.longtone-pro {
    --lt-ink: #23364b;
    --lt-muted: #5d6d7e;
    --lt-line: #dfe6ee;
    --lt-soft: #f5f8fc;
    --lt-accent: #356c9f;
    max-width: 1080px;
    margin: 38px auto;
    color: var(--lt-ink);
    font-size: 1rem;
    line-height: 1.75;
}
.longtone-pro * { box-sizing: border-box; }
.longtone-pro h2,
.longtone-pro h3 { color: var(--lt-ink); line-height: 1.3; }
.longtone-pro h2 { margin: 0 0 16px; font-size: clamp(1.45rem, 2.4vw, 2rem); }
.longtone-pro h3 { margin: 22px 0 9px; font-size: 1.15rem; }
.longtone-pro p { margin: 0 0 15px; }
.longtone-pro__hero {
    padding: clamp(24px, 5vw, 48px);
    border: 1px solid var(--lt-line);
    border-radius: 22px;
    background: linear-gradient(145deg, #f5f9ff, #fff 75%);
}
.longtone-pro__eyebrow {
    color: var(--lt-accent);
    font-size: .78rem;
    font-weight: 800;
    letter-spacing: .09em;
}
.longtone-pro__hero h2 { font-size: clamp(1.8rem, 4vw, 2.65rem); }
.longtone-pro__lead { max-width: 820px; font-size: 1.08rem; }
.longtone-pro__chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 22px; }
.longtone-pro__chips span {
    padding: 6px 12px;
    border: 1px solid var(--lt-line);
    border-radius: 999px;
    background: #fff;
    font-size: .85rem;
}
.longtone-pro__nav,
.longtone-pro__section,
.longtone-pro__footer {
    margin-top: 24px;
    padding: clamp(20px, 4vw, 34px);
    border: 1px solid var(--lt-line);
    border-radius: 18px;
    background: #fff;
}
.longtone-pro__nav { background: var(--lt-soft); }
.longtone-pro__nav ol { margin: 0; padding-left: 24px; columns: 2; column-gap: 34px; }
.longtone-pro__nav li { margin: 5px 0; break-inside: avoid; }
.longtone-pro a { color: #245f93; text-underline-offset: 3px; }
.longtone-pro__grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; margin: 22px 0; }
.longtone-pro__card { padding: 20px; border: 1px solid var(--lt-line); border-radius: 14px; background: #fff; }
.longtone-pro__card h3 { margin-top: 0; }
.longtone-pro__card p { margin-bottom: 0; }
.longtone-pro__figure { margin: 26px 0 8px; padding: 14px; border: 1px solid var(--lt-line); border-radius: 14px; background: var(--lt-soft); }
.longtone-pro__figure img { display: block; width: 100%; height: auto; }
.longtone-pro__figure figcaption { margin-top: 10px; color: var(--lt-muted); font-size: .9rem; }
.longtone-pro__steps { padding-left: 25px; }
.longtone-pro__steps li { margin: 9px 0; padding-left: 4px; }
.longtone-pro__note { margin-top: 22px; padding: 17px 20px; border-left: 4px solid #6e93b8; border-radius: 0 12px 12px 0; background: #f3f7fb; }
.longtone-pro__table-wrap { width: 100%; overflow-x: auto; margin: 20px 0; }
.longtone-pro table { width: 100%; border-collapse: collapse; min-width: 620px; }
.longtone-pro th, .longtone-pro td { padding: 12px 14px; border: 1px solid var(--lt-line); text-align: left; vertical-align: top; }
.longtone-pro th { background: var(--lt-soft); font-weight: 750; }
.longtone-pro__timeline { display: grid; gap: 12px; margin: 22px 0; }
.longtone-pro__timeline article { display: grid; grid-template-columns: 90px 1fr; gap: 16px; padding: 15px; border: 1px solid var(--lt-line); border-radius: 12px; }
.longtone-pro__timeline article > span { color: var(--lt-accent); font-weight: 800; }
.longtone-pro__timeline h3 { margin: 0 0 4px; }
.longtone-pro__timeline p { margin: 0; }
.longtone-pro__checklist { padding-left: 23px; }
.longtone-pro__checklist li { margin: 8px 0; }
.longtone-pro__footer { background: var(--lt-soft); }
@media (max-width: 700px) {
    .longtone-pro { margin: 24px auto; font-size: .97rem; }
    .longtone-pro__grid { grid-template-columns: 1fr; }
    .longtone-pro__nav ol { columns: 1; }
    .longtone-pro__timeline article { grid-template-columns: 1fr; gap: 4px; }
    .longtone-pro__hero, .longtone-pro__section, .longtone-pro__nav, .longtone-pro__footer { padding: 20px; border-radius: 14px; }
}