/* ========================================================================
   About 页面样式 - 与首页蓝色主调统一
   主色: #005bac -> #0077e6
   ======================================================================== */

:root {
    --ab-primary: #005bac;
    --ab-accent: #0077e6;
    --ab-dark: #1a1a1a;
    --ab-text: #333;
    --ab-muted: #666;
    --ab-light: #999;
    --ab-bg-soft: #f8f9fa;
    --ab-bg-card: #ffffff;
    --ab-line: #e8eef5;
    --ab-shadow-sm: 0 4px 15px rgba(0, 0, 0, 0.08);
    --ab-shadow-md: 0 8px 25px rgba(0, 91, 172, 0.12);
    --ab-shadow-lg: 0 12px 40px rgba(0, 91, 172, 0.18);
    --ab-radius: 12px;
    --ab-radius-lg: 16px;
    --ab-container: 1200px;
    --ab-transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ============== 通用容器 ============== */
.ab-container {
    max-width: var(--ab-container);
    margin: 0 auto;
    padding: 0 20px;
    box-sizing: border-box;
}

.ab-section {
    padding: 80px 0;
    box-sizing: border-box;
}

.ab-section--soft {
    background: linear-gradient(180deg, #f8f9fa 0%, #ffffff 100%);
}

.ab-section-head {
    text-align: center;
    margin-bottom: 60px;
}

.ab-section-head h2 {
    font-size: 36px;
    font-weight: bold;
    color: var(--ab-dark);
    margin: 0 0 18px;
    position: relative;
    display: inline-block;
    padding-bottom: 20px;
}

.ab-section-head h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, var(--ab-primary), var(--ab-accent));
    border-radius: 2px;
}

.ab-section-head p {
    font-size: 16px;
    color: var(--ab-muted);
    max-width: 680px;
    margin: 0 auto;
    line-height: 1.8;
}

/* ============== Hero Banner ============== */
.ab-hero {
    position: relative;
    width: 100%;
    height: 560px;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

.ab-hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(0, 91, 172, 0.85) 0%, rgba(0, 119, 230, 0.55) 50%, rgba(0, 0, 0, 0.4) 100%);
    z-index: 1;
}

.ab-hero img {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    z-index: 0;
}

.ab-hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: #fff;
    max-width: 900px;
    padding: 0 20px;
    animation: abHeroFade 1.2s ease;
}

.ab-hero-content h2 {
    font-size: 48px;
    font-weight: 800;
    line-height: 1.3;
    margin: 0 0 22px;
    letter-spacing: 2px;
    background: linear-gradient(180deg, #ffffff 0%, #d9ecff 60%, #a5d3ff 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: #fff;
    filter:
        drop-shadow(0 2px 6px rgba(0, 0, 0, 0.55))
        drop-shadow(0 0 28px rgba(0, 119, 230, 0.45));
}

.ab-hero-content p {
    font-size: 20px;
    line-height: 1.6;
    margin: 0;
    letter-spacing: 1px;
    color: #e6f1ff;
    text-shadow:
        0 1px 2px rgba(0, 0, 0, 0.6),
        0 2px 14px rgba(0, 0, 0, 0.45);
    opacity: 0.95;
}

.ab-hero-scroll {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 3;
    color: #fff;
    font-size: 24px;
    width: 36px;
    height: 36px;
    border: 2px solid rgba(255, 255, 255, 0.6);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    animation: abBounce 2s infinite;
}

@keyframes abHeroFade {
    from { opacity: 0; transform: translateY(30px); }
    to   { opacity: 1; transform: translateY(0); }
}

@keyframes abBounce {
    0%, 100% { transform: translate(-50%, 0); }
    50%      { transform: translate(-50%, 8px); }
}

/* ============== 产品介绍双栏 ============== */
.ab-intro {
    display: grid;
    grid-template-columns: 5fr 6fr;
    gap: 50px;
    align-items: center;
}

.ab-intro-media {
    position: relative;
    border-radius: var(--ab-radius-lg);
    overflow: hidden;
    box-shadow: var(--ab-shadow-md);
    background: #f5f5f5;
    aspect-ratio: 4 / 3;
}

.ab-intro-media video {
    width: 100%;
    height: 100%;
    /*object-fit: cover;*/
    display: block;
    transition: var(--ab-transition);
}

