/* 夏日留言板 v3 - 留言卡片、左滑删除、图片网格、底部操作栏、加载态 */
/* ==================== 留言卡片 ==================== */
.message-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 16px;
    box-shadow: var(--shadow-card);
    animation: cardSpringIn 0.5s var(--transition-spring);
    transition: transform 0.2s, box-shadow 0.2s;
    /* 【优化】跳过视口外卡片的渲染与布局计算，留言数多时滚动更流畅。
       contain-intrinsic-size 给浏览器一个估算高度，避免滚动条抖动。 */
    content-visibility: auto;
    contain-intrinsic-size: 0 120px;
}

.message-card:active {
    transform: scale(0.985);
}

@keyframes cardSpringIn {
    from {
        opacity: 0;
        transform: translateY(-20px) scale(0.96);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.message-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
    position: relative;
}

.message-author {
    display: flex;
    align-items: center;
    gap: 10px;
    position: relative;
}

.author-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    font-weight: 700;
    color: white;
    flex-shrink: 0;
    box-shadow: 0 3px 10px rgba(0,0,0,0.08);
    /* 用自定义属性而非后代选择器取色，避免嵌套回复时跨卡片匹配导致源码顺序决定颜色 */
    background: linear-gradient(135deg,
        var(--avatar-from, var(--mdb-primary)),
        var(--avatar-to, var(--mdb-dark)));
}

.message-card[data-author="MDB"] {
    --avatar-from: var(--mdb-primary);
    --avatar-to: var(--mdb-dark);
}

.message-card[data-author="FJD"] {
    --avatar-from: var(--fjd-primary);
    --avatar-to: var(--fjd-dark);
}

.author-info {
    display: flex;
    flex-direction: column;
    gap: 1px;
}

/* 删除按钮 - 右上č§?*/
.btn-delete {
    position: absolute;
    top: 0;
    right: 0;
    width: 22px;
    height: 22px;
    border: none;
    background: rgba(239, 68, 68, 0.08);
    border-radius: 50%;
    color: #EF4444;
    font-size: 16px;
    line-height: 1;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
    padding: 0;
    flex-shrink: 0;
    z-index: 10;
}

/* 触摸热区扩到 44×44（Apple HIG 最小建议值），视觉尺寸仍是 22px。
   用透明 ::before 撑开而非改 width/height，避免影响布局。（第 13 条） */
.btn-delete::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 44px;
    height: 44px;
    /* 不设背景，纯粹扩大可点区域 */
}

.btn-delete:active {
    background: #EF4444;
    color: white;
    transform: scale(0.85);
}

.author-name {
    font-size: 17px;
    font-weight: 700;
    color: var(--text-primary);
}

.message-time {
    font-size: 13px;
    color: var(--text-tertiary);
    font-weight: 500;
}

.message-content {
    font-size: 17px;
    line-height: 1.7;
    color: var(--text-secondary);
    margin-bottom: 12px;
    word-wrap: break-word;
    white-space: pre-wrap;
}

/* ==================== 左滑删除 ==================== */
.message-card.deleting {
    background: #EF4444 !important;
}

.message-card.deleting .message-header,
.message-card.deleting .message-content,
.message-card.deleting .message-images,
.message-card.deleting .message-footer {
    opacity: 0;
}

.message-card.deleting::after {
    content: '删除';
    position: absolute;
    right: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: white;
    font-size: 14px;
    font-weight: 600;
    pointer-events: none;
}

/* 撤销删除 Toast */
.toast.undo-delete-toast {
    display: flex !important;
    align-items: center;
    gap: 12px;
    padding: 12px 20px;
    background: rgba(45, 52, 54, 0.92);
    white-space: normal;
}

.toast.undo-delete-toast .undo-btn {
    padding: 6px 14px;
    background: rgba(255, 255, 255, 0.15);
    border: none;
    border-radius: var(--radius-pill);
    color: white;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
    margin-left: 8px;
}

.toast.undo-delete-toast .undo-btn:active {
    background: rgba(255, 255, 255, 0.25);
}

/* ==================== 图片网格 ==================== */
.message-images {
    margin-bottom: 12px;
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: inset 0 0 0 1px rgba(13, 43, 62, 0.05);
}

.images-grid {
    display: grid;
    gap: 3px;
    background: rgba(13, 43, 62, 0.04);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.grid-cell {
    position: relative;
    overflow: hidden;
    background: var(--bg-secondary);
    cursor: pointer;
    -webkit-tap-highlight-color: transparent;
}

.grid-cell:active {
    transform: scale(0.985);
}

.grid-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    opacity: 0;
    transform: scale(1.04);
    transition: opacity 0.5s ease, transform 0.6s cubic-bezier(0.22, 1, 0.36, 1);
}

