:root {
    --green: #0b7a5e;
    --green-2: #13a87f;
    --green-soft: #e6f5ef;
    --ink: #14302a;
    --muted: #5d736d;
    --bg: #ffffff;
    --bg-alt: #f4f9f6;
    --line: #e2ece8;
    --shadow: 0 10px 30px rgba(11, 122, 94, .12);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    color: var(--ink);
    background: var(--bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}
a { text-decoration: none; color: inherit; }
img, svg { display: block; }

/* ===== 导航 ===== */
.nav {
    position: sticky; top: 0; z-index: 50;
    background: rgba(255, 255, 255, .85);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--line);
}
.nav-inner {
    max-width: 1120px; margin: 0 auto;
    padding: 14px 20px;
    display: flex; align-items: center; justify-content: space-between;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; }
.brand-logo { color: var(--green); display: flex; }
.brand-name { font-size: 19px; letter-spacing: .3px; }
.brand-name em { font-style: normal; color: var(--green); font-weight: 800; }
.nav-links { display: flex; align-items: center; gap: 26px; font-size: 15px; }
.nav-links a { color: var(--muted); transition: color .2s; }
.nav-links a:hover { color: var(--green); }
.nav-cta {
    background: var(--green); color: #fff !important;
    padding: 8px 18px; border-radius: 999px; font-weight: 600;
    box-shadow: 0 6px 16px rgba(11, 122, 94, .25);
}
.nav-cta:hover { background: var(--green-2); }
.nav-toggle {
    display: none; flex-direction: column; gap: 5px;
    background: none; border: 0; cursor: pointer; padding: 6px;
}
.nav-toggle span { width: 24px; height: 2px; background: var(--ink); border-radius: 2px; }
.nav-mobile {
    display: none; flex-direction: column;
    padding: 8px 20px 16px; gap: 4px;
    border-top: 1px solid var(--line);
}
.nav-mobile a { padding: 10px 4px; color: var(--muted); border-radius: 8px; }
.nav-mobile .nav-cta { text-align: center; color: #fff !important; margin-top: 6px; }

/* ===== Hero ===== */
.hero { position: relative; overflow: hidden; }
.hero-bg {
    position: absolute; inset: 0;
    background:
        radial-gradient(900px 480px at 85% -10%, rgba(19, 168, 127, .18), transparent 60%),
        radial-gradient(700px 400px at 10% 110%, rgba(11, 122, 94, .10), transparent 60%),
        linear-gradient(180deg, #f6fbf8, #ffffff);
}
.hero-inner {
    position: relative;
    max-width: 1120px; margin: 0 auto;
    padding: 70px 20px 80px;
    display: grid; grid-template-columns: 1.05fr .95fr; gap: 40px; align-items: center;
}
.badge {
    display: inline-block; font-size: 13px; font-weight: 600;
    color: var(--green); background: var(--green-soft);
    padding: 6px 14px; border-radius: 999px; margin-bottom: 18px;
}
.hero h1 {
    font-size: 46px; line-height: 1.18; font-weight: 800; letter-spacing: -.5px;
}
.hero-sub { margin: 20px 0 28px; font-size: 17px; color: var(--muted); max-width: 480px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-meta {
    list-style: none; display: flex; gap: 30px; margin-top: 36px;
}
.hero-meta li { display: flex; flex-direction: column; }
.hero-meta strong { font-size: 22px; color: var(--green); }
.hero-meta span { font-size: 13px; color: var(--muted); }

