/* ============================================================
   希舒生物官网 — 主样式表
   设计定调：深色科技感 + 真实细胞/实验室摄影 + 发光卡片边框
   参考基准：公司宣传单页的配色与风格
   ============================================================ */

/* ========== CSS 变量（色彩体系） ========== */
:root {
    /* 主色 —— 希舒蓝 */
    --primary:              #2BA4D4;
    --primary-bright:       #1BC8F0;
    --primary-dark:         #1A82AA;
    --primary-glow:         rgba(27, 200, 240, 0.25);

    /* 深色背景系 */
    --bg-dark:              #0D1B2A;
    --bg-dark-card:         #112233;
    --bg-dark-border:       rgba(43, 164, 212, 0.35);

    /* 浅色背景系 */
    --bg-light:             #ffffff;
    --bg-light-section:     #F0F8FC;
    --bg-light-alt:         #F7FBFD;
    --bg-light-card:        #ffffff;

    /* 文字 */
    --text-on-dark:         #ffffff;
    --text-on-dark-sub:     rgba(255, 255, 255, 0.75);
    --text-primary:         #1A2E3B;
    --text-secondary:       #5A7A8A;

    /* 边框和分割 */
    --border-light:         #D0EAF3;
    --divider:              #EEF6FB;

    /* 圆角 */
    --radius-card:          14px;
    --radius-card-lg:       20px;
    --radius-btn:           28px;
    --radius-input:         8px;

    /* 阴影 */
    --shadow-card:          0 4px 20px rgba(13, 27, 42, 0.12);
    --shadow-card-glow:     0 0 24px rgba(27, 200, 240, 0.20), 0 4px 16px rgba(13, 27, 42, 0.3);
    --shadow-btn:           0 4px 16px rgba(43, 164, 212, 0.45);
}

/* ========== 字体规范 ========== */
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI",
                 "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
                 "Noto Sans SC", sans-serif;
    -webkit-font-smoothing: antialiased;
    color: var(--text-primary);
    padding-top: 76px; /* 导航栏高度补偿 */
}

/* ========== 导航栏 ========== */
#mainNav {
    background: linear-gradient(90deg,
        rgba(232, 246, 252, 0.98) 0%,
        rgba(255, 255, 255, 0.98) 55%,
        rgba(232, 246, 252, 0.98) 100%);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(43, 164, 212, 0.20);
    box-shadow: 0 1px 12px rgba(13, 27, 42, 0.08);
    transition: box-shadow 0.3s ease;
}

#mainNav.scrolled {
    box-shadow: 0 2px 24px rgba(13, 27, 42, 0.15);
}

#mainNav .nav-link {
    color: var(--text-primary);
    font-weight: 500;
    font-size: 0.95rem;
    padding: 0.5rem 1rem;
    transition: color 0.2s;
}

#mainNav .nav-link:hover {
    color: var(--primary);
}

#mainNav .nav-logo {
    transition: opacity 0.2s;
}

/* 下拉菜单 */
.dropdown-menu-custom {
    border: 1px solid var(--border-light);
    border-radius: var(--radius-card);
    box-shadow: 0 8px 30px rgba(13, 27, 42, 0.12);
    padding: 0.5rem 0;
    margin-top: 0.5rem;
}

.dropdown-menu-custom .dropdown-item {
    padding: 0.6rem 1.25rem;
    font-size: 0.9rem;
    color: var(--text-primary);
    transition: background 0.15s, color 0.15s;
}

.dropdown-menu-custom .dropdown-item:hover {
    background: var(--bg-light-section);
    color: var(--primary);
}

/* ========== 主按钮（胶囊形，带光晕） ========== */
.btn-primary-xishu {
    background: linear-gradient(135deg, #2BA4D4, #1A82AA);
    border: none;
    border-radius: var(--radius-btn);
    box-shadow: var(--shadow-btn);
    color: #ffffff;
    padding: 12px 36px;
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    transition: opacity 0.2s, transform 0.2s, box-shadow 0.2s;
    text-decoration: none;
}

