/* ===== 变量 ===== */
:root {
  --bg: #f3f6fb;
  --bg-tint: #e7ecf4;
  --card: #ffffff;
  --card-2: #f8fafc;
  --text: #0f172a;
  --muted: #64748b;
  --border: #e7ebf0;
  --accent: #2563eb;
  --accent-dark: #1d4ed8;
  --accent-soft: #eff4ff;
  --green: #16a34a;
  --yellow: #d97706;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.04), 0 1px 3px rgba(15, 23, 42, 0.06);
  --shadow: 0 4px 16px rgba(15, 23, 42, 0.06), 0 2px 6px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 20px 50px rgba(15, 23, 42, 0.12);
  --radius: 16px;
  --radius-sm: 10px;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
  --mono: "SF Mono", "JetBrains Mono", "Fira Code", Consolas, monospace;
  --maxw: 1120px;
}

/* ===== 重置 ===== */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 84px; }
body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
button { font-family: inherit; }
img, svg { display: block; }
.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.skip-link { position: absolute; left: -9999px; top: 0; z-index: 200; background: var(--accent); color: #fff; padding: 10px 16px; border-radius: 0 0 10px 0; font-size: 0.9rem; font-weight: 600; }
.skip-link:focus { left: 0; outline: 2px solid #fff; }

/* ===== 通用 ===== */
.section { padding: 96px 0; }
.section-tint { background: var(--bg-tint); }
.section-head { margin-bottom: 48px; }
.eyebrow {
  display: inline-block; font-size: 0.82rem; font-weight: 600; letter-spacing: 0.04em;
  color: var(--accent); background: var(--accent-soft);
  padding: 5px 12px; border-radius: 20px; margin-bottom: 14px;
}
.section-title { font-size: 2rem; font-weight: 800; letter-spacing: -0.02em; line-height: 1.25; }
.section-sub { color: var(--muted); margin-top: 12px; font-size: 0.98rem; max-width: 620px; }
.grad {
  background: linear-gradient(100deg, var(--accent), #7c3aed);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 13px 28px; border-radius: 10px; font-size: 0.96rem; font-weight: 600;
  cursor: pointer; border: 1px solid transparent; transition: transform 0.18s, box-shadow 0.18s, background 0.18s, color 0.18s;
}
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-dark); transform: translateY(-2px); box-shadow: 0 10px 24px rgba(37, 99, 235, 0.28); }
.btn-ghost { background: #fff; color: var(--text); border-color: var(--border); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-2px); }
.btn-block { width: 100%; }

.tags { display: flex; flex-wrap: wrap; gap: 8px; }
.tag {
  font-size: 0.78rem; padding: 4px 10px; border-radius: 6px;
  background: var(--bg-tint); border: 1px solid var(--border); color: var(--muted);
}

