/* =========================================
   铭赞网络企业邮箱 - 主样式
   配色：深海军蓝 #0a2540 + 品牌蓝 #2563eb + 暖金 #d4a574
   字体：系统字体栈（无侵权风险）
   ========================================= */

:root {
    --color-bg: #f8fafc;
    --color-bg-alt: #f1f5f9;
    --color-ink: #0a2540;
    --color-ink-soft: #1e293b;
    --color-muted: #64748b;
    --color-line: #e2e8f0;
    --color-brand: #2563eb;
    --color-brand-dark: #1d4ed8;
    --color-gold: #d4a574;
    --color-white: #ffffff;
    --shadow-card: 0 4px 20px rgba(10, 37, 64, 0.06);
    --shadow-card-hover: 0 12px 40px rgba(10, 37, 64, 0.12);
    --shadow-hero: 0 20px 60px rgba(10, 37, 64, 0.18);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --container: 1280px;
    --header-h: 72px;
    --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
    --font-sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
        "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
}

/* Reset */
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
    font-family: var(--font-sans);
    color: var(--color-ink-soft);
    background: var(--color-white);
    line-height: 1.65;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; transition: color .2s var(--ease); }
a:hover { color: var(--color-brand); }
ul, ol { list-style: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }

/* 容器 */
.container {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 32px;
}

/* 通用 */
.reveal {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity .7s var(--ease), transform .7s var(--ease);
}
.reveal.is-visible {
    opacity: 1;
    transform: none;
}

/* ============== Header ============== */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    height: var(--header-h);
    background: rgba(10, 37, 64, 0.85);
    backdrop-filter: saturate(180%) blur(14px);
    -webkit-backdrop-filter: saturate(180%) blur(14px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    transition: background .3s var(--ease);
}
.site-header.is-scrolled {
    background: rgba(10, 37, 64, 0.95);
    box-shadow: 0 6px 24px rgba(0, 0, 0, 0.18);
}

.nav-container {
    max-width: var(--container);
    height: 100%;
    margin: 0 auto;
    padding: 0 32px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 32px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--color-white);
    flex-shrink: 0;
}
.brand:hover { color: var(--color-white); }

.brand-name {
    display: inline-flex;
    align-items: flex-start;
    font-size: 22px;
    font-weight: 700;
    letter-spacing: 1px;
    line-height: 1;
}
.brand-trademark {
    color: var(--color-gold);
    position: relative;
}
.brand-trademark::after {
    content: "";
    position: absolute;
    left: -2px;
    right: -2px;
    bottom: -3px;
    height: 2px;
    background: var(--color-gold);
    transform: scaleX(0.95);
    border-radius: 1px;
}
.brand-rest { color: var(--color-white); margin-left: 2px; }
.brand-r {
    color: var(--color-gold);
    font-size: 12px;
    font-weight: 400;
    margin-left: 2px;
    position: relative;
    top: -8px;
}
.brand-divider {
    color: var(--color-gold);
    font-size: 20px;
    font-weight: 300;
    margin: 0 4px;
    opacity: 0.7;
}
.brand-product {
    color: var(--color-gold);
    font-size: 22px;
    font-weight: 700;
    letter-spacing: 2px;
}

.primary-nav {
    display: flex;
    align-items: center;
    gap: 4px;
}
.primary-nav a {
    color: rgba(255, 255, 255, 0.85);
    font-size: 15px;
    font-weight: 500;
    padding: 8px 14px;
    border-radius: var(--radius-sm);
    transition: all .2s var(--ease);
    position: relative;
}
.primary-nav a::after {
    content: "";
    position: absolute;
    left: 50%;
    bottom: 2px;
    transform: translateX(-50%) scaleX(0);
    width: 24px;
    height: 2px;
    background: var(--color-gold);
    transition: transform .25s var(--ease);
}
.primary-nav a:hover {
    color: var(--color-gold);
}
.primary-nav a:hover::after { transform: translateX(-50%) scaleX(1); }

.nav-toggle {
    display: none;
    width: 40px;
    height: 40px;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
}
.nav-toggle span {
    width: 22px;
    height: 2px;
    background: var(--color-white);
    transition: transform .25s var(--ease);
}

