:root {
    --dos-bg: #0000aa;
    --dos-text: #aaaaaa;
    --dos-highlight: #ffffff;
    --dos-border: #aaaaaa;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    background-color: var(--dos-bg); color: var(--dos-text);
    font-family: 'Perfect DOS VGA 437', 'Courier New', Courier, monospace;
    font-size: 16px; line-height: 1.2;
    padding: 20px;
}
a { text-decoration: none; color: inherit; }
::selection { background: var(--dos-highlight); color: var(--dos-bg); }

.dos-container { max-width: 800px; margin: 0 auto; }

/* DOS Window */
.dos-window {
    border: 2px solid var(--dos-border);
    border-style: double;
    padding: 2px; margin-bottom: 20px;
}
.dos-title {
    background: var(--dos-border); color: var(--dos-bg);
    text-align: center; font-weight: bold; padding: 2px 0;
    margin-bottom: 10px;
}

/* Header */
.dos-header { display: flex; justify-content: space-between; margin-bottom: 20px; }
.dos-brand { font-weight: bold; color: var(--dos-highlight); }
.dos-nav { display: flex; gap: 15px; }
.dos-nav a { padding: 0 5px; }
.dos-nav a:hover, .dos-nav a.active { background: var(--dos-highlight); color: var(--dos-bg); }

/* Hero */
.dos-hero { text-align: center; margin-bottom: 30px; padding: 20px 0; }
.dos-hero h1 { font-size: 24px; color: var(--dos-highlight); margin-bottom: 15px; }
.dos-hero p { margin-bottom: 20px; }
.dos-btn {
    display: inline-block; background: var(--dos-highlight); color: var(--dos-bg);
    padding: 5px 15px; font-weight: bold; margin: 0 10px; cursor: pointer;
}
.dos-btn:hover { background: var(--dos-text); }
.dos-btn-outline {
    display: inline-block; border: 1px solid var(--dos-highlight); color: var(--dos-highlight);
    padding: 4px 14px; font-weight: bold; margin: 0 10px; cursor: pointer;
}
.dos-btn-outline:hover { background: var(--dos-highlight); color: var(--dos-bg); }

/* Stats */
.dos-stats { display: flex; justify-content: space-between; margin-bottom: 30px; }
.ds-item { text-align: center; flex: 1; }
.ds-val { font-size: 20px; color: var(--dos-highlight); font-weight: bold; }
.ds-lbl { font-size: 14px; }

/* Grid */
.dos-grid { display: grid; grid-template-columns: 1fr; gap: 20px; margin-bottom: 30px; }
.dg-card { border: 1px solid var(--dos-border); padding: 15px; }
.dg-card h3 { color: var(--dos-highlight); margin-bottom: 10px; }
.dg-card p { font-size: 14px; }

/* Nodes */
.dos-nodes { margin-bottom: 30px; }
.dos-nodes h2 { color: var(--dos-highlight); margin-bottom: 10px; text-align: center; }
.node-row { display: flex; justify-content: space-between; padding: 5px 10px; }
.node-row:nth-child(even) { background: rgba(170, 170, 170, 0.1); }

/* FAQ */
.dos-faq { margin-bottom: 30px; }
.dos-faq h2 { color: var(--dos-highlight); margin-bottom: 10px; text-align: center; }
.faq-q { color: var(--dos-highlight); margin-bottom: 5px; }
.faq-q::before { content: "Q: "; }
.faq-a { margin-bottom: 15px; padding-left: 20px; }
.faq-a::before { content: "A: "; margin-left: -20px; }

.dos-cursor { display: inline-block; width: 10px; height: 2px; background: var(--dos-highlight); animation: blink 1s step-end infinite; }
@keyframes blink { 0%, 100% { opacity: 1; } 50% { opacity: 0; } }

footer { text-align: center; margin-top: 20px; font-size: 12px; }

@media (min-width: 768px) {
    .dos-grid { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 600px) {
    .dos-header { flex-direction: column; align-items: center; gap: 10px; }
    .dos-stats { flex-direction: column; gap: 15px; }
}