/* ===== 导航 ===== */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(255, 255, 255, 0.78); backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent; transition: border-color 0.3s, box-shadow 0.3s;
}
.nav.scrolled { border-bottom-color: var(--border); box-shadow: var(--shadow-sm); }
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.logo { font-weight: 800; font-size: 1.15rem; }
.logo-bracket { color: var(--accent); }
.nav-links { display: flex; gap: 4px; }
.nav-link { padding: 8px 14px; border-radius: 8px; font-size: 0.92rem; color: var(--muted); font-weight: 500; transition: color 0.2s, background 0.2s; }
.nav-link:hover { color: var(--text); background: var(--bg-tint); }
.nav-link.active { color: var(--accent); background: var(--accent-soft); }
.menu-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 6px; }
.menu-toggle span { width: 24px; height: 2px; background: var(--text); border-radius: 2px; transition: transform 0.3s, opacity 0.3s; }
.menu-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle.open span:nth-child(2) { opacity: 0; }
.menu-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== Hero ===== */
.hero { position: relative; padding: 150px 0 90px; overflow: hidden; background: linear-gradient(180deg, #e6efff 0%, #f3f6fb 100%); }
.hero-bg { position: absolute; inset: 0; z-index: -1; overflow: hidden; }
.blob { position: absolute; border-radius: 50%; filter: blur(70px); opacity: 0.5; }
.blob.b1 { width: 460px; height: 460px; background: #cfe0ff; top: -120px; right: -80px; animation: float 9s ease-in-out infinite; }
.blob.b2 { width: 380px; height: 380px; background: #e6dcff; bottom: -140px; left: -100px; animation: float 11s ease-in-out infinite reverse; }
@keyframes float { 0%, 100% { transform: translate(0, 0); } 50% { transform: translate(20px, -24px); } }
.hero-inner { text-align: center; }
.hero-tag {
  display: inline-block; font-size: 0.84rem; font-weight: 600; color: var(--accent);
  background: var(--accent-soft); border: 1px solid #dbe6ff; padding: 6px 16px; border-radius: 20px; margin-bottom: 22px;
}
.hero-title { font-size: clamp(2.2rem, 5.5vw, 3.6rem); font-weight: 800; letter-spacing: -0.03em; line-height: 1.15; margin-bottom: 18px; }
.hero-sub { color: var(--muted); font-size: 1.05rem; max-width: 600px; margin: 0 auto 30px; }
.hero-actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; margin-bottom: 56px; }
.hero-stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; max-width: 720px; margin: 0 auto; }
.hstat { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px 12px; box-shadow: var(--shadow-sm); }
.hstat-num { display: block; font-size: 1.9rem; font-weight: 800; color: var(--accent); line-height: 1; }
.hstat-label { font-size: 0.82rem; color: var(--muted); margin-top: 6px; display: block; }

/* ===== 关于 ===== */
.about-grid { display: grid; grid-template-columns: 1.4fr 1fr; gap: 56px; align-items: center; }
.about-left p { color: var(--muted); margin-bottom: 16px; }
.about-left strong { color: var(--text); }
.about-left .section-title { margin: 6px 0 18px; }
.advantages { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 24px; }
.adv { display: flex; align-items: center; gap: 10px; font-size: 0.9rem; color: var(--text); }
.adv-ico { color: var(--green); font-weight: 700; }
.about-right { display: flex; flex-direction: column; align-items: center; gap: 22px; }
.about-photo { width: 220px; height: 220px; border-radius: 50%; overflow: hidden; border: 5px solid #fff; box-shadow: var(--shadow-lg); flex-shrink: 0; background: var(--bg-tint); }
.about-photo img { width: 100%; height: 100%; object-fit: cover; }
.about-card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 8px 24px; box-shadow: var(--shadow); }
.about-row { display: flex; justify-content: space-between; align-items: center; padding: 16px 0; border-bottom: 1px solid var(--border); }
.about-row:last-child { border-bottom: none; }
.ar-key { color: var(--muted); font-size: 0.88rem; }
.ar-val { font-weight: 600; font-size: 0.92rem; }
.dot-online { display: inline-block; width: 8px; height: 8px; background: var(--green); border-radius: 50%; margin-right: 4px; animation: pulse 2s infinite; }
@keyframes pulse { 0% { box-shadow: 0 0 0 0 rgba(22, 163, 74, 0.5); } 70% { box-shadow: 0 0 0 7px rgba(22, 163, 74, 0); } 100% { box-shadow: 0 0 0 0 rgba(22, 163, 74, 0); } }

/* ===== 履历 timeline ===== */
.timeline { position: relative; padding-left: 32px; }
.timeline::before { content: ""; position: absolute; left: 7px; top: 6px; bottom: 6px; width: 2px; background: var(--border); }
.tl-item { position: relative; margin-bottom: 28px; }
.tl-item:last-child { margin-bottom: 0; }
.tl-dot { position: absolute; left: -32px; top: 6px; width: 16px; height: 16px; border-radius: 50%; background: #fff; border: 3px solid var(--accent); box-shadow: 0 0 0 4px var(--accent-soft); }
.tl-time { font-family: var(--mono); font-size: 0.8rem; font-weight: 600; color: var(--accent); margin-bottom: 4px; }
.tl-card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px 22px; box-shadow: var(--shadow-sm); transition: transform 0.2s, box-shadow 0.2s; }
.tl-card:hover { transform: translateX(4px); box-shadow: var(--shadow); }
.tl-card h3 { font-size: 1.02rem; margin-bottom: 4px; }
.tl-card p { font-size: 0.88rem; color: var(--muted); }

