:root {
    --flat-bg: #f4f7f6;
    --flat-text: #2c3e50;
    --flat-primary: #3498db;
    --flat-secondary: #e74c3c;
    --flat-accent: #f1c40f;
    --flat-surface: #ffffff;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    background-color: var(--flat-bg); color: var(--flat-text);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
}
a { text-decoration: none; color: inherit; }

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

/* Header */
.flat-header {
    display: flex; justify-content: space-between; align-items: center;
    padding: 20px 0; margin-bottom: 40px;
}
.flat-brand {
    font-size: 28px; font-weight: 800; color: var(--flat-primary);
    display: flex; align-items: center; gap: 10px;
}
.flat-brand::before {
    content: ''; display: inline-block; width: 30px; height: 30px;
    background: var(--flat-secondary); border-radius: 50%;
}
.flat-nav { display: flex; gap: 30px; }
.flat-nav a {
    font-weight: 600; color: #7f8c8d; transition: color 0.2s;
}
.flat-nav a:hover, .flat-nav a.active { color: var(--flat-primary); }

/* Hero */
.flat-hero {
    display: flex; align-items: center; justify-content: space-between;
    background: var(--flat-surface); border-radius: 20px; padding: 60px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05); margin-bottom: 60px;
}
.hero-text { flex: 1; padding-right: 40px;}
.flat-hero h1 { font-size: 48px; font-weight: 800; margin-bottom: 20px; color: var(--flat-text); line-height: 1.2;}
.flat-hero p { font-size: 18px; color: #7f8c8d; margin-bottom: 40px;}
.hero-img {
    flex: 1; min-height: 300px; background: #ecf0f1; border-radius: 20px;
    position: relative; overflow: hidden; display: flex; align-items: center; justify-content: center;
}
.hero-img::before {
    content: ''; position: absolute; width: 150px; height: 150px; background: var(--flat-accent);
    border-radius: 50%; top: -50px; right: -50px;
}
.hero-img::after {
    content: ''; position: absolute; width: 100px; height: 100px; background: var(--flat-primary);
    border-radius: 50%; bottom: -30px; left: -30px;
}
.btn-flat {
    display: inline-block; padding: 15px 35px; font-size: 16px; font-weight: 700;
    color: #fff; background: var(--flat-primary); border-radius: 8px;
    transition: all 0.2s; margin-right: 15px; border: none; cursor: pointer;
}
.btn-flat:hover { background: #2980b9; transform: translateY(-2px); box-shadow: 0 5px 15px rgba(52, 152, 219, 0.3);}
.btn-flat-outline {
    display: inline-block; padding: 13px 33px; font-size: 16px; font-weight: 700;
    color: var(--flat-primary); background: transparent; border-radius: 8px;
    border: 2px solid var(--flat-primary); transition: all 0.2s;
}
.btn-flat-outline:hover { background: var(--flat-primary); color: #fff;}

/* Stats */
.flat-stats {
    display: flex; justify-content: space-between; margin-bottom: 60px;
}
.fs-item {
    flex: 1; text-align: center; padding: 30px; background: var(--flat-surface);
    border-radius: 15px; margin: 0 10px; box-shadow: 0 5px 15px rgba(0,0,0,0.03);
}
.fs-val { font-size: 36px; font-weight: 800; color: var(--flat-secondary); margin-bottom: 5px;}
.fs-lbl { font-size: 14px; font-weight: 600; color: #95a5a6; text-transform: uppercase;}

/* Grid */
.flat-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; margin-bottom: 60px;}
.fg-card {
    background: var(--flat-surface); padding: 40px 30px; border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.03); transition: transform 0.2s;
}
.fg-card:hover { transform: translateY(-5px); box-shadow: 0 10px 25px rgba(0,0,0,0.08);}
.fg-icon {
    width: 60px; height: 60px; background: #e8f4f8; border-radius: 12px;
    display: flex; align-items: center; justify-content: center;
    font-size: 28px; color: var(--flat-primary); margin-bottom: 20px;
}
.fg-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 15px;}
.fg-card p { font-size: 15px; color: #7f8c8d;}

/* Nodes */
.flat-nodes {
    background: var(--flat-surface); padding: 50px; border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05); margin-bottom: 60px;
}
.flat-nodes h2 { font-size: 32px; font-weight: 800; margin-bottom: 30px; text-align: center;}
.node-list { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 20px;}
.node-item {
    background: var(--flat-bg); padding: 15px 20px; border-radius: 10px;
    display: flex; justify-content: space-between; align-items: center;
    font-weight: 600;
}
.node-item span:last-child { color: var(--flat-primary); font-size: 14px;}

/* FAQ */
.flat-faq { margin-bottom: 60px;}
.flat-faq h2 { font-size: 32px; font-weight: 800; margin-bottom: 40px; text-align: center;}
.faq-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 30px;}
.faq-box {
    background: var(--flat-surface); padding: 30px; border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.03);
}
.faq-q { font-size: 18px; font-weight: 700; color: var(--flat-text); margin-bottom: 10px;}
.faq-a { font-size: 15px; color: #7f8c8d;}

footer { text-align: center; padding: 30px; color: #95a5a6; font-size: 14px;}

@media (max-width: 900px) {
    .flat-header { flex-direction: column; gap: 20px; }
    .flat-hero { flex-direction: column; padding: 40px 20px;}
    .hero-text { padding-right: 0; margin-bottom: 40px; text-align: center;}
    .hero-img { width: 100%; min-height: 200px;}
    .flat-stats { flex-wrap: wrap; margin: 0 -10px 40px;}
    .fs-item { min-width: 40%; margin-bottom: 20px;}
    .flat-grid { grid-template-columns: 1fr; }
    .faq-grid { grid-template-columns: 1fr; }
    .btn-flat, .btn-flat-outline { display: block; margin: 10px auto; width: 100%;}
}