.btn-primary-xishu:hover {
    opacity: 0.92;
    transform: translateY(-1px);
    box-shadow: 0 6px 20px rgba(43, 164, 212, 0.55);
    color: #ffffff;
}

.btn-primary-xishu:active {
    transform: translateY(0);
}

/* 小尺寸 */
.btn-primary-xishu.btn-sm {
    padding: 8px 20px;
    font-size: 0.875rem;
}

/* 大尺寸 */
.btn-primary-xishu.btn-lg {
    padding: 14px 44px;
    font-size: 1.1rem;
}

/* 描边按钮 */
.btn-outline-xishu {
    background: transparent;
    border: 2px solid rgba(255, 255, 255, 0.6);
    border-radius: var(--radius-btn);
    color: #ffffff;
    padding: 12px 36px;
    font-size: 1rem;
    font-weight: 600;
    transition: border-color 0.2s, background 0.2s;
}

.btn-outline-xishu:hover {
    border-color: #ffffff;
    background: rgba(255, 255, 255, 0.1);
    color: #ffffff;
}

/* ========== Hero 区 ========== */
.hero-section {
    background:
        linear-gradient(160deg, rgba(13, 27, 42, 0.62) 0%, rgba(15, 38, 64, 0.48) 50%, rgba(26, 58, 92, 0.38) 100%),
        url('/static/website/images/hero-preview.jpg') center center / cover no-repeat;
    position: relative;
    overflow: hidden;
    margin-top: -76px;
    padding: 176px 0 80px;
    color: #ffffff;
}

.hero-section::before {
    content: none;
}

.hero-section > * {
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 800;
    letter-spacing: -0.02em;
    line-height: 1.15;
    color: #ffffff;
}

.hero-subtitle {
    color: rgba(255, 255, 255, 0.80);
    font-size: clamp(1rem, 2vw, 1.25rem);
    margin-top: 1rem;
}

.hero-cta {
    margin-top: 2rem;
}

/* Hero 页内页面变体 */
.hero-page {
    margin-top: -76px;
    padding: 156px 0 60px;
}

/* Hero 波浪底部 */
.hero-wave {
    position: absolute;
    bottom: -1px;
    left: 0;
    right: 0;
    z-index: 2;
}

.hero-wave svg {
    display: block;
    width: 100%;
    height: 60px;
}

/* Hero 视觉占位 */
.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-img-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 14px;
}

.hero-img-frame {
    width: 340px;
    height: 340px;
    border-radius: 50%;
    border: 2px solid rgba(43, 164, 212, 0.7);
    box-shadow:
        0 0 0 6px rgba(43, 164, 212, 0.08),
        0 0 30px rgba(27, 200, 240, 0.45),
        0 0 70px rgba(43, 164, 212, 0.25),
        inset 0 0 30px rgba(0, 0, 0, 0.3);
    overflow: hidden;
    position: relative;
}

.hero-img-circle {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: 0% 100%;
    transform: scale(1.45);
    transform-origin: left bottom;
}

.hero-img-caption {
    display: flex;
    align-items: center;
    gap: 7px;
    font-size: 0.78rem;
    color: rgba(255, 255, 255, 0.70);
    letter-spacing: 0.03em;
}

.caption-dot {
    display: inline-block;
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: #39FF6A;
    box-shadow: 0 0 6px #39FF6A;
    flex-shrink: 0;
}

/* 旧占位符 */
.hero-cell-graphic { display: none; }

/* ========== Section 通用样式 ========== */
.section-light {
    padding: 80px 0;
    background: var(--bg-light);
}

.section-light-alt {
    padding: 80px 0;
    background: var(--bg-light-alt);
}

.section-dark {
    padding: 80px 0;
    background:
        linear-gradient(rgba(10, 20, 35, 0.82), rgba(10, 20, 35, 0.82)),
        url('/static/website/images/lab-exterior.jpg') center 80% / cover no-repeat;
    color: #ffffff;
}