.ab-intro-media:hover video {
    transform: scale(1.02);
}

.ab-intro-media-caption {
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    padding: 20px 24px;
    background: linear-gradient(180deg, transparent 0%, rgba(0, 0, 0, 0.85) 100%);
    color: #fff;
    font-weight: bold;
    font-size: 15px;
    line-height: 1.5;
    pointer-events: none;
    z-index: 1;
}

.ab-intro-body {
    padding: 10px 0;
}

.ab-intro-body .ab-tag {
    display: inline-block;
    padding: 6px 16px;
    background: linear-gradient(135deg, rgba(0, 91, 172, 0.1), rgba(0, 119, 230, 0.1));
    color: var(--ab-primary);
    font-size: 13px;
    font-weight: 600;
    border-radius: 20px;
    margin-bottom: 20px;
    border: 1px solid rgba(0, 91, 172, 0.2);
}

.ab-intro-body h1 {
    font-size: 34px;
    font-weight: bold;
    color: var(--ab-dark);
    margin: 0 0 24px;
    line-height: 1.3;
}

.ab-intro-body h1::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--ab-primary), var(--ab-accent));
    border-radius: 2px;
    margin-top: 16px;
}

.ab-intro-body p {
    font-size: 15px;
    color: var(--ab-text);
    line-height: 1.9;
    margin: 0 0 14px;
    padding-left: 18px;
    position: relative;
}

.ab-intro-body p::before {
    content: '';
    position: absolute;
    left: 0;
    top: 10px;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--ab-accent);
    box-shadow: 0 0 0 4px rgba(0, 119, 230, 0.15);
}

.ab-intro-body .ab-highlight {
    margin-top: 28px;
    padding: 18px 22px;
    background: linear-gradient(135deg, #f0f7ff 0%, #e6f1ff 100%);
    border-left: 4px solid var(--ab-primary);
    border-radius: 8px;
    color: var(--ab-primary);
    font-size: 15px;
    font-weight: 600;
    line-height: 1.6;
}

/* ============== 特性视频卡片 ============== */
.ab-features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.ab-feature {
    text-align: center;
    background: var(--ab-bg-card);
    border-radius: var(--ab-radius);
    padding: 24px;
    box-shadow: var(--ab-shadow-sm);
    transition: var(--ab-transition);
    border: 1px solid transparent;
}

.ab-feature:hover {
    transform: translateY(-8px);
    box-shadow: var(--ab-shadow-lg);
    border-color: rgba(0, 91, 172, 0.15);
}

.ab-video-trigger {
    position: relative;
    cursor: pointer;
    border-radius: 10px;
    overflow: hidden;
    background: #f5f5f5;
    aspect-ratio: 4 / 3;
    margin-bottom: 18px;
}

.ab-video-trigger video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    transition: var(--ab-transition);
}

.ab-video-trigger::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(0, 91, 172, 0.08) 0%, rgba(0, 0, 0, 0) 50%, rgba(0, 91, 172, 0.08) 100%);
    pointer-events: none;
    z-index: 1;
    transition: var(--ab-transition);
}

.ab-video-trigger:hover::before {
    background: linear-gradient(135deg, rgba(0, 91, 172, 0.18) 0%, rgba(0, 0, 0, 0) 50%, rgba(0, 91, 172, 0.18) 100%);
}

.ab-video-trigger:hover video {
    filter: brightness(0.85);
    transform: scale(1.04);
}

.ab-play-icon {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 58px;
    height: 58px;
    background: rgba(0, 91, 172, 0.85);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 6px 20px rgba(0, 91, 172, 0.45);
    transition: var(--ab-transition);
    z-index: 2;
    backdrop-filter: blur(4px);
}

.ab-play-icon svg {
    width: 24px;
    height: 24px;
    fill: #fff;
    margin-left: 4px;
}

.ab-video-trigger:hover .ab-play-icon {
    transform: translate(-50%, -50%) scale(1.15);
    background: var(--ab-accent);
    box-shadow: 0 8px 28px rgba(0, 119, 230, 0.6);
}

.ab-feature h4 {
    font-size: 19px;
    font-weight: bold;
    color: var(--ab-dark);
    margin: 0 0 10px;
}

.ab-feature p {
    font-size: 14px;
    color: var(--ab-muted);
    line-height: 1.7;
    margin: 0;
}

