/* ============================================
   智理软件 - 企业官网样式（浅蓝科技风）
   ============================================ */

/* ===== Reset & Base ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* 主色调 - 浅蓝科技风 */
    --c-primary: #0066ff;
    --c-primary-dark: #0044cc;
    --c-primary-light: #3b82f6;
    --c-primary-lighter: #60a5fa;
    --c-accent: #06b6d4;
    --c-accent-light: #22d3ee;
    /* 中性色 */
    --c-text: #0f172a;
    --c-text-secondary: #475569;
    --c-text-light: #94a3b8;
    --c-bg: #ffffff;
    --c-bg-alt: #f0f7ff;
    --c-bg-tint: #e8f1ff;
    --c-border: #dbe7f5;
    --c-white: #ffffff;
    /* 深色区域 */
    --c-dark: #0a1628;
    --c-dark-light: #162842;
    /* 尺寸 */
    --container: 1200px;
    --header-h: 70px;
    /* 过渡 */
    --t-fast: 0.2s ease;
    --t-base: 0.3s ease;
    --t-slow: 0.5s ease;
    /* 圆角 */
    --r-sm: 8px;
    --r-md: 12px;
    --r-lg: 16px;
    --r-xl: 24px;
    /* 阴影 */
    --shadow-sm: 0 2px 10px rgba(0, 102, 255, 0.06);
    --shadow-md: 0 6px 24px rgba(0, 102, 255, 0.1);
    --shadow-lg: 0 12px 48px rgba(0, 102, 255, 0.15);
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    color: var(--c-text);
    background: var(--c-bg);
    line-height: 1.7;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a { text-decoration: none; color: inherit; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

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

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    font-size: 15px;
    font-weight: 500;
    border-radius: var(--r-md);
    cursor: pointer;
    transition: all var(--t-base);
    border: none;
    letter-spacing: 0.5px;
    font-family: inherit;
}

.btn-primary {
    background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-dark) 100%);
    color: var(--c-white);
    box-shadow: 0 4px 14px rgba(0, 102, 255, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 102, 255, 0.4);
}

.btn-outline {
    background: transparent;
    color: var(--c-white);
    border: 2px solid rgba(255, 255, 255, 0.5);
}

.btn-outline:hover {
    background: var(--c-white);
    color: var(--c-primary);
    border-color: var(--c-white);
}

.btn-full { width: 100%; }

/* ===== Header ===== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-h);
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    z-index: 1000;
    transition: all var(--t-base);
    border-bottom: 1px solid transparent;
}

.header.scrolled {
    box-shadow: var(--shadow-sm);
    border-bottom-color: var(--c-border);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-shrink: 0;
}

.logo-icon { width: 36px; height: 36px; }

.logo-text {
    font-size: 19px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: 1px;
}

.nav-list { display: flex; gap: 8px; }

.nav-link {
    display: block;
    padding: 8px 18px;
    font-size: 15px;
    color: var(--c-text);
    font-weight: 500;
    border-radius: var(--r-sm);
    transition: all var(--t-fast);
    position: relative;
}

.nav-link:hover {
    color: var(--c-primary);
    background: rgba(0, 102, 255, 0.06);
}

.nav-link.active { color: var(--c-primary); }

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 24px;
    height: 3px;
    background: linear-gradient(90deg, var(--c-primary), var(--c-accent));
    border-radius: 2px;
}

/* Mobile menu toggle */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 40px;
    height: 40px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 2.5px;
    background: var(--c-primary);
    border-radius: 2px;
    transition: all var(--t-base);
    margin: 0 auto;
}

.menu-toggle.active span:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }

/* Mobile nav */
.mobile-nav {
    display: none;
    position: fixed;
    top: var(--header-h);
    left: 0;
    width: 100%;
    background: var(--c-white);
    box-shadow: var(--shadow-md);
    transform: translateY(-100%);
    transition: transform var(--t-base);
    z-index: 999;
}

.mobile-nav.open { transform: translateY(0); }

.mobile-nav-list { padding: 16px 24px; }

.mobile-nav-list li { border-bottom: 1px solid var(--c-border); }
.mobile-nav-list li:last-child { border-bottom: none; }

.mobile-nav-link {
    display: block;
    padding: 16px 0;
    font-size: 16px;
    font-weight: 500;
    color: var(--c-text);
    transition: color var(--t-fast);
}

