*, *::before, *::after { box-sizing: border-box; padding: 0; margin: 0; }

body {
    font-family: "Arimo", sans-serif;
    background: #F6F7F8;
    color: #000;
    -webkit-font-smoothing: antialiased;
}

:root {
    --w: #fff;
    --bg: #F6F7F8;
    --b: #000;
    --acc: #217CFC;
    --shadow: 0 8px 44px rgba(0,0,0,0.08);
}

a { color: inherit; text-decoration: none; cursor: pointer; }
img { max-width: 100%; height: auto; display: block; }

/* ─ Page header ─ */
.page-header {
    position: sticky;
    top: 0;
    z-index: 10;
    background: rgba(246, 247, 248, 0.88);
    backdrop-filter: blur(24px) saturate(180%);
    -webkit-backdrop-filter: blur(24px) saturate(180%);
    border-bottom: 1px solid rgba(0,0,0,0.06);
    padding: 1rem 2rem;
    display: flex;
    justify-content: center;
}

.page-header .inner {
    max-width: 1400px;
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
}

.page-header img {
    height: 1.5rem;
    filter: brightness(0);
}

.back-link {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.88rem;
    font-weight: 600;
    color: rgba(0,0,0,0.5);
    letter-spacing: -0.01em;
    transition: color 0.2s;
}

.back-link:hover { color: var(--b); }

.back-link svg { width: 14px; height: 14px; }

/* ─ Article ─ */
article {
    max-width: 740px;
    margin: 0 auto;
    padding: 4.5rem 2rem 7rem;
}

.article-tag {
    display: inline-block;
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--acc);
    margin-bottom: 1.25rem;
}

article h1 {
    font-size: 2.5rem;
    letter-spacing: -0.04em;
    line-height: 1.1;
    color: var(--b);
    margin-bottom: 1.25rem;
}

.article-meta {
    font-size: 0.82rem;
    color: rgba(0,0,0,0.38);
    letter-spacing: -0.01em;
    padding-bottom: 2.5rem;
    margin-bottom: 2.5rem;
    border-bottom: 1px solid rgba(0,0,0,0.08);
}

.article-lead {
    font-size: 1.15rem;
    line-height: 1.72;
    color: rgba(0,0,0,0.68);
    letter-spacing: -0.015em;
    margin-bottom: 2.5rem;
}

article h2 {
    font-size: 1.35rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    color: var(--b);
    margin: 2.8rem 0 0.9rem;
}

article p {
    font-size: 1rem;
    line-height: 1.78;
    color: rgba(0,0,0,0.65);
    letter-spacing: -0.01em;
    margin-bottom: 1.1rem;
}

article ul, article ol {
    margin: 0.8rem 0 1.3rem 1.4rem;
}

article li {
    font-size: 1rem;
    line-height: 1.78;
    color: rgba(0,0,0,0.65);
    letter-spacing: -0.01em;
    margin-bottom: 0.45rem;
}

article strong {
    font-weight: 700;
    color: var(--b);
}

.article-tip {
    background: var(--w);
    border-left: 3px solid var(--acc);
    border-radius: 0 1rem 1rem 0;
    padding: 1.2rem 1.6rem;
    margin: 1.8rem 0;
    box-shadow: var(--shadow);
}

.article-tip p {
    margin: 0;
    color: rgba(0,0,0,0.7);
}

.article-cta {
    margin-top: 4rem;
    background: var(--b);
    border-radius: 2rem;
    padding: 3rem;
    text-align: center;
    color: var(--w);
}

.article-cta h3 {
    font-size: 1.6rem;
    letter-spacing: -0.035em;
    margin-bottom: 0.65rem;
}

.article-cta p {
    color: rgba(255,255,255,0.5);
    margin-bottom: 2rem;
    font-size: 0.95rem;
}

.article-cta a {
    display: inline-block;
    background: var(--acc);
    color: var(--w);
    padding: 0.9rem 2.8rem;
    border-radius: 10rem;
    font-weight: 600;
    font-size: 0.95rem;
    letter-spacing: -0.01em;
    transition: opacity 0.2s;
}

