/* =========================================
   About Us Page Styles
========================================= */

/* Hero Section */
.hero-about {
    position: relative;
    height: 45vh;
    min-height: 320px;
    display: flex;
    align-items: center;
    background-color: var(--color-primary);
    /* Abstract grid pattern */
    background-image: linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
    background-size: 50px 50px;
    overflow: hidden;
}

/* Page-specific AI Hero Backgrounds */
.hero-about.bg-about { background-image: url('../../images/bg_about.png'); background-size: cover; background-position: center; }
.hero-about.bg-academic { background-image: url('../../images/bg_academic.png'); background-size: cover; background-position: center; }
.hero-about.bg-education { background-image: url('../../images/bg_education.png'); background-size: cover; background-position: center; }
.hero-about.bg-journal { background-image: url('../../images/bg_journal.png'); background-size: cover; background-position: center; }
.hero-about.bg-events { background-image: url('../../images/bg_events.png'); background-size: cover; background-position: center; }
.hero-about.bg-community { background-image: url('../../images/bg_community.png'); background-size: cover; background-position: center; }
.hero-about.bg-news { background-image: url('../../images/bg_news.png'); background-size: cover; background-position: center; }

.hero-about::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(15, 23, 42, 0.55);
    z-index: 1;
}

.hero-about-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
    padding-top: 0;
    color: #fff;
}

.hero-about-content h1 {
    font-size: 3.5rem;
    color: #fff;
    margin-bottom: 1rem; /* 增大主标题与副标题之间的间距 */
}

.hero-about-content .subtitle-en {
    font-size: 1.2rem;
    color: var(--color-accent);
    letter-spacing: 1px;
    font-weight: 500;
    margin-bottom: 1.5rem; /* 缩减副标题与正文段落之间的间距 */
    opacity: 0.9;
}

.hero-about-content p.intro {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.8);
    font-weight: 300;
}

/* Section 2: Core Principle (Split Layout Override) */
.about-intro-section {
    padding: 8rem 0;
}

.core-blockquote {
    position: relative;
    padding: 2.5rem 3rem;
    margin-top: 3rem;
    background: #f8f9fa;
    border-left: 6px solid var(--color-accent);
    border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
    box-shadow: var(--shadow-sm);
}

.core-blockquote::before {
    content: '"';
    position: absolute;
    top: 10px;
    left: 15px;
    font-size: 5rem;
    color: rgba(0, 209, 112, 0.15);
    font-family: serif;
    line-height: 1;
}

.core-blockquote p {
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: 0;
    position: relative;
    z-index: 2;
}

.core-blockquote small {
    display: block;
    margin-top: 0.8rem;
    color: var(--color-text-muted);
    font-size: 0.95rem;
}

/* Section 3: Vision & Mission */
.vision-mission-section {
    padding: 8rem 0;
    background-color: var(--color-bg-light);
}

.vm-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
}

.vm-card {
    background: #fff;
    padding: 4rem 3rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    transition: transform var(--transition-smooth);
}

.vm-card:hover {
    transform: translateY(-5px);
}

.vm-icon-wrapper {
    width: 64px;
    height: 64px;
    background: rgba(0, 209, 112, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-accent);
    margin-bottom: 2rem;
}

.vm-icon-wrapper svg {
    width: 32px;
    height: 32px;
}

.vm-card h3 {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
}

.vm-card p {
    font-size: 1.1rem;
    color: var(--color-text-muted);
    line-height: 1.8;
}

/* Section 4: Why NM Detail */
.why-nm-detail {
    padding: 8rem 0;
    background-color: var(--color-primary);
    color: rgba(255, 255, 255, 0.8);
}

.why-nm-detail h2 {
    color: #fff;
}

.why-nm-detail .text-large {
    font-size: 1.4rem;
    color: var(--color-accent);
    font-weight: 500;
    margin-bottom: 2rem;
    line-height: 1.6;
}

.why-nm-detail .subtitle-span {
    font-size: 1.5rem;
    opacity: 0.8;
    font-weight: normal;
}

.why-nm-detail .why-nm-content-container {
    max-width: 800px;
    margin: 0 auto;
    text-align: left;
}

/* Section 5: Identity Timeline Graphic */
.identity-section {
    padding: 8rem 0;
}

.timeline-layout {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 5rem;
    align-items: center;
}

.identity-content h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
}

.identity-list {
    list-style: none;
    margin-bottom: 3rem;
}

.identity-item {
    padding-left: 2rem;
    position: relative;
    margin-bottom: 2rem;
}