.mobile-nav-link:hover { color: var(--c-primary); }

/* ===== Hero ===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    overflow: hidden;
    padding-top: var(--header-h);
}

.hero-bg {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse at 70% 30%, rgba(6, 182, 212, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 30% 70%, rgba(0, 102, 255, 0.2) 0%, transparent 50%),
        linear-gradient(135deg, #0a1628 0%, #0d2150 40%, #0a3a6e 100%);
    z-index: 0;
}

.hero-bg::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(255,255,255,0.04) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.04) 1px, transparent 1px);
    background-size: 50px 50px;
    mask-image: radial-gradient(ellipse at center, black 0%, transparent 75%);
    -webkit-mask-image: radial-gradient(ellipse at center, black 0%, transparent 75%);
}

.hero-bg::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 150px;
    background: linear-gradient(to bottom, transparent, rgba(240, 247, 255, 0.5));
}

/* 装饰光圈 */
.hero-bg .orb {
    content: '';
    position: absolute;
    width: 400px;
    height: 400px;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.3;
}

.hero-content {
    position: relative;
    z-index: 1;
    flex: 1;
    display: flex;
    align-items: center;
    padding-top: 40px;
}

.hero-text { max-width: 720px; }

.hero-badge {
    display: inline-block;
    padding: 8px 20px;
    background: rgba(6, 182, 212, 0.12);
    border: 1px solid rgba(6, 182, 212, 0.3);
    color: var(--c-accent-light);
    border-radius: 30px;
    font-size: 13px;
    font-weight: 500;
    letter-spacing: 1px;
    margin-bottom: 28px;
}

.hero-title {
    font-size: clamp(2.2rem, 5vw, 3.8rem);
    font-weight: 900;
    color: var(--c-white);
    line-height: 1.25;
    margin-bottom: 24px;
    letter-spacing: 2px;
}

.hero-subtitle {
    font-size: clamp(0.95rem, 2vw, 1.1rem);
    color: rgba(255, 255, 255, 0.72);
    line-height: 1.8;
    max-width: 580px;
    margin-bottom: 40px;
}

.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }

/* Hero stats */
.hero-stats { position: relative; z-index: 1; padding-bottom: 50px; }

.stats-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 32px 48px;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: var(--r-lg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    flex: 1;
}

.stat-value {
    display: flex;
    align-items: baseline;
    line-height: 1;
}

.stat-number {
    font-size: clamp(1.8rem, 4vw, 2.6rem);
    font-weight: 900;
    background: linear-gradient(135deg, var(--c-accent-light) 0%, var(--c-primary-lighter) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
}

.stat-plus {
    font-size: clamp(1.2rem, 3vw, 1.6rem);
    font-weight: 700;
    background: linear-gradient(135deg, var(--c-accent-light) 0%, var(--c-primary-lighter) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-left: 2px;
}

.stat-label {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.6);
    white-space: nowrap;
}

.stat-divider {
    width: 1px;
    height: 40px;
    background: rgba(255, 255, 255, 0.15);
    flex-shrink: 0;
}

/* ===== Section Common ===== */
.section { padding: 100px 0; position: relative; }

.section-header {
    text-align: center;
    max-width: 680px;
    margin: 0 auto 64px;
}

.section-header-light .section-tag,
.section-header-light .section-title,
.section-header-light .section-desc { color: var(--c-white); }

.section-tag {
    display: inline-block;
    font-size: 13px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: 3px;
    margin-bottom: 16px;
}

.section-title {
    font-size: clamp(1.6rem, 3.5vw, 2.4rem);
    font-weight: 800;
    color: var(--c-text);
    margin-bottom: 16px;
    letter-spacing: 1px;
}

.section-desc {
    font-size: 16px;
    color: var(--c-text-secondary);
    line-height: 1.7;
}

/* ===== About ===== */
.about { background: var(--c-bg); }

.about-grid {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 64px;
    align-items: start;
}

.about-heading {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--c-text);
    margin-bottom: 24px;
    line-height: 1.5;
}

.about-p {
    font-size: 15px;
    color: var(--c-text-secondary);
    line-height: 2;
    margin-bottom: 20px;
}

.about-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 32px; }

.tag {
    display: inline-block;
    padding: 6px 18px;
    background: var(--c-bg-tint);
    color: var(--c-primary);
    font-size: 13px;
    font-weight: 500;
    border-radius: 20px;
    border: 1px solid var(--c-border);
    transition: all var(--t-fast);
}