/* ===== 服务卡片 ===== */
.services-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.service-card {
  text-align: left; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 24px; cursor: pointer; box-shadow: var(--shadow-sm); transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
}
.service-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: #c9d8ff; }
.service-ico { font-size: 1.7rem; margin-bottom: 12px; width: 52px; height: 52px; display: flex; align-items: center; justify-content: center; background: var(--accent-soft); border-radius: 12px; }
.service-card h3 { font-size: 1.02rem; margin-bottom: 6px; }
.service-card p { font-size: 0.84rem; color: var(--muted); line-height: 1.55; margin-bottom: 14px; }
.service-cta { font-size: 0.82rem; font-weight: 600; color: var(--accent); }

/* ===== 案例 ===== */
.projects-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 22px; }
.project-card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px; box-shadow: var(--shadow-sm); transition: transform 0.2s, box-shadow 0.2s; position: relative; overflow: hidden; }
.project-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.project-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 12px; margin-bottom: 10px; }
.project-head h3 { font-size: 1.1rem; }
.project-desc { color: var(--muted); font-size: 0.9rem; margin-bottom: 14px; }
.project-highlights { margin-bottom: 14px; }
.project-highlights li { position: relative; padding-left: 20px; font-size: 0.85rem; margin-bottom: 6px; }
.project-highlights li::before { content: "▹"; position: absolute; left: 0; color: var(--accent); }
.badge { flex-shrink: 0; font-size: 0.72rem; font-weight: 600; padding: 4px 10px; border-radius: 6px; white-space: nowrap; }
.badge-online { color: var(--green); background: #dcfce7; }
.badge-iter { color: var(--yellow); background: #fef3c7; }
.badge-dev { color: var(--accent); background: var(--accent-soft); }
.badge-built { color: #7c3aed; background: #ede9fe; }

/* ===== 流程 ===== */
.process-steps { display: grid; grid-template-columns: repeat(5, 1fr); gap: 18px; }
.step { position: relative; text-align: center; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px 16px; box-shadow: var(--shadow-sm); transition: transform 0.2s, box-shadow 0.2s; }
.step:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.step-num { font-family: var(--mono); font-size: 1.4rem; font-weight: 800; color: var(--accent); opacity: 0.5; margin-bottom: 10px; }
.step h3 { font-size: 0.98rem; margin-bottom: 6px; }
.step p { font-size: 0.82rem; color: var(--muted); }
.step:not(:last-child)::after { content: "→"; position: absolute; right: -14px; top: 50%; transform: translateY(-50%); color: var(--border); font-size: 1.1rem; z-index: 2; }

/* ===== 报价表 ===== */
.price-table { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-sm); }
.price-row { display: grid; grid-template-columns: 1.6fr 1fr 1fr; padding: 16px 24px; border-bottom: 1px solid var(--border); align-items: center; transition: background 0.2s; }
.price-row:last-child { border-bottom: none; }
.price-row:not(.price-head):hover { background: var(--card-2); }
.price-head { background: var(--card-2); font-size: 0.82rem; color: var(--muted); font-weight: 600; }
.price-row span:nth-child(2) { color: var(--accent); font-weight: 700; }
.price-row.price-note span:nth-child(2) { color: var(--yellow); }
.price-tip { font-size: 0.8rem; color: var(--muted); margin-top: 14px; }

