/* style.css — 一年级语文知识卡片样式 (完全自适应) */
/* 页面标题 - 自适应 */
.page-title {
    font-size: clamp(20px, 5vw, 32px);
    font-weight: 600;
    color: #3d2c1e;
    border-bottom: 4px solid #c9ab8b;
    padding-bottom: 6px;
    margin-bottom: 20px;
    letter-spacing: 2px;
    text-align: center;
    width: 100%;
    max-width: 600px;
}

/* 卡片网格 - 完全自适应 */
.card-grid {
    width: 100%;
    max-width: 1200px;
    display: grid;
    gap: 16px;
    /* 自动适应列数：最小200px，最大1fr */
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    /* 对于超大屏，限制最大列数避免过宽 */
    grid-auto-rows: auto;
}

/* ----- 卡片容器 (自适应高度) ----- */
.card-wrapper {
    perspective: 1200px;
    /* 高度自适应，由内容撑开，但设置最小高度 */
    min-height: 160px;
    height: auto;
    aspect-ratio: 4 / 3; /* 保持卡片比例 */
    cursor: pointer;
    max-width: 100%;
}

.card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transition: transform 0.5s ease;
    transform-style: preserve-3d;
    box-shadow: 0 6px 16px rgba(0,0,0,0.07);
}

.card-wrapper.flipped .card-inner {
    transform: rotateY(180deg);
}

/* ----- 卡片正反面 (使用flex撑开) ----- */
.card-front,
.card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    padding: 14px 12px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
    border: 1px solid #e7d9cc;
    overflow: hidden; /* 防止内容溢出 */
}

.card-front {
    background: #ffffff;
    color: #2b1f14;
}

.card-front .label {
    font-size: clamp(11px, 1.8vw, 14px);
    background: #5A8A6C;
    color: #ffffff;
    padding: 2px 14px;
    border-radius: 40px;
    margin-bottom: 6px;
    letter-spacing: 1px;
    font-weight: 500;
    white-space: nowrap;
}

.card-front .question {
    font-size: clamp(15px, 2.6vw, 22px);
    font-weight: 600;
    line-height: 1.4;
    word-break: break-word;
    max-width: 100%;
}

.card-front .hint {
    font-size: clamp(11px, 1.4vw, 14px);
    color: #8a7a68;
    margin-top: 8px;
    border-top: 1px dashed #ddd2c4;
    padding-top: 8px;
    width: 85%;
}

.card-back {
    background: #F0FFF0;
    transform: rotateY(180deg);
    border-left: 6px solid #5A8A6C;
    color: #1f160f;
}

.card-back .answer-label {
    font-size: clamp(10px, 1.4vw, 13px);
    color: #5A8A6C;
    letter-spacing: 2px;
    margin-bottom: 4px;
    font-weight: 500;
}

.card-back .answer {
    font-size: clamp(14px, 2.4vw, 20px);
    font-weight: 500;
    line-height: 1.5;
    word-break: break-word;
    max-width: 100%;
}

.card-back .extra {
    font-size: clamp(11px, 1.6vw, 15px);
    color: #ffffff;
    margin-top: 6px;
    background: #5A8A6C;
    padding: 3px 14px;
    border-radius: 30px;
    display: inline-block;
    max-width: 90%;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* ----- 分类颜色标记 (保持清晰) ----- */
.card-wrapper[data-type="pinyin"] .card-front { border-top: 5px solid #b0c4b0; }
.card-wrapper[data-type="poem"] .card-front { border-top: 5px solid #dbb8a0; }
.card-wrapper[data-type="idiom"] .card-front { border-top: 5px solid #c0b3a0; }
.card-wrapper[data-type="text"] .card-front { border-top: 5px solid #9fb7c9; }
.card-wrapper[data-type="writing"] .card-front { border-top: 5px solid #c9b1a0; }
.card-wrapper[data-type="radical"] .card-front { border-top: 5px solid #b8a9b0; }
.card-wrapper[data-type="oral"] .card-front { border-top: 5px solid #b5b8a0; }
.card-wrapper[data-type="wisdom"] .card-front { border-top: 5px solid #c0a88a; }

/* ----- 底部注释 ----- */
.footer-note {
    text-align: center;
    letter-spacing: 0.5px;
}

/* ============================================================
   响应式断点 - 精细控制
   ============================================================ */

/* 超小屏手机 (宽度 < 400px) */
@media (max-width: 399px) {
    body { padding: 10px 8px; }
    .card-grid { gap: 10px; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); }
    .card-wrapper { min-height: 130px; aspect-ratio: 3 / 2; }
    .card-front, .card-back { padding: 10px 8px; }
    .card-front .question { font-size: 14px; }
    .card-back .answer { font-size: 13px; }
    .card-back .extra { font-size: 10px; padding: 2px 10px; white-space: normal; }
    .card-front .label { font-size: 10px; padding: 1px 10px; }
    .card-front .hint { font-size: 10px; }
}

/* 小屏手机 (400px - 600px) */
@media (min-width: 400px) and (max-width: 600px) {
    .card-grid { gap: 12px; grid-template-columns: repeat(auto-fill, minmax(165px, 1fr)); }
    .card-wrapper { min-height: 145px; aspect-ratio: 4 / 3; }
    .card-front .question { font-size: 16px; }
    .card-back .answer { font-size: 15px; }
    .card-front, .card-back { padding: 12px 10px; }
}

/* 中屏手机/小平板 (600px - 900px) */
@media (min-width: 601px) and (max-width: 900px) {
    .card-grid { gap: 16px; grid-template-columns: repeat(auto-fill, minmax(190px, 1fr)); }
    .card-wrapper { min-height: 165px; aspect-ratio: 4 / 3; }
    .card-front .question { font-size: 18px; }
    .card-back .answer { font-size: 17px; }
}

/* 平板/小笔记本 (900px - 1200px) */
@media (min-width: 901px) and (max-width: 1200px) {
    .card-grid { gap: 20px; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); }
    .card-wrapper { min-height: 175px; aspect-ratio: 4 / 3; }
    .card-front .question { font-size: 19px; }
    .card-back .answer { font-size: 18px; }
}

/* 大屏桌面 (1200px以上) */
@media (min-width: 1201px) {
    .card-grid { gap: 24px; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); }
    .card-wrapper { min-height: 185px; aspect-ratio: 4 / 3; }
    .card-front .question { font-size: 21px; }
    .card-back .answer { font-size: 20px; }
}

/* ============================================================
   超宽屏优化 (限制最大宽度，保持美观)
   ============================================================ */
@media (min-width: 1600px) {
    .card-grid {
        max-width: 1400px;
        gap: 28px;
        grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    }
    .card-wrapper { min-height: 200px; }
}

/* ============================================================
   横屏手机优化
   ============================================================ */
@media (max-width: 900px) and (orientation: landscape) {
    .card-grid { grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); }
    .card-wrapper { min-height: 150px; aspect-ratio: 4 / 3; }
    .card-front .question { font-size: 16px; }
    .card-back .answer { font-size: 15px; }
}

/* ============================================================
   打印样式 (保留卡片可读性)
   ============================================================ */
@media print {
    .card-wrapper { break-inside: avoid; page-break-inside: avoid; }
    .card-front, .card-back { border: 1px solid #ccc; box-shadow: none; }
    .card-wrapper.flipped .card-inner { transform: none; }
    .card-back { display: block; }
    .footer-note { display: none; }
}