/* ================= 基础重置与变量 ================= */
:root {
    --yellow: #f5e642;
    --yellow-dark: #e6d62f;
    --red: #e02020;
    --ink: #151515;
    --ink-soft: #3a3a3a;
    --muted: #6b6b6b;
    --line: #e8e8e8;
    --bg-soft: #f7f7f5;
    --radius: 18px;
    --shadow: 0 12px 40px rgba(0, 0, 0, 0.08);
    --max: 1180px;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
    font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    color: var(--ink);
    background: #fff;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    padding-bottom: 72px; /* 为移动端底部按钮留出空间 */
}

a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }
.container { width: min(var(--max), calc(100% - 40px)); margin: 0 auto; }

/* ================= 顶部导航 ================= */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.96);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--line);
}
.header-inner {
    width: min(var(--max), calc(100% - 40px));
    margin: 0 auto;
    display: flex;
    align-items: center;
    gap: 28px;
    height: 72px;
}
.brand { display: flex; align-items: center; gap: 6px; font-weight: 800; font-size: 22px; letter-spacing: -0.5px; }

/* Logo D 背景红色，字体黑色 */
.brand-mark {
    width: 32px; height: 32px; border-radius: 8px;
    background: var(--red); color: #000;
    display: grid; place-items: center; font-size: 18px;
}
.brand-text { color: var(--ink); }
.brand-sub { font-size: 13px; color: var(--muted); font-weight: 500; margin-left: 2px; }

.main-nav { display: flex; gap: 4px; margin-left: 8px; }
.nav-item { position: relative; }
.nav-item > a {
    display: block; padding: 10px 14px; font-size: 14px; font-weight: 600; color: var(--ink-soft);
    border-radius: 8px; transition: 0.2s;
}
.nav-item:hover > a { background: var(--bg-soft); color: var(--red); }
.sub-nav {
    position: absolute; top: 100%; left: 0; min-width: 160px;
    background: #fff; border: 1px solid var(--line); border-radius: 12px;
    box-shadow: var(--shadow); padding: 6px;
    display: none; flex-direction: column;
}
.nav-item.has-children:hover .sub-nav { display: flex; }
.sub-nav a { padding: 9px 12px; border-radius: 8px; font-size: 13px; color: var(--ink-soft); }
.sub-nav a:hover { background: var(--bg-soft); color: var(--red); }

/* 右上角按钮区域 */
.header-actions { margin-left: auto; display: flex; align-items: center; gap: 20px; }
.link-login { font-size: 14px; font-weight: 600; color: var(--ink-soft); transition: 0.2s; }
.link-login:hover { color: var(--red); }

.btn {
    display: inline-flex; align-items: center; justify-content: center;
    padding: 10px 22px; border-radius: 999px; font-size: 13px; font-weight: 700;
    transition: 0.2s; border: 1px solid transparent; cursor: pointer;
}
.btn-primary { background: var(--yellow); color: var(--ink); }
.btn-primary:hover { background: var(--yellow-dark); }
.btn-outline { background: transparent; border-color: rgba(255,255,255,0.5); color: #fff; }
.btn-outline:hover { background: rgba(255,255,255,0.1); border-color: #fff; }
.btn-lg { padding: 13px 30px; font-size: 15px; }

.menu-toggle { display: none; border: none; background: none; font-size: 24px; cursor: pointer; margin-left: auto; }

