; color: #2c3e50; margin-bottom: 10px;}
.t-content p { font-size: 14px; color: #7f8c8d;}

/* FAQ */
.net-faq { margin-bottom: 60px; }
.net-faq h2 { font-size: 24px; color: var(--net-primary); margin-bottom: 30px; border-bottom: 1px solid var(--net-border); padding-bottom: 10px;}
.n-faq-item { margin-bottom: 25px; }
.n-fq { font-weight: bold; color: #34495e; font-size: 16px; margin-bottom: 8px; display: flex; align-items: center; gap: 10px;}
.n-fq::before { content: 'Q:'; color: var(--net-primary); }
.n-fa { color: #555; font-size: 14px; padding-left: 25px;}

footer {
    text-align: center; padding: 30px 0; color: #95a5a6; font-size: 13px;
    border-top: 1px solid var(--net-border); margin-top: 40px;
}

@media (max-width: 768px) {
    .t-grid { grid-template-columns: 1fr; }
    .net-header { flex-direction: column; gap: 15px; }
}