/* ============== Hero ============== */
.hero {
    position: relative;
    min-height: 100vh;
    background: linear-gradient(135deg, #0a2540 0%, #112d54 50%, #0a2540 100%);
    color: var(--color-white);
    overflow: hidden;
    padding-top: var(--header-h);
    display: flex;
    align-items: center;
}
.hero-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
}
.hero-network {
    width: 100%;
    height: 100%;
    display: block;
}
.nodes circle {
    animation: nodePulse 3s ease-in-out infinite;
}
.nodes .n1 { animation-delay: 0s; }
.nodes .n2 { animation-delay: 0.3s; }
.nodes .n3 { animation-delay: 0.6s; }
.nodes .n4 { animation-delay: 0.9s; }
.nodes .n5 { animation-delay: 1.2s; }
.nodes .n6 { animation-delay: 1.5s; }
.nodes .n7 { animation-delay: 1.8s; }
.nodes .n8 { animation-delay: 2.1s; }
@keyframes nodePulse {
    0%, 100% { opacity: 0.4; r: 3; }
    50% { opacity: 1; r: 5; }
}
.grid-lines { animation: gridShift 20s linear infinite; }
@keyframes gridShift {
    0% { transform: translateX(0); }
    100% { transform: translateX(-40px); }
}
.links line {
    stroke-dasharray: 200;
    stroke-dashoffset: 200;
    animation: linkDraw 4s ease-in-out infinite;
}
@keyframes linkDraw {
    0% { stroke-dashoffset: 200; }
    50%, 100% { stroke-dashoffset: 0; }
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: var(--container);
    width: 100%;
    margin: 0 auto;
    padding: 0 32px;
    text-align: left;
}
.hero-eyebrow {
    display: inline-block;
    font-size: 13px;
    letter-spacing: 4px;
    color: var(--color-gold);
    text-transform: uppercase;
    margin-bottom: 28px;
    padding: 6px 14px;
    border: 1px solid rgba(212, 165, 116, 0.3);
    border-radius: 100px;
}
.hero-title {
    font-size: clamp(40px, 6vw, 72px);
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -1px;
    margin-bottom: 28px;
    color: var(--color-white);
}
.hero-title-accent {
    background: linear-gradient(135deg, #d4a574 0%, #f0c896 100%);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    font-weight: 700;
}
.hero-subtitle {
    font-size: clamp(15px, 1.6vw, 19px);
    color: rgba(255, 255, 255, 0.75);
    max-width: 720px;
    margin-bottom: 44px;
    line-height: 1.75;
}
.hero-cta {
    display: flex;
    gap: 16px;
    margin-bottom: 56px;
    flex-wrap: wrap;
}
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 600;
    letter-spacing: 1px;
    transition: all .25s var(--ease);
    border: 1px solid transparent;
    white-space: nowrap;
}
.btn-primary {
    background: var(--color-gold);
    color: var(--color-ink);
    border-color: var(--color-gold);
}
.btn-primary:hover {
    background: #e0b585;
    color: var(--color-ink);
    transform: translateY(-2px);
    box-shadow: 0 10px 24px rgba(212, 165, 116, 0.3);
}
.btn-ghost {
    background: transparent;
    color: var(--color-white);
    border-color: rgba(255, 255, 255, 0.3);
}
.btn-ghost:hover {
    background: rgba(255, 255, 255, 0.08);
    color: var(--color-white);
    border-color: rgba(255, 255, 255, 0.6);
}

.hero-tags {
    display: flex;
    gap: 28px;
    flex-wrap: wrap;
    color: rgba(255, 255, 255, 0.55);
    font-size: 14px;
    letter-spacing: 1px;
}
.hero-tags li { white-space: nowrap; }

.hero-scroll {
    position: absolute;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 3;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: rgba(255, 255, 255, 0.5);
    font-size: 11px;
    letter-spacing: 3px;
}
.hero-scroll .scroll-line {
    display: block;
    width: 1px;
    height: 40px;
    background: linear-gradient(to bottom, transparent, var(--color-gold));
    position: relative;
    overflow: hidden;
}
.hero-scroll .scroll-line::after {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 50%;
    background: var(--color-white);
    animation: scrollDot 2s ease-in-out infinite;
}
@keyframes scrollDot {
    0% { transform: translateY(-100%); }
    100% { transform: translateY(200%); }
}

/* ============== Section Head ============== */
section {
    padding: 96px 0;
    position: relative;
}
.section-head {
    text-align: center;
    max-width: 760px;
    margin: 0 auto 64px;
}
.section-eyebrow {
    color: var(--color-gold);
    font-size: 12px;
    letter-spacing: 4px;
    font-weight: 600;
    margin-bottom: 16px;
}
.section-title {
    font-size: clamp(28px, 3.6vw, 42px);
    font-weight: 700;
    color: var(--color-ink);
    line-height: 1.25;
    margin-bottom: 16px;
    letter-spacing: -0.5px;
}
.section-desc {
    font-size: 16px;
    color: var(--color-muted);
    line-height: 1.75;
}

