/* Sift · landing site
   Palette follows the macOS app icon: ink / rice paper / jade / vermilion seal.
   No external fonts or frameworks — fast, private, works offline. */

:root {
  --ink: #14181a;
  --ink-soft: #2a3133;
  --paper: #f6f3ea;
  --paper-2: #fffdf7;
  --jade: #3f7f74;
  --jade-dark: #2d6157;
  --jade-pale: #e7f0ec;
  --seal: #b8412f;
  --seal-pale: #f7e9e4;
  --muted: #6c736f;
  --line: #e3ddd0;
  --line-soft: #eee9dd;
  --shadow: 0 18px 48px rgba(20, 24, 26, .09);
  --shadow-sm: 0 6px 20px rgba(20, 24, 26, .06);
  --radius: 16px;
  --max: 1160px;
}

* { box-sizing: border-box; }
/* Author-level display rules would otherwise override the UA [hidden] rule. */
[hidden] { display: none !important; }
html { scroll-behavior: smooth; scroll-padding-top: 84px; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
               "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
/* HTML width/height 属性会生成 CSS height 提示；必须显式 height:auto，
   否则 max-width:100% 只压缩宽度，图片被纵向拉伸变形。 */
img { max-width: 100%; height: auto; display: block; }
a { color: var(--jade-dark); text-decoration: none; }
a:hover { text-decoration: underline; }
button { font: inherit; cursor: pointer; }
h1, h2, h3, h4 { line-height: 1.3; margin: 0 0 .5em; letter-spacing: -.01em; }
h1 { font-size: clamp(2.3rem, 5vw, 3.7rem); font-weight: 800; }
h2 { font-size: clamp(1.7rem, 3.2vw, 2.4rem); font-weight: 750; }
h3 { font-size: 1.16rem; font-weight: 700; }
p { margin: 0 0 1em; }
strong { font-weight: 700; }
.serif { font-family: "Songti SC", "STSong", "Noto Serif CJK SC", serif; }
.wrap { width: min(var(--max), calc(100% - 40px)); margin-inline: auto; }
.narrow { width: min(820px, calc(100% - 40px)); margin-inline: auto; }

/* ---------- top bar ---------- */
.topbar {
  position: sticky; top: 0; z-index: 40;
  background: rgba(246, 243, 234, .9);
  backdrop-filter: saturate(150%) blur(14px);
  border-bottom: 1px solid var(--line-soft);
}
.topbar .wrap { display: flex; align-items: center; gap: 30px; height: 68px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); font-weight: 750; font-size: 1.05rem; white-space: nowrap; }
.brand:hover { text-decoration: none; }
.brand img { width: 30px; height: 30px; border-radius: 7px; }
.brand small { display: block; font-size: .62rem; font-weight: 500; letter-spacing: .18em; color: var(--muted); line-height: 1; margin-top: 2px; }
.nav { display: flex; gap: 26px; margin-left: auto; align-items: center; }
.nav a { color: var(--ink-soft); font-size: .93rem; white-space: nowrap; }
.nav a:hover { color: var(--jade-dark); text-decoration: none; }
/* .nav a 的颜色优先级高于 .btn-primary，必须显式保留 CTA 的白字 */
.nav a.btn, .nav a.btn:hover, .nav a.btn:focus-visible { color: #fff; }
.nav .nav-cta { margin-left: 8px; }
.menu-toggle { display: none; background: none; border: 0; font-size: 1.5rem; color: var(--ink); padding: 4px 8px; }

/* ---------- buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 22px; border-radius: 10px; border: 1px solid transparent;
  font-size: .95rem; font-weight: 650; line-height: 1.3;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
  text-decoration: none !important; white-space: nowrap;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: var(--ink); color: #fff; box-shadow: 0 8px 20px rgba(20, 24, 26, .16); }
.btn-primary:hover { background: #000; }
.btn-jade { background: var(--jade); color: #fff; box-shadow: 0 8px 20px rgba(63, 127, 116, .22); }
.btn-jade:hover { background: var(--jade-dark); }
.btn-outline { background: transparent; color: var(--ink); border-color: var(--line); }
.btn-outline:hover { border-color: var(--jade); background: var(--paper-2); }
.btn-sm { padding: 8px 15px; font-size: .86rem; }
.btn-block { width: 100%; }
.btn:disabled { opacity: .5; cursor: not-allowed; transform: none; }