.grid-img.loaded {
    opacity: 1;
    transform: scale(1);
}

.more-overlay {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(13, 43, 62, 0.5);
    backdrop-filter: blur(2px);
    color: #fff;
    font-size: 22px;
    font-weight: 700;
    letter-spacing: 0.5px;
    pointer-events: none;
}

/* 1 张图 - 保持原比例完整显ç¤?*/
.images-grid.count-1 {
    grid-template-columns: 1fr;
    background: transparent;
}

.images-grid.count-1 .grid-cell {
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
}

.images-grid.count-1 .grid-img {
    height: auto;
    max-height: 460px;
    object-fit: contain;
}

.images-grid.count-2 {
    grid-template-columns: 1fr 1fr;
}

.images-grid.count-2 .grid-cell {
    aspect-ratio: 1;
}

.images-grid.count-3 {
    grid-template-columns: 1fr 1fr;
}

.images-grid.count-3 .grid-cell:nth-child(1) {
    grid-column: 1 / -1;
    aspect-ratio: 16 / 9;
}

.images-grid.count-3 .grid-cell:nth-child(2),
.images-grid.count-3 .grid-cell:nth-child(3) {
    aspect-ratio: 1;
}

.images-grid.count-4 {
    grid-template-columns: 1fr 1fr;
}

.images-grid.count-4 .grid-cell {
    aspect-ratio: 1;
}

.images-grid.count-5 {
    grid-template-columns: repeat(6, 1fr);
}

.images-grid.count-5 .grid-cell:nth-child(1),
.images-grid.count-5 .grid-cell:nth-child(2) {
    grid-column: span 3;
    aspect-ratio: 16 / 10;
}

.images-grid.count-5 .grid-cell:nth-child(3),
.images-grid.count-5 .grid-cell:nth-child(4),
.images-grid.count-5 .grid-cell:nth-child(5) {
    grid-column: span 2;
    aspect-ratio: 1;
}

.images-grid.count-6 {
    grid-template-columns: repeat(3, 1fr);
}

.images-grid.count-6 .grid-cell {
    aspect-ratio: 1;
}

/* PC 端适配 */
@media (min-width: 768px) {
    .images-grid {
        gap: 4px;
    }

    .images-grid.count-1 .grid-img {
        max-height: 620px;
    }

    /* 2 张图 */
    .images-grid.count-2 img {
        aspect-ratio: 1;
    }

    /* 3 张图 */
    .images-grid.count-3 img:nth-child(1) {
        aspect-ratio: 16 / 9;
    }

    .images-grid.count-3 img:nth-child(2),
    .images-grid.count-3 img:nth-child(3) {
        aspect-ratio: 1;
    }

    /* 4 张图 */
    .images-grid.count-4 img {
        aspect-ratio: 1;
    }

    /* 5 张图 */
    .images-grid.count-5 img:nth-child(1),
    .images-grid.count-5 img:nth-child(2) {
        aspect-ratio: 16 / 10;
    }

    .images-grid.count-5 img:nth-child(3),
    .images-grid.count-5 img:nth-child(4),
    .images-grid.count-5 img:nth-child(5) {
        aspect-ratio: 1;
    }

    /* 6 张图 */
    .images-grid.count-6 img {
        aspect-ratio: 1;
    }
}

/* ==================== 留言底部操作ć ?==================== */
.message-footer {
    display: flex;
    justify-content: flex-end;
    gap: 8px;
    padding-top: 10px;
    border-top: 1px solid rgba(0,0,0,0.04);
    flex-wrap: wrap;
}

/* 回复卡的操作栏不换行：窄宽下按钮文案宁可截断，也别把「回复」拆成两行 */
.message-card-reply .message-footer {
    flex-wrap: nowrap;
    min-width: 0;
}

.message-card-reply .btn-reply,
.message-card-reply .btn-like {
    flex-shrink: 0;
    white-space: nowrap;
}

.message-card-reply .btn-reply span {
    max-width: 72px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.btn-like {
    display: flex;
    align-items: center;
    gap: 5px;
    padding: 8px 16px;
    background: rgba(0,0,0,0.02);
    border: 1px solid rgba(0,0,0,0.04);
    border-radius: var(--radius-pill);
    color: var(--text-tertiary);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    position: relative;
    overflow: visible;
}

.btn-like:active {
    transform: scale(0.95);
}

.btn-like.liked {
    background: rgba(255, 138, 101, 0.12);
    border-color: rgba(255, 138, 101, 0.3);
    color: var(--fjd-dark);
}

.like-icon {
    font-size: 15px;
    transition: transform 0.3s var(--transition-spring);
}

.btn-like.liked .like-icon {
    animation: heartPop 0.4s var(--transition-spring);
}

@keyframes heartPop {
    0% { transform: scale(1); }
    40% { transform: scale(1.5); }
    70% { transform: scale(1.2); }
    100% { transform: scale(1); }
}

