:root {
  --bk-ink: #17242a;
  --bk-muted: #5e6a70;
  --bk-brand: #103943;
  --bk-blue: #1d527b;
  --bk-accent: #ef6a3a;
  --bk-success: #26765a;
  --bk-line: #dfe7e8;
  --bk-soft: #f4f8f8;
  --bk-warm: #fff7f2;
  --bk-white: #fff;
}

html { scroll-behavior: smooth; }
.ddd-bk-page,
.ddd-bk-page * { box-sizing: border-box; }
.ddd-bk-page { color: var(--bk-ink); background: var(--bk-white); font-family: "Microsoft YaHei", "PingFang SC", sans-serif; }
.ddd-bk-container { width: min(1180px, calc(100% - 32px)); margin: 0 auto; }
.ddd-bk-eyebrow,
.ddd-bk-kicker { margin: 0 0 10px; color: var(--bk-accent); font-size: 14px; font-weight: 700; line-height: 22px; letter-spacing: 0; }

.ddd-bk-hero { padding: 66px 0 0; color: var(--bk-white); background: var(--bk-brand); }
.ddd-bk-hero h1 { max-width: 820px; margin: 0; color: var(--bk-white); font-size: 48px; line-height: 1.24; letter-spacing: 0; }
.ddd-bk-lead { max-width: 800px; margin: 18px 0 0; color: rgba(255,255,255,.78); font-size: 17px; line-height: 30px; }
.ddd-bk-hero-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; margin-top: 28px; }
.ddd-bk-primary,
.ddd-bk-secondary { display: inline-flex; min-height: 44px; align-items: center; justify-content: center; padding: 10px 21px; border: 1px solid var(--bk-accent); font-size: 14px; font-weight: 700; line-height: 22px; text-decoration: none; }
.ddd-bk-primary { color: var(--bk-white); background: var(--bk-accent); }
.ddd-bk-secondary { color: var(--bk-white); background: transparent; }
.ddd-bk-primary:hover,
.ddd-bk-primary:focus-visible { background: #d9582b; }
.ddd-bk-secondary:hover,
.ddd-bk-secondary:focus-visible { color: var(--bk-brand); background: var(--bk-white); border-color: var(--bk-white); }
.ddd-bk-hero-facts { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); margin: 46px 0 0; padding: 0; border-top: 1px solid rgba(255,255,255,.2); list-style: none; }
.ddd-bk-hero-facts li { min-width: 0; padding: 22px 24px 24px 0; }
.ddd-bk-hero-facts li + li { padding-left: 28px; border-left: 1px solid rgba(255,255,255,.2); }
.ddd-bk-hero-facts span,
.ddd-bk-hero-facts strong { display: block; }
.ddd-bk-hero-facts span { color: rgba(255,255,255,.58); font-size: 12px; line-height: 20px; }
.ddd-bk-hero-facts strong { margin-top: 5px; color: var(--bk-white); font-size: 14px; line-height: 24px; overflow-wrap: anywhere; }

.ddd-bk-section { padding: 72px 0; }
.ddd-bk-section-heading { max-width: 740px; }
.ddd-bk-section-heading h2,
.ddd-bk-special h2,
.ddd-bk-contact h2 { margin: 0; color: var(--bk-brand); font-size: 32px; line-height: 1.35; letter-spacing: 0; }
.ddd-bk-section-heading > p:last-child { margin: 14px 0 0; color: var(--bk-muted); font-size: 15px; line-height: 27px; }

.ddd-bk-before { background: var(--bk-white); }
.ddd-bk-check-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 0; margin: 34px 0 0; padding: 0; border-top: 1px solid var(--bk-line); border-left: 1px solid var(--bk-line); list-style: none; }
.ddd-bk-check-grid li { display: grid; grid-template-columns: 34px minmax(0, 1fr); gap: 14px; min-height: 158px; padding: 23px 21px; border-right: 1px solid var(--bk-line); border-bottom: 1px solid var(--bk-line); }
.ddd-bk-check-grid li > span { color: var(--bk-accent); font-size: 13px; font-weight: 700; line-height: 24px; }
.ddd-bk-check-grid strong { display: block; color: var(--bk-brand); font-size: 17px; line-height: 25px; }
.ddd-bk-check-grid p { margin: 8px 0 0; color: var(--bk-muted); font-size: 14px; line-height: 24px; }

