:root {
  --bg: #fff;
  --surface: #f7f9f7;
  --surface-strong: #edf4ed;
  --text: #111713;
  --muted: #5d6860;
  --line: #dfe5df;
  --green: #11652f;
  --green-2: #2b8244;
  --amber: #e2a92f;
  --shadow: 0 22px 62px rgba(29, 50, 35, .12);
  --radius: 22px;
  --content: min(1180px, calc(100vw - 48px));
  color-scheme: light;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-synthesis: none;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { scroll-behavior: smooth; scroll-padding-top: 88px; }
body { margin: 0; color: var(--text); background: var(--bg); line-height: 1.6; -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
button, a { -webkit-tap-highlight-color: transparent; }
button { font: inherit; }
img { display: block; max-width: 100%; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; }
.skip-link { position: fixed; z-index: 100; left: 16px; top: -60px; padding: 10px 16px; background: var(--text); color: #fff; border-radius: 8px; }
.skip-link:focus { top: 12px; }

.site-header { width: var(--content); height: 78px; margin: 0 auto; display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 48px; position: relative; z-index: 10; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 790; font-size: 23px; letter-spacing: -.04em; white-space: nowrap; }
.brand-mark { position: relative; width: 30px; height: 30px; display: inline-block; }
.brand-mark::after { content: ""; position: absolute; width: 4px; height: 18px; background: var(--green); border-radius: 5px; left: 14px; bottom: 1px; transform: rotate(-1deg); }
.brand-mark i { position: absolute; width: 15px; height: 9px; border-radius: 90% 10% 90% 10%; background: var(--green-2); transform-origin: right bottom; }
.brand-mark i:nth-child(1) { left: 0; top: 4px; transform: rotate(28deg); }
.brand-mark i:nth-child(2) { right: 0; top: 0; transform: rotate(-28deg) scaleX(-1); background: #8db53c; }
.brand-mark i:nth-child(3) { right: 1px; top: 13px; transform: rotate(-8deg) scale(.74) scaleX(-1); }
.main-nav { display: flex; justify-content: center; gap: 36px; font-size: 14px; font-weight: 570; }
.main-nav a, .site-footer nav a { color: var(--muted); transition: color .18s ease; }
.main-nav a:hover, .site-footer nav a:hover { color: var(--green); }
.theme-switch { display: grid; grid-template-columns: 1fr 1fr; padding: 3px; background: #f1f3f1; border: 1px solid var(--line); border-radius: 11px; }
.theme-switch button { border: 0; color: var(--muted); background: transparent; padding: 7px 13px; border-radius: 8px; cursor: pointer; font-size: 13px; font-weight: 610; }
.theme-switch button[aria-pressed="true"] { color: #fff; background: var(--green); box-shadow: 0 3px 12px rgba(17,101,47,.2); }
.menu-button, .mobile-nav { display: none; }

.hero { min-height: 650px; position: relative; overflow: hidden; display: grid; align-items: center; }
.hero-copy { width: var(--content); margin: 0 auto; position: relative; z-index: 2; padding: 60px 55% 120px 0; }
.hero h1 { max-width: 660px; margin: 0; font-size: clamp(48px, 4.2vw, 60px); line-height: 1.1; letter-spacing: -.065em; font-weight: 820; }
.hero h1 span { display: inline-block; white-space: nowrap; }
.hero-copy > p { max-width: 520px; font-size: 18px; color: var(--muted); margin: 30px 0 28px; line-height: 1.8; }
.hero-actions { display: flex; gap: 12px; }
.button { min-height: 48px; padding: 0 22px; border-radius: 10px; display: inline-flex; align-items: center; justify-content: center; flex-shrink: 0; white-space: nowrap; font-size: 15px; font-weight: 680; border: 1px solid var(--green); transition: transform .18s ease, box-shadow .18s ease, background .18s ease; }
.button:hover { transform: translateY(-2px); }
.button:focus-visible, .theme-switch button:focus-visible, .main-nav a:focus-visible { outline: 3px solid rgba(45, 130, 69, .3); outline-offset: 3px; }
.button.primary { background: var(--green); color: #fff; box-shadow: 0 10px 24px rgba(17,101,47,.2); }
.button.primary:hover { background: #0a5525; box-shadow: 0 14px 30px rgba(17,101,47,.26); }
.button.secondary { background: rgba(255,255,255,.86); color: var(--green); backdrop-filter: blur(8px); }
.proof-list { list-style: none; display: flex; gap: 24px; padding: 0; margin: 36px 0 0; font-size: 12px; color: var(--muted); font-weight: 560; }
.proof-list li { display: flex; align-items: center; flex-shrink: 0; gap: 7px; white-space: nowrap; }
.proof-list li::before { content: ""; width: 6px; height: 6px; flex-shrink: 0; background: var(--green-2); border-radius: 50%; }
.hero-art { position: absolute; inset: 0; overflow: hidden; }
.hero-art picture { position: absolute; inset: 0; transition: opacity .45s ease, transform .7s ease; }
.hero-art img { position: absolute; width: min(860px, 61vw); right: max(-30px, calc((100vw - 1260px) / 2)); top: 32px; }
.nostalgia-art { opacity: 0; pointer-events: none; }

