/* ===== 签牛 55SIGN · 科技风主页样式 ===== */
:root {
    --bg: #060a1a;
    --bg-2: #0a1024;
    --card: rgba(255, 255, 255, 0.04);
    --border: rgba(255, 255, 255, 0.09);
    --text: #eef2ff;
    --text-2: rgba(238, 242, 255, 0.62);
    --c1: #4f7fff;
    --c2: #00e0ff;
    --c3: #7c5cff;
    --grad: linear-gradient(120deg, var(--c1), var(--c2));
}

html { scroll-behavior: smooth; }

body {
    background: var(--bg);
    color: var(--text);
    font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

::selection { background: rgba(79, 127, 255, 0.4); }

/* ---------- 通用按钮 ---------- */
.btn-primary, .btn-ghost {
    display: inline-block;
    height: 40px;
    line-height: 40px;
    padding: 0 22px;
    border-radius: 10px;
    font-size: 15px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    white-space: nowrap;
}

.btn-primary {
    background: var(--grad);
    color: #fff;
    box-shadow: 0 4px 20px rgba(79, 127, 255, 0.45);
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(0, 224, 255, 0.5);
}

.btn-ghost {
    color: var(--text);
    border: 1px solid var(--border);
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(8px);
}
.btn-ghost:hover {
    border-color: var(--c2);
    color: var(--c2);
    transform: translateY(-2px);
}

.btn-lg { height: 52px; line-height: 52px; padding: 0 36px; font-size: 17px; border-radius: 14px; }

/* ---------- 导航 ---------- */
.header {
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 999;
    padding: 18px 0;
    transition: all 0.35s ease;
}
.header.scrolled {
    padding: 10px 0;
    background: rgba(6, 10, 26, 0.78);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
}

.nav {
    width: 1200px;
    max-width: 92%;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo { display: flex; align-items: center; gap: 10px; }
.logo-icon { width: 34px; height: 34px; }
.logo-text {
    font-size: 20px;
    font-weight: 700;
    color: var(--text);
    letter-spacing: 1px;
}
.logo-text em {
    font-style: normal;
    font-size: 11px;
    font-weight: 500;
    margin-left: 6px;
    letter-spacing: 2px;
    background: var(--grad);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    vertical-align: 2px;
}

.nav-right { display: flex; align-items: center; gap: 12px; }
.nav-tagline {
    font-size: 13px;
    color: var(--text-2);
    margin-right: 10px;
    letter-spacing: 1px;
}

/* ---------- Hero ---------- */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    overflow: hidden;
}

.hero-bg { position: absolute; inset: 0; }

.orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(90px);
    opacity: 0.5;
    animation: float 14s ease-in-out infinite;
}
.orb-1 { width: 520px; height: 520px; background: #2743b8; top: -140px; left: -120px; }
.orb-2 { width: 420px; height: 420px; background: #0a5f78; bottom: -100px; right: -80px; animation-delay: -5s; }
.orb-3 { width: 300px; height: 300px; background: #4a2b9e; top: 40%; left: 55%; animation-delay: -9s; opacity: 0.35; }
.orb-4 { width: 460px; height: 460px; background: #1b3a8f; top: -120px; right: -120px; }

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    50% { transform: translate(40px, -40px) scale(1.08); }
}

.grid-overlay {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(120, 160, 255, 0.06) 1px, transparent 1px),
        linear-gradient(90deg, rgba(120, 160, 255, 0.06) 1px, transparent 1px);
    background-size: 56px 56px;
    mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 30%, transparent 75%);
    -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 30%, transparent 75%);
}

.hero-inner { position: relative; z-index: 2; max-width: 860px; padding: 120px 24px 80px; }

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 18px;
    border-radius: 100px;
    border: 1px solid var(--border);
    background: rgba(255, 255, 255, 0.04);
    backdrop-filter: blur(10px);
    font-size: 13px;
    color: var(--text-2);
    letter-spacing: 2px;
}

.pulse-dot {
    width: 8px; height: 8px;
    border-radius: 50%;
    background: var(--c2);
    box-shadow: 0 0 0 0 rgba(0, 224, 255, 0.6);
    animation: pulse 2s infinite;
}
@keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(0, 224, 255, 0.55); }
    70% { box-shadow: 0 0 0 10px rgba(0, 224, 255, 0); }
    100% { box-shadow: 0 0 0 0 rgba(0, 224, 255, 0); }
}

.hero-title {
    margin: 30px 0 20px;
    font-size: 64px;
    font-weight: 800;
    line-height: 1.18;
    letter-spacing: 2px;
}

.grad-text {
    background: var(--grad);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    position: relative;
}

.hero-sub {
    font-size: 19px;
    color: var(--text-2);
    letter-spacing: 1px;
}

.hero-cta {
    margin-top: 44px;
    display: flex;
    gap: 18px;
    justify-content: center;
    flex-wrap: wrap;
}

