/* ============================================================
   umBase 官方网站样式
   设计规范：
   - 圆角统一 12px（卡片类）
   - 响应式断点：<768px 单列 / 768-1024px 双列 / >1024px 多列
   - 使用 rem + clamp 自适应排版
   - 可点击元素 ≥ 44px
   ============================================================ */

:root {
    /* 颜色 */
    --c-primary: #5b6cff;
    --c-primary-2: #8b5cf6;
    --c-accent: #22d3ee;
    --c-bg: #f6f7fb;
    --c-bg-alt: #eef0f8;
    --c-card: #ffffff;
    --c-dark: #0d1030;
    --c-dark-2: #151038;
    --c-text: #101223;
    --c-muted: #5c6280;
    --c-border: #e6e8f2;
    --c-line: rgba(13, 16, 48, 0.08);

    /* 渐变 */
    --grad: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-2) 100%);
    --grad-soft: linear-gradient(135deg, rgba(91,108,255,0.12), rgba(139,92,246,0.12));

    /* 圆角 */
    --radius: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;

    /* 阴影 */
    --shadow-sm: 0 2px 10px rgba(13, 16, 48, 0.05);
    --shadow: 0 12px 40px rgba(13, 16, 48, 0.10);
    --shadow-lg: 0 24px 70px rgba(13, 16, 48, 0.18);

    --maxw: 1180px;
    --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

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

html { scroll-behavior: smooth; scroll-padding-top: 84px; -webkit-text-size-adjust: 100%; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Roboto, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--c-text);
    background: var(--c-bg);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img, svg { display: block; }
button { font-family: inherit; cursor: pointer; }
code, pre { font-family: "SFMono-Regular", "JetBrains Mono", Consolas, "Courier New", monospace; }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 clamp(20px, 4vw, 40px); }
.container--narrow { max-width: 820px; }

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

/* ============ 按钮 ============ */
.btn {
    display: inline-flex; align-items: center; gap: 8px; justify-content: center;
    min-height: 48px; padding: 12px 28px;
    border-radius: 999px; border: none;
    font-size: 16px; font-weight: 600; line-height: 1;
    transition: transform .25s var(--ease), box-shadow .25s var(--ease), background .25s;
    will-change: transform;
}
.btn--primary { background: var(--grad); color: #fff; box-shadow: 0 8px 24px rgba(91,108,255,.35); }
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 14px 32px rgba(91,108,255,.45); }
.btn--ghost { background: rgba(255,255,255,.08); color: #fff; border: 1px solid rgba(255,255,255,.22); backdrop-filter: blur(6px); }
.btn--ghost:hover { background: rgba(255,255,255,.16); transform: translateY(-2px); }
.btn:active { transform: translateY(0) scale(.98); }

.text-link { display: inline-flex; align-items: center; gap: 6px; font-weight: 600; color: var(--c-primary); margin-top: 22px; }
.text-link:hover { gap: 10px; }
.text-link svg { transition: transform .2s; }

/* ============ 顶部导航 ============ */
.nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    transition: background .3s, box-shadow .3s, backdrop-filter .3s;
}
.nav__inner {
    max-width: var(--maxw); margin: 0 auto;
    padding: 16px clamp(20px, 4vw, 40px);
    display: flex; align-items: center; justify-content: space-between; gap: 20px;
}
.nav.is-scrolled {
    background: rgba(255,255,255,.82);
    backdrop-filter: saturate(180%) blur(16px);
    box-shadow: 0 3px 24px rgba(13,16,48,.08);
    border-bottom: 1px solid var(--c-border);
}
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 700; font-size: 20px; letter-spacing: -.3px; }
.brand__mark { display: inline-flex; }
.brand__text { color: #fff; transition: color .3s; }
.nav.is-scrolled .brand__text { color: var(--c-text); }

.nav__links { display: flex; align-items: center; gap: 4px; }
.nav__links a {
    padding: 10px 16px; border-radius: 10px; font-size: 15px; font-weight: 500;
    color: rgba(255,255,255,.85); transition: color .2s, background .2s;
}
.nav__links a:hover { color: #fff; background: rgba(255,255,255,.1); }
.nav.is-scrolled .nav__links a { color: var(--c-muted); }
.nav.is-scrolled .nav__links a:hover { color: var(--c-primary); background: var(--grad-soft); }