.section-cta {
    padding: 80px 0;
    background: linear-gradient(160deg, #0D1B2A 0%, #0F2640 50%, #1A3A5C 100%);
    color: #ffffff;
}

/* ========== 模块标题装饰 ========== */
.section-label {
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

.section-label-dark {
    color: var(--primary-bright);
}

.section-title {
    font-size: clamp(1.6rem, 3vw, 2.2rem);
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.3;
}

.section-title-dark {
    color: #ffffff;
}

.section-lead {
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

.section-subtitle {
    font-size: 1.05rem;
    color: rgba(255, 255, 255, 0.75);
    line-height: 1.7;
}

.text-highlight {
    color: var(--primary);
}

/* ========== 深色服务卡片（宣传单风格） ========== */
.service-card-dark {
    background: var(--bg-dark-card);
    border: 1px solid var(--bg-dark-border);
    border-radius: var(--radius-card-lg);
    padding: 2.5rem 1.5rem;
    transition: border-color 0.3s, box-shadow 0.3s, transform 0.2s;
    color: #ffffff;
    min-height: 280px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

/* 带背景图的服务卡片 */
.service-card-bg {
    background-image:
        linear-gradient(rgba(10, 20, 35, 0.50), rgba(10, 20, 35, 0.50)),
        var(--card-bg);
    background-size: cover;
    background-position: center;
}

.service-card-bg:hover {
    background-image:
        linear-gradient(rgba(10, 20, 35, 0.20), rgba(10, 20, 35, 0.20)),
        var(--card-bg);
}

.service-card-dark:hover {
    border-color: var(--primary-bright);
    box-shadow: var(--shadow-card-glow);
    transform: translateY(-4px);
}

.service-card-title {
    font-size: 1.2rem;
    font-weight: 700;
    color: #ffffff;
    margin-bottom: 0.75rem;
}

.service-card-text {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.6;
    margin-bottom: 0;
}

.card-link-arrow {
    display: inline-block;
    margin-top: 1rem;
    font-size: 1.2rem;
    color: var(--primary-bright);
    transition: transform 0.2s;
}

.service-card-dark:hover .card-link-arrow {
    transform: translateX(4px);
}

.card-icon {
    opacity: 0.6;
}

/* ========== 浅色内容卡片 ========== */
.service-card-light {
    background: var(--bg-light-card);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-card);
    padding: 1.75rem;
    transition: transform 0.2s, box-shadow 0.2s;
}

.service-card-light:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-card);
}

.card-title-sm {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.card-text-sm {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 0;
}

/* ========== 标志性服务（细胞机制页） ========== */
.flagship-service {
    background: linear-gradient(135deg, #F0F8FC 0%, #ffffff 100%);
    border: 1px solid var(--primary);
    border-radius: var(--radius-card-lg);
    padding: 2.5rem;
    position: relative;
}

.flagship-badge {
    position: absolute;
    top: -14px;
    left: 2rem;
    background: var(--primary);
    color: #ffffff;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    padding: 4px 16px;
    border-radius: 20px;
}

.flagship-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 1rem;
}

.flagship-desc {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

/* ========== 优势列表 ========== */
.advantage-list {
    list-style: none;
    padding-left: 0;
    margin-top: 1rem;
}

.advantage-list li {
    padding: 0.4rem 0;
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
    border-bottom: 1px solid var(--divider);
}

.advantage-list li:last-child {
    border-bottom: none;
}

.advantage-list li::before {
    content: '✓ ';
    color: var(--primary);
    font-weight: 700;
}

/* ========== 服务区块 ========== */
.service-block-title {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.service-block-desc {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.service-divider {
    border-top: 1px solid var(--border-light);
    margin: 2rem 0;
}

.research-note {
    color: var(--text-secondary);
    font-style: italic;
}

.service-illustration {
    display: flex;
    justify-content: center;
    align-items: center;
}