/* ---------- hero ---------- */
.hero { padding: 74px 0 44px; position: relative; overflow: hidden; }
.hero::before {
  content: ""; position: absolute; right: -180px; top: -220px;
  width: 620px; height: 620px; border-radius: 50%;
  background: radial-gradient(circle, rgba(63,127,116,.09), transparent 66%);
  pointer-events: none;
}
.hero-grid { display: grid; grid-template-columns: 1.02fr .98fr; gap: 54px; align-items: center; }
.kicker {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: .78rem; letter-spacing: .16em; font-weight: 700;
  color: var(--jade-dark); background: var(--jade-pale);
  border: 1px solid #d5e6df; padding: 6px 13px; border-radius: 999px; margin-bottom: 22px;
}
.kicker::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--jade); }
.hero h1 .hl { color: var(--jade-dark); position: relative; white-space: nowrap; }
.hero h1 .hl::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: 4px; height: 10px;
  background: rgba(63,127,116,.15); z-index: -1; border-radius: 3px;
}
.hero .lede { font-size: 1.1rem; color: var(--ink-soft); max-width: 520px; line-height: 1.85; }
.hero .cta-row { display: flex; gap: 12px; flex-wrap: wrap; margin: 30px 0 18px; }
.hero .micro { font-size: .85rem; color: var(--muted); }
.hero .micro b { color: var(--seal); font-weight: 650; }
.trust { display: flex; gap: 22px; flex-wrap: wrap; margin-top: 26px; padding-top: 22px; border-top: 1px solid var(--line); }
.trust span { font-size: .82rem; color: var(--muted); display: inline-flex; gap: 7px; align-items: center; }
.trust span::before { content: "✓"; color: var(--jade); font-weight: 800; }
.shot {
  background: var(--paper-2); border: 1px solid var(--line); border-radius: 18px;
  padding: 10px; box-shadow: var(--shadow); transform: rotate(-.5deg);
}
.shot img { border-radius: 11px; border: 1px solid var(--line-soft); }
.shot figcaption { font-size: .76rem; color: var(--muted); text-align: center; padding: 9px 0 3px; }

/* ---------- stat strip ---------- */
.stats { background: var(--ink); color: #fff; border-radius: var(--radius); padding: 26px 20px; margin: 26px 0 0; }
.stats .grid4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.stat { text-align: center; border-right: 1px solid rgba(255,255,255,.13); }
.stat:last-child { border-right: 0; }
.stat b { display: block; font-size: 1.75rem; font-weight: 800; letter-spacing: -.02em; }
.stat b em { font-style: normal; color: #8fd0be; }
.stat span { font-size: .8rem; color: #aeb8b4; }

/* ---------- sections ---------- */
section { padding: 84px 0; }
section.alt { background: var(--paper-2); border-top: 1px solid var(--line-soft); border-bottom: 1px solid var(--line-soft); }
.section-head { max-width: 720px; margin-bottom: 44px; }
.section-head .eyebrow { font-size: .78rem; letter-spacing: .18em; font-weight: 750; color: var(--seal); margin-bottom: 12px; }
.section-head p { color: var(--muted); font-size: 1.02rem; margin: 0; }
.cards { display: grid; gap: 18px; }
.cards.c3 { grid-template-columns: repeat(3, 1fr); }
.cards.c2 { grid-template-columns: repeat(2, 1fr); }
.card {
  background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 26px; box-shadow: var(--shadow-sm);
}
.card .num { font-size: .78rem; font-weight: 800; color: var(--jade); letter-spacing: .1em; }
.card .icon {
  width: 42px; height: 42px; border-radius: 11px; display: grid; place-items: center;
  background: var(--jade-pale); color: var(--jade-dark); font-size: 1.25rem; font-weight: 700; margin-bottom: 16px;
}
.card p { color: var(--muted); font-size: .93rem; margin: 0; }
.card h3 { margin-bottom: 8px; }