/* ===== 评价 ===== */
.reviews-layout { display: grid; grid-template-columns: 360px 1fr; gap: 32px; align-items: start; }
.review-form { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px; box-shadow: var(--shadow-sm); position: sticky; top: 90px; }
.review-form h3 { font-size: 1.05rem; margin-bottom: 16px; }
.field { margin-bottom: 16px; }
.field label { display: block; font-size: 0.84rem; color: var(--muted); margin-bottom: 7px; font-weight: 500; }
.field input, .field textarea {
  width: 100%; padding: 11px 14px; background: var(--card-2); border: 1px solid var(--border);
  border-radius: 9px; color: var(--text); font-family: inherit; font-size: 0.92rem; resize: vertical; transition: border-color 0.2s, box-shadow 0.2s;
}
.field input:focus, .field textarea:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); background: #fff; }
.stars-input { display: flex; gap: 6px; font-size: 1.5rem; color: #cbd5e1; }
.stars-input .star { cursor: pointer; transition: color 0.15s; }
.stars-input .star.on { color: #f59e0b; }
.form-hint { font-size: 0.84rem; margin-top: 10px; min-height: 1.2em; }
.form-hint.ok { color: var(--green); }
.form-hint.err { color: #dc2626; }
.review-list { display: flex; flex-direction: column; gap: 14px; }
.review-loading { color: var(--muted); font-size: 0.9rem; padding: 20px; text-align: center; }
.review-item { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px 22px; box-shadow: var(--shadow-sm); }
.review-top { display: flex; justify-content: space-between; align-items: center; margin-bottom: 8px; }
.review-name { font-weight: 700; font-size: 0.95rem; }
.review-stars { color: #f59e0b; font-size: 0.85rem; letter-spacing: 1px; }
.review-content { color: var(--text); font-size: 0.9rem; }
.review-time { color: var(--muted); font-size: 0.76rem; margin-top: 8px; }
.muted-inline { color: var(--muted); font-size: 0.8rem; }

/* ===== 联系 ===== */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; }
.contact-info { display: flex; flex-direction: column; gap: 14px; }
.contact-item { display: flex; align-items: center; gap: 16px; padding: 18px 22px; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow-sm); transition: transform 0.2s, box-shadow 0.2s; }
a.contact-item:hover { transform: translateX(4px); box-shadow: var(--shadow); }
.contact-ico { font-size: 1.4rem; width: 40px; text-align: center; }
.contact-label { font-size: 0.76rem; color: var(--muted); }
.contact-form { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px; box-shadow: var(--shadow-sm); }
.contact-qr { display: flex; align-items: center; justify-content: center; }
.qr-card { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 30px 28px; box-shadow: var(--shadow); text-align: center; max-width: 340px; width: 100%; }
.qr-card img { width: 240px; height: auto; border-radius: 14px; margin: 0 auto 18px; display: block; box-shadow: var(--shadow-sm); }
.qr-title { font-size: 1.08rem; font-weight: 700; margin-bottom: 6px; }
.qr-id { color: var(--accent); font-weight: 600; font-size: 0.98rem; margin-bottom: 10px; }
.qr-hint { color: var(--muted); font-size: 0.84rem; }

/* ===== 页脚 ===== */
.footer { border-top: 1px solid var(--border); padding: 28px 0; }
.footer-inner { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 8px; font-size: 0.85rem; color: var(--muted); }
.footer-meta { font-family: var(--mono); }

/* ===== 返回顶部 ===== */
.back-top { position: fixed; bottom: 26px; left: 26px; z-index: 90; width: 44px; height: 44px; border-radius: 50%; background: var(--accent); color: #fff; border: none; font-size: 1.2rem; font-weight: 700; cursor: pointer; opacity: 0; transform: translateY(20px); pointer-events: none; transition: opacity 0.3s, transform 0.3s, background 0.2s; box-shadow: 0 8px 20px rgba(37, 99, 235, 0.35); }
.back-top.show { opacity: 1; transform: translateY(0); pointer-events: auto; }
.back-top:hover { background: var(--accent-dark); }

/* ===== 滚动渐入（无 JS 时默认可见，绝不藏内容）===== */
.reveal { opacity: 1; transform: none; transition: opacity 0.6s ease, transform 0.6s ease; }
.js .reveal { opacity: 0; transform: translateY(24px); }
.js .reveal.in { opacity: 1; transform: translateY(0); }