.illustration-placeholder {
    width: 100%;
    max-width: 300px;
    aspect-ratio: 4/3;
    background: linear-gradient(135deg, rgba(43, 164, 212, 0.08), rgba(27, 200, 240, 0.05));
    border: 1px dashed var(--border-light);
    border-radius: var(--radius-card);
    display: flex;
    justify-content: center;
    align-items: center;
    color: var(--text-secondary);
    font-size: 0.85rem;
}

.service-illus-img {
    width: 100%;
    aspect-ratio: 4/3;
    object-fit: cover;
    border-radius: var(--radius-card);
    display: block;
}

/* ========== 细胞培养品类卡片背景 ========== */
.culture-card-bg {
    position: relative;
    background-image: linear-gradient(rgba(0,0,0,0.50), rgba(0,0,0,0.50)), var(--cbg);
    background-size: cover;
    background-position: center;
    transition: background 0.4s ease;
}

.culture-card-bg:hover {
    background-image: linear-gradient(rgba(0,0,0,0.30), rgba(0,0,0,0.30)), var(--cbg);
}

.culture-card-bg .card-title-sm,
.culture-card-bg .card-text-sm {
    color: #ffffff;
    position: relative;
    z-index: 1;
}

/* ========== 工具卡片 ========== */
.tool-card {
    background: var(--bg-light-card);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-card);
    padding: 1.25rem 1rem;
    transition: transform 0.2s, box-shadow 0.2s;
}

.tool-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-card);
}

.tool-name {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.tool-desc {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-bottom: 0;
}

/* ========== 亮点标签 ========== */
.featured-badge {
    display: inline-block;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: #ffffff;
    font-size: 0.65rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    padding: 2px 8px;
    border-radius: 4px;
    margin-right: 6px;
    vertical-align: middle;
}

/* ========== 价值叙述 ========== */
.value-statement {
    border-top: 1px solid var(--border-light);
}

.value-statement-text {
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

/* ========== 跨模块引导 ========== */
.cross-module-guide {
    padding: 0.5rem 0;
}

.guide-link {
    color: var(--primary);
    font-weight: 600;
    text-decoration: none;
    transition: color 0.2s;
}

.guide-link:hover {
    color: var(--primary-dark);
}

/* ========== 核心差异化区 ========== */
.core-diff {
    background: linear-gradient(135deg, #F0F8FC 0%, #ffffff 100%);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-card-lg);
}

.diff-text {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.85;
    margin-bottom: 0.75rem;
}

/* ========== 平台说明 ========== */
.platform-note-box {
    background: var(--bg-light-section);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-card);
}

.platform-note-title {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.platform-note-text {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 0;
}

/* ========== 能力背书 ========== */
.credibility-visual {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.credibility-stat {
    text-align: center;
    padding: 1.75rem 1.25rem;
    background: var(--bg-light-card);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-card-lg);
    min-width: 130px;
    flex: 1;
}

.credibility-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--primary);
    line-height: 1.1;
}

.credibility-number-text {
    font-size: 1.6rem;
    letter-spacing: 0.05em;
}

.credibility-label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-top: 0.5rem;
}

.credibility-card {
    background: linear-gradient(135deg, #F0F8FC 0%, #ffffff 100%);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-card-lg);
}

.credibility-text {
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.9;
    margin-bottom: 1rem;
}

.credibility-text:last-child {
    margin-bottom: 0;
}

/* ========== 实验室照片区 ========== */
.lab-section {
    background-image:
        linear-gradient(to bottom, rgba(13, 27, 42, 0.10) 0%, rgba(10, 22, 38, 0.10) 100%),
        url('/static/website/images/lab-microscope-bg.jpg');
    background-size: cover;
    background-position: center 40%;
    background-attachment: fixed;
}

.lab-badge-row {
    display: flex;
    justify-content: center;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.lab-badge {
    display: inline-block;
    padding: 0.35rem 1rem;
    border-radius: 999px;
    background: rgba(43, 164, 212, 0.18);
    border: 1px solid rgba(43, 164, 212, 0.55);
    color: rgba(200, 235, 255, 0.9);
    font-size: 0.82rem;
    letter-spacing: 0.03em;
}