.ddd-bk-onboarding { background: var(--bk-soft); }
.ddd-bk-onboarding-layout { display: grid; grid-template-columns: minmax(270px, .75fr) minmax(0, 1.25fr); gap: 76px; align-items: start; }
.ddd-bk-sticky-heading { position: sticky; top: 28px; }
.ddd-bk-onboarding-list { margin: 0; padding: 0; list-style: none; }
.ddd-bk-onboarding-list li { position: relative; display: grid; grid-template-columns: 46px minmax(0, 1fr); gap: 19px; padding-bottom: 28px; }
.ddd-bk-onboarding-list li:not(:last-child)::before { position: absolute; top: 46px; bottom: 0; left: 22px; width: 1px; background: #bfd0d3; content: ""; }
.ddd-bk-onboarding-list li > span { position: relative; z-index: 1; display: inline-flex; width: 46px; height: 46px; align-items: center; justify-content: center; color: var(--bk-white); background: var(--bk-blue); font-size: 15px; font-weight: 700; }
.ddd-bk-onboarding-list h3 { margin: 0; color: var(--bk-brand); font-size: 19px; line-height: 28px; }
.ddd-bk-onboarding-list p { margin: 7px 0 0; color: var(--bk-muted); font-size: 14px; line-height: 25px; }

#ddd-bk-monthly { scroll-margin-top: 20px; }
.ddd-bk-monthly { color: var(--bk-white); background: var(--bk-blue); }
.ddd-bk-heading-light h2 { color: var(--bk-white); }
.ddd-bk-heading-light > p:last-child { color: rgba(255,255,255,.72); }
.ddd-bk-monthly-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1px; margin: 36px 0 0; padding: 1px; background: rgba(255,255,255,.2); list-style: none; }
.ddd-bk-monthly-step { min-height: 205px; padding: 25px 23px; background: var(--bk-blue); }
.ddd-bk-monthly-step > span { display: block; color: #ffca85; font-size: 13px; font-weight: 700; line-height: 22px; }
.ddd-bk-monthly-step h3 { margin: 13px 0 0; color: var(--bk-white); font-size: 19px; line-height: 27px; }
.ddd-bk-monthly-step p { margin: 9px 0 0; color: rgba(255,255,255,.72); font-size: 14px; line-height: 25px; }

.ddd-bk-materials { background: var(--bk-white); }
.ddd-bk-material-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; margin-top: 34px; }
.ddd-bk-material-group { min-width: 0; padding: 25px 21px; border-top: 3px solid var(--bk-accent); background: var(--bk-soft); }
.ddd-bk-material-group h3 { margin: 0; color: var(--bk-brand); font-size: 18px; line-height: 27px; }
.ddd-bk-material-group ul { margin: 17px 0 0; padding: 0; list-style: none; }
.ddd-bk-material-group li { position: relative; padding: 8px 0 8px 15px; color: var(--bk-muted); border-top: 1px solid var(--bk-line); font-size: 13px; line-height: 23px; }
.ddd-bk-material-group li::before { position: absolute; top: 8px; left: 0; color: var(--bk-accent); content: "·"; font-weight: 700; }

.ddd-bk-result { background: var(--bk-soft); }
.ddd-bk-result-grid { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(320px, .9fr); gap: 50px; }
.ddd-bk-output-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0; margin: 29px 0 0; padding: 0; border-top: 1px solid var(--bk-line); border-left: 1px solid var(--bk-line); list-style: none; }
.ddd-bk-output-list li { min-height: 116px; padding: 20px; border-right: 1px solid var(--bk-line); border-bottom: 1px solid var(--bk-line); background: var(--bk-white); }
.ddd-bk-output-list strong,
.ddd-bk-output-list span { display: block; }
.ddd-bk-output-list strong { color: var(--bk-brand); font-size: 16px; line-height: 25px; }
.ddd-bk-output-list span { margin-top: 6px; color: var(--bk-muted); font-size: 13px; line-height: 23px; }
.ddd-bk-duty-panel { padding: 30px; color: var(--bk-white); background: var(--bk-brand); }
.ddd-bk-duty-panel .ddd-bk-section-heading h2 { color: var(--bk-white); font-size: 27px; }
.ddd-bk-duty-list { margin: 24px 0 0; padding: 0; list-style: none; }
.ddd-bk-duty-list li { position: relative; padding: 13px 0 13px 25px; color: rgba(255,255,255,.82); border-top: 1px solid rgba(255,255,255,.17); font-size: 14px; line-height: 25px; }
.ddd-bk-duty-list li::before { position: absolute; top: 16px; left: 0; width: 10px; height: 10px; border: 2px solid var(--bk-accent); content: ""; }

.ddd-bk-special { padding: 38px 0; color: var(--bk-ink); background: var(--bk-warm); border-top: 1px solid #f0ded5; border-bottom: 1px solid #f0ded5; }
.ddd-bk-special h2 { font-size: 27px; }
.ddd-bk-special > .ddd-bk-container > p:last-child { max-width: 930px; margin: 13px 0 0; color: var(--bk-muted); font-size: 14px; line-height: 26px; }

