/* ===== Reset & Base ===== */
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    :root {
      --blue:   #1d4ed8;
      --blue-l: #3b82f6;
      --blue-bg:#eff6ff;
      --green:  #16a34a;
      --green-l:#22c55e;
      --green-bg:#f0fdf4;
      --amber:  #d97706;
      --amber-bg:#fffbeb;
      --purple: #7c3aed;
      --purple-bg:#f5f3ff;
      --red:    #dc2626;
      --red-bg: #fef2f2;
      --cyan:   #0891b2;
      --cyan-bg:#ecfeff;
      --gray-50:#f8fafc; --gray-100:#f1f5f9; --gray-200:#e2e8f0;
      --gray-400:#94a3b8; --gray-500:#64748b; --gray-700:#334155; --gray-900:#0f172a;
      --radius-sm:8px; --radius:14px; --radius-lg:20px;
      --shadow-sm: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
      --shadow:    0 4px 16px rgba(0,0,0,.07), 0 1px 4px rgba(0,0,0,.04);
      --shadow-lg: 0 12px 40px rgba(0,0,0,.10), 0 2px 8px rgba(0,0,0,.05);
    }
    html { scroll-behavior: smooth; }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
      color: var(--gray-700); background: var(--gray-50); line-height: 1.6;
    }
    a { text-decoration: none; color: inherit; }
    img { display: block; max-width: 100%; }

    /* ===== NAV (沿用前页风格) ===== */
    .navbar {
      position: fixed; top: 0; left: 0; right: 0; z-index: 100;
      height: 64px; background: rgba(255,255,255,.88);
      backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
      border-bottom: 1px solid var(--gray-200);
      display: flex; align-items: center;
      transition: box-shadow .3s;
    }
    .navbar.scrolled { box-shadow: 0 2px 24px rgba(0,0,0,.08); }
    .nav-inner { width: 100%; max-width: 1100px; margin: 0 auto; padding: 0 24px;
      display: flex; align-items: center; justify-content: space-between; }
    .nav-logo { display: flex; align-items: center; gap: 10px; font-weight: 700;
      font-size: 1.05rem; color: var(--gray-900); }
    .nav-logo svg { flex-shrink: 0; }
    .nav-links { display: flex; align-items: center; gap: 4px; }
    .nav-links a { padding: 6px 14px; border-radius: 8px; font-size: .92rem;
      color: var(--gray-500); font-weight: 500; transition: background .2s, color .2s; }
    .nav-links a:hover, .nav-links a.active { background: var(--blue-bg); color: var(--blue); }
    .nav-cta { background: var(--blue); color: #fff !important; border-radius: 8px;
      padding: 8px 18px !important; font-size: .88rem !important; font-weight: 600 !important;
      transition: background .2s, transform .15s !important; }
    .nav-cta:hover { background: #1e40af !important; transform: translateY(-1px) !important; }

    /* ===== HERO ===== */
    .hero {
      margin-top: 64px;
      background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 55%, #0e4f8e 100%);
      padding: 72px 24px 80px; text-align: center; position: relative; overflow: hidden;
    }
    .hero::before {
      content: ''; position: absolute; inset: 0;
      background: radial-gradient(ellipse 80% 60% at 50% 120%, rgba(59,130,246,.25) 0%, transparent 70%);
    }
    .hero-inner { position: relative; max-width: 760px; margin: 0 auto; }
    .hero-badge {
      display: inline-flex; align-items: center; gap: 6px;
      background: rgba(255,255,255,.1); border: 1px solid rgba(255,255,255,.18);
      color: #93c5fd; font-size: .8rem; font-weight: 600; letter-spacing: .06em;
      padding: 5px 14px; border-radius: 999px; margin-bottom: 20px; text-transform: uppercase;
    }
    .hero h1 { font-size: clamp(1.8rem, 5vw, 3rem); font-weight: 800;
      color: #fff; letter-spacing: -.02em; line-height: 1.2; margin-bottom: 16px; }
    .hero h1 em { font-style: normal; color: #60a5fa; }
    .hero p { font-size: 1.05rem; color: #94a3b8; max-width: 540px; margin: 0 auto 32px; }
    .hero-stats { display: flex; justify-content: center; gap: 40px; flex-wrap: wrap; }
    .hero-stat { text-align: center; }
    .hero-stat .num { font-size: 2rem; font-weight: 800; color: #fff; line-height: 1; }
    .hero-stat .num span { font-size: 1rem; color: #60a5fa; }
    .hero-stat .label { font-size: .8rem; color: #64748b; margin-top: 4px; }

    /* ===== FILTER BAR ===== */
    .filter-bar { background: #fff; border-bottom: 1px solid var(--gray-200);
      position: sticky; top: 64px; z-index: 90; }
    .filter-inner { max-width: 1200px; margin: 0 auto; padding: 0 24px;
      display: flex; align-items: center; gap: 8px; overflow-x: auto;
      height: 56px; scrollbar-width: none; }
    .filter-inner::-webkit-scrollbar { display: none; }
    .filter-btn {
      flex-shrink: 0; padding: 6px 16px; border-radius: 999px; border: 1.5px solid var(--gray-200);
      background: transparent; font-size: .85rem; font-weight: 500; color: var(--gray-500);
      cursor: pointer; transition: all .2s; white-space: nowrap;
    }
    .filter-btn:hover { border-color: var(--blue-l); color: var(--blue); background: var(--blue-bg); }
    .filter-btn.active { border-color: var(--blue); background: var(--blue); color: #fff; }

    /* ===== MAIN LAYOUT ===== */
    .page-body { max-width: 1200px; margin: 0 auto; padding: 48px 24px 80px; }

    /* ===== SECTION TITLE ===== */
    .sec-title { margin-bottom: 32px; }
    .sec-title h2 { font-size: 1.5rem; font-weight: 700; color: var(--gray-900); }
    .sec-title p { font-size: .92rem; color: var(--gray-500); margin-top: 6px; }

    /* ===== SERVICE OVERVIEW GRID (服务项说明卡) ===== */
    .services-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
      gap: 16px; margin-bottom: 56px;
    }
    .svc-card {
      background: #fff; border: 1px solid var(--gray-200); border-radius: var(--radius);
      padding: 24px 22px; transition: box-shadow .25s, transform .25s;
      position: relative; overflow: hidden;
    }
    .svc-card::before {
      content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
      border-radius: var(--radius) var(--radius) 0 0;
    }
    .svc-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-3px); }
    .svc-card .icon-wrap {
      width: 44px; height: 44px; border-radius: 10px;
      display: flex; align-items: center; justify-content: center;
      font-size: 1.3rem; margin-bottom: 14px;
    }
    .svc-card h3 { font-size: 1rem; font-weight: 700; color: var(--gray-900); margin-bottom: 8px; }
    .svc-card p { font-size: .85rem; color: var(--gray-500); line-height: 1.7; }
    .svc-card .tag-row { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 14px; }
    .tag { font-size: .73rem; font-weight: 600; padding: 3px 9px; border-radius: 999px; }

    /* color themes */
    .theme-blue  .svc-card::before { background: var(--blue); }
    .theme-blue  .icon-wrap { background: var(--blue-bg); color: var(--blue); }
    .theme-blue  .tag { background: var(--blue-bg); color: var(--blue); }

    .theme-green .svc-card::before { background: var(--green); }
    .theme-green .icon-wrap { background: var(--green-bg); color: var(--green); }
    .theme-green .tag { background: var(--green-bg); color: var(--green); }

    .theme-amber .svc-card::before { background: var(--amber); }
    .theme-amber .icon-wrap { background: var(--amber-bg); color: var(--amber); }
    .theme-amber .tag { background: var(--amber-bg); color: var(--amber); }

    .theme-purple .svc-card::before { background: var(--purple); }
    .theme-purple .icon-wrap { background: var(--purple-bg); color: var(--purple); }
    .theme-purple .tag { background: var(--purple-bg); color: var(--purple); }

    .theme-red  .svc-card::before { background: var(--red); }
    .theme-red  .icon-wrap { background: var(--red-bg); color: var(--red); }
    .theme-red  .tag { background: var(--red-bg); color: var(--red); }

    .theme-cyan .svc-card::before { background: var(--cyan); }
    .theme-cyan .icon-wrap { background: var(--cyan-bg); color: var(--cyan); }
    .theme-cyan .tag { background: var(--cyan-bg); color: var(--cyan); }

    /* ===== CASE CARDS ===== */
    .cases-list { display: flex; flex-direction: column; gap: 28px; }
    .case-card {
      background: #fff; border: 1px solid var(--gray-200); border-radius: var(--radius-lg);
      overflow: hidden; box-shadow: var(--shadow-sm); transition: box-shadow .25s;
      display: grid; grid-template-columns: 280px 1fr;
    }
    .case-card:hover { box-shadow: var(--shadow-lg); }
    .case-aside {
      padding: 32px 28px; display: flex; flex-direction: column; gap: 16px;
      border-right: 1px solid var(--gray-100);
    }
    .case-aside .co-badge {
      width: 52px; height: 52px; border-radius: 12px;
      display: flex; align-items: center; justify-content: center;
      font-size: 1.5rem; margin-bottom: 4px;
    }
    .case-aside h3 { font-size: 1.05rem; font-weight: 700; color: var(--gray-900); }
    .case-aside .co-type { font-size: .8rem; color: var(--gray-400);
      background: var(--gray-100); padding: 2px 8px; border-radius: 4px; 
      display: inline-block; margin-top: 2px; }
    .case-meta { display: flex; flex-direction: column; gap: 8px; margin-top: 4px; }
    .meta-row { display: flex; align-items: center; gap: 8px; font-size: .82rem; color: var(--gray-500); }
    .meta-row .dot { width: 6px; height: 6px; border-radius: 50%; flex-shrink: 0; }
    .case-aside .result-box {
      margin-top: auto; padding: 14px 16px; border-radius: 10px;
      background: var(--green-bg); border: 1px solid #bbf7d0;
    }
    .result-box .r-label { font-size: .72rem; font-weight: 700; color: var(--green); 
      text-transform: uppercase; letter-spacing: .05em; margin-bottom: 6px; }
    .result-box .r-val { font-size: 1.4rem; font-weight: 800; color: var(--green); line-height: 1; }
    .result-box .r-desc { font-size: .78rem; color: #15803d; margin-top: 4px; }

    .case-body { padding: 32px 36px; }
    .case-body .challenge { margin-bottom: 24px; }
    .case-body .challenge h4, .case-body .solution h4, .case-body .timeline-title {
      font-size: .8rem; font-weight: 700; text-transform: uppercase; letter-spacing: .08em;
      color: var(--gray-400); margin-bottom: 12px;
    }
    .case-body .challenge p { font-size: .92rem; color: var(--gray-700); line-height: 1.8; }

    /* 服务清单 chips */
    .svc-chips { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 28px; }
    .chip {
      display: flex; align-items: center; gap: 6px;
      padding: 6px 12px; border-radius: 999px; font-size: .8rem; font-weight: 600;
      border: 1.5px solid; cursor: default;
    }
    .chip-blue   { background: var(--blue-bg);   color: var(--blue);   border-color: #bfdbfe; }
    .chip-green  { background: var(--green-bg);  color: var(--green);  border-color: #bbf7d0; }
    .chip-amber  { background: var(--amber-bg);  color: var(--amber);  border-color: #fde68a; }
    .chip-purple { background: var(--purple-bg); color: var(--purple); border-color: #ddd6fe; }
    .chip-red    { background: var(--red-bg);    color: var(--red);    border-color: #fecaca; }
    .chip-cyan   { background: var(--cyan-bg);   color: var(--cyan);   border-color: #a5f3fc; }

    /* timeline */
    .timeline { position: relative; padding-left: 20px; }
    .timeline::before { content: ''; position: absolute; left: 5px; top: 6px; bottom: 6px;
      width: 1.5px; background: var(--gray-200); }
    .tl-item { position: relative; margin-bottom: 14px; padding-left: 20px; }
    .tl-item::before { content: ''; position: absolute; left: -16px; top: 6px;
      width: 8px; height: 8px; border-radius: 50%; background: var(--blue-l);
      border: 2px solid #fff; box-shadow: 0 0 0 1.5px var(--blue-l); }
    .tl-item:last-child { margin-bottom: 0; }
    .tl-item .tl-date { font-size: .73rem; font-weight: 700; color: var(--blue);
      text-transform: uppercase; letter-spacing: .05em; }
    .tl-item .tl-text { font-size: .85rem; color: var(--gray-700); line-height: 1.6; }

    /* ===== TESTIMONIAL STRIP ===== */
    .testimonial-strip {
      background: linear-gradient(135deg, #0f172a, #1e3a8a);
      border-radius: var(--radius-lg); padding: 48px 40px; margin: 56px 0;
      display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 32px;
    }
    .testi-item { color: #fff; }
    .testi-item .quote { font-size: 2rem; color: #3b82f6; line-height: 1; margin-bottom: 10px; }
    .testi-item p { font-size: .9rem; color: #cbd5e1; line-height: 1.75; margin-bottom: 16px; }
    .testi-author { display: flex; align-items: center; gap: 12px; }
    .testi-avatar { width: 40px; height: 40px; border-radius: 50%;
      background: #1e40af; display: flex; align-items: center; justify-content: center;
      font-size: 1rem; font-weight: 700; color: #93c5fd; flex-shrink: 0; }
    .testi-info .name { font-size: .88rem; font-weight: 700; color: #fff; }
    .testi-info .co   { font-size: .78rem; color: #64748b; }

    /* ===== CTA BANNER ===== */
    .cta-banner {
      background: linear-gradient(135deg, var(--blue) 0%, #0ea5e9 100%);
      border-radius: var(--radius-lg); padding: 48px 40px;
      text-align: center; color: #fff;
    }
    .cta-banner h2 { font-size: 1.7rem; font-weight: 800; margin-bottom: 10px; }
    .cta-banner p  { color: #bfdbfe; margin-bottom: 28px; font-size: .95rem; }
    .cta-btns { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
    .btn-white { background: #fff; color: var(--blue); padding: 12px 28px; border-radius: 10px;
      font-weight: 700; font-size: .95rem; transition: transform .2s, box-shadow .2s; }
    .btn-white:hover { transform: translateY(-2px); box-shadow: 0 8px 20px rgba(0,0,0,.2); }
    .btn-outline-w { background: transparent; color: #fff; border: 2px solid rgba(255,255,255,.5);
      padding: 12px 28px; border-radius: 10px; font-weight: 600; font-size: .95rem;
      transition: border-color .2s; }
    .btn-outline-w:hover { border-color: #fff; }

    /* ===== RESPONSIVE ===== */
    @media (max-width: 900px) {
      .case-card { grid-template-columns: 1fr; }
      .case-aside { border-right: none; border-bottom: 1px solid var(--gray-100); padding: 24px; }
      .case-aside .result-box { display: none; }
      .case-body { padding: 24px; }
    }
    @media (max-width: 640px) {
      .hero { padding: 56px 20px 60px; }
      .hero-stats { gap: 24px; }
      .services-grid { grid-template-columns: 1fr 1fr; }
      .testimonial-strip { padding: 32px 24px; }
      .cta-banner { padding: 36px 24px; }
      .nav-links { display: none; }
    }
    @media (max-width: 400px) {
      .services-grid { grid-template-columns: 1fr; }
    }

    /* ===== HIDDEN (for filter) ===== */
    .case-card.hidden { display: none; }

    /* ===== SCROLL ANIMATION ===== */
    .fade-up { opacity: 0; transform: translateY(24px); transition: opacity .5s, transform .5s; }
    .fade-up.visible { opacity: 1; transform: none; }