/* ===== 软件体验弹窗 ===== */
.demo-overlay { position: fixed; inset: 0; z-index: 200; background: rgba(15, 23, 42, 0.55); backdrop-filter: blur(4px); display: none; align-items: center; justify-content: center; padding: 20px; opacity: 0; transition: opacity 0.25s; }
.demo-overlay.show { display: flex; opacity: 1; }
.demo-modal { position: relative; background: #fff; border-radius: 20px; width: 100%; max-width: 560px; max-height: 88vh; overflow: hidden; box-shadow: var(--shadow-lg); transform: translateY(16px) scale(0.98); transition: transform 0.25s; display: flex; flex-direction: column; }
.demo-overlay.show .demo-modal { transform: translateY(0) scale(1); }
.demo-close { position: absolute; top: 12px; right: 12px; z-index: 5; width: 32px; height: 32px; border-radius: 50%; background: rgba(15,23,42,0.06); border: none; cursor: pointer; font-size: 0.9rem; color: var(--muted); transition: background 0.2s, color 0.2s; }
.demo-close:hover { background: rgba(15,23,42,0.12); color: var(--text); }
.demo-content { overflow-y: auto; padding: 28px 26px; }
.demo-title { font-size: 1.2rem; font-weight: 800; margin-bottom: 2px; }
.demo-desc { color: var(--muted); font-size: 0.86rem; margin-bottom: 18px; }
.demo-note { margin-top: 18px; padding: 12px 14px; background: var(--accent-soft); border-radius: 10px; font-size: 0.82rem; color: var(--accent-dark); }