.hero-stats {
    margin-top: 80px;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 40px;
    flex-wrap: wrap;
}
.stat { display: flex; flex-direction: column; align-items: center; position: relative; }
.stat-num {
    font-size: 38px;
    font-weight: 800;
    background: var(--grad);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}
.stat-suffix {
    position: absolute;
    right: -16px; top: 4px;
    font-size: 20px;
    color: var(--c2);
    font-weight: 700;
}
.stat-label { margin-top: 6px; font-size: 13px; color: var(--text-2); letter-spacing: 2px; }
.stat-divider { width: 1px; height: 44px; background: var(--border); }

.scroll-hint {
    position: absolute;
    bottom: 34px;
    left: 50%;
    transform: translateX(-50%);
    width: 26px; height: 42px;
    border: 2px solid rgba(255, 255, 255, 0.25);
    border-radius: 14px;
    z-index: 2;
}
.scroll-hint span {
    position: absolute;
    left: 50%; top: 8px;
    width: 4px; height: 8px;
    margin-left: -2px;
    border-radius: 2px;
    background: var(--c2);
    animation: scrollDot 1.8s infinite;
}
@keyframes scrollDot {
    0% { opacity: 1; transform: translateY(0); }
    80% { opacity: 0; transform: translateY(14px); }
    100% { opacity: 0; }
}

/* ---------- 通用区块 ---------- */
.section-head { text-align: center; margin-bottom: 64px; padding: 0 20px; }
.section-eyebrow {
    font-size: 12px;
    letter-spacing: 5px;
    color: var(--c2);
    font-weight: 600;
}
.section-title {
    margin-top: 14px;
    font-size: 42px;
    font-weight: 800;
    letter-spacing: 1px;
}
.section-desc { margin-top: 16px; font-size: 16px; color: var(--text-2); }

/* ---------- 产品能力 ---------- */
.features { padding: 120px 0; background: var(--bg); }

.feature-grid {
    width: 1200px;
    max-width: 92%;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.feature-card {
    position: relative;
    padding: 36px 26px;
    border-radius: 20px;
    background: var(--card);
    border: 1px solid var(--border);
    backdrop-filter: blur(12px);
    overflow: hidden;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}
.feature-card:hover {
    transform: translateY(-8px);
    border-color: rgba(0, 224, 255, 0.4);
    background: rgba(255, 255, 255, 0.06);
}

.card-glow {
    position: absolute;
    top: -60px; left: 50%;
    width: 180px; height: 180px;
    transform: translateX(-50%);
    background: radial-gradient(circle, rgba(0, 224, 255, 0.22), transparent 70%);
    opacity: 0;
    transition: opacity 0.4s;
    pointer-events: none;
}
.feature-card:hover .card-glow { opacity: 1; }

.feature-icon {
    width: 58px; height: 58px;
    border-radius: 16px;
    background: linear-gradient(135deg, rgba(79, 127, 255, 0.18), rgba(0, 224, 255, 0.12));
    border: 1px solid rgba(120, 170, 255, 0.25);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 22px;
    transition: transform 0.4s;
}
.feature-card:hover .feature-icon { transform: scale(1.08) rotate(-4deg); }
.feature-icon svg { width: 28px; height: 28px; color: var(--c2); }

.feature-card h3 { font-size: 19px; font-weight: 700; margin-bottom: 14px; letter-spacing: 1px; }
.feature-card p { font-size: 14px; line-height: 1.9; color: var(--text-2); }

/* ---------- 平台价值 ---------- */
.values {
    padding: 120px 0;
    background: var(--bg-2);
    position: relative;
}
.values::before {
    content: "";
    position: absolute;
    top: 0; left: 50%;
    transform: translateX(-50%);
    width: 60%; height: 1px;
    background: linear-gradient(90deg, transparent, rgba(0, 224, 255, 0.4), transparent);
}

.value-grid {
    width: 1200px;
    max-width: 92%;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 22px;
}

.value-item {
    position: relative;
    padding: 34px 36px 34px 100px;
    border-radius: 18px;
    border: 1px solid var(--border);
    background: var(--card);
    transition: all 0.35s ease;
    overflow: hidden;
}
.value-item:hover {
    border-color: rgba(79, 127, 255, 0.45);
    background: rgba(255, 255, 255, 0.055);
    transform: translateX(6px);
}

.value-num {
    position: absolute;
    right: 22px; top: 14px;
    font-size: 44px;
    font-weight: 800;
    color: transparent;
    -webkit-text-stroke: 1px rgba(255, 255, 255, 0.14);
    letter-spacing: 2px;
}

.value-icon {
    position: absolute;
    left: 32px; top: 34px;
    width: 48px; height: 48px;
    border-radius: 13px;
    background: linear-gradient(135deg, rgba(124, 92, 255, 0.18), rgba(0, 224, 255, 0.1));
    border: 1px solid rgba(124, 92, 255, 0.3);
    display: flex;
    align-items: center;
    justify-content: center;
}
.value-icon svg { width: 24px; height: 24px; color: #9db8ff; }

