/* ========== Reset & base ========== */
:root{
    --bg:#0b3a66; /* accent background for hero */
    --card:#0f466f;
    --muted:#a9c3df;
    --surface:#082636;
    --white:#ffffff;
    --radius:12px;
    --gap:20px;
    --max-width:1100px;
    --container-padding:20px;
    --shadow: 0 6px 18px rgba(2,13,26,0.35);
    --text-lg:1.125rem;
    --text-xl:1.5rem;
    --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}
*{box-sizing:border-box}
html,body{height:100%}
body {
    margin: 0;
    font-family: var(--font-stack);
    color: var(--white);
    background: linear-gradient(180deg,#072535 0%, #02181f 100%);
    background-attachment: fixed; /* 鍏抽敭锛氬浐瀹氳儗鏅� */
    background-repeat: no-repeat;
    background-size: cover; /* 瑕嗙洊鏁翠釜瑙嗗彛 */
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    line-height: 1.45;
    -webkit-text-size-adjust: 100%;

}

a{color:inherit;text-decoration:none}
img{max-width:100%;height:auto;display:block}
/* Skip link for accessibility */
.skip-link{
    position:absolute;left:8px;top:8px;padding:8px 12px;background:#fff;color:#012a44;border-radius:6px;z-index:1000;
    transform:translateY(-120%);transition:transform .18s;
}
.skip-link:focus{transform:translateY(0%)}

/* ========== Layout ========== */
.brand{display:flex;align-items:center;gap:14px}
/* === Header 璋冩暣锛屼繚璇佸ぇ logo 涓嶅帇缂╁竷灞€ === */
header {
    padding: 28px var(--container-padding); /* 澧炲姞椤堕儴搴曢儴鍐呰竟璺� */
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    max-width: var(--max-width);
    margin: 0 auto;
}

/* === Logo 鏀惧ぇ鑷� 72px === */
.logo {
    width: 72px;
    height: 72px;
    border-radius: 14px; /* 鍦嗚鐣ュ锛岃瑙夋洿鍗忚皟 */
    background: linear-gradient(180deg, #1b84d6, #0b5ea2);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: var(--white);
    font-size: 1.25rem; /* 瀛楀彿绋嶅ぇ锛屼繚鎸佹瘮渚� */
    box-shadow: var(--shadow);
}

.logo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    border-radius: inherit;
}


nav{display:flex;gap:18px;align-items:center}
.nav-links{display:none} /* mobile: hidden, desktop: shown later */
.btn-ghost{
    padding:8px 12px;border-radius:10px;border:1px solid rgba(255,255,255,0.08);
    background:transparent;font-weight:600;font-size:.95rem;color: #ffffff;
}
/* Hero / main container */
.page{
    max-width:var(--max-width);
    margin:0 auto;
    padding:28px var(--container-padding) 60px;
    padding-bottom: 80px;
}
.hero{
    background: linear-gradient(180deg, rgba(255,255,255,0.03), rgba(255,255,255,0.01));
    border-radius:16px;
    padding:34px;
    box-shadow: 0 8px 30px rgba(2,8,20,0.45);
}
.hero h1{
    margin:6px 0 28px;
    font-size:clamp(1.6rem, 4.5vw, 3.2rem);
    line-height:1.04;
    letter-spacing:-0.02em;
    color:var(--white);
    text-align:center;
    font-weight:800;
}
/* product grid */
.product-grid{
    display:grid;
    grid-template-columns: 1fr;
    gap:var(--gap);
    align-items:stretch;
}
.card{
    background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(0,0,0,0.02));
    border-radius:12px;
    padding:22px;
    text-align:center;
    min-height:150px;
    display:flex;
    flex-direction:column;
    justify-content:center;
    gap:12px;
    border:1px solid rgba(255,255,255,0.04);
    box-shadow: 0 6px 18px rgba(0,0,0,0.35);
    transition:transform .18s ease, box-shadow .18s ease;
}
.card:focus-within, .card:hover{ transform:translateY(-6px); box-shadow: 0 12px 36px rgba(0,0,0,0.45) }
.card .icon{width:64px;height:64px;margin:0 auto;display:inline-flex;align-items:center;justify-content:center}
.card h3{font-size:1.125rem;margin:0;color:var(--white);font-weight:700}
.card p{margin:0;color:var(--muted);font-size:var(--text-lg)}
.card a{outline:none}
/* footer */
footer{
    margin-top:28px;padding:22px;border-radius:12px;background:linear-gradient(180deg, rgba(255,255,255,0.02), rgba(0,0,0,0.02));
    color:var(--muted);
    font-size:.95rem;
}