.section-shell, .section-pad { width: var(--content); margin-inline: auto; }
.workflow { border: 1px solid var(--line); border-radius: var(--radius); background: rgba(255,255,255,.91); box-shadow: 0 10px 40px rgba(29,50,35,.05); position: relative; z-index: 4; margin-top: -42px; }
.workflow-list { list-style: none; margin: 0; padding: 28px 32px; display: grid; grid-template-columns: repeat(4, 1fr); }
.workflow-list li { display: grid; grid-template-columns: 30px 1fr; gap: 12px; padding: 0 28px; position: relative; }
.workflow-list li:not(:last-child)::after { content: "→"; position: absolute; right: -5px; top: 19px; color: #87a38d; font-size: 21px; }
.step-number { width: 25px; height: 25px; border-radius: 50%; background: var(--green); color: #fff; display: grid; place-items: center; font-size: 12px; font-weight: 750; margin-top: 2px; }
.workflow strong { font-size: 17px; }
.workflow p { margin: 6px 0 0; color: var(--muted); font-size: 13px; line-height: 1.55; }

.section-pad { padding-block: 116px; }
.section-heading { text-align: center; max-width: 680px; margin: 0 auto 48px; }
.section-heading h2, .harvest h2, .privacy h2, .final-cta h2 { font-size: clamp(32px, 3.4vw, 48px); line-height: 1.18; letter-spacing: -.05em; margin: 0; }
.section-heading p, .harvest-copy > p { color: var(--muted); margin: 16px 0 0; font-size: 16px; }
.seed-row { display: grid; grid-template-columns: repeat(6, 1fr); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.seed-row article { padding: 36px 18px 34px; text-align: center; position: relative; transition: background .2s ease, transform .2s ease; }
.seed-row article:not(:last-child)::after { content: ""; position: absolute; right: 0; top: 26px; bottom: 26px; width: 1px; background: var(--line); }
.seed-row article:hover { background: var(--surface); transform: translateY(-4px); }
.seed { width: 34px; height: 47px; margin: 0 auto 22px; display: block; background: linear-gradient(135deg, color-mix(in srgb, var(--seed), white 38%), var(--seed) 58%, color-mix(in srgb, var(--seed), black 18%)); border-radius: 65% 35% 62% 38% / 62% 40% 60% 38%; transform: rotate(22deg); box-shadow: inset 6px 3px 10px rgba(255,255,255,.3), 0 8px 18px color-mix(in srgb, var(--seed), transparent 70%); }
.seed-row h3 { margin: 0; font-size: 16px; }
.seed-row p { margin: 10px 0 0; color: var(--muted); font-size: 12px; line-height: 1.6; }

.harvest { display: grid; grid-template-columns: .72fr 1.28fr; gap: 66px; align-items: center; background: var(--surface); border-radius: 32px; padding-inline: 52px; }
.harvest-copy > p { line-height: 1.8; }
.evidence-steps { list-style: none; padding: 0; margin: 34px 0 0; display: grid; gap: 22px; }
.evidence-steps li { display: grid; grid-template-columns: 25px 1fr; gap: 12px; }
.evidence-steps li > span { background: var(--green); color: #fff; width: 22px; height: 22px; border-radius: 50%; display: grid; place-items: center; font-size: 12px; margin-top: 2px; }
.evidence-steps strong { font-size: 15px; }
.evidence-steps p { margin: 3px 0 0; color: var(--muted); font-size: 13px; }
.product-shot { margin: 0; padding: 10px; background: #fff; border: 1px solid var(--line); border-radius: 18px; box-shadow: var(--shadow); transform: rotate(.4deg); }
.product-shot img { border-radius: 10px; border: 1px solid #e7e9e7; }
.product-shot figcaption { color: var(--muted); font-size: 11px; padding: 10px 7px 2px; text-align: center; }

