/**
 * 研修课程（Advanced Courses · 文章卡片）
 * 对应源码 Luckilyring.html「研 修 课 程」区块
 */

.gt-serif {
    font-family: 'Noto Serif SC', serif;
}

/* 外层区块（全宽浅灰背景） */
.gt-ac {
    background: #f9fafb; /* bg-gray-50 */
    padding: 4rem 0; /* 手机 py-16 */
    width: 100%;
}

@media (min-width: 768px) {
    .gt-ac {
        padding: 6rem 0; /* md:py-24 */
    }
}

/* 内容宽度限制 */
.gt-ac-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 1rem;
}

@media (min-width: 768px) {
    .gt-ac-container {
        padding: 0;
    }
}

/* 标题 */
.gt-ac-head {
    text-align: center;
    margin-bottom: 4rem; /* mb-16 */
}

.gt-ac-title {
    font-family: 'Noto Serif SC', serif;
    color: #000;
    font-size: 1.5rem; /* text-2xl */
    line-height: 2rem;
    letter-spacing: 0.4em; /* tracking-[0.4em] */
    margin: 0;
    font-weight: 500;
}

@media (min-width: 768px) {
    .gt-ac-title {
        font-size: 1.875rem; /* md:text-3xl */
        line-height: 2.25rem;
    }
}

.gt-ac-divider {
    width: 2rem;
    height: 1px;
    background: #9ca3af;
    margin: 1.5rem auto 0;
}

/* 网格 */
.gt-ac-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}

@media (min-width: 768px) {
    .gt-ac-grid.cols-2 { grid-template-columns: repeat(2, 1fr); }
    .gt-ac-grid.cols-3 { grid-template-columns: repeat(3, 1fr); }
    .gt-ac-grid.cols-4 { grid-template-columns: repeat(4, 1fr); }
}

/* 单卡片 */
.gt-ac-card {
    display: flex;
    flex-direction: column;
    background: #fff;
    border: 1px solid #e5e7eb;
    transition: box-shadow 0.3s ease;
    overflow: hidden;
    cursor: pointer;
}

.gt-ac-card:hover {
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
}

/* 图片区 */
.gt-ac-card-img {
    display: block;
    aspect-ratio: 4 / 3;
    background: #f3f4f6;
    position: relative;
    overflow: hidden;
}

.gt-ac-card-img img {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.7s ease;
}

.gt-ac-card:hover .gt-ac-card-img img {
    transform: scale(1.05);
}

/* 文字区 */
.gt-ac-card-body {
    padding: 2rem; /* p-8 */
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    gap: 2rem;
}

.gt-ac-card-title {
    font-family: 'Noto Serif SC', serif;
    font-size: 1.25rem; /* text-xl */
    line-height: 1.75rem;
    color: #000;
    letter-spacing: 0.15em;
    margin: 0 0 1rem;
    font-weight: 500;
}

.gt-ac-card-title a {
    color: inherit;
    text-decoration: none;
}

.gt-ac-card-title a:hover {
    color: #4b5563;
}

.gt-ac-card-desc {
    color: #6b7280;
    font-size: 0.875rem;
    line-height: 1.625;
    letter-spacing: 0.025em;
    margin: 0;
    text-align: justify;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* 「探索内容 →」按钮 */
.gt-ac-card-cta {
    display: inline-block;
    width: max-content;
    color: #000;
    font-size: 0.75rem;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    text-decoration: none;
    padding-bottom: 0.25rem;
    border-bottom: 1px solid #000;
    transition: color 0.2s ease, border-color 0.2s ease;
}

.gt-ac-card-cta:hover {
    color: #6b7280;
    border-bottom-color: #6b7280;
}