.tag:hover {
    background: var(--c-primary);
    color: var(--c-white);
    border-color: var(--c-primary);
}

.about-cards { display: flex; flex-direction: column; gap: 20px; }

.about-card {
    padding: 28px;
    background: var(--c-bg-alt);
    border-radius: var(--r-lg);
    border: 1px solid var(--c-border);
    transition: all var(--t-base);
    position: relative;
    overflow: hidden;
}

.about-card::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 4px;
    background: linear-gradient(180deg, var(--c-primary), var(--c-accent));
    transform: scaleY(0);
    transform-origin: top;
    transition: transform var(--t-base);
}

.about-card:hover {
    background: var(--c-white);
    box-shadow: var(--shadow-md);
    transform: translateX(-4px);
}

.about-card:hover::before { transform: scaleY(1); }

.about-card-icon { width: 48px; height: 48px; margin-bottom: 16px; }

.about-card h4 {
    font-size: 17px;
    font-weight: 700;
    color: var(--c-text);
    margin-bottom: 10px;
}

.about-card p {
    font-size: 14px;
    color: var(--c-text-secondary);
    line-height: 1.7;
}

/* ===== Products ===== */
.products { background: var(--c-bg-alt); }

.products-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.product-card {
    background: var(--c-white);
    border-radius: var(--r-lg);
    padding: 36px 32px;
    border: 1px solid var(--c-border);
    transition: all var(--t-base);
    position: relative;
    overflow: hidden;
}

.product-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--c-primary), var(--c-accent));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--t-base);
}

.product-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: transparent;
}

.product-card:hover::before { transform: scaleX(1); }

.product-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 24px;
}

.product-icon {
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, rgba(0, 102, 255, 0.08) 0%, rgba(6, 182, 212, 0.08) 100%);
    border-radius: var(--r-md);
}

.product-num {
    font-size: 2.5rem;
    font-weight: 900;
    color: var(--c-border);
    line-height: 1;
    transition: color var(--t-base);
}

.product-card:hover .product-num {
    background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.product-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--c-text);
    margin-bottom: 12px;
    line-height: 1.4;
}

.product-brief {
    font-size: 14px;
    color: var(--c-text-secondary);
    line-height: 1.8;
    margin-bottom: 24px;
}

.product-features { margin-bottom: 24px; }

.feature-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 0;
    font-size: 14px;
    color: var(--c-text);
}

.feature-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--c-accent);
    flex-shrink: 0;
    box-shadow: 0 0 8px rgba(6, 182, 212, 0.5);
}

.product-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    padding-top: 20px;
    border-top: 1px solid var(--c-border);
}

.p-tag {
    display: inline-block;
    padding: 4px 12px;
    background: rgba(0, 102, 255, 0.08);
    color: var(--c-primary);
    font-size: 12px;
    font-weight: 500;
    border-radius: 4px;
}

/* ===== Advantages ===== */
.advantages {
    background: linear-gradient(135deg, #0a1628 0%, #0d2150 40%, #0a2a5e 100%);
    color: var(--c-white);
    overflow: hidden;
}

.advantages-bg {
    position: absolute;
    inset: 0;
    background-image:
        radial-gradient(circle at 10% 20%, rgba(6, 182, 212, 0.1) 0%, transparent 40%),
        radial-gradient(circle at 90% 80%, rgba(0, 102, 255, 0.2) 0%, transparent 40%);
    z-index: 0;
}

.advantages .container { position: relative; z-index: 1; }

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.advantage-item {
    padding: 36px 28px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--r-lg);
    transition: all var(--t-base);
    backdrop-filter: blur(4px);
}

.advantage-item:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(6, 182, 212, 0.3);
    transform: translateY(-4px);
}

.advantage-icon { width: 52px; height: 52px; margin-bottom: 20px; }

.advantage-item h3 {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--c-white);
    margin-bottom: 12px;
}

.advantage-item p {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.65);
    line-height: 1.8;
}

/* ===== Clients ===== */
.clients { background: var(--c-bg); }

.clients-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 28px;
}

.client-card {
    display: flex;
    background: var(--c-white);
    border-radius: var(--r-lg);
    overflow: hidden;
    border: 1px solid var(--c-border);
    transition: all var(--t-base);
}

.client-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
    border-color: transparent;
}