/* ================= Hero 首屏 ================= */
.hero {
    position: relative;
    min-height: 560px;
    display: flex;
    align-items: center;
    overflow: hidden;
    background: #1b1b1b;
}
.hero-bg {
    position: absolute; inset: 0;
    background:
        radial-gradient(ellipse at 75% 35%, rgba(245, 230, 66, 0.14), transparent 55%),
        radial-gradient(ellipse at 20% 80%, rgba(224, 32, 32, 0.22), transparent 50%),
        linear-gradient(135deg, #141414 0%, #2a1f1f 55%, #3d2424 100%);
}
.hero-bg::after {
    content: "";
    position: absolute; inset: 0;
    background-image:
        linear-gradient(rgba(255,255,255,0.035) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.035) 1px, transparent 1px);
    background-size: 48px 48px;
    mask-image: linear-gradient(to bottom, rgba(0,0,0,0.7), transparent 90%);
}
.hero-content {
    position: relative; z-index: 2;
    width: min(var(--max), calc(100% - 40px));
    margin: 0 auto;
    padding: 80px 0 60px;
    color: #fff;
}
.hero-kicker {
    display: inline-block;
    font-size: 13px; font-weight: 600; letter-spacing: 0.5px;
    color: var(--yellow); background: rgba(245, 230, 66, 0.1);
    border: 1px solid rgba(245, 230, 66, 0.25);
    padding: 5px 14px; border-radius: 999px; margin-bottom: 22px;
}
.hero h1 {
    font-size: clamp(34px, 5vw, 56px);
    line-height: 1.18;
    letter-spacing: -1.5px;
    font-weight: 800;
    margin-bottom: 20px;
}
.hero-sub { max-width: 620px; font-size: 15px; color: rgba(255,255,255,0.72); margin-bottom: 30px; }
.hero-cta { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 48px; }

.hero-stats {
    display: grid; grid-template-columns: repeat(4, 1fr);
    border-top: 1px solid rgba(255,255,255,0.12);
    padding-top: 26px;
    gap: 20px;
}
.stat strong { display: block; font-size: 24px; font-weight: 800; color: var(--yellow); }
.stat span { font-size: 12px; color: rgba(255,255,255,0.6); }

/* ================= 区块通用 ================= */
.section { padding: 88px 0; }
.section-head { text-align: center; max-width: 680px; margin: 0 auto 44px; }
.section-head h2 { font-size: clamp(26px, 3.4vw, 38px); letter-spacing: -0.8px; margin-bottom: 12px; }
.section-head p { color: var(--muted); font-size: 14px; }
.highlight { background: linear-gradient(transparent 58%, var(--yellow) 58%); padding: 0 2px; }

/* ================= 核心优势 ================= */
.feature-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.feature-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 30px 28px;
    transition: 0.25s;
    box-shadow: 0 2px 0 rgba(0,0,0,0.02);
}
.feature-card:hover { border-color: #d0d0d0; box-shadow: var(--shadow); transform: translateY(-3px); }
.feature-icon {
    width: 46px; height: 46px; border-radius: 12px;
    background: var(--bg-soft); display: grid; place-items: center;
    font-size: 22px; margin-bottom: 18px;
}
.feature-card h3 { font-size: 18px; margin-bottom: 10px; letter-spacing: -0.3px; }
.feature-card p { font-size: 13.5px; color: var(--muted); margin-bottom: 16px; }
.feature-link { font-size: 13px; font-weight: 700; color: var(--red); }
.feature-link:hover { text-decoration: underline; }

/* ================= 数据信任区 ================= */
.trust-section { background: var(--bg-soft); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.trust-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 60px; align-items: center; }
.trust-copy h2 { font-size: clamp(26px, 3.2vw, 36px); letter-spacing: -0.8px; margin-bottom: 20px; }
.trust-copy p { font-size: 14px; color: var(--ink-soft); margin-bottom: 14px; }
.trust-copy strong { color: var(--ink); font-weight: 800; }
.trust-metrics { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.metric {
    background: #fff; border: 1px solid var(--line); border-radius: 16px;
    padding: 24px 20px; text-align: left;
}
.metric strong { display: block; font-size: 28px; font-weight: 800; letter-spacing: -1px; color: var(--ink); }
.metric span { font-size: 12px; color: var(--muted); }

/* ================= 市场活动 & 文章展示 ================= */
.activity-grid, .news-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.activity-card, .news-card {
    background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
    padding: 26px 24px; display: flex; flex-direction: column;
    transition: 0.2s;
}
.activity-card:hover, .news-card:hover { border-color: #d0d0d0; box-shadow: var(--shadow); }