.privacy { display: grid; grid-template-columns: .7fr 1.35fr .9fr; gap: 60px; align-items: center; }
.privacy-copy ul, .requirements ul { list-style: none; padding: 0; margin: 30px 0; display: grid; gap: 15px; }
.privacy-copy li, .requirements li { position: relative; padding-left: 28px; color: var(--muted); font-size: 14px; }
.privacy-copy li::before, .requirements li::before { content: "✓"; position: absolute; left: 0; color: var(--green); font-weight: 800; }
.text-link { color: var(--green); font-size: 14px; font-weight: 680; }
.requirements { padding: 28px; border: 1px solid var(--line); border-radius: 20px; background: var(--surface); }
.requirements h3 { margin: 0; font-size: 18px; }
.requirements ul { margin: 20px 0; gap: 10px; }
.requirements p { color: var(--muted); font-size: 12px; margin: 0; }
.privacy-illustration { min-height: 250px; display: grid; place-items: center; }
.house { position: relative; width: 168px; height: 142px; background: #eef3ef; border: 3px solid #cbd6cd; border-radius: 9px; display: block; box-shadow: 0 25px 40px rgba(30,66,40,.07); }
.roof { position: absolute; width: 126px; height: 126px; background: #f5f7f5; border: 3px solid #cbd6cd; transform: rotate(45deg); top: -62px; left: 18px; border-radius: 8px; z-index: -1; }
.door { position: absolute; width: 55px; height: 82px; border: 3px solid #9eaea2; background: white; left: 54px; bottom: -3px; border-radius: 20px 20px 3px 3px; }
.lock { position: absolute; display: grid; place-items: center; width: 56px; height: 56px; border-radius: 16px; background: var(--green); color: #fff; font-style: normal; font-size: 26px; left: 54px; bottom: 31px; box-shadow: 0 12px 25px rgba(17,101,47,.23); }

.final-cta { min-height: 184px; margin-bottom: 52px; padding: 40px 64px; border-radius: 28px; display: flex; align-items: center; justify-content: space-between; background: linear-gradient(105deg, #f2f7f0, #e7f1e4); position: relative; overflow: hidden; }
.final-cta::after { content: ""; position: absolute; width: 300px; height: 160px; border: 1px solid #c7dac9; border-radius: 50%; right: 140px; bottom: -125px; box-shadow: 0 0 0 26px rgba(199,218,201,.3), 0 0 0 52px rgba(199,218,201,.16); }
.final-cta > * { position: relative; z-index: 1; }
.final-cta h2 { font-size: 34px; }
.final-cta p { margin: 8px 0 0; color: var(--muted); }
.site-footer { width: var(--content); min-height: 110px; margin: 0 auto; border-top: 1px solid var(--line); display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 40px; }
.site-footer p { font-size: 13px; color: var(--muted); }
.site-footer nav { display: flex; gap: 28px; font-size: 13px; }

/* 青春农场保留同一信息架构，只改变时代情绪。 */
html[data-theme="nostalgia"] { --bg: #eaf8fb; --surface: #fffaf0; --surface-strong: #fff1cf; --text: #29441c; --muted: #586b48; --line: #d6d6b9; --green: #548523; --green-2: #77a72e; --amber: #e5a83e; --shadow: 0 18px 46px rgba(91,91,41,.16); }
[data-theme="nostalgia"] .agent-art { opacity: 0; pointer-events: none; }
[data-theme="nostalgia"] .nostalgia-art { opacity: 1; }
[data-theme="nostalgia"] .hero { min-height: 690px; background: #dff4fb; }
[data-theme="nostalgia"] .hero-art::after { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, rgba(224,246,252,.96) 0%, rgba(224,246,252,.75) 32%, transparent 56%); }
[data-theme="nostalgia"] .hero-art img { width: 100%; height: 100%; right: 0; top: 0; object-fit: cover; object-position: center; }
[data-theme="nostalgia"] .hero h1 { color: #365e22; text-shadow: 0 2px rgba(255,255,255,.4); }
[data-theme="nostalgia"] .theme-switch { background: rgba(255,255,255,.76); border-color: #cbd7b7; }
[data-theme="nostalgia"] .workflow { background: rgba(255,250,240,.96); border: 2px solid #dfc990; box-shadow: 0 8px 0 rgba(160,111,43,.09), 0 18px 42px rgba(90,72,24,.12); }
[data-theme="nostalgia"] .step-number { border-radius: 7px; background: #a96825; box-shadow: inset 0 2px rgba(255,255,255,.3); }
[data-theme="nostalgia"] .seed-row { border-color: #c8bb89; }
[data-theme="nostalgia"] .seed-row article:hover { background: rgba(255,250,225,.8); }
[data-theme="nostalgia"] .harvest { background: #fff8e7; border: 2px solid #e2ca91; box-shadow: inset 0 0 0 6px rgba(229,168,62,.07); }
[data-theme="nostalgia"] .final-cta { background: linear-gradient(105deg, #fff7df, #e9f3cf); border: 1px solid #d8c289; }

