* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(180deg, #e8f4ff 0%, #f6fbff 100%);
    color: #0d2f4f;
}

.page-shell {
    display: grid;
    grid-template-columns: 280px minmax(0, 1fr);
    gap: 24px;
    max-width: 1120px;
    margin: 0 auto;
    padding: 32px 24px;
}

.sidebar-toggle {
    position: absolute;
    opacity: 0;
    pointer-events: none;
}

.hero-top {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 18px;
}

.sidebar-toggle-btn {
    width: 46px;
    height: 46px;
    border-radius: 16px;
    border: 1px solid rgba(15, 82, 167, 0.14);
    background: rgba(255, 255, 255, 0.9);
    box-shadow: 0 10px 24px rgba(15, 82, 167, 0.08);
    cursor: pointer;
    padding: 10px;
    transition: transform 0.2s ease, background-color 0.2s ease;
    display: inline-flex;
    flex-direction: column;
    justify-content: space-between;
}

.sidebar-toggle-btn span {
    display: block;
    width: 100%;
    height: 3px;
    border-radius: 999px;
    background: #0d2f4f;
}

.sidebar-backdrop {
    position: fixed;
    inset: 0;
    background: rgba(13, 47, 79, 0.3);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    z-index: 15;
    transition: opacity 0.25s ease, visibility 0.25s ease;
}

.sidebar {
    background: rgba(255, 255, 255, 0.85);
    border: 1px solid rgba(15, 82, 167, 0.12);
    border-radius: 22px;
    padding: 28px 22px;
    box-shadow: 0 20px 45px rgba(15, 82, 167, 0.08);
    display: flex;
    flex-direction: column;
    gap: 28px;
    min-height: fit-content;
}

.sidebar-brand {
    display: flex;
    align-items: center;
    gap: 16px;
}

.brand-mark {
    width: 54px;
    height: 54px;
    border-radius: 16px;
    display: grid;
    place-items: center;
    font-size: 1.65rem;
    font-weight: 700;
    color: #ffffff;
    background: linear-gradient(135deg, #1a5db3, #4386e0);
}

.sidebar-brand h2 {
    margin: 0;
    font-size: 1.35rem;
    color: #0a3d71;
}

.sidebar-brand p {
    margin: 4px 0 0;
    color: #4b6b8f;
    font-size: 0.95rem;
}

.sidebar-nav {
    display: grid;
    gap: 12px;
}

.sidebar-nav a {
    display: block;
    padding: 14px 16px;
    border-radius: 14px;
    color: #0d2f4f;
    text-decoration: none;
    background: rgba(15, 82, 167, 0.06);
    transition: transform 0.16s ease, background-color 0.16s ease;
}

.sidebar-nav a:hover {
    background: rgba(15, 82, 167, 0.12);
    transform: translateX(3px);
}

.sidebar-note {
    padding: 18px 16px;
    border-radius: 16px;
    background: #f1f8ff;
    color: #1d456d;
    font-size: 0.96rem;
    line-height: 1.6;
}

.hero {
    background: rgba(255, 255, 255, 0.82);
    border: 1px solid rgba(15, 82, 167, 0.15);
    border-radius: 18px;
    padding: 28px 24px;
    box-shadow: 0 18px 40px rgba(15, 82, 167, 0.1);
    text-align: center;
    margin-bottom: 24px;
}

.hero h1 {
    margin: 0;
    font-size: clamp(2.5rem, 4vw, 3.5rem);
    color: #0a3d71;
}

.hero-subtitle {
    margin: 14px auto 0;
    max-width: 720px;
    color: #275a90;
    font-size: 1rem;
    line-height: 1.6;
}

.info-card {
    background: rgba(255, 255, 255, 0.92);
    border: 1px solid rgba(15, 82, 167, 0.12);
    border-radius: 16px;
    padding: 22px 24px;
    margin-bottom: 20px;
}

.info-card h2 {
    margin-top: 0;
    margin-bottom: 12px;
    font-size: 1.4rem;
    color: #154575;
}

.info-card ul,
.info-card ol {
    margin: 0;
    padding-left: 1.3rem;
    color: #1b3b60;
}

.info-card li {
    margin-bottom: 0.75rem;
    line-height: 1.7;
}

.info-card li strong {
    color: #0d2f4f;
}

@media (max-width: 840px) {
    .page-shell {
        grid-template-columns: 1fr;
        padding: 24px 18px;
    }

    .sidebar {
        position: fixed;
        inset: 0 auto auto 0;
        width: min(280px, 80vw);
        max-width: 320px;
        height: 100vh;
        transform: translateX(-110%);
        transition: transform 0.25s ease;
        z-index: 20;
        margin: 0;
        border-radius: 0 24px 24px 0;
    }

    .sidebar-toggle:checked ~ .page-shell .sidebar {
        transform: translateX(0);
    }

    .sidebar-backdrop {
        display: block;
    }

    .sidebar-toggle:checked ~ .sidebar-backdrop {
        opacity: 1;
        visibility: visible;
        pointer-events: auto;
    }

    .sidebar {
        order: 0;
    }

    .sidebar-toggle-btn {
        display: inline-flex;
    }

    .hero {
        text-align: left;
    }

    .hero,
    .info-card,
    .sidebar {
        padding: 20px;
    }
}

@media (max-width: 620px) {
    .page-shell {
        padding: 20px 16px;
    }

    .hero,
    .info-card {
        padding: 20px;
    }
}

.site-header {
    background: rgba(255, 255, 255, 0.95);
    border-bottom: 1px solid rgba(15, 82, 167, 0.15);
    padding: 16px 24px;
    text-align: center;
    margin-bottom: 32px;
}

.navbar {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 1.25rem;
    flex-wrap: wrap;
}

.navbar a {
    color: #0d2f4f;
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s ease, transform 0.2s ease;
}

.navbar a:hover,
.navbar a:focus-visible {
    color: #0a3d71;
    transform: translateY(-1px);
}

@media (max-width: 620px) {
    .navbar {
        gap: 1rem;
    }
}