/* ========================================
   生图平台 (Shengtu) - 核心样式
   Modern Minimalist with Dynamic Ambient Glow
   ======================================== */

:root {
    --bg: #FFFFFF;
    --bg-secondary: #F5F5F7;
    --text: #1D1D1F;
    --text-secondary: #86868B;
    --accent: #000000;
    --accent-text: #FFFFFF;
    --glass-bg: rgba(255,255,255,0.72);
    --glass-border: rgba(255,255,255,0.3);
    --shadow: 0 8px 32px rgba(0,0,0,0.08);
    --shadow-lg: 0 24px 80px rgba(0,0,0,0.12);
    --radius: 16px;
    --radius-sm: 10px;
    --radius-xs: 8px;
    --ambient-color: rgba(120,120,255,0.15);
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #121212;
        --bg-secondary: #1E1E1E;
        --text: #F5F5F7;
        --text-secondary: #86868B;
        --accent: #FFFFFF;
        --accent-text: #000000;
        --glass-bg: rgba(30,30,30,0.75);
        --glass-border: rgba(255,255,255,0.08);
        --shadow: 0 8px 32px rgba(0,0,0,0.3);
        --shadow-lg: 0 24px 80px rgba(0,0,0,0.5);
    }
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html {
    font-family: -apple-system, BlinkMacSystemFont, 'Inter', 'SF Pro Display',
                 'PingFang SC', 'Microsoft YaHei', sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    overflow-x: hidden;
    transition: background var(--transition);
}

/* 环境光背景 */
.ambient-glow {
    position: fixed;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    pointer-events: none;
    z-index: 0;
    opacity: 0.5;
    transition: background 2s ease;
    background: radial-gradient(ellipse at 30% 20%, var(--ambient-color), transparent 60%),
                radial-gradient(ellipse at 70% 80%, var(--ambient-color), transparent 60%);
}

@media (prefers-reduced-transparency: reduce) {
    .ambient-glow { display: none; }
}

/* ===== 顶部导航 ===== */
.nav-bar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 20px;
    background: transparent;
    transition: background var(--transition);
}

.nav-bar.scrolled {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--glass-border);
}

.nav-logo {
    font-size: 18px;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.3px;
}

.nav-actions {
    display: flex;
    gap: 8px;
}

.nav-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 14px;
    border: none;
    border-radius: 20px;
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    color: var(--text);
    font-size: 14px;
    cursor: pointer;
    transition: all var(--transition);
    border: 1px solid var(--glass-border);
}

.nav-btn:hover {
    transform: scale(1.03);
    box-shadow: var(--shadow);
}

.nav-btn svg {
    width: 18px;
    height: 18px;
}

/* ===== 瀑布流画廊 ===== */
.gallery-container {
    position: relative;
    z-index: 1;
    padding: 72px 12px 120px;
    max-width: 1600px;
    margin: 0 auto;
}

.masonry {
    column-count: 2;
    column-gap: 10px;
}

@media (min-width: 768px) {
    .gallery-container { padding: 72px 20px 120px; }
    .masonry { column-count: 3; column-gap: 14px; }
}

@media (min-width: 1024px) {
    .masonry { column-count: 4; column-gap: 16px; }
}

@media (min-width: 1440px) {
    .masonry { column-count: 5; column-gap: 16px; }
}

.masonry-item {
    break-inside: avoid;
    margin-bottom: 10px;
    border-radius: var(--radius-sm);
    overflow: hidden;
    position: relative;
    cursor: pointer;
    transition: transform var(--transition);
}

@media (min-width: 768px) {
    .masonry-item { margin-bottom: 14px; }
}

.masonry-item:hover {
    transform: scale(1.02);
}

.masonry-item img {
    width: 100%;
    display: block;
    border-radius: var(--radius-sm);
    background: var(--bg-secondary);
}

.masonry-item .overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 40px 12px 12px;
    background: linear-gradient(transparent, rgba(0,0,0,0.6));
    border-radius: 0 0 var(--radius-sm) var(--radius-sm);
    opacity: 0;
    transition: opacity var(--transition);
}

.masonry-item:hover .overlay {
    opacity: 1;
}

.overlay-text {
    color: #fff;
    font-size: 12px;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* 骨架屏 */
.skeleton {
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    animation: skeleton-pulse 1.5s infinite ease-in-out;
}

@keyframes skeleton-pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.4; }
}

/* ===== 底部创作按钮 ===== */
.fab-create {
    position: fixed;
    bottom: 28px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 200;
    padding: 14px 32px;
    border: none;
    border-radius: 50px;
    background: var(--accent);
    color: var(--accent-text);
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 4px 24px rgba(0,0,0,0.2);
    transition: all var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
    letter-spacing: 0.3px;
}

