* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif; color: #1f2937; line-height: 1.7; background: #f8fafc; }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 20px; }

.topbar { background: #fff; border-bottom: 1px solid #e5e7eb; position: sticky; top: 0; z-index: 10; }
.topbar .wrap { display: flex; align-items: center; justify-content: space-between; height: 60px; }
.logo { font-size: 20px; font-weight: 700; color: #111827; }
nav a { margin-left: 18px; color: #4b5563; text-decoration: none; font-size: 15px; }
nav a:hover { color: #2563eb; }

.hero { background: linear-gradient(135deg, #2563eb, #7c3aed); color: #fff; text-align: center; padding: 56px 20px 48px; }
.hero h1 { font-size: 34px; margin-bottom: 12px; }
.hero .sub { font-size: 18px; opacity: .95; }

/* 三步路径 */
.steps { max-width: 1080px; margin: -26px auto 0; padding: 0 20px; display: flex; align-items: stretch; gap: 12px; position: relative; z-index: 5; }
.step { flex: 1; background: #fff; border: 1px solid #e5e7eb; border-radius: 12px; padding: 20px; text-align: center; box-shadow: 0 4px 12px rgba(0,0,0,.06); }
.step .num { display: inline-flex; width: 34px; height: 34px; border-radius: 50%; background: #2563eb; color: #fff; align-items: center; justify-content: center; font-weight: 700; font-size: 18px; margin-bottom: 10px; }
.step h3 { font-size: 16px; margin-bottom: 6px; }
.step p { font-size: 13px; color: #6b7280; }
.step-arrow { align-self: center; font-size: 22px; color: #cbd5e1; flex-shrink: 0; }

.block { max-width: 1080px; margin: 44px auto; padding: 0 20px; }
.block h2 { font-size: 24px; margin-bottom: 14px; color: #111827; }
.step-tag { display: inline-block; background: #2563eb; color: #fff; font-size: 14px; padding: 2px 12px; border-radius: 20px; margin-right: 8px; }
.block .lead { color: #4b5563; margin-bottom: 18px; }
.block h3 { font-size: 18px; margin: 22px 0 12px; color: #1f2937; }

.choice-box { background: #fff; border: 1px solid #e5e7eb; border-radius: 12px; padding: 22px; margin-bottom: 18px; }
.choice-box h3 { margin-top: 0; }

.software { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 12px; margin: 14px 0; }
.soft { background: #f8fafc; border: 1px solid #e5e7eb; border-radius: 10px; padding: 16px; }
.soft h4 { font-size: 16px; color: #2563eb; margin-bottom: 6px; }
.soft p { font-size: 14px; color: #4b5563; }
.soft .how { font-size: 13px; color: #6b7280; margin-top: 8px; }

.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 12px; margin: 12px 0 20px; }
.cell { background: #fff; border: 1px solid #e5e7eb; border-radius: 10px; padding: 16px; }
.cell strong { display: block; color: #111827; margin-bottom: 4px; }
.cell span { font-size: 13px; color: #6b7280; }
.cell.cat { border-left: 3px solid #2563eb; }

.highlight { background: #fff; border: 1px solid #e5e7eb; border-radius: 12px; padding: 28px; }
.list { list-style: none; }
.list li { padding: 9px 0; border-bottom: 1px dashed #e5e7eb; font-size: 15px; }
.list li:last-child { border-bottom: none; }

.tip { margin-top: 14px; font-size: 14px; color: #6b7280; background: #eff6ff; border-radius: 8px; padding: 10px 14px; }

footer { text-align: center; padding: 40px 20px; color: #6b7280; border-top: 1px solid #e5e7eb; background: #fff; }
footer .small { font-size: 13px; margin-top: 6px; }

@media (max-width: 640px) {
  .hero h1 { font-size: 25px; }
  nav a { margin-left: 10px; font-size: 13px; }
  .steps { flex-direction: column; }
  .step-arrow { transform: rotate(90deg); align-self: center; }
}

/* ===== 小屏/手机 强化排版 ===== */
@media (max-width: 640px) {
  .wrap { padding: 0 14px; }
  .topbar .wrap { height: auto; padding: 10px 14px; flex-wrap: wrap; }
  nav { display: flex; flex-wrap: wrap; gap: 2px 14px; }
  nav a { margin-left: 0; }

  .hero { padding: 40px 16px 36px; }
  .hero h1 { font-size: 23px; line-height: 1.4; }
  .hero .sub { font-size: 16px; }

  .steps { margin-top: -20px; padding: 0 14px; }
  .step { padding: 16px; }

  .block { margin: 32px auto; padding: 0 14px; }
  .block h2 { font-size: 21px; }
  .block h3 { font-size: 17px; }

  /* 卡片全部改单列，不再挤 */
  .software { grid-template-columns: 1fr; }
  .grid { grid-template-columns: 1fr; }
  .cell, .soft { padding: 15px; }

  .choice-box { padding: 16px; }
  .tip { font-size: 13px; line-height: 1.6; }
}

/* ===== 中屏（平板/窄窗口）两步改三列，避免太挤 ===== */
@media (min-width: 641px) and (max-width: 900px) {
  .grid { grid-template-columns: repeat(2, 1fr); }
  .software { grid-template-columns: 1fr 1fr; }
}

/* 软件卡片可点击样式 */
a.soft-link { text-decoration: none; color: inherit; display: block; }
a.soft-link .soft { cursor: pointer; transition: border-color .15s, box-shadow .15s, transform .15s; height: 100%; }
a.soft-link:hover .soft { border-color: #2563eb; box-shadow: 0 6px 18px rgba(37,99,235,.12); transform: translateY(-2px); }
.soft .goto { font-size: 13px; color: #2563eb; margin-top: 10px; font-weight: 600; }

/* 进阶区 CTA 按钮 */
.cta { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 18px; }
.btn { display: inline-block; background: #2563eb; color: #fff; text-decoration: none; border-radius: 10px; padding: 12px 20px; font-size: 15px; font-weight: 600; transition: background .15s; }
.btn:hover { background: #1d4ed8; }
.btn-ghost { background: #fff; color: #2563eb; border: 1px solid #2563eb; }
.btn-ghost:hover { background: #eff6ff; }
@media (max-width: 640px) { .cta { flex-direction: column; } .btn { text-align: center; } }