/* ==========================================
   Case Studies 页专属样式
   ========================================== */

/* Hero */
.cs-hero {
    position: relative;
    min-height: 400px;
    display: flex;
    align-items: center;
    padding: 80px 20px;
    overflow: hidden;
    color: #fff;
}
.cs-hero-overlay {
    position: absolute; inset: 0;
    background: url('../images/banner/automated-aluminum-extrusion-factory.webp') center/cover no-repeat;
    z-index: 0;
}
.cs-hero::after {
    content: "";
    position: absolute; inset: 0;
    background: linear-gradient(90deg, rgba(15,42,74,0.92) 0%, rgba(15,42,74,0.6) 60%, rgba(15,42,74,0.3) 100%);
    z-index: 1;
}
.cs-hero-content {
    position: relative;
    z-index: 2;
    max-width: 1200px;
    margin: 0 auto;
    width: 100%;
}
.cs-hero-label {
    font-size: 13px;
    letter-spacing: 3px;
    color: var(--c-primary-light);
    font-weight: 600;
    margin-bottom: 18px;
}
.cs-hero h1 {
    font-size: 52px;
    font-weight: 800;
    line-height: 1.1;
    margin: 0 0 20px;
}
.cs-hero p {
    font-size: 16px;
    color: #cbd5e1;
    line-height: 1.6;
    max-width: 620px;
    margin: 0;
}

/* Filter */
.cs-filter {
    background: #fff;
    border-bottom: 1px solid var(--c-border);
    position: sticky;
    top: 68px;
    z-index: 100;
}
.cs-filter-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    justify-content: center;
}
.cs-filter-btn {
    background: #f1f5f9;
    color: #334155;
    border: 1px solid var(--c-border);
    padding: 10px 22px;
    border-radius: 30px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.25s;
}
.cs-filter-btn:hover {
    background: #e0f2fe;
    border-color: var(--c-primary-light);
    color: #0284c7;
}
.cs-filter-btn.active {
    background: var(--c-primary);
    color: #fff;
    border-color: var(--c-primary);
}

/* Case Grid */
.cs-grid-section {
    padding: 60px 20px 80px;
    background: var(--c-bg-soft);
}
.cs-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}
.cs-card {
    background: #fff;
    border: 1px solid var(--c-border);
    border-radius: 14px;
    overflow: hidden;
    transition: transform 0.3s, box-shadow 0.3s, border-color 0.3s;
    display: flex;
    flex-direction: column;
}
.cs-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 20px 40px -16px rgba(15,42,74,0.18);
    border-color: var(--c-primary);
}
.cs-img {
    position: relative;
    width: 100%;
    height: 280px;
    overflow: hidden;
    background: #f1f5f9;
}
.cs-img img {
    width: 100%; height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}
.cs-card:hover .cs-img img { transform: scale(1.05); }
.cs-tag {
    position: absolute;
    top: 16px; left: 16px;
    background: var(--c-primary);
    color: #fff;
    padding: 6px 14px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.5px;
}
.cs-info {
    padding: 28px 28px 30px;
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}
.cs-info h3 {
    font-size: 20px;
    font-weight: 700;
    color: var(--c-dark);
    margin: 0 0 12px;
    line-height: 1.4;
}
.cs-info p {
    font-size: 14px;
    color: var(--c-text-muted);
    line-height: 1.6;
    margin: 0 0 18px;
    flex-grow: 1;
}
.cs-meta {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    font-size: 12px;
    color: #94a3b8;
    padding-top: 16px;
    border-top: 1px solid #f1f5f9;
    margin-bottom: 16px;
}
.cs-link {
    color: var(--c-primary);
    text-decoration: none;
    font-weight: 600;
    font-size: 14px;
    align-self: flex-start;
    transition: color 0.2s;
}
.cs-link:hover { color: var(--c-primary-hover); }

/* CTA */
.cs-cta {
    padding: 80px 20px;
    background: linear-gradient(135deg, #0a2540 0%, #1e3c72 100%);
    color: #fff;
    text-align: center;
}
.cs-cta h2 {
    font-size: 36px;
    font-weight: 800;
    margin: 0 0 16px;
}
.cs-cta p {
    font-size: 16px;
    color: #cbd5e1;
    margin: 0 auto 30px;
    max-width: 620px;
    line-height: 1.6;
}
.cs-cta-btn {
    display: inline-block;
    background: var(--c-primary);
    color: #fff;
    padding: 14px 32px;
    border-radius: 6px;
    text-decoration: none;
    font-size: 15px;
    font-weight: 600;
    transition: background 0.2s;
}
.cs-cta-btn:hover { background: var(--c-primary-hover); }

/* Responsive */
@media (max-width: 900px) {
    .cs-hero h1 { font-size: 38px; }
    .cs-grid { grid-template-columns: 1fr; gap: 24px; }
    .cs-filter { position: static; }
}
@media (max-width: 600px) {
    .cs-hero { min-height: 320px; padding: 60px 20px; }
    .cs-hero h1 { font-size: 28px; }
    .cs-hero p { font-size: 14px; }
    .cs-filter-inner { justify-content: flex-start; overflow-x: auto; flex-wrap: nowrap; padding: 16px 20px; }
    .cs-filter-btn { flex-shrink: 0; }
    .cs-info { padding: 22px; }
    .cs-info h3 { font-size: 17px; }
    .cs-cta h2 { font-size: 26px; }
}