:root {
    --bg: #f7f9fc;
    --card: #ffffff;
    --text: #13233a;
    --muted: #5f7188;
    --primary: #0f3d8c;
    --primary-dark: #0c2f6a;
    --accent: #1f6fff;
    --border: #dbe4f0;
    --success: #eaf4ff;
    --shadow: 0 12px 35px rgba(15, 61, 140, 0.12);
    --max: 1180px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: Inter, Arial, Helvetica, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.45;
}

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

.container {
    width: min(var(--max), calc(100% - 32px));
    margin: 0 auto;
}

header {
    position: sticky;
    top: 0;
    z-index: 20;
    backdrop-filter: blur(10px);
    background: rgba(247, 249, 252, 0.82);
    border-bottom: 1px solid rgba(219, 228, 240, 0.7);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
    min-height: 76px;
}

.logo {
    font-weight: 800;
    letter-spacing: 0.2px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 24px;
    color: var(--muted);
    font-weight: 600;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    min-height: 52px;
    padding: 0 22px;
    border-radius: 14px;
    border: 0;
    font-weight: 700;
    cursor: pointer;
    transition: 0.2s ease;
}

.btn-primary {
    background: var(--primary);
    color: #fff;
    box-shadow: var(--shadow);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.btn-secondary {
    background: #fff;
    color: var(--primary);
    border: 1px solid var(--border);
}

.full-width {
    width: 100%;
}

.badge {
    display: inline-block;
    padding: 8px 12px;
    border-radius: 999px;
    background: var(--success);
    color: var(--primary);
    font-size: 14px;
    font-weight: 700;
}

.hero {
    padding: 54px 0 42px;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1.05fr 0.95fr;
    gap: 34px;
    align-items: center;
}

.hero h1 {
    margin: 14px 0 14px;
    font-size: clamp(34px, 5vw, 62px);
    line-height: 1.02;
    letter-spacing: -1.4px;
}

.hero p.lead {
    margin: 0 0 24px;
    color: var(--muted);
    font-size: 19px;
    max-width: 640px;
}

.hero-actions {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    margin-bottom: 20px;
}

.hero-points {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 12px;
    margin-top: 26px;
}

.mini-card,
.card,
.sim-card,
details {
    background: var(--card);
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.mini-card {
    border-radius: 16px;
    padding: 16px;
}

.mini-card strong {
    display: block;
    font-size: 18px;
    margin-bottom: 6px;
}

.muted {
    color: var(--muted);
}

.hero-side-card,
.sim-card {
    border-radius: 24px;
    padding: 26px;
}

.sim-card h3 {
    margin: 0 0 8px;
    font-size: 28px;
}

.sim-card p {
    margin: 0 0 18px;
    color: var(--muted);
}

.rule-box {
    display: grid;
    gap: 12px;
    margin: 18px 0 22px;
}

.rule-line {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    padding: 14px 16px;
    border: 1px solid var(--border);
    border-radius: 16px;
    background: #fbfdff;
}

section {
    padding: 34px 0;
}

.section-head {
    text-align: center;
    max-width: 760px;
    margin: 0 auto 28px;
}

.section-head h2 {
    margin: 0 0 10px;
    font-size: clamp(28px, 4vw, 42px);
    line-height: 1.08;
    letter-spacing: -0.8px;
}

.section-head p {
    margin: 0;
    color: var(--muted);
    font-size: 18px;
}

.steps,
.faq-grid,
.levels-grid {
    display: grid;
    gap: 18px;
}

.steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.levels-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.faq-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.card {
    border-radius: 20px;
    padding: 22px;
}

.step-no {
    width: 40px;
    height: 40px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: var(--success);
    color: var(--primary);
    border-radius: 12px;
    font-weight: 800;
    margin-bottom: 14px;
}

.card h3,
.card h4 {
    margin: 0 0 8px;
    font-size: 22px;
}

.card p {
    margin: 0;
    color: var(--muted);
}

.level-card {
    position: relative;
}

.level-badge {
    display: inline-block;
    margin-bottom: 12px;
    padding: 6px 10px;
    border-radius: 999px;
    background: var(--success);
    color: var(--primary);
    font-size: 13px;
    font-weight: 700;
}

.sim-layout {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
    margin-bottom: 18px;
}

.form-group {
    margin-bottom: 18px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 700;
}

.form-group select {
    width: 100%;
    min-height: 48px;
    border-radius: 14px;
    border: 1px solid var(--border);
    padding: 0 14px;
    font-size: 15px;
    background: #fff;
}

.result-panel {
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 16px;
    background: #fbfdff;
    margin-bottom: 12px;
}

.result-label {
    display: block;
    color: var(--muted);
    font-size: 14px;
    margin-bottom: 6px;
}

.helper-text {
    margin-top: 12px;
    color: var(--muted);
}

.calculator-card {
    margin-top: 18px;
}

.sim-row {
    margin-bottom: 18px;
}

.sim-row label {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 10px;
    font-weight: 700;
}

input[type="range"] {
    width: 100%;
    accent-color: var(--primary);
}

.sim-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
    margin: 18px 0 20px;
}

.sim-box {
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 16px;
    background: #fbfdff;
}

.sim-box span {
    display: block;
    color: var(--muted);
    font-size: 14px;
    margin-bottom: 6px;
}

.sim-box strong {
    font-size: 24px;
}

details {
    border-radius: 16px;
    padding: 18px 18px 16px;
}

summary {
    list-style: none;
    cursor: pointer;
    font-weight: 700;
}

summary::-webkit-details-marker {
    display: none;
}

details p {
    margin: 12px 0 0;
    color: var(--muted);
}

.cta-band {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: white;
    border-radius: 28px;
    padding: 34px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    box-shadow: var(--shadow);
}

.cta-band h2 {
    margin: 0 0 8px;
    font-size: clamp(28px, 4vw, 44px);
}

.cta-band p {
    margin: 0;
    color: rgba(255, 255, 255, 0.85);
}

footer {
    padding: 28px 0 42px;
    color: var(--muted);
}

.footer-grid {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    padding-top: 22px;
    border-top: 1px solid var(--border);
    flex-wrap: wrap;
}

@media (max-width: 980px) {

    .hero-grid,
    .steps,
    .levels-grid,
    .faq-grid,
    .sim-layout {
        grid-template-columns: 1fr;
    }

    .hero-points,
    .sim-grid {
        grid-template-columns: 1fr 1fr;
    }

    .cta-band {
        flex-direction: column;
        align-items: flex-start;
    }

    .nav-links {
        display: none;
    }
}

@media (max-width: 640px) {
    .hero {
        padding-top: 30px;
    }

    .hero h1 {
        font-size: 38px;
    }

    .hero p.lead,
    .section-head p {
        font-size: 16px;
    }

    .hero-points,
    .sim-grid {
        grid-template-columns: 1fr;
    }

    .container {
        width: min(var(--max), calc(100% - 20px));
    }

    .sim-card,
    .card,
    .mini-card,
    .cta-band {
        padding: 20px;
    }
}