/* ============== Stats ============== */
.stats { background: var(--color-bg); }

.stat-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}
.stat-card {
    background: var(--color-white);
    padding: 40px 28px;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-card);
    text-align: center;
    border-top: 3px solid var(--color-gold);
    transition: all .3s var(--ease);
}
.stat-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-card-hover);
}
.stat-num {
    font-size: 56px;
    font-weight: 800;
    color: var(--color-ink);
    line-height: 1;
    margin-bottom: 12px;
    letter-spacing: -1px;
}
.stat-num sup {
    font-size: 24px;
    color: var(--color-gold);
    font-weight: 600;
    margin-left: 2px;
    top: -16px;
}
.stat-label {
    font-size: 17px;
    font-weight: 600;
    color: var(--color-ink);
    margin-bottom: 8px;
}
.stat-desc {
    font-size: 13px;
    color: var(--color-muted);
    line-height: 1.6;
}

/* ============== Features ============== */
.features { background: var(--color-white); }

.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}
.feature-card {
    background: var(--color-white);
    padding: 40px 32px;
    border-radius: var(--radius-md);
    border: 1px solid var(--color-line);
    transition: all .3s var(--ease);
    position: relative;
    overflow: hidden;
}
.feature-card::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--color-brand), var(--color-gold));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform .4s var(--ease);
}
.feature-card:hover {
    border-color: transparent;
    box-shadow: var(--shadow-card-hover);
    transform: translateY(-4px);
}
.feature-card:hover::before { transform: scaleX(1); }

.feature-icon {
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.08), rgba(212, 165, 116, 0.08));
    color: var(--color-brand);
    margin-bottom: 24px;
    transition: all .3s var(--ease);
}
.feature-icon svg { width: 28px; height: 28px; }
.feature-card:hover .feature-icon {
    background: linear-gradient(135deg, var(--color-brand), var(--color-ink));
    color: var(--color-white);
    transform: scale(1.05);
}
.feature-card h3 {
    font-size: 20px;
    font-weight: 700;
    color: var(--color-ink);
    margin-bottom: 12px;
}
.feature-card p {
    font-size: 14.5px;
    color: var(--color-muted);
    line-height: 1.75;
}

/* ============== Scenarios ============== */
.scenarios { background: var(--color-bg); }

.scenario-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}
.scenario-card {
    background: var(--color-white);
    padding: 32px 28px;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-card);
    transition: all .3s var(--ease);
    position: relative;
    overflow: hidden;
}
.scenario-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-card-hover);
}
.scenario-num {
    display: block;
    font-size: 14px;
    font-weight: 700;
    color: var(--color-gold);
    letter-spacing: 2px;
    margin-bottom: 12px;
}
.scenario-card h3 {
    font-size: 19px;
    font-weight: 700;
    color: var(--color-ink);
    margin-bottom: 10px;
}
.scenario-card p {
    font-size: 14px;
    color: var(--color-muted);
    line-height: 1.7;
}

/* ============== Process ============== */
.process { background: var(--color-white); }

.process-list {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 16px;
    position: relative;
}
.process-list::before {
    content: "";
    position: absolute;
    top: 36px;
    left: 10%;
    right: 10%;
    height: 2px;
    background: linear-gradient(90deg, var(--color-brand), var(--color-gold));
    z-index: 0;
}
.process-step {
    text-align: center;
    position: relative;
    z-index: 1;
    padding: 0 8px;
}
.step-num {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 72px;
    height: 72px;
    border-radius: 50%;
    background: var(--color-white);
    color: var(--color-ink);
    font-size: 22px;
    font-weight: 800;
    margin-bottom: 24px;
    border: 2px solid var(--color-gold);
    transition: all .3s var(--ease);
    letter-spacing: 1px;
}
.process-step:hover .step-num {
    background: var(--color-ink);
    color: var(--color-gold);
    transform: scale(1.05);
}
.process-step h3 {
    font-size: 18px;
    font-weight: 700;
    color: var(--color-ink);
    margin-bottom: 10px;
}
.process-step p {
    font-size: 13.5px;
    color: var(--color-muted);
    line-height: 1.7;
}