/* 点赞粒子容器 */
.particle {
    position: absolute;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    pointer-events: none;
    animation: particleBurst 0.6s ease-out forwards;
}

@keyframes particleBurst {
    0% {
        opacity: 1;
        transform: translate(0, 0) scale(1);
    }
    100% {
        opacity: 0;
        transform: translate(var(--tx), var(--ty)) scale(0.3);
    }
}


/* ==================== 加载状ć€?==================== */
.load-more {
    text-align: center;
    margin-top: 20px;
}

/* ==================== 嵌套回复 ==================== */
/* 回复容器：时间轴式引导线，每条回复在线上有独立节点 */
/* 深度上限为 2，depth=2 的回复不再产生更深的容器（子孙会被拍平成它的兄弟），
   所以缩进最多累加两级，不会无界增长 */
.message-replies {
    position: relative;
    margin-top: 14px;
    padding-left: 20px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

/* 主引导线：贯穿到最后一条回复中部再淡出 */
.message-replies::before {
    content: '';
    position: absolute;
    left: 4px;
    top: 3px;
    bottom: 18px;
    width: 2px;
    border-radius: 2px;
    background: linear-gradient(180deg,
        var(--reply-line, rgba(77, 208, 225, 0.5)) 0%,
        var(--reply-line, rgba(77, 208, 225, 0.5)) 82%,
        transparent 100%);
}

/* 起点节点：带双层光晕，强化“从父留言分支出来” */
.message-replies::after {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--reply-dot, var(--mdb-primary));
    box-shadow: 0 0 0 3px var(--bg-card),
                0 0 0 5px var(--reply-glow, rgba(77, 208, 225, 0.16));
}

/* 回复卡片：实色底 + 内描边，明确区分于父卡片的纯白 */
.message-card-reply {
    position: relative;
    background: var(--reply-bg, #F5FDFE);
    padding: 11px 13px;
    border-radius: 14px;
    border: 1px solid var(--reply-border, rgba(77, 208, 225, 0.18));
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.45);
    animation: replySlideIn 0.42s var(--transition-spring);
}

/* 每张回复卡向左伸一小段横支线，接到主引导线上 */
.message-card-reply::before {
    content: '';
    position: absolute;
    left: -10px;
    top: 21px;
    width: 9px;
    height: 2px;
    border-radius: 1px;
    background: var(--reply-line, rgba(77, 208, 225, 0.5));
    opacity: 0.75;
}

/* 回复卡片从左侧滑入，区别于父卡片的弹入 */
@keyframes replySlideIn {
    from {
        opacity: 0;
        transform: translateX(-10px) scale(0.98);
    }
    to {
        opacity: 1;
        transform: translateX(0) scale(1);
    }
}

/* 按发言人着色：一眼看出是谁在回复。
   改用不透明实色，避免嵌套时叠加变深。色值约等于白底叠 0.10 alpha 的角色色，
   比原 0.16 浅一档，配合头像、边框、引导线仍可清晰区分角色。 */
.message-card-reply[data-author="MDB"] {
    --reply-bg: #EDFAFC;
    --reply-border: rgba(77, 208, 225, 0.24);
}

.message-card-reply[data-author="FJD"] {
    --reply-bg: #FFF4F1;
    --reply-border: rgba(255, 138, 101, 0.24);
}

/* 容器引导线与节点跟随第一条回复的作者取色。
   两个角色都显式声明，不依赖 var() 兜底值，避免「兜底恰好等于某角色色」
   这种看似正确、实则没按角色取色的假象。 */
.message-replies:has(> .message-card-reply[data-author="MDB"]:first-child) {
    --reply-line: rgba(77, 208, 225, 0.5);
    --reply-dot: var(--mdb-primary);
    --reply-glow: rgba(77, 208, 225, 0.16);
}

.message-replies:has(> .message-card-reply[data-author="FJD"]:first-child) {
    --reply-line: rgba(255, 138, 101, 0.5);
    --reply-dot: var(--fjd-primary);
    --reply-glow: rgba(255, 138, 101, 0.16);
}

/* 头部压缩：昵称与时间同行，短回复不再撑成三行 */
.message-card-reply .message-header {
    padding-bottom: 0;
    margin-bottom: 7px;
}

.message-card-reply .author-info {
    flex-direction: row;
    align-items: baseline;
    gap: 7px;
}

.message-card-reply .author-avatar {
    width: 26px;
    height: 26px;
    font-size: 11px;
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.1),
                0 0 0 2px var(--bg-card);
}

.message-card-reply .message-author {
    gap: 8px;
}

.message-card-reply .author-name {
    font-size: 14px;
}

.message-card-reply .message-time {
    font-size: 11.5px;
    font-weight: 500;
    opacity: 0.75;
}