.lab-photo-card {
    border-radius: var(--radius-card);
    overflow: hidden;
    position: relative;
}

.lab-photo-card::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(26, 130, 170, 0.30) 0%, rgba(43, 164, 212, 0.18) 100%);
    pointer-events: none;
    border-radius: var(--radius-card);
}

.lab-photo-img {
    width: 100%;
    aspect-ratio: 16/10;
    object-fit: cover;
    display: block;
    transition: transform 0.5s ease;
}

.lab-photo-card:hover .lab-photo-img {
    transform: scale(1.03);
}

.lab-photo-caption {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 0.5rem 0.9rem;
    background: linear-gradient(to top, rgba(10, 22, 38, 0.78), transparent);
    color: rgba(255, 255, 255, 0.85);
    font-size: 0.8rem;
    letter-spacing: 0.04em;
}

.lab-photo-placeholder {
    aspect-ratio: 16/10;
    background: linear-gradient(135deg, rgba(43, 164, 212, 0.1), rgba(27, 200, 240, 0.05));
    border: 1px solid var(--bg-dark-border);
    border-radius: var(--radius-card);
    display: flex;
    justify-content: center;
    align-items: center;
    color: rgba(255, 255, 255, 0.4);
    font-size: 0.9rem;
}

/* ========== 价值观卡片 ========== */
.value-card {
    padding: 2rem 1.5rem;
}

.value-number {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary);
    opacity: 0.3;
    margin-bottom: 0.5rem;
}

.value-title {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.value-text {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ========== 关于我们叙事 ========== */
.about-narrative p {
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.9;
    margin-bottom: 1.25rem;
}

.about-pillar-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 1rem;
    padding-left: 1rem;
    border-left: 3px solid var(--primary);
}

.about-pillar-text {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.9;
}

/* ========== 联系我们 ========== */
.contact-info-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.contact-info-item {
    display: flex;
    gap: 1rem;
    align-items: flex-start;
}

.contact-info-icon {
    font-size: 1.3rem;
    color: var(--primary);
    flex-shrink: 0;
    width: 32px;
    text-align: center;
}

.contact-info-label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.2rem;
}

.contact-info-value {
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 0;
}

.contact-note {
    background: var(--bg-light-section);
    border-radius: var(--radius-card);
}

.inquiry-form-card {
    background: var(--bg-light-card);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-card-lg);
    box-shadow: var(--shadow-card);
}

.form-title {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text-primary);
}

/* ========== 询价表单通用样式 ========== */
.inquiry-form .form-label {
    color: rgba(255, 255, 255, 0.85);
    font-size: 0.9rem;
    font-weight: 500;
}

.inquiry-form .form-control {
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: var(--radius-input);
    color: #ffffff;
    padding: 0.65rem 1rem;
    font-size: 0.9rem;
    transition: border-color 0.2s, background 0.2s;
}

.inquiry-form .form-control::placeholder {
    color: rgba(255, 255, 255, 0.35);
}

.inquiry-form .form-control:focus {
    background: rgba(255, 255, 255, 0.12);
    border-color: var(--primary-bright);
    box-shadow: 0 0 0 3px rgba(27, 200, 240, 0.15);
    color: #ffffff;
    outline: none;
}

/* 浅色背景下的表单（联系我们页面） */
.contact-info-list ~ .inquiry-form-card .form-control,
.inquiry-form-card .form-control {
    background: var(--bg-light);
    border: 1px solid var(--border-light);
    color: var(--text-primary);
}

.inquiry-form-card .form-control::placeholder {
    color: #A0B8C4;
}

.inquiry-form-card .form-control:focus {
    background: var(--bg-light);
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(43, 164, 212, 0.15);
    color: var(--text-primary);
}

.inquiry-form-card .form-label {
    color: var(--text-primary);
}

/* ========== 表单提示信息 ========== */
.form-alert {
    border-radius: var(--radius-input);
    padding: 0.75rem 1rem;
    font-size: 0.9rem;
}