.nav__actions { display: flex; align-items: center; gap: 12px; }
.nav__cta {
    min-height: 44px; padding: 10px 20px; border-radius: 999px;
    background: var(--grad); color: #fff !important; font-size: 15px; font-weight: 600;
    display: inline-flex; align-items: center;
    transition: transform .2s, box-shadow .2s;
}
.nav__cta:hover { transform: translateY(-2px); box-shadow: 0 10px 24px rgba(91,108,255,.4); }

.nav__toggle {
    display: none; width: 44px; height: 44px; padding: 12px;
    background: rgba(255,255,255,.1); border: 1px solid rgba(255,255,255,.18);
    border-radius: 10px; flex-direction: column; justify-content: center; gap: 5px;
}
.nav__toggle span { display: block; height: 2px; width: 100%; background: #fff; border-radius: 2px; transition: transform .25s, opacity .2s; }
.nav.is-scrolled .nav__toggle { background: var(--c-bg); border-color: var(--c-border); }
.nav.is-scrolled .nav__toggle span { background: var(--c-text); }
.nav__toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav__toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav__toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ============ Hero ============ */
.hero {
    position: relative; color: #fff;
    padding: calc(140px + 4vw) 0 90px;
    background: radial-gradient(1200px 600px at 80% -10%, #2a2f6b 0%, transparent 60%),
                radial-gradient(1000px 500px at 0% 110%, #4a1f76 0%, transparent 55%),
                linear-gradient(160deg, #0d1030 0%, #151038 100%);
    overflow: hidden;
}
.hero__bg { position: absolute; inset: 0; pointer-events: none; }
.hero__grid {
    position: absolute; inset: 0;
    background-image: linear-gradient(rgba(255,255,255,.04) 1px, transparent 1px),
                      linear-gradient(90deg, rgba(255,255,255,.04) 1px, transparent 1px);
    background-size: 56px 56px;
    mask-image: radial-gradient(ellipse 75% 70% at 50% 30%, #000 40%, transparent 100%);
}
.hero__orb { position: absolute; border-radius: 50%; filter: blur(80px); opacity: .5; }
.hero__orb--1 { width: 420px; height: 420px; top: -120px; right: 8%; background: var(--c-primary); }
.hero__orb--2 { width: 380px; height: 380px; bottom: -160px; left: -80px; background: var(--c-primary-2); }
.hero__orb--3 { width: 260px; height: 260px; top: 40%; left: 40%; background: var(--c-accent); opacity: .22; }

.hero__inner {
    position: relative; max-width: var(--maxw); margin: 0 auto;
    padding: 0 clamp(20px, 4vw, 40px);
    display: grid; grid-template-columns: 1.05fr .95fr; gap: clamp(32px, 5vw, 72px); align-items: center;
}

.hero__badge {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 8px 16px; border-radius: 999px; font-size: 14px; font-weight: 500;
    background: rgba(255,255,255,.08); border: 1px solid rgba(255,255,255,.14);
    backdrop-filter: blur(8px); color: rgba(255,255,255,.9); margin-bottom: 24px;
}
.hero__badge-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--c-accent); box-shadow: 0 0 0 4px rgba(34,211,238,.25); animation: pulse 2s infinite; }
@keyframes pulse { 0%,100% { box-shadow: 0 0 0 3px rgba(34,211,238,.25);} 50% { box-shadow: 0 0 0 7px rgba(34,211,238,.08);} }

.hero__title { font-size: clamp(40px, 6.4vw, 72px); line-height: 1.08; font-weight: 800; letter-spacing: -1.5px; margin-bottom: 24px; }
.hero__subtitle { font-size: clamp(16px, 2vw, 19px); color: rgba(255,255,255,.72); max-width: 520px; margin-bottom: 34px; }
.hero__subtitle strong { color: #fff; font-weight: 600; }
.hero__cta { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 48px; }

.hero__stats {
    display: grid; grid-template-columns: repeat(4, auto); gap: 24px 36px;
    padding-top: 32px; border-top: 1px solid rgba(255,255,255,.12);
}
.hstat__num { display: block; font-size: clamp(26px, 3vw, 40px); font-weight: 800; letter-spacing: -1px; }
.hstat__num em { font-style: normal; font-size: .55em; font-weight: 700; }
.hstat__label { display: block; font-size: 13px; color: rgba(255,255,255,.6); margin-top: 4px; }

/* Hero 代码窗口 */
.hero__visual { position: relative; }
.code-win {
    background: rgba(18, 20, 46, .92); border: 1px solid rgba(255,255,255,.12);
    border-radius: var(--radius-lg); box-shadow: var(--shadow-lg); overflow: hidden;
    animation: float 6s ease-in-out infinite;
}
.code-win--mcp { margin: 20px 0 0 auto; width: 86%; animation-delay: -3s; }
.code-win__bar { display: flex; align-items: center; gap: 8px; padding: 12px 16px; background: rgba(255,255,255,.04); border-bottom: 1px solid rgba(255,255,255,.08); }
.dot { width: 11px; height: 11px; border-radius: 50%; }
.dot--r { background: #ff5f57; } .dot--y { background: #febc2e; } .dot--g { background: #28c840; }
.code-win__title { margin-left: 8px; font-size: 12px; color: rgba(255,255,255,.5); }
.code-win__body { padding: 18px 20px; font-size: 13.5px; line-height: 1.75; overflow-x: auto; color: #e6e8f5; }
.c-k { color: #c792ea; } .c-f { color: #82aaff; } .c-s { color: #c3e88d; } .c-c { color: #5c6370; font-style: italic; } .c-n { color: #f78c6c; } .c-o { color: #22d3ee; }
@keyframes float { 0%,100% { transform: translateY(0);} 50% { transform: translateY(-10px);} }

/* ============ 技术栈条 ============ */
.techbar { background: #0a0c26; color: rgba(255,255,255,.5); border-top: 1px solid rgba(255,255,255,.06); overflow: hidden; }
.techbar__track { display: flex; align-items: center; gap: 28px; white-space: nowrap; padding: 14px 0; animation: marquee 28s linear infinite; font-size: 15px; font-weight: 500; }
.techbar__track i { font-style: normal; color: var(--c-accent); }
@keyframes marquee { from { transform: translateX(0); } to { transform: translateX(-50%); } }

/* ============ 通用分区 ============ */
.section { padding: clamp(64px, 9vw, 120px) 0; }
.section--alt { background: var(--c-bg-alt); }
.section--contact { background: linear-gradient(160deg, #0d1030, #1b1340); color: #fff; }

.sec-head { max-width: 680px; margin: 0 auto clamp(36px, 5vw, 60px); text-align: center; }
.sec-tag {
    display: inline-block; padding: 6px 16px; border-radius: 999px;
    font-size: 13px; font-weight: 600; letter-spacing: .4px;
    background: var(--grad-soft); color: var(--c-primary); margin-bottom: 16px;
}
.sec-tag--light { background: rgba(255,255,255,.1); color: var(--c-accent); }
.sec-title { font-size: clamp(28px, 4.4vw, 44px); font-weight: 800; letter-spacing: -1px; line-height: 1.15; margin-bottom: 16px; }
.sec-lead { font-size: clamp(15px, 1.8vw, 18px); color: var(--c-muted); }

/* ============ 产品概述 ============ */
.overview-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 20px; }
.ov-card {
    background: var(--c-card); border: 1px solid var(--c-border); border-radius: var(--radius-lg);
    padding: 28px; box-shadow: var(--shadow-sm); transition: transform .3s var(--ease), box-shadow .3s, border-color .3s;
}
.ov-card:hover { transform: translateY(-6px); box-shadow: var(--shadow); border-color: rgba(91,108,255,.3); }
.ov-card__icon {
    width: 52px; height: 52px; border-radius: 14px; display: grid; place-items: center;
    background: var(--grad-soft); color: var(--c-primary); margin-bottom: 18px;
}
.ov-card__icon svg { width: 26px; height: 26px; }
.ov-card h3 { font-size: 18px; margin-bottom: 10px; }
.ov-card p { font-size: 15px; color: var(--c-muted); }

.ov-quote {
    margin-top: 40px; padding: 32px 36px; border-radius: var(--radius-lg);
    background: var(--grad-soft); border: 1px solid rgba(91,108,255,.15);
    display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 20px;
}
.ov-quote blockquote { font-size: clamp(16px, 2vw, 20px); font-weight: 500; color: var(--c-text); max-width: 700px; }