/* 手机视觉 */
.hero-visual { display: flex; justify-content: center; }
.phone {
    width: 250px; height: 500px; border-radius: 38px;
    background: #0e1f1a; padding: 12px;
    box-shadow: 0 30px 60px rgba(11, 122, 94, .25), inset 0 0 0 2px #1c2f29;
    position: relative;
}
.phone-notch {
    position: absolute; top: 12px; left: 50%; transform: translateX(-50%);
    width: 90px; height: 16px; background: #0e1f1a; border-radius: 0 0 12px 12px; z-index: 2;
}
.phone-screen {
    width: 100%; height: 100%; border-radius: 28px;
    background: linear-gradient(180deg, #0b7a5e, #13a87f 55%, #0e1f1a);
    color: #fff; padding: 34px 18px 18px;
    display: flex; flex-direction: column; gap: 16px;
}
.pulse-wrap { display: flex; justify-content: center; padding-top: 10px; }
.heart-pulse { width: 100%; }
.ecg { fill: none; stroke: #fff; stroke-width: 2.5; stroke-linecap: round; stroke-linejoin: round; }
.ecg {
    stroke-dasharray: 600; stroke-dashoffset: 600;
    animation: draw 2.4s linear infinite;
}
@keyframes draw { to { stroke-dashoffset: 0; } }
.screen-status {
    display: inline-flex; align-items: center; gap: 8px;
    background: rgba(255, 255, 255, .16); padding: 8px 12px; border-radius: 12px;
    font-size: 13px; align-self: flex-start;
}
.dot { width: 8px; height: 8px; border-radius: 50%; }
.dot.ok { background: #7CFFB2; box-shadow: 0 0 0 3px rgba(124, 255, 178, .3); }
.screen-loc { font-size: 14px; opacity: .95; }
.screen-contact {
    margin-top: auto; background: rgba(255, 255, 255, .14);
    border-radius: 14px; padding: 12px 14px;
}
.screen-contact span { font-size: 12px; opacity: .8; }
.screen-contact strong { display: block; font-size: 15px; }

/* ===== 按钮 ===== */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 8px;
    padding: 12px 22px; border-radius: 999px; font-weight: 600; font-size: 15px;
    cursor: pointer; transition: transform .15s, box-shadow .2s, background .2s;
    border: 1px solid transparent;
}
.btn-primary {
    background: var(--green); color: #fff;
    box-shadow: 0 8px 20px rgba(11, 122, 94, .28);
}
.btn-primary:hover { background: var(--green-2); transform: translateY(-1px); }
.btn-ghost { background: transparent; border-color: var(--line); color: var(--ink); }
.btn-ghost:hover { border-color: var(--green); color: var(--green); }
.btn-lg { padding: 15px 30px; font-size: 16px; }
.btn-block { width: 100%; }

/* ===== 通用 section ===== */
.section { max-width: 1120px; margin: 0 auto; padding: 76px 20px; }
.section-alt { max-width: none; background: var(--bg-alt); }
.section-alt > * { max-width: 1120px; margin-left: auto; margin-right: auto; }
.section-head { text-align: center; margin-bottom: 46px; }
.section-head h2 { font-size: 32px; font-weight: 800; letter-spacing: -.3px; }
.section-head p { margin-top: 12px; color: var(--muted); font-size: 16px; }

/* ===== 功能卡片 ===== */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.card {
    background: #fff; border: 1px solid var(--line); border-radius: 18px;
    padding: 26px 22px; transition: transform .2s, box-shadow .2s;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.card-icon { font-size: 30px; margin-bottom: 12px; }
.card h3 { font-size: 18px; margin-bottom: 8px; }
.card p { color: var(--muted); font-size: 14.5px; }

/* ===== 工作原理 ===== */
.steps {
    display: flex; align-items: stretch; gap: 12px; flex-wrap: wrap; justify-content: center;
}
.step {
    background: #fff; border: 1px solid var(--line); border-radius: 16px;
    padding: 24px 20px; flex: 1 1 200px; max-width: 250px;
}
.step-no {
    display: inline-flex; align-items: center; justify-content: center;
    width: 34px; height: 34px; border-radius: 50%;
    background: var(--green); color: #fff; font-weight: 700; margin-bottom: 12px;
}
.step h3 { font-size: 17px; margin-bottom: 8px; }
.step p { color: var(--muted); font-size: 14px; }
.step-arrow { align-self: center; font-size: 26px; color: var(--green); }

