/* ===== 基础变量（参照参考站配色） ===== */
:root {
    --primary: #007BFF;          /* 参考站主色蓝 */
    --primary-dark: #0062cc;
    --accent: #00CD76;           /* 参考站强调绿 */
    --accent-dark: #00a85e;
    --bg-start: #f8f9fa;         /* 参考站渐变起点 */
    --bg-end: #e9ecef;           /* 参考站渐变终点 */
    --navy: #0f1b2d;             /* 深海蓝（页脚/深色块） */
    --text: #333333;             /* 主文字 */
    --text-muted: #666666;       /* 次文字 */
    --text-light: #999999;
    --white: #ffffff;
    --border: #e9ecef;
    --radius: 16px;              /* 参考站卡片圆角 */
    --radius-sm: 10px;
    --shadow-sm: 0 2px 12px rgba(15, 27, 45, 0.06);
    --shadow-md: 0 8px 30px rgba(15, 27, 45, 0.10);
    --shadow-lg: 0 16px 50px rgba(15, 27, 45, 0.14);
    --container: 1200px;
    --font: Arial, "Microsoft YaHei", "PingFang SC", "Helvetica Neue", sans-serif;
}

/* ===== Reset ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
    font-family: var(--font);
    font-size: 16px;
    line-height: 1.7;
    color: var(--text);
    /* 参考站整体浅灰渐变背景 */
    background: linear-gradient(135deg, var(--bg-start) 0%, var(--bg-end) 100%);
    background-attachment: fixed;
    overflow-x: hidden;
}
a { color: var(--primary); text-decoration: none; transition: color .2s ease; }
a:hover { color: var(--primary-dark); }
img { max-width: 100%; display: block; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }
input, textarea { font-family: inherit; font-size: 15px; }

.container { max-width: var(--container); margin: 0 auto; padding: 0 24px; }

/* ===== 顶部导航 ===== */
.top-nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: saturate(180%) blur(12px);
    -webkit-backdrop-filter: saturate(180%) blur(12px);
    border-bottom: 1px solid rgba(233, 236, 239, 0.6);
    transition: box-shadow .3s ease, background .3s ease;
}
.top-nav.scrolled { box-shadow: var(--shadow-sm); background: rgba(255, 255, 255, 0.95); }
.nav-inner {
    max-width: var(--container); margin: 0 auto; padding: 0 24px;
    height: 68px; display: flex; align-items: center; justify-content: space-between;
}
.logo { display: flex; flex-direction: column; line-height: 1.1; color: var(--navy); }
.logo-text { font-size: 22px; font-weight: 700; letter-spacing: 2px; color: var(--navy); }
.logo-sub { font-size: 10px; letter-spacing: 3px; color: var(--text-light); margin-top: 2px; }
.nav-links { display: flex; align-items: center; gap: 8px; }
.nav-link {
    color: var(--text); font-size: 15px; font-weight: 500;
    padding: 8px 16px; border-radius: 8px; position: relative;
    transition: color .2s ease, background .2s ease;
}
.nav-link:hover { color: var(--primary); background: rgba(0, 123, 255, 0.06); }
.nav-link.active { color: var(--primary); }
.nav-link.active::after {
    content: ""; position: absolute; left: 50%; bottom: 2px; transform: translateX(-50%);
    width: 20px; height: 2px; border-radius: 2px; background: var(--primary);
}
.nav-cta {
    margin-left: 12px; padding: 9px 22px; border-radius: 8px;
    background: var(--primary); color: var(--white) !important; font-size: 14px; font-weight: 600;
    transition: background .2s ease, transform .2s ease;
}
.nav-cta:hover { background: var(--primary-dark); transform: translateY(-1px); }
.menu-toggle { display: none; flex-direction: column; gap: 5px; padding: 6px; }
.menu-toggle span { width: 24px; height: 2px; background: var(--navy); border-radius: 2px; transition: .3s; }
.menu-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== Hero 首屏 ===== */
.hero {
    position: relative; min-height: 100vh; display: flex; align-items: center; justify-content: center;
    text-align: center; padding: 120px 24px 80px;
    background:
        radial-gradient(circle at 20% 20%, rgba(0, 123, 255, 0.08) 0%, transparent 45%),
        radial-gradient(circle at 80% 30%, rgba(0, 205, 118, 0.08) 0%, transparent 45%),
        linear-gradient(135deg, var(--bg-start) 0%, var(--bg-end) 100%);
    overflow: hidden;
}
.hero-inner { max-width: 820px; position: relative; z-index: 2; }
.hero-tag {
    display: inline-block; font-size: 13px; letter-spacing: 3px; color: var(--primary);
    font-weight: 600; margin-bottom: 24px; padding: 6px 18px;
    background: rgba(0, 123, 255, 0.08); border-radius: 30px;
}
.hero-title {
    font-size: clamp(32px, 5.5vw, 52px); font-weight: 700; line-height: 1.3;
    color: var(--navy); margin-bottom: 24px; letter-spacing: 1px;
}
.hero-desc {
    font-size: clamp(15px, 2vw, 18px); color: var(--text-muted);
    max-width: 600px; margin: 0 auto 40px; line-height: 1.8;
}
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

/* 按钮 */
.btn {
    display: inline-block; padding: 14px 36px; font-size: 15px; font-weight: 600;
    border-radius: 10px; transition: all .25s ease; cursor: pointer; border: 2px solid transparent;
}
.btn-primary { background: var(--primary); color: var(--white); }
.btn-primary:hover { background: var(--primary-dark); color: var(--white); transform: translateY(-2px); box-shadow: 0 10px 24px rgba(0, 123, 255, 0.3); }
.btn-outline { background: transparent; color: var(--primary); border-color: var(--primary); }
.btn-outline:hover { background: var(--primary); color: var(--white); transform: translateY(-2px); }
.btn-block { width: 100%; }

/* ===== 通用 Section ===== */
.section { padding: 100px 0; position: relative; }
.section-head { text-align: center; max-width: 700px; margin: 0 auto 64px; }
.section-tag {
    font-size: 13px; letter-spacing: 4px; color: var(--accent); font-weight: 700;
    margin-bottom: 12px;
}
.section-title { font-size: clamp(26px, 3.5vw, 36px); font-weight: 700; color: var(--navy); margin-bottom: 14px; }
.section-desc { font-size: 16px; color: var(--text-muted); }

/* ===== 关于我们 ===== */
.about-grid { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 60px; align-items: center; }
.about-text p { color: var(--text-muted); margin-bottom: 20px; font-size: 16px; line-height: 1.9; }
.about-values { display: flex; flex-direction: column; gap: 18px; }
.value-item {
    background: var(--white); border-radius: var(--radius-sm); padding: 22px 26px;
    border-left: 3px solid var(--accent); box-shadow: var(--shadow-sm);
    transition: transform .25s ease;
}
.value-item:hover { transform: translateX(4px); }
.value-name { font-size: 18px; font-weight: 600; color: var(--primary); letter-spacing: 2px; display: block; margin-bottom: 4px; }
.value-desc { font-size: 15px; color: var(--text-muted); }

/* ===== 核心业务卡片 ===== */
.cards-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.card {
    background: var(--white); border-radius: var(--radius); padding: 36px 32px;
    border: 1px solid var(--border); box-shadow: var(--shadow-sm);
    transition: transform .3s ease, box-shadow .3s ease, border-color .3s ease;
    position: relative; overflow: hidden;
}
.card::before {
    content: ""; position: absolute; top: 0; left: 0; width: 100%; height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    transform: scaleX(0); transform-origin: left; transition: transform .35s ease;
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: rgba(0, 123, 255, 0.2); }
.card:hover::before { transform: scaleX(1); }
.card-index {
    font-size: 14px; font-weight: 700; letter-spacing: 2px; color: var(--accent);
    margin-bottom: 16px; font-family: Arial, sans-serif;
}
.card-title { font-size: 20px; font-weight: 600; color: var(--navy); margin-bottom: 14px; }
.card-desc { font-size: 15px; color: var(--text-muted); line-height: 1.8; }

/* ===== 联系我们 ===== */
.contact { background: linear-gradient(180deg, transparent, rgba(255,255,255,0.5)); }
.contact-grid { display: grid; grid-template-columns: 0.9fr 1.1fr; gap: 48px; align-items: stretch; }
.contact-info { display: flex; flex-direction: column; gap: 24px; height: 100%; }
.info-item {
    background: var(--white); border-radius: var(--radius-sm); padding: 20px 24px;
    border-left: 3px solid var(--primary); box-shadow: var(--shadow-sm);
    transition: transform .25s ease;
    flex: 1 1 0;
}
.info-item:hover { transform: translateX(4px); }
.info-label { display: block; font-size: 13px; color: var(--text-light); letter-spacing: 1px; margin-bottom: 6px; }
.info-text { font-size: 16px; color: var(--navy); font-weight: 500; }

.contact-form {
    background: var(--white); border-radius: var(--radius); padding: 36px;
    box-shadow: var(--shadow-md); border: 1px solid var(--border);
    display: flex; flex-direction: column; gap: 16px;
    height: 100%;
}
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.contact-form input,
.contact-form textarea {
    width: 100%; padding: 13px 16px; border: 1px solid var(--border); border-radius: 8px;
    background: var(--bg-start); color: var(--text); transition: border-color .2s ease, background .2s ease, box-shadow .2s ease;
    box-sizing: border-box;
}
.contact-form input::placeholder,
.contact-form textarea::placeholder { color: var(--text-light); }
.contact-form input:focus,
.contact-form textarea:focus {
    outline: none; border-color: var(--primary); background: var(--white);
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.1);
}
.contact-form textarea { resize: vertical; flex: 1 1 auto; min-height: 240px; }
.contact-form .btn-block { margin-top: auto; }
.form-tip { font-size: 14px; text-align: center; min-height: 20px; margin-top: 4px; }
.form-tip.success { color: var(--accent-dark); }
.form-tip.error { color: #e03131; }

/* ===== 页脚 ===== */
.footer {
    background: var(--white);
    color: var(--text-muted);
    padding: 48px 0 24px;
}
.footer-inner {
    display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 24px;
    padding-bottom: 28px;
}
.footer-brand .logo-text { color: var(--navy); font-size: 24px; }
.footer-slogan { font-size: 14px; color: var(--text-light); margin-top: 8px; letter-spacing: 2px; }
.footer-links { display: flex; gap: 28px; flex-wrap: wrap; }
.footer-links a { color: var(--text-muted); font-size: 14px; }
.footer-links a:hover { color: var(--primary); }
.footer-bottom { text-align: center; padding-top: 24px; font-size: 13px; color: var(--text-light); }
.footer-meta { margin-top: 6px; font-size: 12px; }

/* ===== 滚动渐入动画 ===== */
.reveal { opacity: 0; transform: translateY(30px); transition: opacity .7s ease, transform .7s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }
.reveal:nth-child(2) { transition-delay: .1s; }
.reveal:nth-child(3) { transition-delay: .2s; }

/* ===== 响应式 ===== */
@media (max-width: 980px) {
    .about-grid { grid-template-columns: 1fr; gap: 40px; }
    .contact-grid { grid-template-columns: 1fr; gap: 36px; }
    .cards-grid { grid-template-columns: 1fr; }
}
@media (max-width: 760px) {
    .menu-toggle { display: flex; }
    .nav-links {
        position: fixed; top: 68px; left: 0; right: 0; flex-direction: column; align-items: stretch;
        background: rgba(255,255,255,0.98); backdrop-filter: blur(12px);
        padding: 16px 24px 24px; gap: 4px; box-shadow: var(--shadow-md);
        transform: translateY(-150%); transition: transform .35s ease; visibility: hidden;
    }
    .nav-links.open { transform: translateY(0); visibility: visible; }
    .nav-link { padding: 14px 16px; border-radius: 8px; }
    .nav-link.active::after { display: none; }
    .nav-cta { margin: 8px 0 0; text-align: center; }
    .section { padding: 70px 0; }
    .section-head { margin-bottom: 44px; }
    .cards-grid { grid-template-columns: 1fr; }
    .form-row { grid-template-columns: 1fr; }
    .hero { padding: 110px 20px 60px; min-height: 92vh; }
    .footer-inner { flex-direction: column; text-align: center; }
}
@media (max-width: 420px) {
    .btn { padding: 13px 28px; }
    .hero-actions { flex-direction: column; }
    .hero-actions .btn { width: 100%; }
}

/* ===== 减少动画偏好 ===== */
@media (prefers-reduced-motion: reduce) {
    * { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
    .reveal { opacity: 1; transform: none; }
}