.ddd-bk-faq { background: var(--bk-white); }
.ddd-bk-faq-list { margin-top: 30px; border-top: 1px solid var(--bk-line); }
.ddd-bk-faq details { border-bottom: 1px solid var(--bk-line); }
.ddd-bk-faq summary { position: relative; padding: 22px 48px 22px 0; color: var(--bk-brand); font-size: 17px; font-weight: 700; line-height: 27px; cursor: pointer; list-style: none; }
.ddd-bk-faq summary::-webkit-details-marker { display: none; }
.ddd-bk-faq summary::after { position: absolute; top: 23px; right: 8px; color: var(--bk-accent); content: "+"; font-size: 24px; font-weight: 400; }
.ddd-bk-faq details[open] summary::after { content: "-"; }
.ddd-bk-faq details p { max-width: 900px; margin: -4px 0 22px; color: var(--bk-muted); font-size: 14px; line-height: 26px; }

.ddd-bk-contact { padding: 44px 0; color: var(--bk-white); background: var(--bk-brand); }
.ddd-bk-contact-layout { display: grid; grid-template-columns: minmax(0, 1fr) 190px; gap: 48px; align-items: center; }
.ddd-bk-contact h2 { color: var(--bk-white); }
.ddd-bk-contact p:not(.ddd-bk-kicker) { max-width: 720px; margin: 11px 0 0; color: rgba(255,255,255,.74); font-size: 14px; line-height: 25px; }
.ddd-bk-contact-phone { display: inline-block; margin-top: 16px; color: var(--bk-white); font-size: 27px; font-weight: 700; line-height: 35px; text-decoration: none; }
.ddd-bk-contact figure { margin: 0; text-align: center; }
.ddd-bk-contact img { display: block; width: 154px; height: 154px; margin: 0 auto; padding: 5px; object-fit: contain; background: var(--bk-white); }
.ddd-bk-contact figcaption { margin-top: 7px; color: rgba(255,255,255,.68); font-size: 12px; line-height: 20px; }
.ddd-bk-notice { padding: 18px 0; color: var(--bk-muted); background: var(--bk-warm); border-bottom: 1px solid #f0ded5; font-size: 13px; line-height: 23px; }
.ddd-bk-notice strong { color: var(--bk-accent); }

@media screen and (max-width: 980px) {
  .ddd-bk-check-grid,
  .ddd-bk-monthly-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .ddd-bk-material-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media screen and (max-width: 760px) {
  .ddd-bk-container { width: calc(100% - 32px); }
  .ddd-bk-hero { padding-top: 48px; }
  .ddd-bk-hero h1 { font-size: 36px; }
  .ddd-bk-lead { font-size: 15px; line-height: 27px; }
  .ddd-bk-hero-facts { grid-template-columns: 1fr; margin-top: 36px; }
  .ddd-bk-hero-facts li { padding: 15px 0; }
  .ddd-bk-hero-facts li + li { padding-left: 0; border-top: 1px solid rgba(255,255,255,.2); border-left: 0; }
  .ddd-bk-section { padding: 52px 0; }
  .ddd-bk-section-heading h2,
  .ddd-bk-contact h2 { font-size: 27px; }
  .ddd-bk-check-grid,
  .ddd-bk-monthly-grid,
  .ddd-bk-material-grid,
  .ddd-bk-output-list,
  .ddd-bk-result-grid,
  .ddd-bk-onboarding-layout,
  .ddd-bk-contact-layout { grid-template-columns: 1fr; }
  .ddd-bk-check-grid li,
  .ddd-bk-monthly-step { min-height: 0; }
  .ddd-bk-onboarding-layout,
  .ddd-bk-result-grid { gap: 32px; }
  .ddd-bk-sticky-heading { position: static; }
  .ddd-bk-duty-panel { padding: 25px 21px; }
  .ddd-bk-special h2 { font-size: 24px; }
  .ddd-bk-contact-layout { gap: 28px; }
  .ddd-bk-contact figure { display: grid; grid-template-columns: 120px minmax(0, 1fr); gap: 15px; align-items: center; text-align: left; }
  .ddd-bk-contact img { width: 120px; height: 120px; margin: 0; }
}

@media screen and (max-width: 440px) {
  .ddd-bk-hero-actions { align-items: stretch; flex-direction: column; }
  .ddd-bk-primary,
  .ddd-bk-secondary { width: 100%; }
  .ddd-bk-check-grid li { grid-template-columns: 30px minmax(0, 1fr); gap: 10px; padding: 20px 17px; }
}

@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }