/* ============================================================================
   星盾 StarShield · Design System
   ----------------------------------------------------------------------------
   设计依据：ui-ux-pro-max 设计引擎（Gaming 配色 + Cyberpunk 深色语汇）
   风格：深空 / 星尘 / 盾面六边格 —— 以「星」造氛围，以「盾」立信任
   约束：
     1. 不引入外部字体 / 图标 CDN（中国大陆可达性 + 首屏阻塞）
     2. 全部图标使用内联 SVG，不使用 emoji 充当图标
     3. 所有交互元素 cursor:pointer，过渡 150~300ms，不动 layout
     4. 正文对比度 ≥ 4.5:1，焦点环可见
     5. 尊重 prefers-reduced-motion
   ========================================================================== */

/* ------------------------------------------------------------------ 1. Token */
:root {
    /* 底色：由深到浅三级，避免死黑 */
    --bg-0: #05050C;
    --bg-1: #08080F;
    --bg-2: #0B0B18;
    --bg-3: #101024;

    /* 玻璃面 */
    --surface: rgba(255, 255, 255, .032);
    --surface-hi: rgba(255, 255, 255, .06);
    --surface-solid: #0E0E1C;

    /* 描边 */
    --line: rgba(255, 255, 255, .085);
    --line-hi: rgba(167, 139, 250, .32);
    --line-cyan: rgba(34, 211, 238, .3);

    /* 品牌主色：紫（宇宙 / 星云） */
    --violet-700: #6D28D9;
    --violet-600: #7C3AED;
    --violet-500: #8B5CF6;
    --violet-400: #A78BFA;
    --violet-300: #C4B5FD;

    /* 辅助色：青（数据 / 链路 / 扫描） */
    --cyan-500: #06B6D4;
    --cyan-400: #22D3EE;
    --cyan-300: #67E8F9;

    /* 语义色 */
    --rose-500: #F43F5E;   /* 攻击 / 告警 */
    --emerald-400: #34D399; /* 正常 / 防护生效 */

    /* 文字层级 */
    --text: #E9EBF7;
    --text-dim: #AEB6CF;
    --text-mute: #7F88A6;

    /* 排版 */
    --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI",
        "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC",
        sans-serif;
    --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
        "Liberation Mono", monospace;

    /* 间距节奏（4 的倍数） */
    --sp-1: 4px;
    --sp-2: 8px;
    --sp-3: 12px;
    --sp-4: 16px;
    --sp-5: 20px;
    --sp-6: 24px;
    --sp-8: 32px;
    --sp-10: 40px;
    --sp-12: 48px;
    --sp-16: 64px;
    --sp-20: 80px;
    --sp-24: 96px;
    --sp-32: 128px;

    /* 圆角 */
    --r-sm: 8px;
    --r-md: 12px;
    --r-lg: 16px;
    --r-xl: 22px;
    --r-pill: 999px;

    /* 阴影 */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, .4);
    --shadow-md: 0 8px 28px rgba(0, 0, 0, .45);
    --shadow-lg: 0 24px 70px rgba(0, 0, 0, .6);
    --glow-violet: 0 0 0 1px rgba(124, 58, 237, .35), 0 12px 40px rgba(124, 58, 237, .22);
    --glow-cyan: 0 0 0 1px rgba(34, 211, 238, .28), 0 12px 40px rgba(34, 211, 238, .16);

    /* 层级 */
    --z-base: 1;
    --z-nav: 50;
    --z-float: 60;

    --maxw: 1200px;
    --ease: cubic-bezier(.22, .61, .36, 1);
}

/* ------------------------------------------------------------------ 2. Reset */
*,
*::before,
*::after { box-sizing: border-box; }

html {
    -webkit-text-size-adjust: 100%;
    scroll-behavior: smooth;
    scroll-padding-top: 96px;
}

body {
    margin: 0;
    background: var(--bg-0);
    color: var(--text);
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.72;
    letter-spacing: .01em;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

h1, h2, h3, h4 {
    margin: 0;
    font-weight: 600;
    line-height: 1.24;
    letter-spacing: -0.02em;
    color: #fff;
}

p { margin: 0; }

a {
    color: var(--violet-300);
    text-decoration: none;
    transition: color .2s var(--ease);
}

a:hover { color: var(--cyan-300); }

img { max-width: 100%; display: block; }

ul, ol { margin: 0; padding: 0; list-style: none; }

button {
    font: inherit;
    color: inherit;
    background: none;
    border: 0;
    cursor: pointer;
}

/* 焦点可见（键盘导航） */
:focus-visible {
    outline: 2px solid var(--cyan-400);
    outline-offset: 3px;
    border-radius: 4px;
}

::selection {
    background: rgba(124, 58, 237, .45);
    color: #fff;
}

/* 光标与滚动条：浏览器默认值不属于任何设计系统，按本套调色板重画 */
html {
    caret-color: var(--violet-400);
    scrollbar-color: rgba(167, 139, 250, .3) rgba(255, 255, 255, .03);
    scrollbar-width: thin;
}

::-webkit-scrollbar { width: 10px; height: 10px; }

::-webkit-scrollbar-track { background: rgba(255, 255, 255, .03); }

::-webkit-scrollbar-thumb {
    border: 2px solid transparent;
    border-radius: var(--r-pill);
    background: rgba(167, 139, 250, .28);
    background-clip: padding-box;
}

::-webkit-scrollbar-thumb:hover { background: rgba(167, 139, 250, .5); background-clip: padding-box; }

::-webkit-scrollbar-corner { background: transparent; }

/* ------------------------------------------------------------------ 3. 布局 */
.st-container {
    width: 100%;
    max-width: var(--maxw);
    margin: 0 auto;
    padding: 0 var(--sp-6);
}

.st-section {
    position: relative;
    padding: var(--sp-24) 0;
}

.st-section--tight { padding: var(--sp-16) 0; }

.st-section--alt { background: var(--bg-1); }

.st-section--edge::before {
    content: '';
    position: absolute;
    inset: 0 0 auto;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--line), transparent);
}

/* 段落标题 */
.st-head {
    max-width: 720px;
    margin: 0 auto var(--sp-12);
    text-align: center;
}

.st-head--left {
    margin-left: 0;
    text-align: left;
}

.st-head h2 {
    font-size: clamp(28px, 3.4vw, 40px);
    margin-bottom: var(--sp-4);
}

.st-head p {
    color: var(--text-dim);
    font-size: 16px;
    line-height: 1.8;
}

/* 渐变文字：inline-block + 内边距，避免中文/西文字形下缘被裁断 */
.st-grad {
    display: inline-block;
    padding-bottom: .1em;
    margin-bottom: -.1em;
    background: linear-gradient(102deg, var(--violet-300) 0%, var(--cyan-300) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    -webkit-box-decoration-break: clone;
    box-decoration-break: clone;
}

/* ------------------------------------------------------------------ 4. 按钮 */
.st-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--sp-2);
    height: 46px;
    padding: 0 26px;
    border-radius: var(--r-pill);
    font-size: 15px;
    font-weight: 600;
    letter-spacing: .01em;
    white-space: nowrap;
    cursor: pointer;
    transition: transform .2s var(--ease), box-shadow .25s var(--ease),
        background-color .2s var(--ease), border-color .2s var(--ease);
}

.st-btn svg { width: 18px; height: 18px; flex: none; }

.st-btn--primary {
    color: #fff;
    background: linear-gradient(135deg, var(--violet-600), var(--violet-500) 55%, var(--cyan-500));
    box-shadow: 0 10px 30px rgba(124, 58, 237, .32);
}

.st-btn--primary:hover {
    color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 16px 42px rgba(124, 58, 237, .45);
}

.st-btn--ghost {
    color: var(--text);
    border: 1px solid var(--line);
    background: var(--surface);
}

.st-btn--ghost:hover {
    color: #fff;
    border-color: var(--line-hi);
    background: var(--surface-hi);
    transform: translateY(-2px);
}

.st-btn--sm { height: 38px; padding: 0 18px; font-size: 14px; }

.st-btn[disabled],
.st-btn.is-disabled {
    opacity: .55;
    pointer-events: none;
}

/* ------------------------------------------------------------------ 5. 导航 */
.st-nav {
    position: fixed;
    top: var(--sp-4);
    left: 50%;
    z-index: var(--z-nav);
    width: calc(100% - 32px);
    max-width: 1160px;
    transform: translateX(-50%);
    transition: background-color .3s var(--ease), border-color .3s var(--ease),
        box-shadow .3s var(--ease), backdrop-filter .3s var(--ease);
    border: 1px solid transparent;
    border-radius: var(--r-pill);
}

.st-nav__inner {
    display: flex;
    align-items: center;
    gap: var(--sp-6);
    height: 68px;
    padding: 0 var(--sp-5) 0 var(--sp-6);
}

.st-nav.is-stuck {
    background: rgba(8, 8, 16, .78);
    border-color: var(--line);
    box-shadow: var(--shadow-md);
    -webkit-backdrop-filter: blur(18px) saturate(140%);
    backdrop-filter: blur(18px) saturate(140%);
}

/* Logo */
.st-logo {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    flex: none;
    color: #fff;
    font-size: 18px;
    font-weight: 700;
    letter-spacing: .02em;
}

.st-logo:hover { color: #fff; }

.st-logo__mark {
    position: relative;
    width: 30px;
    height: 34px;
    display: grid;
    place-items: center;
}

.st-logo__mark svg { width: 30px; height: 34px; }

.st-logo__text small {
    display: block;
    margin-top: -3px;
    color: var(--text-mute);
    font-size: 9.5px;
    font-weight: 500;
    letter-spacing: .22em;
    text-transform: uppercase;
}

/* 菜单 */
.st-nav__menu {
    display: flex;
    align-items: center;
    gap: 2px;
    margin: 0 auto;
}

.st-nav__link {
    position: relative;
    display: block;
    padding: 8px 13px;
    border-radius: var(--r-pill);
    color: var(--text-dim);
    font-size: 14px;
    font-weight: 500;
    transition: color .2s var(--ease), background-color .2s var(--ease);
}

.st-nav__link:hover {
    color: #fff;
    background: var(--surface);
}

.st-nav__link.is-active { color: #fff; }

.st-nav__link.is-active::after {
    content: '';
    position: absolute;
    left: 50%;
    bottom: 2px;
    width: 16px;
    height: 2px;
    transform: translateX(-50%);
    border-radius: 2px;
    background: linear-gradient(90deg, var(--violet-400), var(--cyan-400));
}

.st-nav__actions {
    display: flex;
    align-items: center;
    gap: var(--sp-2);
    flex: none;
}

.st-nav__toggle {
    display: none;
    width: 40px;
    height: 40px;
    margin-left: auto;
    border: 1px solid var(--line);
    border-radius: var(--r-md);
    color: var(--text);
    place-items: center;
}

.st-nav__toggle svg { width: 20px; height: 20px; }

/* 移动端抽屉 */
.st-drawer {
    position: fixed;
    inset: 0;
    z-index: var(--z-nav);
    display: none;
    padding: 84px var(--sp-6) var(--sp-6);
    background: rgba(5, 5, 12, .96);
    -webkit-backdrop-filter: blur(20px);
    backdrop-filter: blur(20px);
}

.st-drawer.is-open { display: block; }

.st-drawer a {
    display: block;
    padding: var(--sp-4) 0;
    border-bottom: 1px solid var(--line);
    color: var(--text);
    font-size: 16px;
}

.st-drawer .st-btn { width: 100%; margin-top: var(--sp-6); }

/* ------------------------------------------------------------------ 6. 首屏 */
.st-hero {
    position: relative;
    overflow: hidden;
    padding: 168px 0 var(--sp-20);
    isolation: isolate;
}

/* 星野画布 */
.st-hero__stars {
    position: absolute;
    inset: 0;
    z-index: -3;
    width: 100%;
    height: 100%;
    opacity: .85;
    pointer-events: none;
}

/* 极光 + 网格 */
.st-hero::before {
    content: '';
    position: absolute;
    inset: -20% -10% auto;
    z-index: -2;
    height: 780px;
    background:
        radial-gradient(46% 52% at 22% 18%, rgba(124, 58, 237, .30), transparent 68%),
        radial-gradient(40% 46% at 78% 6%, rgba(34, 211, 238, .16), transparent 66%),
        radial-gradient(58% 50% at 50% 0%, rgba(109, 40, 217, .18), transparent 72%);
    filter: blur(6px);
    pointer-events: none;
}

.st-hero::after {
    content: '';
    position: absolute;
    inset: 0;
    z-index: -1;
    background-image:
        linear-gradient(rgba(255, 255, 255, .028) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, .028) 1px, transparent 1px);
    background-size: 64px 64px;
    -webkit-mask-image: radial-gradient(70% 62% at 50% 26%, #000 0%, transparent 78%);
    mask-image: radial-gradient(70% 62% at 50% 26%, #000 0%, transparent 78%);
    pointer-events: none;
}

.st-hero__grid {
    display: grid;
    grid-template-columns: 1.02fr .98fr;
    gap: var(--sp-16);
    align-items: center;
}

.st-hero__badge {
    display: inline-flex;
    align-items: center;
    gap: var(--sp-3);
    margin-bottom: var(--sp-6);
    padding: 6px 14px 6px 6px;
    border: 1px solid var(--line);
    border-radius: var(--r-pill);
    background: var(--surface);
    font-size: 13px;
    color: var(--text-dim);
}

.st-hero__badge b {
    padding: 3px 9px;
    border-radius: var(--r-pill);
    background: linear-gradient(135deg, var(--violet-600), var(--cyan-500));
    color: #fff;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: .06em;
}

.st-hero h1 {
    font-size: clamp(34px, 4.6vw, 58px);
    line-height: 1.14;
    letter-spacing: -0.03em;
    margin-bottom: var(--sp-5);
}

/* 首屏标题逐行从遮罩里升起来。容器自己留 .14em 底部内边距，
   否则 overflow:hidden 会把中文与渐变字的下缘切掉。 */
.st-hero h1 .st-line {
    display: block;
    overflow: hidden;
    padding-bottom: .14em;
    margin-bottom: -.14em;
}

.st-hero h1 .st-line__in {
    display: block;
    transform: translate3d(0, 108%, 0);
    animation: st-line-up .95s var(--ease) forwards;
}

.st-hero h1 .st-line:nth-child(2) .st-line__in { animation-delay: .11s; }

@keyframes st-line-up {
    to { transform: translate3d(0, 0, 0); }
}

/* 副标题比标题轻一档：模糊化开，不做位移堆叠 */
.st-hero__lede {
    animation: st-blur-in .85s var(--ease) .3s forwards;
    opacity: 0;
}

@keyframes st-blur-in {
    from { opacity: 0; filter: blur(9px); transform: translateY(12px); }
    to { opacity: 1; filter: blur(0); transform: none; }
}

/* 按钮与数据随后补位，把注意力依次交给可操作的东西 */
.st-hero__cta { animation: st-rise .7s var(--ease) .46s both; }
.st-hero__meta { animation: st-rise .7s var(--ease) .58s both; }

@keyframes st-rise {
    from { opacity: 0; transform: translateY(14px); }
    to { opacity: 1; transform: none; }
}

.st-hero__lede {
    max-width: 540px;
    color: var(--text-dim);
    font-size: 17px;
    line-height: 1.82;
}

.st-hero__cta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--sp-3);
    margin-top: var(--sp-8);
}

.st-hero__meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--sp-6);
    margin-top: var(--sp-10);
    padding-top: var(--sp-6);
    border-top: 1px solid var(--line);
}

.st-hero__meta div { min-width: 96px; }

.st-hero__meta dt {
    color: var(--text-mute);
    font-size: 12.5px;
    letter-spacing: .04em;
}

.st-hero__meta dd {
    margin: 2px 0 0;
    font-size: 22px;
    font-weight: 600;
    color: #fff;
    font-variant-numeric: tabular-nums;
    letter-spacing: -0.02em;
}

.st-hero__meta dd span {
    font-size: 12px;
    font-weight: 500;
    color: var(--text-mute);
    letter-spacing: 0;
}

/* ------------------------------------------------------------------ 7. 盾面可视化 */
.st-shield {
    position: relative;
    aspect-ratio: 1 / 1;
    width: 100%;
    max-width: 520px;
    margin: 0 auto;
    display: grid;
    place-items: center;
}

/* 同心环 */
.st-shield__ring {
    position: absolute;
    border-radius: 50%;
    border: 1px solid var(--line);
}

.st-shield__ring--1 { inset: 4%; border-color: rgba(167, 139, 250, .16); }
.st-shield__ring--2 { inset: 16%; border-color: rgba(167, 139, 250, .12); }
.st-shield__ring--3 { inset: 28%; border-color: rgba(34, 211, 238, .14); }

/* 扫描线 */
.st-shield__sweep {
    position: absolute;
    inset: 4%;
    border-radius: 50%;
    background: conic-gradient(from 0deg,
            rgba(34, 211, 238, 0) 0deg,
            rgba(34, 211, 238, .30) 34deg,
            rgba(34, 211, 238, 0) 76deg);
    -webkit-mask-image: radial-gradient(circle, transparent 18%, #000 20%);
    mask-image: radial-gradient(circle, transparent 18%, #000 20%);
    animation: st-sweep 6s linear infinite;
    opacity: .8;
}

@keyframes st-sweep {
    to { transform: rotate(360deg); }
}

/* 盾牌主体 */
.st-shield__core {
    position: relative;
    z-index: 2;
    width: 44%;
    filter: drop-shadow(0 18px 46px rgba(124, 58, 237, .4));
}

.st-shield__core svg { width: 100%; height: auto; }

/* 环绕节点 */
.st-shield__node {
    position: absolute;
    display: flex;
    align-items: center;
    gap: 7px;
    padding: 6px 12px 6px 8px;
    border: 1px solid var(--line);
    border-radius: var(--r-pill);
    background: rgba(11, 11, 24, .82);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
    font-size: 12px;
    font-weight: 500;
    color: var(--text-dim);
    white-space: nowrap;
    animation: st-float 7s ease-in-out infinite;
}

.st-shield__node i {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--emerald-400);
    box-shadow: 0 0 8px var(--emerald-400);
    flex: none;
}

.st-shield__node--attack i {
    background: var(--rose-500);
    box-shadow: 0 0 8px var(--rose-500);
    animation: st-blink 1.1s steps(2, start) infinite;
}

@keyframes st-blink {
    50% { opacity: .25; }
}

@keyframes st-float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-9px); }
}

.st-shield__node--a { top: 9%; left: -6%; animation-delay: -.4s; }
.st-shield__node--b { top: 27%; right: -8%; animation-delay: -2.2s; }
.st-shield__node--c { bottom: 22%; left: -9%; animation-delay: -3.6s; }
.st-shield__node--d { bottom: 8%; right: -3%; animation-delay: -1.3s; }

/* 攻击被拦截的脉冲 */
.st-shield__pulse {
    position: absolute;
    inset: 4%;
    border-radius: 50%;
    border: 1px solid rgba(244, 63, 94, .5);
    animation: st-pulse 3.4s ease-out infinite;
    opacity: 0;
}

.st-shield__pulse:nth-of-type(2) { animation-delay: 1.15s; }
.st-shield__pulse:nth-of-type(3) { animation-delay: 2.3s; }

@keyframes st-pulse {
    0% { transform: scale(.72); opacity: .0; }
    12% { opacity: .55; }
    100% { transform: scale(1.02); opacity: 0; }
}

/* ------------------------------------------------------------------ 8. 数据条 */
.st-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    border: 1px solid var(--line);
    border-radius: var(--r-xl);
    background: linear-gradient(180deg, var(--surface), transparent);
    overflow: hidden;
}

.st-stat {
    padding: var(--sp-8) var(--sp-6);
    text-align: center;
    border-right: 1px solid var(--line);
}

.st-stat:last-child { border-right: 0; }

.st-stat__num {
    font-size: clamp(26px, 3vw, 38px);
    font-weight: 600;
    line-height: 1.1;
    letter-spacing: -0.03em;
    color: #fff;
    font-variant-numeric: tabular-nums;
}

.st-stat__num em {
    font-style: normal;
    font-size: .58em;
    color: var(--violet-300);
    margin-left: 2px;
}

.st-stat__label {
    margin-top: var(--sp-2);
    color: var(--text-mute);
    font-size: 13px;
    letter-spacing: .02em;
}

/* ------------------------------------------------------------------ 9. 卡片 */
.st-card {
    position: relative;
    padding: var(--sp-6);
    border: 1px solid var(--line);
    border-radius: var(--r-lg);
    background: var(--surface);
    transition: transform .25s var(--ease), border-color .25s var(--ease),
        background-color .25s var(--ease), box-shadow .25s var(--ease);
}

.st-card:hover {
    transform: translateY(-4px);
    border-color: var(--line-hi);
    background: var(--surface-hi);
    box-shadow: var(--shadow-md);
}

/* --------------------------------------------------- 论点清单（产品优势）
   这一屏讲的是"为什么选星盾"，不是功能清单，所以不做卡片：
   连续两屏同尺寸的「图标 + 标题 + 正文」卡片会把整页读成一堵砖墙。
   论点走无边框条目 + 细分隔线，功能留给下面的 .st-cap 卡片。 */
.st-adv-list {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: var(--sp-12);
}

.st-adv {
    display: flex;
    gap: var(--sp-4);
    align-items: flex-start;
    padding: var(--sp-6) 0;
    border-top: 1px solid var(--line);
}

/* 首行（两列的前两条）不要横线，否则会和上面的标题挤在一起 */
.st-adv:nth-child(-n+2) { border-top: 0; }

.st-adv .st-ico {
    flex: none;
    width: 38px;
    height: 38px;
    margin-bottom: 0;
    border-radius: 11px;
    background: rgba(124, 58, 237, .16);
}

.st-adv .st-ico svg { width: 20px; height: 20px; }

.st-adv__body h3 {
    font-size: 16px;
    margin-bottom: 6px;
}

.st-adv__body p {
    color: var(--text-dim);
    font-size: 13.5px;
    line-height: 1.78;
}

/* 图标容器 */
.st-ico {
    display: grid;
    place-items: center;
    width: 44px;
    height: 44px;
    margin-bottom: var(--sp-5);
    border: 1px solid var(--line);
    border-radius: var(--r-md);
    background: linear-gradient(160deg, rgba(124, 58, 237, .22), rgba(34, 211, 238, .08));
    color: var(--violet-300);
    transition: color .25s var(--ease), border-color .25s var(--ease),
        transform .25s var(--ease);
}

.st-ico svg { width: 22px; height: 22px; }

.st-card:hover .st-ico {
    color: var(--cyan-300);
    border-color: var(--line-hi);
    transform: translateY(-2px);
}

.st-card h3 {
    font-size: 17px;
    margin-bottom: var(--sp-3);
}

.st-card p {
    color: var(--text-dim);
    font-size: 14px;
    line-height: 1.82;
}

/* 优势网格 */
.st-grid-4 {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: var(--sp-4);
}

/* 能力网格（带编号） */
.st-grid-3 {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--sp-4);
}

.st-cap {
    display: flex;
    gap: var(--sp-4);
    padding: var(--sp-6);
    border: 1px solid var(--line);
    border-radius: var(--r-lg);
    background: var(--surface);
    transition: border-color .25s var(--ease), background-color .25s var(--ease);
}

.st-cap:hover {
    border-color: var(--line-hi);
    background: var(--surface-hi);
}

.st-cap__ico {
    display: grid;
    place-items: center;
    flex: none;
    width: 40px;
    height: 40px;
    border-radius: 10px;
    background: rgba(124, 58, 237, .16);
    color: var(--violet-300);
}

.st-cap__ico svg { width: 20px; height: 20px; }

.st-cap h3 {
    font-size: 16px;
    margin-bottom: var(--sp-2);
}

.st-cap p {
    color: var(--text-dim);
    font-size: 13.5px;
    line-height: 1.8;
}

/* ------------------------------------------------------------------ 10. 架构图 */
.st-arch {
    position: relative;
    padding: var(--sp-8) var(--sp-6);
    border: 1px solid var(--line);
    border-radius: var(--r-xl);
    background:
        radial-gradient(60% 80% at 50% 0%, rgba(124, 58, 237, .12), transparent 70%),
        var(--bg-2);
    overflow: hidden;
}

.st-arch__flow {
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: var(--sp-3);
    align-items: stretch;
}

.st-arch__step {
    position: relative;
    padding: var(--sp-5) var(--sp-4);
    border: 1px solid var(--line);
    border-radius: var(--r-md);
    background: rgba(255, 255, 255, .025);
    text-align: center;
}

.st-arch__step span {
    display: inline-grid;
    place-items: center;
    width: 34px;
    height: 34px;
    margin-bottom: var(--sp-3);
    border-radius: 50%;
    background: rgba(124, 58, 237, .18);
    color: var(--violet-300);
}

.st-arch__step span svg { width: 18px; height: 18px; }

.st-arch__step h4 {
    font-size: 14px;
    margin-bottom: 6px;
}

.st-arch__step p {
    color: var(--text-mute);
    font-size: 12.5px;
    line-height: 1.7;
}

/* 链路箭头 */
.st-arch__step:not(:last-child)::after {
    content: '';
    position: absolute;
    top: 50%;
    right: -10px;
    width: 20px;
    height: 1px;
    background: linear-gradient(90deg, var(--violet-500), var(--cyan-400));
    opacity: .55;
}

.st-arch__step:not(:last-child)::before {
    content: '';
    position: absolute;
    top: 50%;
    right: -10px;
    width: 5px;
    height: 5px;
    margin-top: -2px;
    border-radius: 50%;
    background: var(--cyan-400);
    box-shadow: 0 0 10px var(--cyan-400);
    animation: st-flow 2.6s linear infinite;
}

@keyframes st-flow {
    0% { transform: translateX(-20px); opacity: 0; }
    30% { opacity: 1; }
    100% { transform: translateX(0); opacity: 0; }
}

/* 拦截层 */
.st-arch__shield-line {
    display: flex;
    align-items: center;
    gap: var(--sp-4);
    margin: var(--sp-6) 0;
    color: var(--text-mute);
    font-size: 12.5px;
}

.st-arch__shield-line::before,
.st-arch__shield-line::after {
    content: '';
    flex: 1;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--line), transparent);
}

.st-arch__shield-line b {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 5px 14px;
    border: 1px solid rgba(244, 63, 94, .3);
    border-radius: var(--r-pill);
    background: rgba(244, 63, 94, .08);
    color: #FCA5B5;
    font-weight: 500;
}

/* ------------------------------------------------------------------ 11. 实时面板 */
.st-live {
    display: grid;
    grid-template-columns: 1.35fr .65fr;
    gap: var(--sp-4);
}

.st-panel {
    border: 1px solid var(--line);
    border-radius: var(--r-lg);
    background: var(--bg-2);
    overflow: hidden;
}

.st-panel__bar {
    display: flex;
    align-items: center;
    gap: var(--sp-2);
    padding: 12px var(--sp-5);
    border-bottom: 1px solid var(--line);
    color: var(--text-mute);
    font-size: 12.5px;
}

.st-panel__bar .dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--emerald-400);
    box-shadow: 0 0 8px var(--emerald-400);
}

.st-panel__bar b {
    color: var(--text);
    font-weight: 500;
}

.st-panel__bar time {
    margin-left: auto;
    font-family: var(--font-mono);
    font-size: 11.5px;
    color: var(--text-mute);
}

.st-chart {
    display: block;
    width: 100%;
    height: 260px;
}

.st-panel__body { padding: var(--sp-5); }

.st-meter + .st-meter { margin-top: var(--sp-5); }

.st-meter__top {
    display: flex;
    justify-content: space-between;
    margin-bottom: 7px;
    font-size: 13px;
    color: var(--text-dim);
}