/* ---------- comparison table ---------- */
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--radius); background: var(--paper-2); }
table { width: 100%; border-collapse: collapse; font-size: .93rem; min-width: 660px; }
th, td { padding: 16px 20px; text-align: left; border-bottom: 1px solid var(--line-soft); vertical-align: top; }
thead th { background: #f0ece1; font-weight: 750; font-size: .86rem; letter-spacing: .03em; }
thead th.good { background: var(--jade); color: #fff; }
tbody tr:last-child td { border-bottom: 0; }
tbody tr:hover { background: #faf7ef; }
td:first-child { font-weight: 650; color: var(--ink); }
td.bad { color: #9a5c4d; }
td.good { color: var(--jade-dark); font-weight: 600; background: rgba(63,127,116,.045); }
.table-note { font-size: .82rem; color: var(--muted); margin-top: 14px; }

/* ---------- pain / steps ---------- */
.pain-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
.pain {
  display: flex; gap: 14px; padding: 18px 20px; background: var(--paper-2);
  border: 1px solid var(--line); border-left: 3px solid var(--seal); border-radius: 10px;
}
.pain .mark { color: var(--seal); font-weight: 800; font-size: 1.1rem; line-height: 1.4; }
.pain b { display: block; font-size: .96rem; }
.pain span { font-size: .86rem; color: var(--muted); }
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; counter-reset: step; }
.step { position: relative; padding: 24px 22px; background: var(--paper-2); border: 1px solid var(--line); border-radius: var(--radius); }
.step::before {
  counter-increment: step; content: "0" counter(step);
  display: block; font-size: 1.5rem; font-weight: 800; color: var(--jade); margin-bottom: 10px;
}
.step p { font-size: .9rem; color: var(--muted); margin: 0; }

/* ---------- pricing ---------- */
.price-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; align-items: stretch; }
.plan {
  background: var(--paper-2); border: 1px solid var(--line); border-radius: 18px;
  padding: 28px 26px; display: flex; flex-direction: column; position: relative;
}
.plan.featured { border: 2px solid var(--jade); box-shadow: var(--shadow); transform: translateY(-6px); }
.plan .tag {
  position: absolute; top: -13px; left: 50%; transform: translateX(-50%);
  background: var(--jade); color: #fff; font-size: .74rem; font-weight: 700;
  padding: 4px 14px; border-radius: 999px; white-space: nowrap;
}
.plan h3 { font-size: 1.22rem; margin-bottom: 4px; }
.plan .who { font-size: .83rem; color: var(--muted); margin-bottom: 18px; }
.plan .price { font-size: 2.5rem; font-weight: 800; letter-spacing: -.03em; line-height: 1.1; }
.plan .price small { font-size: .9rem; font-weight: 600; color: var(--muted); letter-spacing: 0; }
.plan .early { font-size: .82rem; color: var(--seal); font-weight: 650; margin: 6px 0 0; min-height: 1.4em; }
.plan ul { list-style: none; padding: 0; margin: 20px 0 26px; flex: 1; }
.plan li { font-size: .9rem; padding: 7px 0 7px 24px; position: relative; color: var(--ink-soft); }
.plan li::before { content: "✓"; position: absolute; left: 0; color: var(--jade); font-weight: 800; }
.plan li.off { color: #a3a8a4; }
.plan li.off::before { content: "—"; color: #b8bdb9; }
.guarantee { margin-top: 26px; display: flex; gap: 20px; flex-wrap: wrap; font-size: .86rem; color: var(--muted); }
.guarantee span::before { content: "◆"; color: var(--jade); margin-right: 7px; font-size: .7rem; }

/* ---------- fit / quote ---------- */
.fit { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.fit .box { padding: 26px; border-radius: var(--radius); border: 1px solid var(--line); background: var(--paper-2); }
.fit .box.no { background: #fbf5f1; border-color: #eeded6; }
.fit ul { margin: 0; padding-left: 20px; font-size: .92rem; color: var(--ink-soft); }
.fit li { margin-bottom: 7px; }
.quote {
  padding: 34px 38px; border-left: 4px solid var(--jade); background: var(--jade-pale);
  border-radius: 0 var(--radius) var(--radius) 0; font-size: 1.08rem; color: var(--ink-soft);
}
.quote b { color: var(--jade-dark); }