/* demo: 手机框 */
.phone { width: 240px; margin: 0 auto; background: #0f172a; border-radius: 28px; padding: 10px; box-shadow: var(--shadow-lg); }
.phone-screen { background: #fff; border-radius: 20px; overflow: hidden; min-height: 360px; }
.phone-notch { height: 22px; background: #0f172a; display: flex; align-items: center; justify-content: center; }
.phone-notch::after { content: ""; width: 60px; height: 6px; background: #1e293b; border-radius: 3px; }
.phone-body { padding: 12px; }
/* demo: 浏览器框 */
.browser { border: 1px solid var(--border); border-radius: 12px; overflow: hidden; box-shadow: var(--shadow); }
.browser-bar { background: var(--card-2); padding: 8px 12px; display: flex; gap: 6px; align-items: center; border-bottom: 1px solid var(--border); }
.browser-bar i { width: 10px; height: 10px; border-radius: 50%; background: #cbd5e1; }
.browser-bar i:first-child { background: #f87171; }
.browser-bar i:nth-child(2) { background: #fbbf24; }
.browser-bar i:nth-child(3) { background: #34d399; }
.browser-bar span { margin-left: 10px; font-size: 0.72rem; color: var(--muted); font-family: var(--mono); }
.browser-body { background: #fff; min-height: 200px; }
/* demo 通用组件 */
.demo-shop-h { font-size: 0.8rem; color: var(--muted); margin-bottom: 8px; }
.demo-product { display: flex; align-items: center; gap: 10px; padding: 8px; border: 1px solid var(--border); border-radius: 10px; margin-bottom: 8px; }
.demo-product .pi { width: 38px; height: 38px; border-radius: 8px; background: var(--accent-soft); display: flex; align-items: center; justify-content: center; font-size: 1.1rem; }
.demo-product .pn { flex: 1; font-size: 0.82rem; font-weight: 600; }
.demo-product .pp { font-size: 0.82rem; color: var(--accent); font-weight: 700; }
.demo-add { background: var(--accent); color: #fff; border: none; border-radius: 6px; padding: 4px 10px; font-size: 0.74rem; cursor: pointer; }
.demo-add:hover { background: var(--accent-dark); }
.demo-cart { margin-top: 10px; padding: 10px 12px; background: var(--card-2); border-radius: 10px; display: flex; justify-content: space-between; align-items: center; font-size: 0.82rem; font-weight: 600; }
.demo-cart b { color: var(--accent); }
.demo-input, .demo-select { width: 100%; padding: 9px 12px; border: 1px solid var(--border); border-radius: 8px; font-size: 0.86rem; font-family: inherit; margin-bottom: 10px; }
.demo-success { text-align: center; padding: 24px 12px; color: var(--green); }
.demo-success .big { font-size: 2.4rem; margin-bottom: 8px; }
.dash-card { background: var(--card-2); border: 1px solid var(--border); border-radius: 10px; padding: 12px; margin-bottom: 10px; }
.dash-card .lab { font-size: 0.74rem; color: var(--muted); margin-bottom: 6px; }
.bars { display: flex; align-items: flex-end; gap: 6px; height: 60px; }
.bars .bar { flex: 1; background: linear-gradient(180deg, var(--accent), #93b4ff); border-radius: 4px 4px 0 0; transition: height 0.6s ease; }
.quiz-q { font-size: 0.9rem; font-weight: 600; margin-bottom: 12px; }
.quiz-opt { display: block; width: 100%; text-align: left; padding: 10px 14px; border: 1px solid var(--border); border-radius: 9px; background: #fff; font-size: 0.86rem; cursor: pointer; margin-bottom: 8px; transition: border-color 0.2s, background 0.2s; }
.quiz-opt:hover { border-color: var(--accent); }
.quiz-opt.correct { border-color: var(--green); background: #dcfce7; color: var(--green); }
.quiz-opt.wrong { border-color: #dc2626; background: #fee2e2; color: #dc2626; }
.calc-display { background: #0f172a; color: #fff; border-radius: 10px; padding: 16px; text-align: right; font-size: 1.6rem; font-family: var(--mono); margin-bottom: 10px; min-height: 56px; }
.calc-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
.calc-btn { padding: 14px 0; border: 1px solid var(--border); border-radius: 9px; background: #fff; font-size: 0.95rem; cursor: pointer; transition: background 0.15s; }
.calc-btn:hover { background: var(--card-2); }
.calc-btn.op { background: var(--accent-soft); color: var(--accent); }
.calc-btn.eq { background: var(--accent); color: #fff; }
.preview-mock { border: 1px solid var(--border); border-radius: 12px; overflow: hidden; background: var(--card-2); }
.preview-mock .pm-bar { background: #fff; padding: 10px 14px; border-bottom: 1px solid var(--border); font-size: 0.82rem; font-weight: 600; }
.preview-mock .pm-body { padding: 18px; }
.preview-feat { font-size: 0.84rem; color: var(--muted); padding: 6px 0; }
.preview-feat::before { content: "✓ "; color: var(--green); font-weight: 700; }