.form-alert.alert-success {
    background: rgba(25, 135, 84, 0.2);
    border: 1px solid rgba(25, 135, 84, 0.4);
    color: #75b798;
}

.form-alert.alert-danger {
    background: rgba(220, 53, 69, 0.2);
    border: 1px solid rgba(220, 53, 69, 0.4);
    color: #ea868f;
}

/* ========== Min-vh-75（Hero区用） ========== */
.min-vh-75 {
    min-height: 75vh;
}

/* ========== 页脚 ========== */
.site-footer {
    background: linear-gradient(135deg, #2BA4D4 0%, #1A82AA 100%);
    color: #ffffff;
    padding: 36px 0 20px;
}

.footer-heading {
    font-weight: 700;
    margin-bottom: 1rem;
    font-size: 1rem;
    color: #ffffff;
}

.footer-text {
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.85);
    line-height: 1.7;
}

.footer-links {
    font-size: 0.85rem;
}

.footer-links li {
    margin-bottom: 0.3rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    transition: color 0.2s;
}

.footer-links a:hover {
    color: #ffffff;
}

.footer-divider {
    border-color: rgba(255, 255, 255, 0.25);
    margin: 1.2rem 0 1rem;
}

.footer-copyright {
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.65);
}

.footer-copyright a {
    color: rgba(255, 255, 255, 0.65);
    text-decoration: none;
    transition: color 0.2s;
}

.footer-copyright a:hover {
    color: rgba(255, 255, 255, 0.9);
}

/* ========== 返回顶部按钮 ========== */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 44px;
    height: 44px;
    background: var(--primary);
    color: #ffffff;
    border: none;
    border-radius: 50%;
    font-size: 1.3rem;
    font-weight: 700;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: opacity 0.3s, visibility 0.3s, transform 0.3s, background 0.2s;
    box-shadow: 0 4px 16px rgba(43, 164, 212, 0.4);
    z-index: 1050;
    display: flex;
    justify-content: center;
    align-items: center;
    line-height: 1;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--primary-dark);
}

/* ========== 滚动动画 ========== */
.fade-in-up {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in-up.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ========== 图片懒加载 ========== */
img[data-src] {
    opacity: 0;
    transition: opacity 0.4s;
}

img[data-src].loaded {
    opacity: 1;
}

/* ========== 响应式 ========== */
@media (max-width: 991.98px) {
    .hero-section {
        padding: 136px 0 50px;
    }

    .hero-page {
        padding: 126px 0 40px;
    }

    .section-light,
    .section-light-alt,
    .section-dark,
    .section-cta {
        padding: 50px 0;
    }

    .min-vh-75 {
        min-height: auto;
    }

    .service-card-dark {
        min-height: auto;
        padding: 1.75rem 1.25rem;
    }

    .flagship-service {
        padding: 1.5rem;
    }

    .credibility-visual {
        gap: 1rem;
    }

    .credibility-stat {
        min-width: 120px;
        padding: 1.5rem 1rem;
    }

    .credibility-number {
        font-size: 2rem;
    }

    .nav-logo {
        height: 28px;
    }

    #mainNav .nav-link {
        padding: 0.5rem 0;
    }

    #mainNav .btn-primary-xishu {
        margin-top: 0.5rem;
    }

    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 40px;
        height: 40px;
        font-size: 1.1rem;
    }

    .hero-wave svg {
        height: 30px;
    }
}

@media (max-width: 767.98px) {
    .hero-title {
        font-size: 1.75rem;
    }

    .section-title {
        font-size: 1.4rem;
    }

    .about-pillar-title {
        font-size: 1.1rem;
    }

    .service-block-title {
        font-size: 1.15rem;
    }
}

@media (max-width: 575.98px) {
    body {
        padding-top: 64px;
    }

    .hero-section {
        padding: 116px 0 30px;
    }

    .btn-primary-xishu.btn-lg {
        padding: 12px 32px;
        font-size: 1rem;
    }
}