.identity-item::before {
    content: '';
    position: absolute;
    left: 0;
    top: 8px;
    width: 12px;
    height: 12px;
    background-color: var(--color-accent);
    border-radius: 50%;
}

.identity-item h4 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
    color: var(--color-primary-light);
}

.identity-item p {
    color: var(--color-text-muted);
    font-size: 0.95rem;
}

.identity-conclusion {
    padding: 2rem;
    background: rgba(0, 209, 112, 0.05);
    border-radius: var(--radius-md);
    border: 1px solid rgba(0, 209, 112, 0.2);
}

.identity-conclusion p {
    color: var(--color-primary);
    font-weight: 600;
    margin: 0;
}

.concentric-circles {
    position: relative;
    width: 100%;
    aspect-ratio: 1/1;
    display: flex;
    align-items: center;
    justify-content: center;
}

.circle {
    position: absolute;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    font-weight: 600;
    transition: all var(--transition-smooth);
}

.circle-1 {
    width: 100%;
    height: 100%;
    background: #f8f9fa;
    border: 2px dashed #e9ecef;
    color: var(--color-text-muted);
    z-index: 1;
    align-items: flex-start;
}

.circle-1 span {
    margin-top: 4%;
}

.circle-2 {
    width: 70%;
    height: 70%;
    background: #e9ecef;
    color: var(--color-text-main);
    z-index: 2;
    box-shadow: var(--shadow-sm);
    align-items: flex-start;
}

.circle-2 span {
    margin-top: 6%;
}

.circle-3 {
    width: 40%;
    height: 40%;
    background: var(--color-accent);
    color: #fff;
    z-index: 3;
    box-shadow: 0 10px 25px rgba(0, 209, 112, 0.4);
}

.circle span {
    padding: 1rem;
    font-size: 0.9rem;
}

.circle-3 span {
    font-size: 1.1rem;
    font-weight: 700;
}

/* Section 6: Scope and Borders */
.scope-section {
    padding: 8rem 0;
}

.scope-container {
    max-width: 900px;
    margin: 0 auto;
    background: #fff;
    border: 1px solid #e9ecef;
    border-radius: var(--radius-lg);
    padding: 5rem 4rem;
    text-align: center;
    box-shadow: var(--shadow-sm);
}

.scope-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 2rem;
    background: rgba(10, 28, 46, 0.05);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-primary);
}

.scope-icon svg {
    width: 40px;
    height: 40px;
}

.scope-container h2 {
    font-size: 2.2rem;
    margin-bottom: 1.5rem;
}

.scope-container .lead {
    font-size: 1.1rem;
    color: var(--color-text-muted);
    margin-bottom: 3rem;
}

.scope-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    text-align: left;
}

.scope-block {
    padding: 2.5rem;
    border-radius: var(--radius-md);
}

.scope-block.negative {
    background: #fff5f5;
    border: 1px solid #ffe3e3;
}

.scope-block.negative h4 {
    color: #e03131;
}

.scope-block.positive {
    background: rgba(0, 209, 112, 0.05);
    border: 1px solid rgba(0, 209, 112, 0.15);
}

.scope-block.positive h4 {
    color: var(--color-accent);
}

.scope-block h4 {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.scope-block p {
    color: var(--color-text-main);
    font-size: 1rem;
    line-height: 1.6;
}

.scope-footer {
    margin-top: 4rem;
    padding-top: 2rem;
    border-top: 1px solid #e9ecef;
    color: var(--color-text-muted);
    font-weight: 500;
}

/* ================== Mobile Responsiveness (Max Width: 768px) ================== */
@media (max-width: 768px) {
    .hero-about-content h1 {
        font-size: 1.8rem;
    }

    .hero-about-content .subtitle-en {
        font-size: 0.95rem;
        margin-bottom: 1rem;
    }

    .hero-about-content p.intro {
        font-size: 1.05rem;
    }

    .vm-grid,
    .timeline-layout,
    .scope-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .core-blockquote {
        padding: 1.5rem 1.5rem 1.5rem 2.5rem;
    }

    .core-blockquote::before {
        font-size: 4rem;
        top: 0;
        left: 5px;
    }

    .core-blockquote p {
        font-size: 1.15rem;
    }

    .circle span {
        padding: 0.5rem;
        font-size: 0.8rem;
    }

    .circle-3 span {
        font-size: 0.95rem;
    }

    .concentric-circles {
        max-width: 320px;
        margin: 2rem auto 0;
    }
}