.fab-create:hover {
    transform: translateX(-50%) scale(1.05);
    box-shadow: 0 8px 40px rgba(0,0,0,0.3);
}

.fab-create:active {
    transform: translateX(-50%) scale(0.97);
}

/* ===== 底部抽屉 (Bottom Sheet) ===== */
.sheet-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.4);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    z-index: 300;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition);
}

.sheet-overlay.active {
    opacity: 1;
    pointer-events: auto;
}

.bottom-sheet {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 301;
    background: var(--glass-bg);
    backdrop-filter: blur(40px) saturate(180%);
    -webkit-backdrop-filter: blur(40px) saturate(180%);
    border-radius: 24px 24px 0 0;
    border-top: 1px solid var(--glass-border);
    padding: 12px 20px 34px;
    transform: translateY(100%);
    transition: transform 0.4s cubic-bezier(0.32, 0.72, 0, 1);
    max-height: 85vh;
    overflow-y: auto;
}

.bottom-sheet.active {
    transform: translateY(0);
}

@media (min-width: 768px) {
    .bottom-sheet {
        left: 50%;
        right: auto;
        transform: translateX(-50%) translateY(100%);
        max-width: 800px;
        width: 100%;
        border-radius: 24px 24px 0 0;
    }
    .bottom-sheet.active {
        transform: translateX(-50%) translateY(0);
    }
}

.sheet-handle {
    width: 36px;
    height: 4px;
    background: var(--text-secondary);
    opacity: 0.3;
    border-radius: 2px;
    margin: 0 auto 20px;
}

.sheet-title {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 16px;
    text-align: center;
}

/* 输入区域 */
.input-area {
    position: relative;
    display: flex;
    align-items: flex-end;
    gap: 10px;
    background: var(--bg-secondary);
    border-radius: var(--radius);
    padding: 10px;
    border: 2px solid transparent;
    transition: border-color var(--transition);
}

.input-area:focus-within {
    border-color: var(--accent);
}

.ref-preview {
    position: relative;
    width: 56px;
    height: 56px;
    border-radius: var(--radius-xs);
    overflow: hidden;
    flex-shrink: 0;
    display: none;
}

.ref-preview.visible {
    display: block;
}

.ref-preview img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.ref-preview .ref-remove {
    position: absolute;
    top: 2px;
    right: 2px;
    width: 20px;
    height: 20px;
    background: rgba(0,0,0,0.6);
    color: #fff;
    border: none;
    border-radius: 50%;
    font-size: 12px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    line-height: 1;
}

.upload-btn {
    width: 44px;
    height: 44px;
    border: none;
    border-radius: var(--radius-xs);
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    transition: color var(--transition);
}

.upload-btn:hover {
    color: var(--text);
}

.upload-btn svg {
    width: 22px;
    height: 22px;
}

.prompt-input {
    flex: 1;
    min-height: 44px;
    max-height: 120px;
    border: none;
    background: transparent;
    color: var(--text);
    font-size: 16px;
    line-height: 1.5;
    resize: none;
    outline: none;
    font-family: inherit;
    padding: 10px 0;
}

.prompt-input::placeholder {
    color: var(--text-secondary);
}

.send-btn {
    width: 44px;
    height: 44px;
    border: none;
    border-radius: 50%;
    background: var(--accent);
    color: var(--accent-text);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    transition: all var(--transition);
    opacity: 0.4;
    pointer-events: none;
}

.send-btn.ready {
    opacity: 1;
    pointer-events: auto;
}

.send-btn:hover {
    transform: scale(1.08);
}

.send-btn svg {
    width: 20px;
    height: 20px;
}

/* ===== 进度气泡 ===== */
.progress-bubble {
    position: fixed;
    z-index: 250;
    display: none;
    align-items: center;
    gap: 10px;
    padding: 10px 16px;
    border-radius: 50px;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    box-shadow: var(--shadow);
    cursor: pointer;
    transition: all var(--transition);
    animation: bubble-breathe 2s infinite ease-in-out;
}

/* 移动端顶部，桌面端右下 */
.progress-bubble {
    top: 72px;
    right: 16px;
}

@media (min-width: 768px) {
    .progress-bubble {
        top: auto;
        bottom: 100px;
        right: 32px;
    }
}

.progress-bubble.visible {
    display: flex;
}

.progress-bubble.completed {
    animation: none;
}

@keyframes bubble-breathe {
    0%, 100% { box-shadow: var(--shadow), 0 0 0 0 rgba(120,120,255,0.3); }
    50% { box-shadow: var(--shadow), 0 0 0 8px rgba(120,120,255,0); }
}

