:root {
    --blue: #0088cb;
    --ink: #31333e;
    --text: #4c4f60;
    --muted: #6f6c7f;
    --line: #f0f0f0;
    --bg: #f7f6f9;
}

* { box-sizing: border-box; }

body {
    font-family: "Microsoft YaHei", "PingFang SC", sans-serif;
    margin: 0;
    padding: 0;
    background: #fff;
    color: var(--text);
    line-height: 1.6;
}

.container { max-width: 1140px; margin: 0 auto; padding: 0 15px; }
.container-narrow { max-width: 900px; }
a { text-decoration: none; transition: 0.3s; color: var(--blue); }

.header {
    background: #fff;
    padding: 15px 0;
    border-bottom: 1px solid #f7f6f9;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-flex { display: flex; align-items: center; justify-content: space-between; gap: 20px; }

.logo {
    display: flex;
    align-items: center;
    font-size: 22px;
    font-weight: bold;
    color: var(--blue);
    flex-shrink: 0;
}

.logo img { width: 28px; height: 28px; margin-right: 10px; object-fit: contain; }

.nav-list { display: flex; list-style: none; margin: 0; padding: 0; gap: 22px; align-items: center; }
.nav-list a { color: #36324a; font-weight: 500; font-size: 15px; }
.nav-list a:hover,
.nav-list a.active { color: var(--blue); }

.menu-btn {
    display: none;
    border: 1px solid #e6e6e6;
    background: #fff;
    color: var(--ink);
    border-radius: 8px;
    padding: 6px 12px;
    font-size: 18px;
    cursor: pointer;
}

.download-wrapper { padding: 80px 0; background: #fff; border-bottom: 1px solid #f9f9f9; }
.download-flex { display: flex; align-items: center; gap: 60px; flex-wrap: wrap; }
.download-media { flex: 1.2; min-width: 280px; }
.download-media img { width: 100%; border-radius: 15px; box-shadow: 0 20px 50px rgba(0,0,0,0.1); display: block; }
.download-media.phone { text-align: center; }
.download-media.phone img { width: 80%; max-width: 380px; margin: 0 auto; border-radius: 28px; }
.download-content { flex: 1; min-width: 280px; }
.download-content h1 { font-size: 38px; color: var(--ink); margin: 0 0 20px; line-height: 1.2; }
.download-content p { font-size: 16px; color: var(--muted); margin: 0 0 35px; }

.btn-group-vertical { display: flex; flex-direction: column; gap: 15px; max-width: 380px; }

.btn-dl {
    display: flex;
    align-items: center;
    padding: 16px 25px;
    background: var(--blue);
    color: #fff;
    border-radius: 12px;
    font-weight: 600;
    font-size: 16px;
    border: none;
    cursor: pointer;
}

.btn-dl:hover { background: #36324a; transform: translateY(-3px); box-shadow: 0 5px 15px rgba(0,136,203,0.3); color: #fff; }
.btn-dl img { width: 24px; height: 24px; margin-right: 15px; filter: brightness(0) invert(1); object-fit: contain; }
.btn-dl .txt { flex: 1; }
.sys-info { margin-top: 4px; font-size: 13px; color: #999; display: block; }

h2.section-title { font-size: 30px; color: var(--ink); margin: 0 0 30px; text-align: center; font-weight: bold; }

.feature-section { padding: 80px 0; background: var(--bg); }
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.feature-card { background: #fff; padding: 45px 30px; border-radius: 16px; text-align: center; transition: 0.3s; }
.feature-card:hover { transform: translateY(-5px); box-shadow: 0 10px 30px rgba(0,0,0,0.05); }
.feature-card img { width: 110px; height: 110px; margin-bottom: 25px; object-fit: contain; }
.feature-card h3 { color: var(--blue); font-size: 22px; margin: 0 0 15px; }
.feature-card p { font-size: 14px; color: var(--muted); margin: 0; line-height: 1.8; }

.info-section { padding: 80px 0; background: #fff; }
.info-flex { display: flex; gap: 50px; flex-wrap: wrap; }
.info-column { flex: 1; min-width: 280px; }
.info-column h2 {
    text-align: left;
    font-size: 26px;
    color: var(--ink);
    border-left: 5px solid var(--blue);
    padding-left: 15px;
    margin: 0 0 35px;
}

.step-item { margin-bottom: 25px; display: flex; gap: 20px; }
.step-num {
    background: var(--blue);
    color: #fff;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    font-weight: bold;
    font-size: 15px;
}
.step-text h4 { margin: 0 0 8px; color: var(--ink); font-size: 17px; }
.step-text p { margin: 0; font-size: 14px; color: var(--muted); }