/* ---------- faq ---------- */
.faq { display: grid; gap: 12px; }
.faq details { background: var(--paper-2); border: 1px solid var(--line); border-radius: 12px; padding: 18px 22px; }
.faq summary { cursor: pointer; font-weight: 680; font-size: 1rem; list-style: none; display: flex; justify-content: space-between; gap: 16px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--jade); font-weight: 800; flex: none; }
.faq details[open] summary::after { content: "−"; }
.faq details p { margin: 14px 0 0; color: var(--muted); font-size: .93rem; }
.faq details p:first-of-type { color: var(--ink-soft); }

/* ---------- CTA band ---------- */
.cta-band { background: var(--ink); color: #fff; border-radius: 20px; padding: 52px 46px; display: flex; align-items: center; justify-content: space-between; gap: 30px; flex-wrap: wrap; }
.cta-band h2 { color: #fff; margin-bottom: 8px; }
.cta-band p { color: #b8c1bd; margin: 0; font-size: .96rem; }
.cta-band .btn-primary { background: #fff; color: var(--ink); }
.cta-band .btn-primary:hover { background: var(--jade-pale); }
.cta-band .btn-outline { color: #fff; border-color: rgba(255,255,255,.35); }
.cta-band .btn-outline:hover { background: rgba(255,255,255,.08); }
.cta-band .actions { display: flex; gap: 12px; flex-wrap: wrap; }

/* ---------- footer ---------- */
footer { border-top: 1px solid var(--line); padding: 46px 0 34px; font-size: .86rem; color: var(--muted); }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 30px; margin-bottom: 34px; }
.footer-grid h4 { font-size: .84rem; color: var(--ink); letter-spacing: .08em; margin-bottom: 12px; }
.footer-grid a { display: block; padding: 3px 0; color: var(--muted); }
.footer-grid a:hover { color: var(--jade-dark); }
.footer-brand p { max-width: 320px; }
.footer-bottom { border-top: 1px solid var(--line-soft); padding-top: 20px; display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }

/* ---------- crumbs / article ---------- */
.page-head { padding: 54px 0 10px; }
.page-head h1 { font-size: clamp(2rem, 4vw, 3rem); }
.page-head p { color: var(--muted); font-size: 1.05rem; max-width: 760px; }
.crumbs { font-size: .8rem; color: var(--muted); margin-bottom: 18px; }
.crumbs a { color: var(--muted); }
.fact {
  background: var(--jade-pale); border: 1px solid #d5e6df; border-radius: 12px;
  padding: 18px 22px; font-size: .95rem; color: var(--ink-soft); margin: 22px 0 34px;
}
.fact b { color: var(--jade-dark); }
.prose h2 { margin-top: 46px; font-size: 1.6rem; }
.prose h3 { margin-top: 28px; }
.prose p, .prose li { color: var(--ink-soft); }
.prose table { margin: 18px 0; }
.note { border-left: 3px solid var(--seal); padding: 4px 0 4px 18px; color: var(--muted); font-size: .92rem; }