footer nav {
    display: flex;
    flex-wrap: wrap;          /* 鑷姩鎹㈣ */
    justify-content: left;  /* 灞呬腑瀵归綈 */
    gap: 10px;                /* 閾炬帴闂磋窛 */
    margin-top: 8px;
}

footer nav a {
    color: var(--muted);
    font-size: 0.9rem;
    text-decoration: none;
}

footer nav a:hover {
    color: #ffffff;
}

.footer-cert {
    margin-top: 16px;
    display: flex;
    justify-content: center;
    align-items: stretch;
    gap: 24px;
    flex-wrap: wrap;
    font-size: 0.85rem;
    color: var(--muted);

    border-top: 1px solid rgba(255,255,255,0.08);
    padding-top: 12px;
}

.cert-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 6px;
    text-align: center;
    text-decoration: none;
    color: inherit;
    padding: 8px 12px;
    border-radius: 10px;
    transition: all 0.2s ease;
}

.cert-item img {
    height: 50px;
    width: auto;
    object-fit: contain;
}

.cert-item a {
    color: inherit;
    text-decoration: none;
}

.cert-item:hover {
    background: rgba(255,255,255,0.06);
    transform: translateY(-2px);
}

/* ========== Desktop / wider screens ========== */
@media (max-width: 720px) {
    #topNav {
        position: absolute;
        top: 70px; /* 鏍规嵁 header 楂樺害寰皟 */
        left: 50%;
        transform: translateX(-50%);
        width: 90%;
        background: rgba(255, 255, 255, 0.08);
        backdrop-filter: blur(12px); /* 鍏抽敭锛氱幓鐠冩ā绯婃晥鏋� */
        -webkit-backdrop-filter: blur(12px);
        border: 1px solid rgba(255,255,255,0.1);
        border-radius: 14px;
        flex-direction: column;
        align-items: center;
        gap: 14px;
        padding: 18px 0;
        box-shadow: 0 10px 30px rgba(0,0,0,0.4);
        z-index: 999;
        opacity: 0;
        transform-origin: top center;
        pointer-events: none;
        transition: all 0.25s ease;
    }

    #topNav[aria-hidden="false"] {
        opacity: 1;
        pointer-events: auto;
        transform: translateX(-50%) scale(1);
    }

    #topNav a {
        color: #fff;
        font-size: 1.05rem;
        font-weight: 600;
        padding: 8px 20px;
        border-radius: 10px;
        transition: background 0.2s ease;
    }

    #topNav a:hover {
        background: rgba(255,255,255,0.1);
    }

    header {
        position: relative;
        z-index: 1000;
    }
}



@media (max-width: 600px) {
    footer nav {
        flex-direction: column;   /* 鎵嬫満绔栨帓鏇存暣榻� */
        align-items: flex-start;
        gap: 6px;
    }

    .footer-cert {
        gap: 14px;                /* 缂╁皬闂磋窛 */
        justify-content: space-around; /* 鏇村潎鍖€鍒嗗竷 */
    }

    .cert-item {
        flex: 1 1 30%;            /* 姣忎釜鍗犱竴鍒楋紙鏈€澶�3鍒楋級 */
        min-width: 90px;          /* 闃叉澶獎 */
        padding: 10px 6px;        /* 鏇撮€傚悎瑙︽帶 */
    }