/* ============ 核心功能 ============ */
.feat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 20px; }
.feat-card {
    background: var(--c-card); border: 1px solid var(--c-border); border-radius: var(--radius-lg);
    padding: 28px; transition: transform .3s var(--ease), box-shadow .3s, border-color .3s; position: relative; overflow: hidden;
}
.feat-card::after {
    content: ""; position: absolute; top: -60px; right: -60px; width: 140px; height: 140px; border-radius: 50%;
    background: var(--grad); opacity: 0; filter: blur(50px); transition: opacity .4s;
}
.feat-card:hover { transform: translateY(-6px); box-shadow: var(--shadow); border-color: rgba(91,108,255,.28); }
.feat-card:hover::after { opacity: .14; }
.feat-card__icon {
    width: 54px; height: 54px; border-radius: 16px; display: grid; place-items: center;
    background: var(--grad); color: #fff; margin-bottom: 18px; box-shadow: 0 8px 20px rgba(91,108,255,.28);
}
.feat-card__icon svg { width: 26px; height: 26px; }
.feat-card h3 { font-size: 18px; margin-bottom: 10px; }
.feat-card p { font-size: 14.5px; color: var(--c-muted); }
.feat-card code { background: var(--c-bg-alt); padding: 1px 6px; border-radius: 6px; font-size: .85em; color: var(--c-primary); }

/* ============ 技术优势 ============ */
.adv-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 20px; margin-bottom: 36px; }
.adv-card {
    background: var(--c-card); border: 1px solid var(--c-border); border-radius: var(--radius-lg);
    padding: 28px; position: relative; overflow: hidden; transition: transform .3s var(--ease), box-shadow .3s;
}
.adv-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.adv-card--dark { background: linear-gradient(160deg, #111433, #1b1340); color: #fff; border: none; }
.adv-card--dark p { color: rgba(255,255,255,.72); }
.adv-card--dark strong { color: #fff; }
.adv-card__num { font-size: 13px; font-weight: 700; color: var(--c-primary); letter-spacing: 1px; }
.adv-card--dark .adv-card__num { color: var(--c-accent); }
.adv-card h3 { font-size: 19px; margin: 10px 0; }
.adv-card p { font-size: 15px; color: var(--c-muted); }
.adv-card code { background: rgba(91,108,255,.1); color: var(--c-primary); padding: 1px 6px; border-radius: 6px; font-size: .85em; }

.adv-provider { background: var(--c-card); border: 1px solid var(--c-border); border-radius: var(--radius-lg); padding: 28px; }
.adv-provider__title { font-size: 15px; margin-bottom: 16px; color: var(--c-muted); font-weight: 600; }
.adv-provider__grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 12px; }
.prov { background: var(--c-bg-alt); border-radius: var(--radius); padding: 16px; }
.prov__name { display: block; font-family: "SFMono-Regular", Consolas, monospace; font-weight: 700; color: var(--c-primary); margin-bottom: 6px; }
.prov__desc { font-size: 13px; color: var(--c-muted); }

/* ============ 应用场景 ============ */
.scene-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 20px; }
.scene-card {
    background: var(--c-card); border: 1px solid var(--c-border); border-radius: var(--radius-lg);
    padding: 28px; display: flex; gap: 18px; transition: transform .3s var(--ease), box-shadow .3s, border-color .3s;
}
.scene-card:hover { transform: translateY(-5px); box-shadow: var(--shadow); border-color: rgba(91,108,255,.28); }
.scene-card__icon { flex: 0 0 auto; width: 52px; height: 52px; border-radius: 14px; background: var(--grad-soft); color: var(--c-primary); display: grid; place-items: center; }
.scene-card__icon svg { width: 26px; height: 26px; }
.scene-card h3 { font-size: 18px; margin-bottom: 8px; }
.scene-card p { font-size: 14.5px; color: var(--c-muted); }