.st-meter__top b {
    color: #fff;
    font-variant-numeric: tabular-nums;
    font-weight: 600;
}

.st-meter__track {
    height: 6px;
    border-radius: 3px;
    background: rgba(255, 255, 255, .11);
    overflow: hidden;
}

.st-meter__fill {
    height: 100%;
    border-radius: 3px;
    background: linear-gradient(90deg, var(--violet-500), var(--cyan-400));
    transition: width .8s var(--ease);
}

.st-meter__fill--rose {
    background: linear-gradient(90deg, #F43F5E, #FB7185);
}

/* 日志流 */
.st-logs {
    margin-top: var(--sp-5);
    padding-top: var(--sp-4);
    border-top: 1px solid var(--line);
    font-family: var(--font-mono);
    font-size: 11.5px;
    line-height: 1.95;
    color: var(--text-mute);
    max-height: 92px;
    overflow: hidden;
}

.st-logs div { display: flex; gap: 8px; }

.st-logs i {
    font-style: normal;
    color: var(--violet-400);
    flex: none;
}

.st-logs em {
    font-style: normal;
    color: #FCA5B5;
}

/* ------------------------------------------------------------------ 12. 场景 */
.st-grid-2 {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--sp-4);
}

.st-scene {
    position: relative;
    padding: var(--sp-6);
    border: 1px solid var(--line);
    border-radius: var(--r-lg);
    background: var(--surface);
    transition: border-color .25s var(--ease), background-color .25s var(--ease);
}

/* 场景标题前的引导点。原先这里是 3px 的竖向彩条 —— 卡片左侧色条是被点名的
   廉价装饰，换成与标题同行的短标记，信息层级不变。 */
.st-scene h3 {
    position: relative;
    padding-left: 18px;
    font-size: 16px;
    margin-bottom: var(--sp-3);
}

.st-scene h3::before {
    content: '';
    position: absolute;
    left: 0;
    top: .62em;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--violet-400);
    box-shadow: 0 0 0 3px rgba(124, 58, 237, .18);
    transition: background-color .25s var(--ease), box-shadow .25s var(--ease);
}

.st-scene:hover {
    border-color: var(--line-hi);
    background: var(--surface-hi);
}

.st-scene:hover h3::before {
    background: var(--cyan-300);
    box-shadow: 0 0 0 3px rgba(34, 211, 238, .18);
}

.st-scene p {
    color: var(--text-dim);
    font-size: 13.5px;
    line-height: 1.82;
}

/* ------------------------------------------------------------------ 13. 节点 */
.st-regions {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: var(--sp-3);
}

.st-region {
    padding: var(--sp-5);
    border: 1px solid var(--line);
    border-radius: var(--r-md);
    background: var(--surface);
    transition: border-color .25s var(--ease);
}

.st-region:hover { border-color: var(--line-cyan); }

.st-region__top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--sp-3);
}

.st-region h4 { font-size: 14px; }

.st-region__badge {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    font-size: 11px;
    color: var(--emerald-400);
}

.st-region__badge::before {
    content: '';
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: currentColor;
    box-shadow: 0 0 6px currentColor;
}

.st-region ul {
    display: flex;
    flex-wrap: wrap;
    gap: 5px;
}

.st-region li {
    padding: 2px 9px;
    border: 1px solid var(--line);
    border-radius: var(--r-pill);
    color: var(--text-mute);
    font-size: 11.5px;
}

/* ------------------------------------------------------------------ 14. 流程 */
.st-steps {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: var(--sp-4);
    counter-reset: ststep;
}

.st-steps--5 { grid-template-columns: repeat(5, minmax(0, 1fr)); }

.st-step {
    position: relative;
    padding-top: var(--sp-8);
    border-top: 1px solid var(--line);
    counter-increment: ststep;
}

.st-step::before {
    content: '0' counter(ststep);
    position: absolute;
    top: -1px;
    left: 0;
    padding-top: var(--sp-4);
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: .1em;
    color: var(--violet-400);
    background: var(--bg-0);
    padding-right: 10px;
    margin-top: -9px;
}

.st-section--alt .st-step::before { background: var(--bg-1); }

.st-step h3 {
    font-size: 16px;
    margin-bottom: var(--sp-3);
}

.st-step p {
    color: var(--text-dim);
    font-size: 13.5px;
    line-height: 1.8;
}

/* ------------------------------------------------------------------ 15. 套餐 */
.st-plans {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: var(--sp-4);
}

.st-plan {
    position: relative;
    display: flex;
    flex-direction: column;
    padding: var(--sp-6) var(--sp-5);
    border: 1px solid var(--line);
    border-radius: var(--r-lg);
    background: var(--surface);
    transition: transform .25s var(--ease), border-color .25s var(--ease),
        box-shadow .25s var(--ease);
}

.st-plan:hover {
    transform: translateY(-5px);
    border-color: var(--line-hi);
    box-shadow: var(--shadow-md);
}

.st-plan--hot {
    border-color: var(--line-hi);
    background: linear-gradient(180deg, rgba(124, 58, 237, .14), rgba(124, 58, 237, .02));
    box-shadow: var(--glow-violet);
}

.st-plan__tag {
    position: absolute;
    top: -11px;
    left: 50%;
    transform: translateX(-50%);
    padding: 3px 12px;
    border-radius: var(--r-pill);
    background: linear-gradient(135deg, var(--violet-600), var(--cyan-500));
    color: #fff;
    font-size: 11px;
    font-weight: 600;
    white-space: nowrap;
}

.st-plan__name {
    font-size: 16px;
    font-weight: 600;
    color: #fff;
}

.st-plan__price {
    margin: var(--sp-4) 0 var(--sp-5);
    padding-bottom: var(--sp-5);
    border-bottom: 1px solid var(--line);
}