/* ===== 下载 ===== */
.download-box { display: flex; justify-content: center; }
.download-pc {
    display: flex; gap: 36px; align-items: center;
    background: #fff; border: 1px solid var(--line); border-radius: 22px;
    padding: 32px 40px; box-shadow: var(--shadow);
}
.download-pc[hidden], .download-mobile[hidden] { display: none !important; }
.qr-card { text-align: center; }
.qr-frame {
    width: 200px; height: 200px; padding: 12px; border-radius: 16px;
    background: #fff; border: 1px solid var(--line);
    display: flex; align-items: center; justify-content: center;
}
.qr-tip { margin-top: 12px; font-size: 14px; color: var(--muted); }
.download-actions { display: flex; flex-direction: column; gap: 12px; max-width: 280px; }
.dl-label { font-size: 14px; color: var(--muted); }
.dl-note { font-size: 13px; color: var(--muted); line-height: 1.5; }
.download-mobile { width: 100%; max-width: 420px; text-align: center; }

/* ===== 微信内下载引导蒙层 ===== */
.wechat-overlay {
    position: fixed; inset: 0; z-index: 100;
    background: rgba(0, 0, 0, .88);
    display: flex; flex-direction: column; align-items: flex-end;
    padding: 28px 24px;
}
.wechat-overlay[hidden] { display: none !important; }
.wechat-overlay-inner {
    width: 100%; display: flex; flex-direction: column; align-items: center;
}
.wechat-arrow {
    margin-top: 8px; margin-right: 12px;
    animation: floatArrow 1.2s ease-in-out infinite;
}
@keyframes floatArrow {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-8px); }
}
.wechat-tip {
    color: #fff; font-size: 17px; line-height: 1.7; text-align: center;
    margin-top: 20px; padding: 0 10px;
}
.wechat-tip strong { color: #7CFFB2; }
.wechat-close {
    margin-top: 40px; background: transparent; color: #fff; border: 1px solid rgba(255,255,255,.5);
    padding: 10px 32px; border-radius: 999px; font-size: 15px; cursor: pointer;
}
.wechat-close:active { background: rgba(255,255,255,.15); }

/* ===== 页脚 ===== */
.footer { background: #0e1f1a; color: #cfe7df; }
.footer-inner {
    max-width: 1120px; margin: 0 auto; padding: 40px 20px;
    display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 16px;
}
.foot-brand .brand-name { color: #fff; }
.foot-brand em { color: #7CFFB2; }
.foot-brand p { margin-top: 8px; font-size: 14px; opacity: .8; }
.foot-meta { display: flex; flex-direction: column; gap: 4px; font-size: 13px; opacity: .8; text-align: right; }

/* ===== 响应式 ===== */
@media (max-width: 860px) {
    .nav-links { display: none; }
    .nav-toggle { display: flex; }
    .nav-mobile.open { display: flex; }
    .hero-inner { grid-template-columns: 1fr; padding: 50px 20px 60px; gap: 28px; }
    .hero-visual { order: -1; }
    .hero h1 { font-size: 36px; }
    .hero-meta { gap: 22px; }
    .cards { grid-template-columns: 1fr 1fr; }
    .steps { flex-direction: column; align-items: stretch; }
    .step { max-width: none; }
    .step-arrow { transform: rotate(90deg); align-self: center; }
    .download-pc { flex-direction: column; padding: 28px 24px; gap: 24px; }
}
@media (max-width: 560px) {
    .section { padding: 56px 18px; }
    .section-head h2 { font-size: 26px; }
    .cards { grid-template-columns: 1fr; }
    .hero h1 { font-size: 30px; }
    .hero-meta { flex-wrap: wrap; gap: 16px 22px; }
    .footer-inner { flex-direction: column; align-items: flex-start; }
    .foot-meta { text-align: left; }
}