/* =====================================================================
 * knowledge.css — 知識中心（BenQ 風，走前台黑白哲學）
 * 重點：卡片固定高度 / 列對齊，根治參考頁「標籤數不一 → 高度參差」排版問題。
 * ===================================================================== */

.kc-page {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* ---------- Hero ---------- */
.kc-hero {
    text-align: center;
    padding: clamp(2.5rem, 6vw, 4.5rem) 1rem 2rem;
}
.kc-hero__title {
    font-size: var(--benq-h1, clamp(2.25rem, 4vw, 3rem));
    font-weight: 800;
    color: var(--benq-black, #111827);
    letter-spacing: -0.02em;
    margin-bottom: .75rem;
}
.kc-hero__subtitle {
    font-size: var(--benq-lede-size, clamp(1rem, 1.4vw, 1.25rem));
    color: var(--benq-text-soft, #6B7280);
    max-width: 640px;
    margin: 0 auto 2rem;
    line-height: 1.7;
}

/* 搜尋框 */
.kc-search {
    max-width: 680px;
    margin: 0 auto;
    position: relative;
}
.kc-search__input {
    width: 100%;
    height: 56px;
    padding: 0 3rem 0 3.25rem;
    border: 1.5px solid var(--benq-border, #E5E7EB);
    border-radius: 999px;
    font-size: 1rem;
    transition: border-color var(--benq-transition-fast, .1s);
}
.kc-search__input:focus {
    outline: none;
    border-color: var(--benq-pri, #7231C6);
    box-shadow: 0 0 0 3px rgba(114, 49, 198, .12);
}
.kc-search__icon {
    position: absolute;
    left: 1.25rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--benq-text-soft, #6B7280);
    pointer-events: none;
}

/* ---------- 主題標籤 pills ---------- */
.kc-topics {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: .6rem;
    max-width: 760px;
    margin: 1.75rem auto 0;
}
.kc-topic {
    display: inline-block;
    padding: .5rem 1.1rem;
    border: 1.5px solid var(--benq-border, #E5E7EB);
    border-radius: 999px;
    font-size: .95rem;
    font-weight: 600;
    color: var(--benq-text, #111827);
    text-decoration: none;
    background: #fff;
    transition: all var(--benq-transition-fast, .1s);
}
.kc-topic:hover {
    border-color: var(--benq-pri, #7231C6);
    color: var(--benq-pri, #7231C6);
}
.kc-topic.is-active {
    background: var(--benq-black, #111827);
    border-color: var(--benq-black, #111827);
    color: #fff;
}

/* ---------- Section 標題 ---------- */
.kc-section {
    margin: clamp(2.5rem, 6vw, 4rem) 0;
}
.kc-section__head {
    display: flex;
    align-items: baseline;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
    position: relative;
}
.kc-section__title {
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 800;
    color: var(--benq-black, #111827);
    text-align: center;
}
.kc-section__more {
    font-size: .95rem;
    font-weight: 600;
    color: var(--benq-pri, #7231C6);
    text-decoration: none;
    white-space: nowrap;
}
.kc-section__more:hover { color: var(--benq-pri-dark, #5B21B6); }

/* ---------- Featured 大卡 ---------- */
.kc-featured {
    display: block;
    text-decoration: none;
    color: inherit;
    margin-bottom: 2rem;
}
.kc-featured__media {
    aspect-ratio: 16 / 7;
    overflow: hidden;
    border-radius: var(--benq-radius-media, 24px);
    background: var(--benq-surface-gray, #F2F2F2);
}
.kc-featured__media img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform .4s ease;
}
.kc-featured:hover .kc-featured__media img { transform: scale(1.03); }
.kc-featured__date {
    text-align: center;
    color: var(--benq-text-soft, #6B7280);
    font-size: .9rem;
    margin: 1.25rem 0 .5rem;
}
.kc-featured__title {
    text-align: center;
    font-size: clamp(1.35rem, 2.4vw, 1.9rem);
    font-weight: 700;
    color: var(--benq-black, #111827);
    line-height: 1.4;
    max-width: 820px;
    margin: 0 auto .75rem;
    /* 固定 2 行，避免長短不一影響版面 */
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* ---------- 卡片網格（equal-height，避排版問題核心）---------- */
.kc-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.75rem 1.5rem;
    align-items: stretch; /* 每列卡片等高 */
}
@media (max-width: 1100px) { .kc-grid { grid-template-columns: repeat(3, 1fr); } }
@media (max-width: 820px)  { .kc-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 520px)  { .kc-grid { grid-template-columns: 1fr; } }