@media (max-width: 980px) {
  :root { --content: min(100% - 34px, 760px); }
  .site-header { grid-template-columns: auto 1fr auto; gap: 18px; }
  .main-nav { display: none; }
  .theme-switch { justify-self: end; }
  .hero { min-height: 780px; align-items: start; }
  .hero-copy { padding: 58px 0 410px; }
  .hero-art img { width: 760px; max-width: none; top: 330px; right: 50%; transform: translateX(50%); }
  [data-theme="nostalgia"] .hero-art::after { background: linear-gradient(180deg, rgba(224,246,252,.98) 0%, rgba(224,246,252,.82) 40%, transparent 70%); }
  [data-theme="nostalgia"] .hero-art img { top: 0; transform: none; right: 0; width: 100%; }
  .workflow { margin-top: -20px; }
  .workflow-list { grid-template-columns: repeat(2, 1fr); gap: 28px 0; }
  .workflow-list li:nth-child(2)::after { display: none; }
  .seed-row { grid-template-columns: repeat(3, 1fr); }
  .seed-row article:nth-child(3)::after { display: none; }
  .harvest { grid-template-columns: 1fr; gap: 38px; }
  .privacy { grid-template-columns: .7fr 1.3fr; }
  .requirements { grid-column: 1 / -1; }
}

@media (max-width: 640px) {
  :root { --content: calc(100% - 28px); }
  .site-header { height: 68px; grid-template-columns: auto 1fr auto; }
  .brand { font-size: 20px; }
  .theme-switch { position: fixed; z-index: 20; left: 50%; transform: translateX(-50%); bottom: 14px; box-shadow: 0 8px 28px rgba(24,49,31,.22); background: rgba(244,247,244,.94); backdrop-filter: blur(16px); }
  .theme-switch button { padding-inline: 17px; }
  .menu-button { display: grid; width: 40px; height: 40px; border: 1px solid var(--line); border-radius: 10px; background: var(--bg); align-content: center; justify-content: center; gap: 6px; }
  .menu-button span { width: 18px; height: 2px; border-radius: 3px; background: var(--text); }
  .mobile-nav { position: absolute; z-index: 12; right: 14px; top: 60px; width: 180px; padding: 10px; background: var(--bg); border: 1px solid var(--line); border-radius: 15px; box-shadow: var(--shadow); }
  .mobile-nav:not([hidden]) { display: grid; }
  .mobile-nav a { padding: 11px 12px; font-size: 14px; border-radius: 8px; }
  .mobile-nav a:hover { background: var(--surface); }
  .hero { min-height: 710px; }
  .hero-copy { padding: 45px 0 365px; }
  .hero h1 { font-size: 43px; }
  .hero-copy > p { font-size: 16px; margin-top: 22px; }
  .hero-actions { align-items: stretch; flex-direction: column; width: min(100%, 320px); }
  .proof-list { display: grid; grid-template-columns: 1fr 1fr; gap: 8px 16px; margin-top: 24px; }
  .hero-art img { width: 620px; top: 392px; }
  [data-theme="nostalgia"] .hero { min-height: 750px; }
  [data-theme="nostalgia"] .hero-copy { padding-bottom: 390px; }
  [data-theme="nostalgia"] .hero-art img { object-position: 62% center; }
  .workflow-list { grid-template-columns: 1fr; padding: 26px 22px; }
  .workflow-list li { padding: 0; }
  .workflow-list li::after { display: none; }
  .section-pad { padding-block: 76px; }
  .section-heading { text-align: left; margin-bottom: 32px; }
  .seed-row { grid-template-columns: repeat(2, 1fr); }
  .seed-row article:nth-child(3)::after { display: block; }
  .seed-row article:nth-child(2n)::after { display: none; }
  .harvest { padding: 54px 20px; border-radius: 24px; }
  .privacy { grid-template-columns: 1fr; gap: 30px; }
  .privacy-illustration { min-height: 180px; transform: scale(.78); }
  .requirements { grid-column: auto; }
  .final-cta { padding: 38px 24px; display: grid; gap: 26px; margin-bottom: 30px; }
  .final-cta h2 { font-size: 30px; }
  .site-footer { padding: 30px 0 90px; grid-template-columns: 1fr auto; gap: 10px; }
  .site-footer p { grid-row: 2; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; }
}