.st-plan__price .cur {
    color: var(--violet-300);
    font-size: 14px;
    vertical-align: 8px;
}

.st-plan__price .num {
    font-size: 36px;
    font-weight: 600;
    line-height: 1;
    letter-spacing: -0.03em;
    color: #fff;
    font-variant-numeric: tabular-nums;
}

.st-plan__price .cyc {
    margin-left: 3px;
    color: var(--text-mute);
    font-size: 12.5px;
}

.st-plan__price .custom {
    font-size: 22px;
    font-weight: 600;
    color: var(--violet-300);
}

.st-plan__specs {
    flex: 1;
    margin-bottom: var(--sp-5);
}

.st-plan__specs li {
    display: flex;
    justify-content: space-between;
    gap: var(--sp-3);
    padding: 6px 0;
    font-size: 13px;
    color: var(--text-dim);
}

.st-plan__specs b {
    color: #fff;
    font-weight: 600;
    font-variant-numeric: tabular-nums;
}

.st-plan .st-btn { width: 100%; }

/* ------------------------------------------------------------------ 16. 终章 CTA */
.st-final {
    position: relative;
    overflow: hidden;
    padding: var(--sp-24) 0;
    text-align: center;
}

.st-final::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(52% 70% at 50% 0%, rgba(124, 58, 237, .26), transparent 70%),
        radial-gradient(40% 50% at 80% 100%, rgba(34, 211, 238, .12), transparent 70%);
    pointer-events: none;
}

.st-final__inner {
    position: relative;
    z-index: 1;
    max-width: 720px;
    margin: 0 auto;
}

.st-final h2 {
    font-size: clamp(30px, 3.8vw, 44px);
    margin-bottom: var(--sp-4);
}

.st-final p {
    color: var(--text-dim);
    font-size: 16.5px;
    margin-bottom: var(--sp-8);
}

.st-final__cta {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--sp-3);
}

.st-final__note {
    margin-top: var(--sp-6);
    color: var(--text-mute);
    font-size: 12.5px;
}

/* ------------------------------------------------------------------ 17. 页脚 */
.st-footer {
    border-top: 1px solid var(--line);
    background: var(--bg-1);
    padding: var(--sp-16) 0 var(--sp-8);
}

.st-footer__top {
    display: grid;
    grid-template-columns: 1.6fr repeat(3, 1fr);
    gap: var(--sp-8);
    padding-bottom: var(--sp-10);
    border-bottom: 1px solid var(--line);
}

.st-footer__brand p {
    max-width: 300px;
    margin-top: var(--sp-4);
    color: var(--text-mute);
    font-size: 13px;
    line-height: 1.8;
}

.st-footer h5 {
    margin: 0 0 var(--sp-4);
    color: #fff;
    font-size: 13px;
    font-weight: 600;
    letter-spacing: .04em;
}

.st-footer__links li { margin-bottom: 9px; }

.st-footer__links a {
    display: inline-block;
    padding: 4px 0;
    color: var(--text-mute);
    font-size: 13px;
}

.st-footer__links a:hover { color: var(--violet-300); }

.st-footer__bottom {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: var(--sp-3);
    padding-top: var(--sp-6);
    color: var(--text-mute);
    font-size: 12.5px;
}

.st-footer__bottom .sep { margin: 0 8px; opacity: .4; }

.st-footer__bottom a { color: var(--text-mute); }

.st-footer__bottom a:hover { color: var(--violet-300); }

/* ------------------------------------------------------------------ 18. 浮窗客服 */
.st-fix {
    position: fixed;
    right: 20px;
    bottom: 84px;
    z-index: var(--z-float);
}

.st-fix__btn {
    position: relative;
    display: grid;
    place-items: center;
    width: 48px;
    height: 48px;
    border: 1px solid var(--line);
    border-radius: 50%;
    background: rgba(11, 11, 24, .9);
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
    color: var(--violet-300);
    box-shadow: var(--shadow-md);
    cursor: pointer;
    transition: border-color .2s var(--ease), color .2s var(--ease);
}

.st-fix__btn:hover {
    border-color: var(--line-hi);
    color: var(--cyan-300);
}

.st-fix__btn svg { width: 22px; height: 22px; }

.st-fix__tip {
    position: absolute;
    right: 58px;
    top: 50%;
    transform: translateY(-50%) translateX(6px);
    padding: 10px 14px;
    border: 1px solid var(--line);
    border-radius: var(--r-md);
    background: var(--surface-solid);
    box-shadow: var(--shadow-md);
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: opacity .2s var(--ease), transform .2s var(--ease);
}

.st-fix__btn:hover + .st-fix__tip,
.st-fix__tip:hover {
    opacity: 1;
    transform: translateY(-50%) translateX(0);
    pointer-events: auto;
}

.st-fix__tip b {
    display: block;
    margin-bottom: 3px;
    color: #fff;
    font-size: 13px;
}

.st-fix__tip span {
    color: var(--text-dim);
    font-size: 12px;
}

/* 回到顶部 */
.st-top {
    position: fixed;
    right: 20px;
    bottom: 24px;
    z-index: var(--z-float);
    display: grid;
    place-items: center;
    width: 48px;
    height: 48px;
    border: 1px solid var(--line);
    border-radius: 50%;
    background: rgba(11, 11, 24, .9);
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
    color: var(--text-dim);
    opacity: 0;
    pointer-events: none;
    transition: opacity .25s var(--ease), color .2s var(--ease),
        border-color .2s var(--ease);
}