.value-item h3 { font-size: 19px; font-weight: 700; margin-bottom: 10px; letter-spacing: 1px; }
.value-item p { font-size: 14px; line-height: 1.9; color: var(--text-2); }

/* ---------- 下载 ---------- */
.download {
    position: relative;
    padding: 120px 0 130px;
    overflow: hidden;
    background: var(--bg);
}
.dl-bg { position: absolute; inset: 0; }

.dl-panel {
    position: relative;
    z-index: 2;
    width: 980px;
    max-width: 92%;
    margin: 0 auto;
    padding: 52px 48px;
    border-radius: 26px;
    background: rgba(255, 255, 255, 0.035);
    border: 1px solid var(--border);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 56px;
    flex-wrap: wrap;
    box-shadow: 0 30px 80px rgba(0, 0, 0, 0.4);
}

.qr-card { text-align: center; }
.qr-frame {
    padding: 14px;
    border-radius: 18px;
    background: #fff;
    box-shadow: 0 0 0 1px rgba(0, 224, 255, 0.25), 0 12px 40px rgba(0, 224, 255, 0.16);
    transition: transform 0.35s;
}
.qr-card:hover .qr-frame { transform: scale(1.04); }
.qr-frame img { display: block; width: 148px; height: 148px; }

.qr-meta { margin-top: 14px; }
.qr-platform { display: block; font-size: 15px; font-weight: 600; letter-spacing: 1px; }
.qr-ver { display: block; margin-top: 4px; font-size: 12px; color: var(--text-2); }

.dl-actions { display: flex; flex-direction: column; gap: 14px; min-width: 190px; }
.dl-tip { font-size: 14px; color: var(--text-2); letter-spacing: 2px; text-align: center; }

.dl-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    height: 48px;
    border-radius: 12px;
    border: 1px solid var(--border);
    background: rgba(255, 255, 255, 0.04);
    color: var(--text);
    font-size: 15px;
    transition: all 0.3s;
}
.dl-btn .iconfont { font-size: 18px; }
.dl-btn:hover {
    background: var(--grad);
    border-color: transparent;
    color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(79, 127, 255, 0.4);
}

/* ---------- 页脚 ---------- */
.footer {
    padding: 40px 20px;
    text-align: center;
    background: #04060f;
    border-top: 1px solid var(--border);
    font-size: 14px;
    color: var(--text-2);
}
.footer-links { margin-bottom: 14px; }
.footer-links a {
    color: var(--text-2);
    margin: 0 14px;
    transition: color 0.3s;
}
.footer-links a:hover { color: var(--c2); }
.footer-copy a { color: var(--text-2); margin-left: 10px; }
.footer-copy a:hover { color: var(--c2); }

/* ---------- 滚动入场 ---------- */
.reveal {
    opacity: 0;
    transform: translateY(36px);
    transition: opacity 0.8s cubic-bezier(0.22, 1, 0.36, 1), transform 0.8s cubic-bezier(0.22, 1, 0.36, 1);
}
.reveal.in-view { opacity: 1; transform: translateY(0); }
.feature-card.reveal:nth-child(2) { transition-delay: 0.1s; }
.feature-card.reveal:nth-child(3) { transition-delay: 0.2s; }
.feature-card.reveal:nth-child(4) { transition-delay: 0.3s; }
.value-item.reveal:nth-child(2) { transition-delay: 0.08s; }
.value-item.reveal:nth-child(3) { transition-delay: 0.16s; }
.value-item.reveal:nth-child(4) { transition-delay: 0.24s; }

/* ---------- 响应式 ---------- */
@media screen and (max-width: 1024px) {
    .feature-grid { grid-template-columns: repeat(2, 1fr); }
}

@media screen and (max-width: 768px) {
    .nav-tagline { display: none; }
    .btn-primary, .btn-ghost { height: 34px; line-height: 34px; padding: 0 14px; font-size: 13px; border-radius: 8px; }
    .btn-lg { height: 46px; line-height: 46px; padding: 0 26px; font-size: 15px; }

    .hero-title { font-size: 38px; }
    .hero-sub { font-size: 15px; }
    .hero-stats { gap: 22px; }
    .stat-num { font-size: 26px; }
    .stat-divider { display: none; }

    .section-title { font-size: 28px; }
    .features, .values, .download { padding: 72px 0; }

    .feature-grid { grid-template-columns: 1fr; }
    .value-grid { grid-template-columns: 1fr; }
    .value-item { padding: 26px 24px 26px 88px; }
    .value-icon { left: 24px; top: 26px; }

    .dl-panel { padding: 36px 22px; gap: 30px; }
    .scroll-hint { display: none; }
}