.kc-card {
    display: flex;
    flex-direction: column;
    height: 100%;
    text-decoration: none;
    color: inherit;
}
.kc-card__media {
    aspect-ratio: 16 / 9;           /* 圖固定比例 */
    overflow: hidden;
    border-radius: var(--benq-radius, 12px);
    background: var(--benq-surface-gray, #F2F2F2);
}
.kc-card__media img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform .3s ease;
}
.kc-card:hover .kc-card__media img { transform: scale(1.04); }

.kc-card__body {
    display: flex;
    flex-direction: column;
    padding-top: .9rem;
    flex: 1;
}
.kc-card__date {
    color: var(--benq-text-soft, #6B7280);
    font-size: .82rem;
    margin-bottom: .4rem;
}
.kc-card__title {
    font-size: 1.02rem;
    font-weight: 700;
    color: var(--benq-black, #111827);
    line-height: 1.45;
    margin: 0 0 .6rem;
    /* 固定 2 行高：長標題截斷、短標題佔位，確保各卡標題區等高 */
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    min-height: 2.9em;
}
.kc-card:hover .kc-card__title { color: var(--benq-pri, #7231C6); }

/* 標籤區：固定單行高度 + 隱藏溢出 → 標籤數不一也不撐高卡片 */
.kc-card__tags {
    display: flex;
    flex-wrap: wrap;
    gap: .35rem;
    margin-top: auto;
    height: 1.75rem;
    overflow: hidden;
}
.kc-tag {
    display: inline-block;
    padding: .18rem .6rem;
    border: 1px solid var(--benq-border, #E5E7EB);
    border-radius: 999px;
    font-size: .72rem;
    color: var(--benq-text-soft, #6B7280);
    white-space: nowrap;
    line-height: 1.2;
}

/* ---------- 空狀態 ---------- */
.kc-empty {
    text-align: center;
    color: var(--benq-text-soft, #6B7280);
    padding: 4rem 1rem;
}

/* ---------- 文章詳情 ---------- */
.kc-article {
    max-width: 820px;
    margin: 0 auto;
    padding: clamp(2rem, 5vw, 3.5rem) 1rem;
}
.kc-article__cover {
    aspect-ratio: 16 / 8;
    overflow: hidden;
    border-radius: var(--benq-radius-media, 24px);
    margin-bottom: 2rem;
    background: var(--benq-surface-gray, #F2F2F2);
}
.kc-article__cover img { width: 100%; height: 100%; object-fit: cover; }
.kc-article__meta {
    color: var(--benq-text-soft, #6B7280);
    font-size: .9rem;
    text-align: center;
    margin-bottom: .75rem;
}
.kc-article__title {
    font-size: clamp(1.75rem, 3.5vw, 2.5rem);
    font-weight: 800;
    color: var(--benq-black, #111827);
    text-align: center;
    line-height: 1.35;
    margin-bottom: 1.25rem;
}
.kc-article__tags {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: .5rem;
    margin-bottom: 2.5rem;
}
.kc-article__body {
    font-size: 1.05rem;
    line-height: 1.9;
    color: var(--benq-text, #111827);
}
.kc-article__body img { max-width: 100%; height: auto; border-radius: var(--benq-radius, 12px); }
.kc-article__back {
    display: inline-flex;
    align-items: center;
    gap: .4rem;
    margin-top: 2.5rem;
    color: var(--benq-pri, #7231C6);
    text-decoration: none;
    font-weight: 600;
}
.kc-article__back:hover { color: var(--benq-pri-dark, #5B21B6); }