* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
    background: #f5f7fa;
    color: #222;
    line-height: 1.6;
}

a {
    color: #222;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

.container {
    width: min(1100px, calc(100% - 32px));
    margin: 0 auto;
}

header {
    background: #fff;
    border-bottom: 1px solid #e5e7eb;
    position: sticky;
    top: 0;
    z-index: 10;
}

.header-inner {
    min-height: 64px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.logo {
    font-size: 21px;
    font-weight: 700;
}

nav {
    display: flex;
    flex-wrap: wrap;
    gap: 18px;
}

nav a {
    font-size: 14px;
    color: #444;
}

.hero {
    padding: 64px 0 42px;
    text-align: center;
}

.hero h1 {
    margin: 0 0 14px;
    font-size: clamp(34px, 6vw, 52px);
    line-height: 1.15;
}

.hero p {
    max-width: 680px;
    margin: 0 auto;
    color: #555;
    font-size: 18px;
}

.section {
    padding: 28px 0;
}

.card {
    background: #fff;
    border: 1px solid #e5e7eb;
    border-radius: 12px;
    padding: 28px;
    margin-bottom: 24px;
}

h2 {
    margin-top: 0;
    font-size: 28px;
}

h3 {
    font-size: 21px;
    margin-top: 28px;
}

.table-wrap {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
    min-width: 620px;
}

th,
td {
    padding: 13px 14px;
    border-bottom: 1px solid #e5e7eb;
    text-align: left;
}

th {
    background: #f8fafc;
    font-weight: 700;
}

.size-link {
    font-weight: 700;
}

.note {
    background: #f8fafc;
    border-left: 4px solid #222;
    padding: 16px 18px;
    margin: 20px 0;
}

.ad-box {
    min-height: 90px;
    border: 1px dashed #cbd5e1;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #94a3b8;
    margin: 28px 0;
}

.grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.tool-card {
    display: block;
    background: #fff;
    border: 1px solid #e5e7eb;
    border-radius: 10px;
    padding: 20px;
}

.tool-card strong {
    display: block;
    margin-bottom: 6px;
}

.faq-item {
    padding: 18px 0;
    border-bottom: 1px solid #e5e7eb;
}

.faq-item:last-child {
    border-bottom: 0;
}

footer {
    margin-top: 48px;
    background: #fff;
    border-top: 1px solid #e5e7eb;
    padding: 30px 0;
}

.footer-inner {
    display: flex;
    justify-content: space-between;
    gap: 20px;
    flex-wrap: wrap;
}

.footer-links {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.small {
    color: #666;
    font-size: 14px;
}

@media (max-width: 768px) {
    .header-inner {
        align-items: flex-start;
        flex-direction: column;
        padding: 14px 0;
    }

    nav {
        gap: 12px;
    }

    .hero {
        padding: 46px 0 30px;
    }

    .card {
        padding: 20px;
    }

    .grid {
        grid-template-columns: 1fr;
    }
}