/* ============ 客户案例 ============ */
.case-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 20px; }
.case-card {
    background: var(--c-card); border: 1px solid var(--c-border); border-radius: var(--radius-lg);
    padding: 26px; display: flex; flex-direction: column; transition: transform .3s var(--ease), box-shadow .3s, border-color .3s;
}
.case-card:hover { transform: translateY(-6px); box-shadow: var(--shadow); border-color: rgba(91,108,255,.28); }
.case-card__top { display: flex; align-items: center; justify-content: space-between; margin-bottom: 18px; }
.case-card__logo {
    width: 52px; height: 52px; border-radius: 14px; display: grid; place-items: center;
    font-size: 14px; font-weight: 800; letter-spacing: .5px; color: #fff;
    background: linear-gradient(135deg, var(--c1), var(--c2));
}
.case-card__tag {
    font-size: 12px; font-weight: 600; padding: 5px 12px; border-radius: 999px;
    background: var(--c-bg-alt); color: var(--c-muted);
}
.case-card h3 { font-size: 18px; margin-bottom: 10px; }
.case-card p { font-size: 14.5px; color: var(--c-muted); margin-bottom: 16px; }
.case-card__points { list-style: none; margin-top: auto; display: grid; gap: 8px; }
.case-card__points li { font-size: 13.5px; color: var(--c-text); display: flex; align-items: center; gap: 8px; }
.case-card__points li::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: var(--grad); flex: 0 0 auto; }

/* ============ FAQ ============ */
.faq-list { display: grid; gap: 14px; }
.faq {
    background: var(--c-card); border: 1px solid var(--c-border); border-radius: var(--radius-lg);
    overflow: hidden; transition: box-shadow .3s, border-color .3s;
}
.faq[open] { box-shadow: var(--shadow-sm); border-color: rgba(91,108,255,.25); }
.faq summary {
    list-style: none; cursor: pointer; padding: 20px 24px;
    display: flex; align-items: center; justify-content: space-between; gap: 16px;
    font-size: 16.5px; font-weight: 600; min-height: 44px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq__icon { position: relative; width: 18px; height: 18px; flex: 0 0 auto; }
.faq__icon::before, .faq__icon::after {
    content: ""; position: absolute; background: var(--c-primary); border-radius: 2px; transition: transform .3s var(--ease);
}
.faq__icon::before { top: 50%; left: 0; width: 100%; height: 2px; transform: translateY(-50%); }
.faq__icon::after { left: 50%; top: 0; height: 100%; width: 2px; transform: translateX(-50%); }
.faq[open] .faq__icon::after { transform: translateX(-50%) rotate(90deg); }
.faq__body { padding: 0 24px 22px; color: var(--c-muted); font-size: 15px; }
.faq__body code { background: var(--c-bg-alt); color: var(--c-primary); padding: 1px 6px; border-radius: 6px; font-size: .85em; }

/* ============ 联系咨询 ============ */
.contact-grid { display: grid; grid-template-columns: .9fr 1.1fr; gap: clamp(32px, 5vw, 60px); align-items: start; }
.contact-info .sec-title { margin-bottom: 18px; }
.contact-info__lead { color: rgba(255,255,255,.7); font-size: 16px; margin-bottom: 28px; max-width: 460px; }
.contact-info__list { list-style: none; display: grid; gap: 16px; margin-bottom: 32px; }
.contact-info__list li { display: flex; align-items: center; gap: 14px; }
.ci-ico { width: 46px; height: 46px; border-radius: 12px; background: rgba(255,255,255,.08); border: 1px solid rgba(255,255,255,.12); display: grid; place-items: center; color: var(--c-accent); flex: 0 0 auto; }
.ci-ico svg { width: 22px; height: 22px; }
.contact-info__list strong { display: block; font-size: 15px; }
.contact-info__list span { font-size: 14px; color: rgba(255,255,255,.6); }
.contact-info__badge {
    display: inline-flex; align-items: center; gap: 8px; padding: 10px 16px;
    border-radius: 999px; background: rgba(255,255,255,.06); border: 1px solid rgba(255,255,255,.12);
    font-size: 13.5px; color: rgba(255,255,255,.75);
}
.ci-badge-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--c-accent); }