.client-logo {
    flex-shrink: 0;
    width: 140px;
    background: linear-gradient(135deg, var(--c-primary) 0%, var(--c-primary-dark) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.client-logo-text {
    color: var(--c-accent-light);
    font-size: 1.1rem;
    font-weight: 700;
    text-align: center;
    line-height: 1.4;
    letter-spacing: 1px;
}

.client-body { flex: 1; padding: 28px; }

.client-body h3 {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--c-text);
    margin-bottom: 4px;
}

.client-tagline {
    font-size: 13px;
    color: var(--c-primary);
    font-weight: 500;
    margin-bottom: 12px;
}

.client-desc {
    font-size: 14px;
    color: var(--c-text-secondary);
    line-height: 1.8;
    margin-bottom: 20px;
}

.client-results { display: flex; gap: 24px; }

.result-item { display: flex; flex-direction: column; gap: 2px; }

.result-value {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--c-primary);
}

.result-label { font-size: 12px; color: var(--c-text-light); }

/* ===== Contact ===== */
.contact { background: var(--c-bg-alt); }

.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: start;
}

.contact-info .section-tag,
.contact-info .section-title { text-align: left; }

.contact-info .section-header { text-align: left; margin: 0 0 24px; }

.contact-lead {
    font-size: 15px;
    color: var(--c-text-secondary);
    line-height: 1.8;
    margin-bottom: 40px;
}

.contact-items { display: flex; flex-direction: column; gap: 24px; }

.contact-item { display: flex; align-items: center; gap: 16px; }

.contact-icon {
    width: 48px;
    height: 48px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--c-white);
    border: 1px solid var(--c-border);
    border-radius: var(--r-md);
    color: var(--c-primary);
    transition: all var(--t-fast);
}

.contact-item:hover .contact-icon {
    background: var(--c-primary);
    color: var(--c-white);
    border-color: var(--c-primary);
}

.contact-icon svg { width: 24px; height: 24px; }

.contact-label { display: block; font-size: 13px; color: var(--c-text-light); margin-bottom: 4px; }
.contact-value { display: block; font-size: 15px; font-weight: 600; color: var(--c-text); }

/* Contact form */
.contact-form-wrapper {
    background: var(--c-white);
    border-radius: var(--r-xl);
    padding: 40px;
    box-shadow: var(--shadow-md);
}

.form-title { font-size: 1.3rem; font-weight: 700; color: var(--c-text); margin-bottom: 8px; }
.form-subtitle { font-size: 14px; color: var(--c-text-secondary); margin-bottom: 28px; }

.form-group { margin-bottom: 16px; }

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 14px 16px;
    border: 1.5px solid var(--c-border);
    border-radius: var(--r-sm);
    font-size: 14px;
    font-family: inherit;
    color: var(--c-text);
    background: var(--c-bg);
    transition: all var(--t-fast);
    outline: none;
    -webkit-appearance: none;
    appearance: none;
}

.form-group select {
    cursor: pointer;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 8'%3E%3Cpath d='M1 1L6 6L11 1' stroke='%2394a3b8' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 16px center;
    background-size: 12px;
    padding-right: 40px;
}

.form-group textarea { resize: vertical; min-height: 80px; }

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: var(--c-primary);
    box-shadow: 0 0 0 3px rgba(0, 102, 255, 0.1);
}

.form-group input::placeholder,
.form-group textarea::placeholder { color: var(--c-text-light); }

.form-note {
    margin-top: 16px;
    padding: 12px 16px;
    background: rgba(6, 182, 212, 0.08);
    color: #0a6b80;
    border-radius: var(--r-sm);
    font-size: 14px;
    font-weight: 500;
    text-align: center;
}

/* ===== Footer ===== */
.footer {
    background: var(--c-dark);
    color: rgba(255, 255, 255, 0.7);
    padding: 64px 0 24px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 40px;
}

.footer-brand .logo { margin-bottom: 20px; }
.footer-brand .logo-text { color: var(--c-white); -webkit-text-fill-color: var(--c-white); }

.footer-desc { font-size: 14px; line-height: 1.8; max-width: 320px; }

.footer-col h4 { font-size: 15px; font-weight: 700; color: var(--c-white); margin-bottom: 20px; }
.footer-col ul li { margin-bottom: 12px; }
.footer-col ul li a,
.footer-col ul li { font-size: 14px; color: rgba(255, 255, 255, 0.6); transition: color var(--t-fast); }
.footer-col ul li a:hover { color: var(--c-accent-light); }