.st-top.is-on {
    opacity: 1;
    pointer-events: auto;
}

.st-top:hover {
    color: #fff;
    border-color: var(--line-hi);
}

.st-top svg { width: 20px; height: 20px; }

/* ------------------------------------------------------------------ 19. 滚动出场
   全站同一种淡入会让每一屏看起来一样。这里把起始位移交给每个区块自己定义
   （--rx / --ry / --rs），入场延迟交给 JS 按元素序号写 --d，出来的节奏是：
   清单逐条落、能力卡从左侧滑入、套餐从下方浮起、节点从两端向中间聚。 */
.st-reveal {
    opacity: 0;
    transform: translate3d(var(--rx, 0px), var(--ry, 18px), 0) scale(var(--rs, 1));
    transition: opacity .6s var(--ease), transform .7s var(--ease);
    transition-delay: var(--d, 0ms);
}

.st-reveal.is-in {
    opacity: 1;
    transform: none;
}

.st-adv { --ry: 14px; }
.st-cap { --rx: -16px; --ry: 0px; }
.st-scene { --ry: 12px; }
.st-plan { --ry: 20px; --rs: .985; }
.st-region { --rx: 14px; --ry: 0px; }
.st-region:nth-child(even) { --rx: -14px; }

/* ------------------------------------------------------------------ 20. 响应式 */
@media (max-width: 1100px) {
    .st-hero { padding-top: 148px; }
    .st-hero__grid { gap: var(--sp-10); }
    .st-grid-4 { grid-template-columns: repeat(2, 1fr); }
    .st-grid-3 { grid-template-columns: repeat(2, 1fr); }
    .st-plans { grid-template-columns: repeat(2, 1fr); }
    .st-regions { grid-template-columns: repeat(2, 1fr); }
    .st-steps { grid-template-columns: repeat(2, 1fr); row-gap: var(--sp-8); }
    .st-footer__top { grid-template-columns: 1fr 1fr 1fr; }
    .st-footer__brand { grid-column: 1 / -1; }
}

@media (max-width: 900px) {
    .st-nav__menu { display: none; }
    .st-nav__actions { display: none; }
    .st-nav__toggle { display: grid; }
    .st-hero__grid { grid-template-columns: 1fr; }
    .st-shield { max-width: 380px; }
    .st-stats { grid-template-columns: repeat(2, 1fr); }
    .st-stat:nth-child(2) { border-right: 0; }
    .st-stat:nth-child(1),
    .st-stat:nth-child(2) { border-bottom: 1px solid var(--line); }
    .st-arch__flow { grid-template-columns: repeat(2, 1fr); }
    .st-arch__step:not(:last-child)::after,
    .st-arch__step:not(:last-child)::before { display: none; }
    .st-live { grid-template-columns: 1fr; }
}

@media (max-width: 760px) {
    body { font-size: 15px; }
    .st-section { padding: var(--sp-16) 0; }
    .st-container { padding: 0 var(--sp-4); }
    .st-nav { top: 10px; width: calc(100% - 20px); }
    .st-nav__inner { height: 60px; padding: 0 var(--sp-3) 0 var(--sp-4); }

    /* 触屏上 38px 的小按钮点不准，统一抬到 44px 的可点区域 */
    .st-btn--sm { height: 44px; }
    .st-nav__toggle { width: 44px; height: 44px; }

    /* 论点清单收成单列，第二条重新要有分隔线；横向滑入在单列里没有意义 */
    .st-adv-list { grid-template-columns: 1fr; }
    .st-adv { padding: var(--sp-5) 0; }
    .st-adv:nth-child(2) { border-top: 1px solid var(--line); }
    .st-region, .st-region:nth-child(even) { --rx: 0px; --ry: 12px; }

    /* 页脚链接在触屏上要够得着 */
    .st-footer__links a { padding: 8px 0; }
    .st-hero { padding-top: 108px; padding-bottom: var(--sp-12); }
    .st-hero h1 { letter-spacing: -0.02em; }
    .st-hero__lede { font-size: 15.5px; }
    .st-hero__cta .st-btn { flex: 1; min-width: 140px; }
    .st-hero__meta { gap: var(--sp-4); }
    .st-shield__node { font-size: 11px; padding: 4px 9px 4px 7px; }
    .st-shield__node--a { left: -2%; }
    .st-shield__node--b { right: -2%; }
    .st-shield__node--c { left: -3%; }
    .st-grid-4, .st-grid-3, .st-grid-2,
    .st-plans, .st-regions, .st-steps { grid-template-columns: 1fr; }
    .st-stats { grid-template-columns: 1fr; }
    .st-stat { border-right: 0; border-bottom: 1px solid var(--line); }
    .st-stat:last-child { border-bottom: 0; }
    .st-arch__flow { grid-template-columns: 1fr; }
    .st-footer__top { grid-template-columns: 1fr 1fr; }
    .st-footer__bottom { flex-direction: column; text-align: center; }
    .st-fix { right: 14px; bottom: 78px; }
    .st-top { right: 14px; bottom: 20px; }
    .st-chart { height: 200px; }
}

/* ------------------------------------------------------------------ 21. 降级 */
/* 减少动态偏好：动画直接结束，但颜色/边框这类状态反馈保留，否则用户点下去
   看不出发生了什么。位移动画（卡片上浮、入场滑动）一并去掉。 */
@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }

    *,
    *::before,
    *::after {
        animation-duration: .01ms !important;
        animation-iteration-count: 1 !important;
        transition-property: color, background-color, border-color, box-shadow, opacity !important;
        transition-duration: .12s !important;
    }

    .st-reveal { opacity: 1; transform: none; }
}

@media print {
    .st-nav, .st-fix, .st-top, .st-hero__stars { display: none; }
    body { background: #fff; color: #000; }
}