.article-cta a:hover { opacity: 0.85; }

/* ─ Footer ─ */
.page-footer {
    background: var(--b);
    padding: 3.5rem 2rem 2rem;
    display: flex;
    justify-content: center;
}

.page-footer .inner {
    max-width: 1400px;
    width: 100%;
}

.page-footer-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-bottom: 2rem;
    border-bottom: 1px solid rgba(255,255,255,0.08);
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    gap: 1.5rem;
}

.page-footer img {
    height: 1.5rem;
    filter: brightness(0) invert(1);
}

.page-footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem 1.8rem;
}

.page-footer-links a {
    font-size: 0.84rem;
    color: rgba(255,255,255,0.45);
    letter-spacing: -0.01em;
    transition: color 0.2s;
}

.page-footer-links a:hover { color: #fff; }

.page-footer-bottom {
    display: flex;
    flex-wrap: wrap;
    gap: 0.4rem 1.8rem;
    font-size: 0.73rem;
    color: rgba(255,255,255,0.25);
    letter-spacing: -0.01em;
    align-items: center;
}

.footer-age {
    background: rgba(255,255,255,0.07);
    color: rgba(255,255,255,0.38);
    padding: 0.18rem 0.5rem;
    border-radius: 0.3rem;
    font-weight: 700;
    font-size: 0.68rem;
    letter-spacing: 0.03em;
}

/* ─ Mobile ─ */
@media (max-width: 768px) {
    .page-header {
        padding: 0.85rem 1.2rem;
        padding-top: calc(0.85rem + env(safe-area-inset-top, 0px));
    }
    .page-header .inner { gap: .75rem; }
    .page-header img { height: 1.35rem; }
    .back-link { font-size: 0.82rem; }
    .back-link svg { width: 13px; height: 13px; }

    article {
        padding: 2.5rem 1.2rem 4rem;
    }
    .article-tag { font-size: 0.68rem; margin-bottom: 1rem; }
    article h1 {
        font-size: 1.9rem;
        letter-spacing: -0.03em;
        line-height: 1.15;
        margin-bottom: 1rem;
    }
    .article-meta {
        padding-bottom: 1.5rem;
        margin-bottom: 1.5rem;
        font-size: 0.78rem;
    }
    .article-lead {
        font-size: 1.02rem;
        line-height: 1.65;
        margin-bottom: 2rem;
    }
    article h2 {
        font-size: 1.2rem;
        margin: 2rem 0 0.7rem;
    }
    article p, article li {
        font-size: 0.96rem;
        line-height: 1.72;
    }
    article ul, article ol { margin-left: 1.1rem; }
    .article-tip {
        padding: 1rem 1.2rem;
        border-radius: 0 0.85rem 0.85rem 0;
        margin: 1.4rem 0;
    }
    .article-cta {
        margin-top: 2.5rem;
        padding: 2rem 1.5rem;
        border-radius: 1.5rem;
    }
    .article-cta h3 { font-size: 1.25rem; }
    .article-cta p { font-size: 0.88rem; margin-bottom: 1.5rem; }
    .article-cta a {
        padding: 0.8rem 2rem;
        font-size: 0.9rem;
        width: 100%;
        text-align: center;
        box-sizing: border-box;
    }

    .page-footer {
        padding: 2.5rem 1.2rem 1.5rem;
        padding-bottom: calc(1.5rem + env(safe-area-inset-bottom, 0px));
    }
    .page-footer-top {
        flex-direction: column;
        align-items: flex-start;
        gap: 1.25rem;
        padding-bottom: 1.5rem;
        margin-bottom: 1.25rem;
    }
    .page-footer-links { gap: 0.3rem 1.4rem; }
    .page-footer-bottom { font-size: 0.7rem; gap: 0.35rem 1.2rem; }
}

@media (max-width: 480px) {
    article h1 { font-size: 1.55rem; }
    .article-lead { font-size: 0.97rem; }
    .article-cta { padding: 1.5rem 1rem; }
    .article-cta h3 { font-size: 1.15rem; }
}