.footer-bottom {
    padding-top: 24px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
}

.footer-bottom p { font-size: 13px; color: rgba(255, 255, 255, 0.4); }

/* ===== Back to top ===== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--c-primary), var(--c-primary-dark));
    color: var(--c-white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all var(--t-base);
    z-index: 900;
    box-shadow: var(--shadow-md);
}

.back-to-top svg { width: 24px; height: 24px; }
.back-to-top.show { opacity: 1; visibility: visible; }
.back-to-top:hover { transform: translateY(-4px); box-shadow: 0 8px 30px rgba(0, 102, 255, 0.4); }

/* ===== Animations ===== */
.fade-up { opacity: 0; transform: translateY(40px); transition: opacity 0.7s ease, transform 0.7s ease; }
.fade-up.visible { opacity: 1; transform: translateY(0); }
.fade-up:nth-child(2) { transition-delay: 0.1s; }
.fade-up:nth-child(3) { transition-delay: 0.2s; }

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .about-grid { grid-template-columns: 1fr; gap: 40px; }
    .products-grid { grid-template-columns: repeat(2, 1fr); }
    .advantages-grid { grid-template-columns: repeat(2, 1fr); }
    .contact-wrapper { grid-template-columns: 1fr; gap: 40px; }
    .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
    .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 768px) {
    :root { --header-h: 60px; }
    .container { padding: 0 16px; }
    .nav { display: none; }
    .menu-toggle { display: flex; }
    .mobile-nav { display: block; }
    .logo-text { font-size: 16px; }

    .hero { min-height: auto; padding-top: calc(var(--header-h) + 30px); padding-bottom: 30px; }
    .hero-content { padding-top: 20px; }
    .hero-badge { font-size: 12px; padding: 6px 16px; margin-bottom: 20px; }
    .hero-subtitle { margin-bottom: 28px; }
    .hero-actions { gap: 12px; }
    .btn { padding: 12px 24px; font-size: 14px; }
    .hero-stats { padding-bottom: 30px; }
    .stats-row { flex-wrap: wrap; gap: 20px; padding: 24px 20px; justify-content: center; }
    .stat-item { min-width: 40%; }
    .stat-divider { display: none; }

    .section { padding: 60px 0; }
    .section-header { margin-bottom: 40px; }
    .about-cards { gap: 16px; }
    .about-card { padding: 24px 20px; }
    .products-grid { grid-template-columns: 1fr; gap: 20px; }
    .product-card { padding: 28px 24px; }
    .advantages-grid { grid-template-columns: 1fr; gap: 16px; }
    .advantage-item { padding: 28px 24px; }
    .clients-grid { grid-template-columns: 1fr; gap: 20px; }
    .client-card { flex-direction: column; }
    .client-logo { width: 100%; height: 70px; padding: 16px; }
    .client-body { padding: 24px 20px; }
    .client-results { gap: 20px; }
    .contact-form-wrapper { padding: 24px 20px; }
    .footer { padding: 40px 0 20px; }
    .footer-grid { grid-template-columns: 1fr; gap: 28px; }
    .back-to-top { bottom: 20px; right: 16px; width: 42px; height: 42px; }
    .back-to-top svg { width: 20px; height: 20px; }
}

@media (max-width: 380px) {
    .hero-title { font-size: 1.8rem; }
    .stats-row { gap: 16px; }
    .stat-item { min-width: 45%; }
}

@media print {
    .header, .back-to-top, .menu-toggle, .mobile-nav, .hero-actions, .contact-form-wrapper { display: none !important; }
    .hero-bg { background: white; }
    .hero-title, .hero-subtitle, .hero-badge, .stat-number, .stat-label, .stat-plus { color: #0f172a; }
}

/* ===== 上传图片渲染样式 ===== */
.logo-icon-img {
    height: 40px;
    width: auto;
    border-radius: 8px;
    object-fit: contain;
}

.about-card-icon-img {
    width: 48px;
    height: 48px;
    object-fit: contain;
    margin-bottom: 16px;
}

.product-icon-img {
    width: 48px;
    height: 48px;
    object-fit: contain;
}

.advantage-icon-img {
    width: 48px;
    height: 48px;
    object-fit: contain;
}

.client-logo-img {
    max-width: 100%;
    max-height: 80px;
    object-fit: contain;
    border-radius: 6px;
}