/* ===== 聊天机器人 ===== */
.chat-fab { position: fixed; bottom: 26px; right: 26px; z-index: 150; width: 68px; height: 68px; border-radius: 50%; background: var(--accent); color: #fff; border: none; cursor: pointer; box-shadow: 0 12px 32px rgba(37, 99, 235, 0.42); display: flex; align-items: center; justify-content: center; transition: transform 0.2s; }
.chat-fab:hover { transform: scale(1.06); }
.chat-fab-badge { position: absolute; top: -3px; right: -3px; background: #ef4444; color: #fff; font-size: 0.7rem; width: 20px; height: 20px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: 700; border: 2px solid #fff; }
.chat-panel { position: fixed; bottom: 26px; right: 26px; z-index: 160; width: 384px; max-width: calc(100vw - 32px); height: 540px; max-height: calc(100vh - 48px); background: #fff; border-radius: 18px; box-shadow: var(--shadow-lg); display: none; flex-direction: column; overflow: hidden; transform: translateY(20px); opacity: 0; transition: transform 0.25s, opacity 0.25s; }
.chat-panel.show { display: flex; transform: translateY(0); opacity: 1; }
.chat-head { background: var(--accent); color: #fff; padding: 16px 18px; display: flex; align-items: center; justify-content: space-between; }
.chat-head-info { display: flex; align-items: center; gap: 10px; }
.chat-avatar { width: 42px; height: 42px; border-radius: 50%; background: rgba(255,255,255,0.2); display: flex; align-items: center; justify-content: center; font-size: 1.3rem; }
.chat-head-info strong { display: block; font-size: 0.98rem; line-height: 1.2; }
.chat-head-info small { font-size: 0.76rem; opacity: 0.85; }
.chat-close { background: none; border: none; color: #fff; font-size: 1.1rem; cursor: pointer; opacity: 0.85; }
.chat-close:hover { opacity: 1; }
.chat-body { flex: 1; overflow-y: auto; padding: 18px; background: var(--bg-tint); display: flex; flex-direction: column; gap: 12px; }
.msg { max-width: 82%; padding: 10px 14px; border-radius: 14px; font-size: 0.92rem; line-height: 1.5; white-space: pre-wrap; word-break: break-word; }
.msg.bot { background: #fff; border: 1px solid var(--border); border-bottom-left-radius: 4px; align-self: flex-start; }
.msg.user { background: var(--accent); color: #fff; border-bottom-right-radius: 4px; align-self: flex-end; }
.chat-quick { display: flex; flex-wrap: wrap; gap: 7px; padding: 10px 14px; border-top: 1px solid var(--border); background: #fff; }
.chat-quick .chip { font-size: 0.82rem; padding: 6px 12px; border-radius: 14px; background: var(--accent-soft); color: var(--accent); border: 1px solid #dbe6ff; cursor: pointer; transition: background 0.15s; }
.chat-quick .chip:hover { background: #dbe6ff; }
.chat-input-row { display: flex; gap: 8px; padding: 12px 14px; border-top: 1px solid var(--border); background: #fff; }
.chat-input-row input { flex: 1; padding: 11px 14px; border: 1px solid var(--border); border-radius: 20px; font-size: 0.92rem; font-family: inherit; }
.chat-input-row input:focus { outline: none; border-color: var(--accent); }
.chat-send { background: var(--accent); color: #fff; border: none; border-radius: 20px; padding: 0 18px; font-size: 0.88rem; cursor: pointer; font-weight: 600; }
.chat-send:hover { background: var(--accent-dark); }

/* ===== 响应式 ===== */
@media (max-width: 960px) {
  .about-grid { grid-template-columns: 1fr; gap: 32px; }
  .services-grid { grid-template-columns: repeat(2, 1fr); }
  .projects-grid { grid-template-columns: 1fr; }
  .process-steps { grid-template-columns: repeat(2, 1fr); gap: 14px; }
  .step:not(:last-child)::after { display: none; }
  .reviews-layout { grid-template-columns: 1fr; }
  .review-form { position: static; }
  .contact-grid { grid-template-columns: 1fr; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
  .container { padding: 0 18px; }
  .section { padding: 64px 0; }
  .section-title { font-size: 1.5rem; }
  .nav-links { position: fixed; top: 68px; right: 0; left: 0; flex-direction: column; gap: 0; background: rgba(255,255,255,0.98); backdrop-filter: blur(14px); border-bottom: 1px solid var(--border); padding: 12px; transform: translateY(-160%); transition: transform 0.3s; }
  .nav-links.open { transform: translateY(0); }
  .nav-link { padding: 13px; border-radius: 8px; }
  .menu-toggle { display: flex; }
  .services-grid { grid-template-columns: 1fr; }
  .process-steps { grid-template-columns: 1fr; }
  .price-row { padding: 13px 16px; font-size: 0.84rem; grid-template-columns: 1.3fr 1fr 0.8fr; gap: 6px; }
  .price-head { font-size: 0.72rem; }
  .advantages { grid-template-columns: 1fr; }
  .hero-actions { flex-direction: column; width: 100%; }
  .hero-actions .btn { width: 100%; }
  .chat-panel { right: 12px; bottom: 12px; width: calc(100vw - 24px); }
  .chat-fab { bottom: 20px; right: 20px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
  html { scroll-behavior: auto; }
}