.bubble-spinner {
    width: 24px;
    height: 24px;
    border: 2.5px solid var(--text-secondary);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.bubble-thumb {
    width: 36px;
    height: 36px;
    border-radius: 8px;
    object-fit: cover;
    display: none;
}

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

/* ===== 详情弹窗 ===== */
.detail-modal {
    position: fixed;
    inset: 0;
    z-index: 400;
    display: none;
    background: rgba(0,0,0,0.6);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

.detail-modal.active {
    display: flex;
    align-items: flex-end;
    justify-content: center;
}

@media (min-width: 768px) {
    .detail-modal.active {
        align-items: center;
    }
}

.detail-panel {
    background: var(--bg);
    width: 100%;
    max-height: 92vh;
    border-radius: 24px 24px 0 0;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    animation: slide-up 0.4s cubic-bezier(0.32, 0.72, 0, 1);
}

@keyframes slide-up {
    from { transform: translateY(100%); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

@media (min-width: 768px) {
    .detail-panel {
        max-width: 1000px;
        max-height: 85vh;
        border-radius: var(--radius);
        flex-direction: row;
        animation: modal-pop 0.35s cubic-bezier(0.32, 0.72, 0, 1);
    }
    @keyframes modal-pop {
        from { transform: scale(0.92); opacity: 0; }
        to { transform: scale(1); opacity: 1; }
    }
}

.detail-image-section {
    flex-shrink: 0;
    background: #000;
    display: flex;
    align-items: center;
    justify-content: center;
    max-height: 45vh;
    overflow: hidden;
}

@media (min-width: 768px) {
    .detail-image-section {
        width: 60%;
        max-height: none;
    }
}

.detail-image-section img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.detail-timeline-section {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    min-height: 0;
}

.detail-close {
    position: absolute;
    top: 16px;
    right: 16px;
    width: 36px;
    height: 36px;
    border: none;
    border-radius: 50%;
    background: rgba(0,0,0,0.5);
    color: #fff;
    font-size: 18px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10;
    transition: all var(--transition);
}

.detail-close:hover {
    background: rgba(0,0,0,0.7);
    transform: scale(1.1);
}

/* 时间线气泡 */
.timeline {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.timeline-item {
    display: flex;
    gap: 10px;
    max-width: 90%;
}

.timeline-item.user {
    align-self: flex-end;
    flex-direction: row-reverse;
}

.timeline-avatar {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    flex-shrink: 0;
}

.timeline-bubble {
    padding: 10px 14px;
    border-radius: 16px;
    font-size: 14px;
    line-height: 1.5;
    word-break: break-word;
}

.timeline-item.user .timeline-bubble {
    background: var(--accent);
    color: var(--accent-text);
    border-bottom-right-radius: 4px;
}

.timeline-item.ai .timeline-bubble {
    background: var(--bg-secondary);
    color: var(--text);
    border-bottom-left-radius: 4px;
}

.timeline-bubble img {
    max-width: 200px;
    border-radius: var(--radius-xs);
    margin-top: 6px;
}

/* 时间线图片可点击引用 */
.timeline-img-clickable {
    cursor: pointer;
    transition: all var(--transition);
    border: 2px solid transparent;
}

.timeline-img-clickable:hover {
    border-color: var(--accent);
    opacity: 0.85;
    transform: scale(1.02);
}

.timeline-time {
    font-size: 11px;
    color: var(--text-secondary);
    margin-top: 4px;
    padding: 0 14px;
}

.timeline-item.user .timeline-time {
    text-align: right;
}

/* ===== 空状态 ===== */
.empty-state {
    text-align: center;
    padding: 80px 20px;
    color: var(--text-secondary);
}

.empty-state svg {
    width: 64px;
    height: 64px;
    margin-bottom: 16px;
    opacity: 0.3;
}

.empty-state p {
    font-size: 15px;
}

/* ===== Toast ===== */
.toast {
    position: fixed;
    bottom: 100px;
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    padding: 12px 24px;
    border-radius: 50px;
    background: var(--accent);
    color: var(--accent-text);
    font-size: 14px;
    font-weight: 500;
    z-index: 500;
    opacity: 0;
    pointer-events: none;
    transition: all var(--transition);
    white-space: nowrap;
}

.toast.visible {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
    pointer-events: auto;
}

/* ===== 页面切换 ===== */
.page {
    display: none;
}

.page.active {
    display: block;
}

/* ===== 懒加载淡入 ===== */
.lazy-img {
    opacity: 0;
    transition: opacity 0.4s ease;
}