.message-card-reply .message-content {
    font-size: 15px;
    line-height: 1.6;
    margin-bottom: 0;
    padding-left: 34px;
}

/* footer 去掉分隔线，缩成轻量图标条 */
.message-card-reply .message-footer {
    padding-top: 8px;
    margin-top: 2px;
    border-top: none;
    gap: 6px;
}

/* 回复卡内按钮压到最小可点尺寸，不抢主卡片视觉 */
.message-card-reply .btn-like,
.message-card-reply .btn-reply {
    padding: 5px 11px;
    font-size: 12.5px;
    background: transparent;
    border-color: transparent;
}

.message-card-reply .btn-like:active,
.message-card-reply .btn-reply:active {
    background: rgba(0, 0, 0, 0.04);
}

.message-card-reply .reply-btn-icon {
    width: 14px;
    height: 14px;
}

.message-card-reply .like-icon {
    font-size: 13px;
}

/* 删除按钮缩小并降透明度，只在按下时显色 */
.message-card-reply .btn-delete {
    width: 18px;
    height: 18px;
    font-size: 13px;
    opacity: 0.45;
}

.message-card-reply .btn-delete:active {
    opacity: 1;
}

/* 深夜模式适配：底色加深、内高光反向为内阴影 */
html[data-theme="night"] .message-card-reply {
    --reply-bg: #15303E;
    --reply-border: rgba(255, 255, 255, 0.1);
    box-shadow: inset 0 -1px 0 rgba(0, 0, 0, 0.22);
}

html[data-theme="night"] .message-card-reply[data-author="MDB"] {
    --reply-bg: #0E3C4F;
    --reply-border: rgba(77, 208, 225, 0.28);
}

html[data-theme="night"] .message-card-reply[data-author="FJD"] {
    --reply-bg: #2B2028;
    --reply-border: rgba(255, 138, 101, 0.28);
}

html[data-theme="night"] .message-replies {
    --reply-line: rgba(77, 208, 225, 0.42);
    --reply-glow: rgba(77, 208, 225, 0.22);
}

html[data-theme="night"] .message-replies:has(> .message-card-reply[data-author="MDB"]:first-child) {
    --reply-line: rgba(77, 208, 225, 0.42);
    --reply-dot: var(--mdb-primary);
    --reply-glow: rgba(77, 208, 225, 0.22);
}

html[data-theme="night"] .message-replies:has(> .message-card-reply[data-author="FJD"]:first-child) {
    --reply-line: rgba(255, 138, 101, 0.42);
    --reply-dot: var(--fjd-primary);
    --reply-glow: rgba(255, 138, 101, 0.22);
}

html[data-theme="night"] .message-card-reply .btn-like:active,
html[data-theme="night"] .message-card-reply .btn-reply:active {
    background: rgba(255, 255, 255, 0.07);
}

/* 新回复插入后的短暂高亮：改用外发光而非整块变底色，观感更柔和 */
.message-card.just-replied {
    animation: justRepliedGlow 1.6s ease-out;
}

@keyframes justRepliedGlow {
    0%, 100% {
        box-shadow: 0 0 0 0 rgba(255, 241, 118, 0);
    }
    25% {
        box-shadow: 0 0 0 3px rgba(255, 241, 118, 0.55),
                    0 4px 18px rgba(255, 241, 118, 0.3);
    }
}

html[data-theme="night"] .message-card.just-replied {
    animation: justRepliedGlowNight 1.6s ease-out;
}

@keyframes justRepliedGlowNight {
    0%, 100% {
        box-shadow: 0 0 0 0 rgba(77, 208, 225, 0);
    }
    25% {
        box-shadow: 0 0 0 3px rgba(77, 208, 225, 0.5),
                    0 4px 18px rgba(77, 208, 225, 0.28);
    }
}

/* 降低动效偏好：关闭回复相关动画 */
@media (prefers-reduced-motion: reduce) {
    .message-card-reply {
        animation: none;
    }

    .message-card.just-replied {
        animation: none;
    }
}

.btn-load-more {
    padding: 12px 28px;
    background: var(--bg-card);
    border: 1px solid rgba(0,0,0,0.06);
    border-radius: var(--radius-pill);
    color: var(--text-secondary);
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    box-shadow: var(--shadow-soft);
}

.btn-load-more:active {
    background: var(--mdb-light);
    color: var(--mdb-dark);
    border-color: rgba(77, 208, 225, 0.2);
}

/* FJD 用户的加载更多按钮使用橘红色 */
body[data-identity="FJD"] .btn-load-more:active {
    background: var(--fjd-light);
    color: var(--fjd-dark);
    border-color: rgba(255, 138, 101, 0.2);
}

.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-tertiary);
}

.empty-icon {
    font-size: 64px;
    margin-bottom: 16px;
    opacity: 0.6;
}

.empty-text {
    font-size: 16px;
    font-weight: 500;
}