.contact-formwrap { background: var(--c-card); border-radius: var(--radius-xl); padding: clamp(24px, 4vw, 40px); box-shadow: var(--shadow-lg); }
.contact-form { display: grid; gap: 18px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.form-field { display: flex; flex-direction: column; gap: 7px; }
.form-field label { font-size: 14px; font-weight: 600; color: var(--c-text); }
.form-field label em { color: #ef4444; font-style: normal; }
.form-field input, .form-field select, .form-field textarea {
    width: 100%; font-family: inherit; font-size: 15px; color: var(--c-text);
    padding: 13px 16px; border-radius: var(--radius); border: 1.5px solid var(--c-border);
    background: var(--c-bg); transition: border-color .2s, box-shadow .2s; min-height: 48px;
}
.form-field textarea { resize: vertical; min-height: 110px; }
.form-field input:focus, .form-field select:focus, .form-field textarea:focus {
    outline: none; border-color: var(--c-primary); box-shadow: 0 0 0 4px rgba(91,108,255,.14); background: #fff;
}
.form-field .field-error { border-color: #ef4444; }
.form-foot { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 14px; }
.form-hint { font-size: 13px; color: var(--c-muted); }
.form-msg { font-size: 14px; min-height: 22px; }
.form-msg.is-ok { color: #059669; }
.form-msg.is-err { color: #dc2626; }

/* ============ 页脚 ============ */
.footer { background: #0a0c26; color: rgba(255,255,255,.62); padding-top: 70px; }
.footer__inner {
    display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; padding-bottom: 50px;
}
.footer__brand .brand__text { color: #fff; }
.footer__brand p { margin-top: 16px; font-size: 14px; line-height: 1.7; }
.footer__col h4 { color: #fff; font-size: 15px; margin-bottom: 18px; }
.footer__col a { display: block; font-size: 14px; padding: 6px 0; transition: color .2s; }
.footer__col a:hover { color: #fff; }
.footer__bottom {
    border-top: 1px solid rgba(255,255,255,.08);
    padding: 22px clamp(20px, 4vw, 40px); display: flex; flex-wrap: wrap; gap: 12px;
    justify-content: space-between; font-size: 13px; color: rgba(255,255,255,.4);
    max-width: var(--maxw); margin: 0 auto;
}

/* ============ 返回顶部 ============ */
.backtop {
    position: fixed; right: 24px; bottom: 24px; z-index: 90;
    width: 48px; height: 48px; border-radius: 50%; border: none;
    background: var(--grad); color: #fff; display: grid; place-items: center;
    box-shadow: 0 10px 26px rgba(91,108,255,.4);
    opacity: 0; visibility: hidden; transform: translateY(12px);
    transition: opacity .3s, visibility .3s, transform .3s var(--ease);
}
.backtop.show { opacity: 1; visibility: visible; transform: translateY(0); }
.backtop:hover { transform: translateY(-3px); }

/* ============ 滚动动画 ============ */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.in { opacity: 1; transform: none; }

/* ============ 响应式 ============ */
@media (max-width: 1024px) {
    .hero__inner { grid-template-columns: 1fr; }
    .hero__visual { max-width: 560px; width: 100%; }
    .contact-grid { grid-template-columns: 1fr; }
    .footer__inner { grid-template-columns: 1fr 1fr; }
    .hero__stats { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    html { scroll-padding-top: 70px; }
    .nav__toggle { display: flex; }
    .nav__links {
        position: absolute; top: 100%; left: 0; right: 0;
        flex-direction: column; align-items: stretch; gap: 4px;
        background: #fff; padding: 14px; margin: 0 clamp(20px, 4vw, 40px);
        border-radius: 16px; box-shadow: var(--shadow-lg);
        display: none; animation: drop .25s var(--ease);
    }
    .nav__links.open { display: flex; }
    @keyframes drop { from { opacity: 0; transform: translateY(-8px);} to { opacity: 1; transform: none;} }
    .nav__links a { color: var(--c-text); padding: 14px 16px; border-radius: 12px; }
    .nav__links a:hover { background: var(--c-bg-alt); color: var(--c-primary); }
    .nav__cta { display: none; }

    .hero { padding-top: 130px; }
    .form-row { grid-template-columns: 1fr; }
    .footer__inner { grid-template-columns: 1fr; gap: 28px; }
    .ov-quote { flex-direction: column; align-items: flex-start; }
    .form-foot { flex-direction: column; align-items: stretch; }
}

@media (prefers-reduced-motion: reduce) {
    * { animation: none !important; transition: none !important; }
    html { scroll-behavior: auto; }
    .reveal { opacity: 1; transform: none; }
}