/* ============== 视频模态框 ============== */
.ab-modal {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.88);
    z-index: 9999;
    align-items: center;
    justify-content: center;
    animation: abFadeIn 0.3s ease;
    backdrop-filter: blur(6px);
}

.ab-modal.is-open {
    display: flex;
}

.ab-modal-content {
    position: relative;
    max-width: 90%;
    max-height: 90%;
    animation: abSlideUp 0.35s ease;
}

.ab-modal-close {
    position: absolute;
    top: -44px;
    right: 0;
    background: none;
    border: none;
    color: #fff;
    font-size: 32px;
    cursor: pointer;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--ab-transition);
    z-index: 10000;
}

.ab-modal-close:hover {
    color: #ff5252;
    transform: scale(1.2) rotate(90deg);
}

.ab-modal-video {
    max-width: 100%;
    max-height: 78vh;
    display: block;
    border-radius: 10px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.6);
}

.ab-modal-title {
    color: #fff;
    text-align: center;
    margin: 18px 0 0;
    font-size: 20px;
    font-weight: 600;
}

@keyframes abFadeIn {
    from { opacity: 0; }
    to   { opacity: 1; }
}

@keyframes abSlideUp {
    from { transform: translateY(30px); opacity: 0; }
    to   { transform: translateY(0); opacity: 1; }
}

/* ============== 质量保障网格 ============== */
.ab-quality-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.ab-quality-card {
    background: var(--ab-bg-card);
    border-radius: var(--ab-radius);
    overflow: hidden;
    box-shadow: var(--ab-shadow-sm);
    transition: var(--ab-transition);
    border: 1px solid var(--ab-line);
}

.ab-quality-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--ab-shadow-lg);
    border-color: rgba(0, 91, 172, 0.2);
}

.ab-quality-image {
    position: relative;
    width: 100%;
    height: 220px;
    background: linear-gradient(135deg, #eef4fb 0%, #dde8f5 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.ab-quality-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--ab-transition);
}

.ab-quality-card:hover .ab-quality-image img {
    transform: scale(1.06);
}

.ab-quality-number {
    position: absolute;
    top: 14px;
    left: 14px;
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--ab-primary), var(--ab-accent));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    color: #fff;
    font-size: 16px;
    box-shadow: 0 4px 12px rgba(0, 91, 172, 0.4);
    z-index: 2;
}

.ab-quality-content {
    padding: 24px;
}

.ab-quality-title {
    font-size: 19px;
    font-weight: bold;
    color: var(--ab-dark);
    margin: 0 0 12px;
    line-height: 1.4;
    position: relative;
    padding-bottom: 12px;
}

.ab-quality-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 36px;
    height: 3px;
    background: linear-gradient(90deg, var(--ab-primary), var(--ab-accent));
    border-radius: 2px;
}

.ab-quality-desc {
    font-size: 14px;
    color: var(--ab-muted);
    line-height: 1.8;
    margin: 0;
}

/* ============== 响应式 ============== */
@media (max-width: 1024px) {
    .ab-section { padding: 60px 0; }
    .ab-hero { height: 480px; }
    .ab-hero-content h2 { font-size: 40px; }
    .ab-hero-content p { font-size: 18px; }

    .ab-intro {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .ab-features-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }

    .ab-quality-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }
}

@media (max-width: 768px) {
    .ab-section { padding: 50px 0; }
    .ab-section-head { margin-bottom: 40px; }
    .ab-section-head h2 { font-size: 28px; }
    .ab-section-head p { font-size: 14px; }

    .ab-hero { height: 400px; }
    .ab-hero-content h2 { font-size: 30px; letter-spacing: 1px; }
    .ab-hero-content p { font-size: 16px; }

    .ab-intro-body h1 { font-size: 26px; }
    .ab-intro-body p { font-size: 14px; }

    .ab-features-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .ab-feature { padding: 20px; }

    .ab-quality-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .ab-quality-image { height: 200px; }
    .ab-quality-content { padding: 20px; }
}

@media (max-width: 480px) {
    .ab-container { padding: 0 16px; }
    .ab-hero { height: 340px; }
    .ab-hero-content h2 { font-size: 24px; }
    .ab-hero-content p { font-size: 14px; }
    .ab-intro-body h1 { font-size: 22px; }
    .ab-section-head h2 { font-size: 24px; }
    .ab-feature h4 { font-size: 17px; }
    .ab-quality-title { font-size: 17px; }
}