/* ============== FAQ ============== */
.faq { background: var(--color-bg); }

.faq-list {
    max-width: 960px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 12px;
}
.faq-item {
    background: var(--color-white);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-card);
    overflow: hidden;
    transition: box-shadow .3s var(--ease);
}
.faq-item[open] { box-shadow: var(--shadow-card-hover); }
.faq-item summary {
    list-style: none;
    cursor: pointer;
    padding: 22px 28px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    user-select: none;
    position: relative;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-q {
    font-size: 16px;
    font-weight: 600;
    color: var(--color-ink);
    flex: 1;
    line-height: 1.5;
}
.faq-item[open] .faq-q { color: var(--color-brand); }
.faq-toggle {
    width: 28px;
    height: 28px;
    flex-shrink: 0;
    position: relative;
    border-radius: 50%;
    background: var(--color-bg-alt);
    transition: all .3s var(--ease);
}
.faq-toggle::before,
.faq-toggle::after {
    content: "";
    position: absolute;
    top: 50%;
    left: 50%;
    width: 12px;
    height: 2px;
    background: var(--color-ink);
    transform: translate(-50%, -50%);
    transition: transform .3s var(--ease);
}
.faq-toggle::after { transform: translate(-50%, -50%) rotate(90deg); }
.faq-item[open] .faq-toggle { background: var(--color-brand); }
.faq-item[open] .faq-toggle::before { background: var(--color-white); }
.faq-item[open] .faq-toggle::after { transform: translate(-50%, -50%) rotate(0); }
.faq-a {
    padding: 0 28px 24px;
    color: var(--color-muted);
    font-size: 14.5px;
    line-height: 1.85;
    border-top: 1px solid var(--color-line);
    padding-top: 18px;
    margin-top: 4px;
    animation: faqFade .35s var(--ease);
}
@keyframes faqFade {
    from { opacity: 0; transform: translateY(-8px); }
    to { opacity: 1; transform: none; }
}

/* ============== Contact ============== */
.contact { background: var(--color-white); }

.contact-grid {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 56px;
    align-items: center;
    max-width: 1080px;
    margin: 0 auto;
}
.contact-info {
    display: flex;
    flex-direction: column;
    gap: 24px;
}
.info-block {
    padding: 20px 24px;
    background: var(--color-bg);
    border-left: 3px solid var(--color-gold);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    transition: all .25s var(--ease);
}
.info-block:hover {
    background: var(--color-white);
    box-shadow: var(--shadow-card);
    transform: translateX(4px);
}
.info-block h3 {
    font-size: 13px;
    color: var(--color-muted);
    font-weight: 500;
    letter-spacing: 1.5px;
    margin-bottom: 6px;
    text-transform: uppercase;
}
.info-block p {
    font-size: 17px;
    color: var(--color-ink);
    font-weight: 600;
}
.info-block a:hover { color: var(--color-brand); }
.weibo-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: #e6162d;
}
.weibo-link:hover { color: #ff3344; }

.contact-qr { display: flex; justify-content: center; }
.qr-card {
    background: var(--color-white);
    padding: 24px;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-card);
    text-align: center;
    border: 1px solid var(--color-line);
    max-width: 280px;
    width: 100%;
}
.qr-card img {
    width: 220px;
    height: 220px;
    margin: 0 auto 14px;
    border-radius: var(--radius-sm);
    object-fit: cover;
}
.qr-card p {
    color: var(--color-muted);
    font-size: 14px;
    font-weight: 500;
}

/* ============== Sitemap ============== */
.sitemap-section {
    background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-white) 100%);
}
.sitemap-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
}
.sitemap-col {
    background: var(--color-white);
    padding: 28px 24px;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-card);
    transition: all .3s var(--ease);
}
.sitemap-col:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-card-hover);
}
.sitemap-col h3 {
    font-size: 15px;
    font-weight: 700;
    color: var(--color-ink);
    margin-bottom: 18px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--color-gold);
    position: relative;
}
.sitemap-col ul {
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.sitemap-col a {
    font-size: 13.5px;
    color: var(--color-muted);
    display: inline-block;
    transition: all .2s var(--ease);
    padding-left: 12px;
    position: relative;
}
.sitemap-col a::before {
    content: "›";
    position: absolute;
    left: 0;
    color: var(--color-gold);
    transition: transform .2s var(--ease);
}
.sitemap-col a:hover {
    color: var(--color-brand);
    transform: translateX(2px);
}
.sitemap-col a:hover::before { transform: translateX(2px); }

/* ============== Footer ============== */
.site-footer {
    background: var(--color-ink);
    color: rgba(255, 255, 255, 0.6);
    padding: 48px 0 28px;
    border-top: 3px solid var(--color-gold);
}
.footer-top {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 32px;
    padding-bottom: 32px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    margin-bottom: 24px;
    flex-wrap: wrap;
}
.footer-brand {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--color-white);
    flex-wrap: wrap;
}
.footer-tagline {
    width: 100%;
    margin-top: 12px;
    font-size: 13px;
    color: rgba(255, 255, 255, 0.5);
    letter-spacing: 1px;
}
.footer-links {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
}
.footer-links a {
    color: rgba(255, 255, 255, 0.65);
    font-size: 14px;
}
.footer-links a:hover { color: var(--color-gold); }