.activity-tag, .news-tag {
    align-self: flex-start; font-size: 11px; font-weight: 700;
    background: rgba(224, 32, 32, 0.08); color: var(--red);
    padding: 4px 10px; border-radius: 999px; margin-bottom: 14px;
}
.news-tag { background: rgba(21, 21, 21, 0.05); color: var(--ink); }

.activity-card h3, .news-card h3 { font-size: 17px; margin-bottom: 10px; line-height: 1.4; }
.activity-card p, .news-card p { font-size: 13px; color: var(--muted); flex: 1; }

.activity-meta, .news-meta { 
    font-size: 12px; color: var(--ink-soft); margin-top: 18px; padding-top: 14px; 
    border-top: 1px dashed var(--line); display: flex; justify-content: space-between; 
}

/* 专门用于文章区的背景色区分 */
.news-section { background: #fafafa; }

/* ================= 底部 ================= */
.site-footer { background: #fff; border-top: 1px solid var(--line); padding-top: 60px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 0.6fr 0.6fr; gap: 48px; padding-bottom: 44px; }
.brand-footer { margin-bottom: 16px; }
.footer-brand p { font-size: 13px; color: var(--muted); max-width: 420px; margin-bottom: 10px; }
.footer-note { font-size: 12px; color: #999; }
.footer-links { display: flex; flex-direction: column; gap: 8px; }
.footer-links h4 { font-size: 13px; font-weight: 800; margin-bottom: 8px; }
.footer-links a { font-size: 13px; color: var(--muted); }
.footer-links a:hover { color: var(--red); }
.footer-bottom {
    border-top: 1px solid var(--line);
    padding: 18px 0;
    display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap;
    font-size: 12px; color: #999;
    width: min(var(--max), calc(100% - 40px)); margin: 0 auto;
}

/* ================= 移动端 ================= */
.mobile-fixed-bar { display: none; }

@media (max-width: 960px) {
    .main-nav {
        display: none;
        position: absolute; top: 72px; left: 0; right: 0;
        background: #fff; border-bottom: 1px solid var(--line);
        flex-direction: column; padding: 12px 20px 20px; gap: 2px;
        box-shadow: 0 20px 40px rgba(0,0,0,0.08);
    }
    .main-nav.open { display: flex; }
    .nav-item > a { padding: 12px 10px; font-size: 15px; }
    .sub-nav {
        position: static; display: flex; box-shadow: none; border: none;
        padding: 0 0 8px 14px; background: transparent;
    }
    .sub-nav a { font-size: 13px; padding: 7px 10px; }

    /* 移动端隐藏右上角按钮，使用底部悬浮栏 */
    .header-actions { display: none; }
    .menu-toggle { display: block; }

    .hero { min-height: auto; }
    .hero-content { padding: 56px 0 48px; }
    .hero-stats { grid-template-columns: 1fr 1fr; gap: 18px; }

    .feature-grid { grid-template-columns: 1fr; }
    .trust-grid { grid-template-columns: 1fr; gap: 34px; }
    .activity-grid, .news-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; gap: 30px; }

    .mobile-fixed-bar {
        display: grid; grid-template-columns: 1fr 1fr; gap: 10px;
        position: fixed; left: 0; right: 0; bottom: 0; z-index: 200;
        background: #fff; border-top: 1px solid var(--line);
        padding: 10px 14px calc(10px + env(safe-area-inset-bottom));
        box-shadow: 0 -8px 24px rgba(0,0,0,0.06);
    }
    .mobile-btn {
        display: flex; align-items: center; justify-content: center;
        height: 46px; border-radius: 999px; font-size: 15px; font-weight: 700;
    }
    .mobile-btn-primary { background: var(--yellow); color: var(--ink); }
    .mobile-btn-outline { border: 1.5px solid var(--ink); color: var(--ink); }
}

@media (max-width: 520px) {
    .hero-stats { grid-template-columns: 1fr 1fr; }
    .stat strong { font-size: 20px; }
    .section { padding: 64px 0; }
    .hero-cta .btn { flex: 1; justify-content: center; }
}