.lazy-img.loaded {
    opacity: 1;
}

/* ===== 下拉加载更多 ===== */
.load-more {
    text-align: center;
    padding: 20px;
    color: var(--text-secondary);
    font-size: 14px;
}

.load-more .loading-dots::after {
    content: '';
    animation: dots 1.5s infinite;
}

@keyframes dots {
    0%, 20% { content: '.'; }
    40% { content: '..'; }
    60%, 100% { content: '...'; }
}

/* 隐藏文件输入 */
.hidden-input {
    display: none;
}

/* ===== 删除按钮 ===== */
.delete-btn {
    position: absolute;
    top: 8px;
    right: 8px;
    width: 28px;
    height: 28px;
    border: none;
    border-radius: 50%;
    background: rgba(0,0,0,0.5);
    color: #fff;
    font-size: 16px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 5;
    opacity: 0;
    transition: opacity var(--transition), background var(--transition);
    line-height: 1;
}

.masonry-item:hover .delete-btn {
    opacity: 1;
}

.delete-btn:hover {
    background: rgba(220,38,38,0.85);
}

/* ===== 以此图为基础按钮 ===== */
.use-as-ref-btn {
    display: inline-block;
    margin-top: 6px;
    padding: 4px 12px;
    border: 1px solid var(--glass-border);
    border-radius: 14px;
    background: var(--bg-secondary);
    color: var(--text-secondary);
    font-size: 12px;
    cursor: pointer;
    transition: all var(--transition);
}

.use-as-ref-btn:hover {
    color: var(--text);
    background: var(--accent);
    color: var(--accent-text);
    border-color: var(--accent);
}

/* ===== 详情页续聊输入区 ===== */
.detail-input-area {
    display: flex;
    align-items: flex-end;
    gap: 8px;
    margin-top: 16px;
    padding: 10px;
    background: var(--bg-secondary);
    border-radius: var(--radius);
    border: 2px solid transparent;
    transition: border-color var(--transition);
}

.detail-input-area:focus-within {
    border-color: var(--accent);
}

.detail-input-area .prompt-input {
    flex: 1;
    min-height: 40px;
    max-height: 100px;
}

.detail-input-area .send-btn {
    width: 40px;
    height: 40px;
}

.detail-generating {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-top: 16px;
    padding: 12px 16px;
    background: var(--bg-secondary);
    border-radius: var(--radius);
    font-size: 13px;
    color: var(--text-secondary);
}

.detail-generating .bubble-spinner {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
}

/* ===== 创作对话框 (Chat Dialog) ===== */
.chat-dialog-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.5);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    z-index: 300;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition);
}

.chat-dialog-overlay.active {
    opacity: 1;
    pointer-events: auto;
}

.chat-dialog {
    position: fixed;
    z-index: 301;
    background: var(--bg);
    display: none;
    flex-direction: column;
    overflow: hidden;
    /* 移动端：全屏 */
    inset: 0;
    border-radius: 0;
    animation: slide-up 0.4s cubic-bezier(0.32, 0.72, 0, 1);
}

.chat-dialog.active {
    display: flex;
}

@media (min-width: 768px) {
    .chat-dialog {
        inset: auto;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%);
        width: 540px;
        height: 75vh;
        max-height: 700px;
        border-radius: var(--radius);
        box-shadow: var(--shadow-lg);
        animation: modal-pop 0.35s cubic-bezier(0.32, 0.72, 0, 1);
    }
}

.chat-dialog-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    border-bottom: 1px solid var(--glass-border);
    flex-shrink: 0;
}

.chat-dialog-title {
    font-size: 17px;
    font-weight: 700;
}

.chat-dialog-close {
    width: 32px;
    height: 32px;
    border: none;
    border-radius: 50%;
    background: var(--bg-secondary);
    color: var(--text);
    font-size: 18px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
}

.chat-dialog-close:hover {
    background: var(--accent);
    color: var(--accent-text);
}

.chat-dialog-body {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    min-height: 0;
}

.chat-empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    color: var(--text-secondary);
    text-align: center;
    gap: 12px;
}

.chat-empty-state svg {
    width: 48px;
    height: 48px;
    opacity: 0.25;
}

.chat-empty-state p {
    font-size: 15px;
}

.chat-dialog-footer {
    padding: 12px 16px;
    padding-bottom: max(12px, env(safe-area-inset-bottom));
    border-top: 1px solid var(--glass-border);
    flex-shrink: 0;
}

.chat-dialog-footer .detail-input-area {
    margin-top: 0;
}