/* ---------- purchase modal ---------- */
.overlay {
  position: fixed; inset: 0; z-index: 90; background: rgba(16, 20, 21, .6);
  backdrop-filter: blur(4px); display: none; align-items: center; justify-content: center; padding: 20px;
}
.overlay.open { display: flex; }
.modal {
  background: var(--paper-2); border-radius: 20px; width: min(520px, 100%);
  max-height: min(92vh, 860px); box-shadow: 0 30px 80px rgba(0,0,0,.3);
  position: relative; padding: 0; display: flex; flex-direction: column; overflow: hidden;
}
/* 内容区可滚动，主按钮固定在底部，避免被挤到视口之外。 */
.modal-body { flex: 1 1 auto; min-height: 0; overflow-y: auto; overscroll-behavior: contain; padding: 28px 28px 8px; }
.modal-foot { flex: none; padding: 10px 28px 16px; background: var(--paper-2); border-top: 1px solid var(--line-soft); box-shadow: 0 -10px 18px rgba(20, 24, 26, .05); }
.modal .close { position: absolute; top: 16px; right: 18px; z-index: 2; background: none; border: 0; font-size: 1.6rem; color: var(--muted); line-height: 1; }
.modal h2 { font-size: 1.5rem; margin-bottom: 4px; }
.modal .sub { color: var(--muted); font-size: .88rem; margin-bottom: 20px; }
.order-summary { background: var(--paper); border: 1px solid var(--line); border-radius: 12px; padding: 16px 18px; margin-bottom: 18px; }
.order-summary .row { display: flex; justify-content: space-between; font-size: .9rem; padding: 4px 0; }
.order-summary .row.total { border-top: 1px solid var(--line); margin-top: 8px; padding-top: 10px; font-weight: 750; font-size: 1.05rem; }
.order-summary .row.total b { color: var(--seal); font-size: 1.3rem; }
.field { margin-bottom: 14px; }
.field label { display: block; font-size: .84rem; font-weight: 650; margin-bottom: 6px; }
.field input {
  width: 100%; padding: 11px 13px; border: 1px solid var(--line); border-radius: 9px;
  background: #fff; font-size: .93rem; color: var(--ink); outline: none;
}
.field input:focus { border-color: var(--jade); box-shadow: 0 0 0 3px rgba(63,127,116,.12); }
.demo-note { background: #fcf4e2; border: 1px solid #eddcb4; color: #8a6a25; font-size: .82rem; padding: 10px 14px; border-radius: 9px; margin-bottom: 16px; }
.pay-tabs { display: flex; gap: 8px; margin: 4px 0 14px; }
.pay-tab { flex: 1; padding: 9px 6px; border: 1px solid var(--line); background: #fff; border-radius: 9px; font-size: .85rem; font-weight: 650; color: var(--ink-soft); }
.pay-tab.active { border-color: var(--jade); background: var(--jade-pale); color: var(--jade-dark); }
.pay-box { text-align: center; padding: 18px; border: 1px dashed var(--line); border-radius: 12px; background: var(--paper); margin-bottom: 14px; }
.qr-frame {
  width: 186px; height: 186px; margin: 0 auto 12px; background: #fff;
  border: 1px solid var(--line); border-radius: 10px; display: grid; place-items: center;
  color: var(--muted); font-size: .8rem; text-align: center; padding: 12px; overflow: hidden;
}
.qr-frame img { width: 100%; height: 100%; object-fit: contain; }
.pay-box p { font-size: .84rem; color: var(--muted); margin: 0; }
.order-id { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: .95rem; letter-spacing: .04em; color: var(--ink); background: var(--paper); padding: 10px 12px; border-radius: 9px; border: 1px solid var(--line); display: flex; justify-content: space-between; align-items: center; gap: 10px; margin-bottom: 14px; }
.order-id button { background: none; border: 0; color: var(--jade-dark); font-size: .82rem; font-weight: 650; white-space: nowrap; }
.delivery { font-size: .84rem; color: var(--muted); background: var(--jade-pale); border-radius: 10px; padding: 14px 16px; margin-top: 14px; }
.delivery b { color: var(--jade-dark); }
.toast {
  position: fixed; left: 50%; bottom: 34px; transform: translate(-50%, 20px);
  background: var(--ink); color: #fff; padding: 11px 20px; border-radius: 10px;
  font-size: .88rem; opacity: 0; pointer-events: none; transition: all .25s ease; z-index: 120;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }

/* ---------- responsive ---------- */
@media (max-width: 980px) {
  .hero-grid { grid-template-columns: 1fr; gap: 36px; }
  .hero { padding-top: 46px; }
  .cards.c3, .price-grid, .steps { grid-template-columns: 1fr; }
  .plan.featured { transform: none; }
  .stats .grid4 { grid-template-columns: repeat(2, 1fr); row-gap: 22px; }
  .stat:nth-child(2) { border-right: 0; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .nav { display: none; position: absolute; top: 68px; left: 0; right: 0; background: var(--paper-2); border-bottom: 1px solid var(--line); padding: 16px 20px; flex-direction: column; align-items: stretch; gap: 14px; }
  .nav.open { display: flex; }
  .nav .nav-cta { margin-left: 0; }
  .menu-toggle { display: block; margin-left: auto; }
}
@media (max-width: 680px) {
  section { padding: 58px 0; }
  .cards.c2, .pain-list, .fit { grid-template-columns: 1fr; }
  .stats .grid4 { grid-template-columns: 1fr 1fr; }
  .cta-band { padding: 34px 26px; }
  .footer-grid { grid-template-columns: 1fr; gap: 20px; }
  .hero .cta-row .btn { flex: 1; }
  .modal-body { padding: 22px 22px 10px; }
  .modal-foot { padding: 10px 22px 16px; }
  th, td { padding: 13px 14px; }
}