    .cert-item img {
        height: 40px;             /* 鍥炬爣缂╁皬 */
    }

    .cert-item span,
    .cert-item a {
        font-size: 0.75rem;       /* 瀛椾綋鏇撮€傞厤鎵嬫満 */
        line-height: 1.3;
        word-break: break-all;    /* 闃叉澶囨鍙锋拺鐖� */
    }
}
@media(min-width:720px){
    .nav-links{display:flex;gap:22px}
    .product-grid{
        grid-template-columns: repeat(2,1fr);
    }
    header{padding:22px var(--container-padding)}
    .hero{padding:48px}
    .card{padding:28px}
}
@media(min-width:1080px){
    .product-grid{
        grid-template-columns: repeat(2,1fr);
        gap:26px;
    }
    header{padding:28px;align-items:center}
}

/* ========== Accessibility & reduced motion ========== */
@media (prefers-reduced-motion: reduce){
    *{transition:none!important}
}
/* focus visible */
:focus{outline: none}
.focus-ring{box-shadow:0 0 0 3px rgba(27,132,214,0.25);border-radius:8px}


/* ========== 鏂囩珷璧勮妯″潡 ========== */
.article-grid{
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--gap);
    margin-top: 16px;
}
@media(min-width:720px){
    .article-grid{
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }
}
@media(min-width:1080px){
    .article-grid{
        grid-template-columns: repeat(3, 1fr);
        gap: 24px;
    }
}

.article-card{
    background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(0,0,0,0.02));
    border-radius: var(--radius);
    padding: 18px 20px;
    text-align: left;
    border: 1px solid rgba(255,255,255,0.04);
    box-shadow: var(--shadow);
    transition: transform .18s ease, box-shadow .18s ease;
}
.article-card:hover, .article-card:focus-within{
    transform: translateY(-4px);
    box-shadow: 0 12px 30px rgba(0,0,0,0.45);
}
.article-card a{
    color: var(--white);
    text-decoration: none;
    display: block;
}
.article-card h3{
    font-size: 1.125rem;
    margin: 0 0 6px;
    font-weight: 700;
    color: var(--white);
}
.article-card p{
    font-size: var(--text-lg);
    color: var(--muted);
    margin: 0;
}

/* ========== 杈呭姪鎸夐挳 btn-secondary ========== */
.btn-secondary{
    display: inline-block;
    padding: 10px 20px;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--white);
    background: rgba(255,255,255,0.08);
    border-radius: var(--radius);
    border: 1px solid rgba(255,255,255,0.12);
    text-align: center;
    transition: all 0.18s ease;
    cursor: pointer;
    text-decoration: none;
}
.btn-secondary:hover, .btn-secondary:focus{
    background: rgba(255,255,255,0.15);
    transform: translateY(-2px);
}

/* ========== Intro 鍘诲崱鐗囧寲锛堥珮绾х増锛� ========== */
.intro{
    text-align: center;
    max-width: 780px;
    margin: 0 auto 36px;
    padding: 10px 10px;

    /* 鉂� 鍘绘帀鍗＄墖鎰� */
    background: none;
    border: none;
    box-shadow: none;

    position: relative;
}

/* 鉁� subtle 鍏夋劅锛堜笉浼氭姠鍗＄墖椋庡ご锛� */
.intro::before{
    content: "";
    position: absolute;
    top: -40px;
    left: 50%;
    transform: translateX(-50%);
    width: 420px;
    height: 200px;
    background: radial-gradient(circle, rgba(90,200,250,0.15), transparent 70%);
    filter: blur(40px);
    z-index: 0;
}

.intro-text{
    position: relative;
    z-index: 1;

    font-size: 1.12rem;
    line-height: 1.75;
    color: rgba(255,255,255,0.9);
}

/* 涓氬姟楂樹寒 */
.highlight{
    color: #5AC8FA;
    font-weight: 600;
}

/* 鏍稿績浠峰€兼笎鍙橈紙淇濈暀AI鎰燂級 */
.highlight-strong{
    background: linear-gradient(90deg,#5AC8FA,#8E7CF5);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: 700;
}

.intro-text strong{
    color: #ffffff;
    font-weight: 700;
}


@media (max-width: 600px){
    .intro-text{
        font-size: 1rem;
        line-height: 1.65;
    }
}