.faq-item { margin-bottom: 20px; border-bottom: 1px solid var(--line); padding-bottom: 20px; }
.faq-item h4 { color: var(--blue); margin: 0 0 10px; font-size: 16px; }
.faq-item p { margin: 0; font-size: 14px; color: var(--muted); }

.page-title { text-align: center; padding: 60px 0 40px; }
.page-title h1 { font-size: 36px; color: var(--ink); margin: 0 0 10px; }
.page-title p { color: var(--muted); font-size: 16px; margin: 0; }

.faq-page { background: var(--bg); }
.faq-container {
    background: #fff;
    border-radius: 16px;
    padding: 10px 8px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    margin-bottom: 80px;
}
.faq-acc { border-bottom: 1px solid var(--line); }
.faq-acc:last-child { border-bottom: none; }
.faq-question {
    display: flex;
    align-items: center;
    padding: 18px 16px;
    cursor: pointer;
    background: transparent;
    border: none;
    width: 100%;
    text-align: left;
    font: inherit;
}
.faq-question:hover { background: #fafafa; }
.faq-question img { width: 32px; height: 32px; margin-right: 15px; object-fit: contain; }
.faq-question h3 { margin: 0; font-size: 17px; color: var(--ink); font-weight: 600; flex: 1; }
.faq-question::after { content: "+"; font-size: 22px; color: var(--blue); font-weight: bold; }
.faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.3s ease; background: #f9f9f9; }
.faq-answer p { padding: 15px 20px 15px 63px; margin: 0; color: var(--muted); font-size: 15px; }
.faq-acc.active .faq-answer { max-height: 280px; }
.faq-acc.active .faq-question::after { content: "−"; }

.about-section { padding: 60px 0 80px; }
.about-section h1 { font-size: 32px; color: var(--ink); text-align: center; margin: 0 0 10px; }
.about-section .subtitle { text-align: center; color: #999; font-size: 14px; margin: 0 0 40px; }
.about-section h2 { font-size: 22px; color: var(--blue); margin: 36px 0 12px; border-left: 4px solid var(--blue); padding-left: 12px; }
.about-section p { font-size: 15px; color: #555; margin: 0 0 15px; }
.about-section ul { padding-left: 20px; margin: 0; }
.about-section li { font-size: 15px; color: #555; margin-bottom: 10px; }
.highlight-box { background: var(--bg); border-radius: 12px; padding: 28px; margin: 36px 0; }
.highlight-box p { margin: 0; text-align: center; font-size: 16px; color: var(--ink); font-weight: 500; }

.footer { background: #f9f9f9; padding: 60px 0 20px; color: #666; font-size: 14px; }
.footer-grid { display: grid; grid-template-columns: 1.3fr 1fr 1fr; gap: 40px; }
.footer a { color: #666; }
.footer a:hover { color: var(--blue); }
.footer-logo { display: flex; align-items: center; font-size: 20px; font-weight: bold; color: var(--blue); margin-bottom: 15px; }
.footer-logo img { width: 30px; height: 30px; margin-right: 10px; object-fit: contain; }
.footer-col h4 { color: #333; margin: 0 0 18px; font-size: 16px; }
.footer-col ul { list-style: none; padding: 0; margin: 0; }
.footer-col li { margin-bottom: 10px; }
.footer-copy { text-align: center; border-top: 1px solid #eee; margin-top: 30px; padding-top: 20px; }
.footer-copy p { margin: 0; }

@media (max-width: 991px) {
    .feature-grid { grid-template-columns: repeat(2, 1fr); }
    .download-flex, .info-flex { flex-direction: column; }
    .download-content h1, .download-content p { text-align: center; }
    .btn-group-vertical { margin: 0 auto; }
    .sys-info { text-align: center; }
    .menu-btn { display: block; }
    .nav-list {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: #fff;
        flex-direction: column;
        align-items: flex-start;
        padding: 12px 20px 18px;
        gap: 14px;
        border-bottom: 1px solid #f0f0f0;
        box-shadow: 0 12px 24px rgba(0,0,0,0.06);
    }
    body.nav-open .nav-list { display: flex; }
}

@media (max-width: 600px) {
    .feature-grid, .footer-grid { grid-template-columns: 1fr; }
    .download-content h1, .page-title h1 { font-size: 30px; }
    .download-wrapper, .feature-section, .info-section { padding: 48px 0; }
}