.footer-bottom {
    text-align: center;
    font-size: 13px;
    color: rgba(255, 255, 255, 0.5);
    line-height: 1.8;
}
.footer-bottom a { color: var(--color-gold); }
.footer-bottom a:hover { color: var(--color-white); }

/* ============== Floating Toolbar ============== */
.floating-toolbar {
    position: fixed;
    right: 24px;
    bottom: 24px;
    z-index: 90;
    display: flex;
    flex-direction: column;
    gap: 8px;
    background: var(--color-white);
    border-radius: 14px;
    box-shadow: 0 8px 32px rgba(10, 37, 64, 0.18);
    padding: 6px;
    border: 1px solid var(--color-line);
    opacity: 0;
    transform: translateX(20px);
    transition: all .3s var(--ease);
}
.floating-toolbar.is-visible {
    opacity: 1;
    transform: none;
}
.tool {
    width: 52px;
    height: 52px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
    color: var(--color-ink-soft);
    font-size: 11px;
    transition: all .2s var(--ease);
    gap: 2px;
}
.tool svg { width: 18px; height: 18px; }
.tool:hover {
    background: var(--color-ink);
    color: var(--color-gold);
}

/* ============== Responsive ============== */
@media (max-width: 1024px) {
    .feature-grid,
    .scenario-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .stat-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .process-list {
        grid-template-columns: repeat(3, 1fr);
        row-gap: 36px;
    }
    .process-list::before { display: none; }
    .sitemap-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    :root { --header-h: 60px; }
    .container { padding: 0 20px; }
    .nav-container { padding: 0 20px; gap: 12px; }

    .nav-toggle { display: flex; }
    .nav-toggle.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
    .nav-toggle.is-open span:nth-child(2) { opacity: 0; }
    .nav-toggle.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

    .primary-nav {
        position: fixed;
        top: var(--header-h);
        left: 0;
        right: 0;
        background: var(--color-ink);
        flex-direction: column;
        align-items: stretch;
        padding: 16px 20px;
        gap: 0;
        max-height: 0;
        overflow: hidden;
        transition: max-height .3s var(--ease);
        border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    }
    .primary-nav.is-open { max-height: 480px; }
    .primary-nav a {
        padding: 14px 8px;
        font-size: 15px;
        border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    }
    .primary-nav a:last-child { border-bottom: none; }
    .primary-nav a::after { display: none; }

    section { padding: 64px 0; }
    .section-head { margin-bottom: 40px; }

    .stat-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
    .stat-card { padding: 28px 16px; }
    .stat-num { font-size: 40px; }
    .stat-num sup { font-size: 18px; top: -12px; }

    .feature-grid,
    .scenario-grid { grid-template-columns: 1fr; }
    .feature-card,
    .scenario-card { padding: 28px 24px; }

    .process-list { grid-template-columns: 1fr; row-gap: 8px; }
    .step-num { width: 60px; height: 60px; font-size: 18px; margin-bottom: 16px; }

    .faq-item summary { padding: 18px 20px; }
    .faq-q { font-size: 15px; }
    .faq-a { padding: 16px 20px 20px; font-size: 14px; }

    .contact-grid { grid-template-columns: 1fr; gap: 36px; }
    .info-block { padding: 16px 18px; }
    .info-block p { font-size: 15px; }

    .sitemap-grid { grid-template-columns: 1fr; gap: 16px; }
    .sitemap-col { padding: 22px 20px; }

    .footer-top { flex-direction: column; align-items: flex-start; }
    .footer-bottom { font-size: 12px; }
    .footer-bottom p { padding: 0 8px; }

    .floating-toolbar { right: 12px; bottom: 12px; }
    .tool { width: 46px; height: 46px; font-size: 10px; }

    .hero-cta { flex-direction: column; align-items: stretch; }
    .btn { width: 100%; }
    .hero-tags { gap: 16px; font-size: 12px; }
}

@media (max-width: 420px) {
    .hero-title { font-size: 36px; }
    .stat-grid { grid-template-columns: 1fr; }
}

/* Reduce motion */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
    .reveal { opacity: 1; transform: none; }
}

/* Print friendly */
@media print {
    .site-header, .floating-toolbar, .hero-bg, .hero-scroll { display: none; }
    body { color: #000; background: #fff; }
    section { padding: 20px 0; page-break-inside: avoid; }
}