/* ==========================================================================
   产品服务页样式 - HEDU 蓝色调版本
   ========================================================================== */

/* ============== 业务 Tab 导航 ============== */
.biz-tabs {
    background-color: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 84px;
    z-index: 50;
}

.biz-nav {
    display: flex;
    gap: 0;
    overflow-x: auto;
    scrollbar-width: thin;
}

.biz-tab {
    flex: 1;
    padding: 20px 24px;
    text-align: center;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text-muted);
    border-bottom: 3px solid transparent;
    transition: var(--transition);
    white-space: nowrap;
    min-width: 130px;
}

.biz-tab:hover {
    color: var(--color-primary);
    background-color: var(--color-bg-alt);
}

.biz-tab.active {
    color: var(--color-primary);
    font-weight: 600;
    border-bottom-color: var(--color-accent);
    background-color: rgba(30, 136, 229, 0.05);
}

/* ============== 业务板块 ============== */
.biz-section {
    padding: clamp(72px, 9vw, 130px) 0;
    border-bottom: 1px solid var(--color-border-light);
}

.biz-section:last-of-type {
    border-bottom: none;
}

.biz-alt {
    background-color: var(--color-bg-alt);
}

.biz-grid {
    display: grid;
    grid-template-columns: 1fr 1.1fr;
    gap: 96px;
    align-items: center;
}

.biz-grid-reverse .biz-visual {
    order: 2;
}

.biz-visual {
    aspect-ratio: 1;
    border-radius: 16px;
    overflow: hidden;
    position: relative;
    box-shadow: var(--shadow-xl);
}

.biz-visual-card {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    color: var(--color-white);
    padding: 56px;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    position: relative;
    overflow: hidden;
}

.biz-visual-card::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1), transparent 50%);
}

.biz-visual-card::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--color-accent), transparent);
}

.biz-visual-card-2 { background: linear-gradient(135deg, #0D47A1 0%, #1976D2 100%); }
.biz-visual-card-3 { background: linear-gradient(135deg, #00695C 0%, #00ACC1 100%); }
.biz-visual-card-4 { background: linear-gradient(135deg, #1565C0 0%, #1E88E5 100%); }
.biz-visual-card-5 { background: linear-gradient(135deg, #283593 0%, #3F51B5 100%); }
.biz-visual-card-6 { background: linear-gradient(135deg, #0D47A1 0%, #00ACC1 100%); }

.biz-num {
    position: absolute;
    top: 32px;
    left: 44px;
    font-family: var(--font-serif);
    font-size: 4.8rem;
    font-weight: 400;
    font-style: italic;
    color: rgba(255, 255, 255, 0.22);
    line-height: 1;
    letter-spacing: -0.02em;
}

.biz-visual-card h3 {
    color: var(--color-white);
    font-size: clamp(1.4rem, 2.2vw, 1.75rem);
    margin-bottom: 8px;
    position: relative;
    z-index: 1;
}

.biz-visual-card p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.85rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    margin: 0;
    position: relative;
    z-index: 1;
}

.biz-content h2 {
    font-size: clamp(1.45rem, 2.4vw, 1.95rem);
    margin-bottom: 20px;
    color: var(--color-primary);
    line-height: 1.25;
}

.biz-content p {
    font-size: 0.95rem;
    line-height: 1.9;
    color: var(--color-text-muted);
    margin-bottom: 22px;
}

.biz-content strong {
    color: var(--color-primary);
    font-weight: 600;
}

.biz-list {
    margin-top: 28px;
}

.biz-list li {
    padding: 13px 0;
    font-size: 0.92rem;
    color: var(--color-text);
    line-height: 1.6;
    border-bottom: 1px dashed var(--color-border);
}

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

/* ============== 服务承诺 ============== */
.promise-row {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 28px;
}

.promise-block {
    background-color: rgba(255, 255, 255, 0.04);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 12px;
    padding: 40px 28px;
    text-align: center;
    transition: var(--transition);
}

.promise-block:hover {
    background-color: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-4px);
}

.promise-word {
    font-family: var(--font-display);
    font-size: clamp(1.4rem, 2.4vw, 1.8rem);
    font-weight: 800;
    background: linear-gradient(135deg, #FFFFFF 0%, var(--color-accent-light) 100%);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    line-height: 1.25;
    margin-bottom: 16px;
    letter-spacing: 0.06em;
}

.promise-block h4 {
    color: var(--color-white);
    font-size: 1.05rem;
    margin-bottom: 10px;
}

.promise-block p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.85rem;
    line-height: 1.65;
    margin: 0;
}

/* ============== 响应式 ============== */
@media (max-width: 1024px) {
    .biz-grid {
        grid-template-columns: 1fr;
        gap: 56px;
    }
    .biz-grid-reverse .biz-visual {
        order: 0;
    }
    .biz-visual {
        aspect-ratio: 16 / 10;
        max-width: 600px;
        margin: 0 auto;
    }
    .promise-row {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 640px) {
    .biz-tabs {
        top: 68px;
    }
    .biz-tab {
        padding: 16px 16px;
        font-size: 0.85rem;
        min-width: 100px;
    }
    .biz-visual-card {
        padding: 36px;
    }
    .biz-num {
        top: 20px;
        left: 32px;
        font-size: 3.4rem;
    }
    .promise-row {
        grid-template-columns: 1fr;
    }
}