/* ========== 基础变量与重置 ========== */
:root {
    /* iOS 26 玻璃色调 */
    --glass-bg: rgba(255, 255, 255, 0.15);
    --glass-bg-strong: rgba(255, 255, 255, 0.25);
    --glass-border: rgba(255, 255, 255, 0.2);
    --glass-border-strong: rgba(255, 255, 255, 0.35);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    --glass-shadow-strong: 0 25px 50px rgba(0, 0, 0, 0.15);
    
    /* 动态背景色 */
    --accent-1: #667eea;
    --accent-2: #764ba2;
    --accent-3: #f093fb;
    --accent-4: #4facfe;
    
    /* 文字颜色 */
    --text-primary: #1a1a2e;
    --text-secondary: rgba(26, 26, 46, 0.6);
    --text-light: rgba(255, 255, 255, 0.9);
    
    /* 圆角 */
    --radius-sm: 12px;
    --radius-md: 20px;
    --radius-lg: 28px;
    --radius-xl: 32px;
    
    /* 动画 */
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-spring: 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

html {
    font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', Roboto, sans-serif;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
}

body {
    min-height: 100vh;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
    background-attachment: fixed;
    color: var(--text-primary);
    overflow-x: hidden;
    padding-bottom: env(safe-area-inset-bottom);
}

/* ========== 动态背景 ========== */
.ambient-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
    overflow: hidden;
}

.blob {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.6;
    animation: float 20s infinite ease-in-out;
}

.blob-1 {
    width: 600px;
    height: 600px;
    background: var(--accent-1);
    top: -200px;
    right: -200px;
    animation-delay: 0s;
}

.blob-2 {
    width: 500px;
    height: 500px;
    background: var(--accent-3);
    bottom: -150px;
    left: -150px;
    animation-delay: -7s;
}

.blob-3 {
    width: 400px;
    height: 400px;
    background: var(--accent-4);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation-delay: -14s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    25% { transform: translate(50px, -50px) scale(1.1); }
    50% { transform: translate(-30px, 30px) scale(0.9); }
    75% { transform: translate(30px, 50px) scale(1.05); }
}

/* ========== 玻璃导航 ========== */
.glass-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: 12px 20px;
    padding-top: max(12px, env(safe-area-inset-top));
    background: var(--glass-bg);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--glass-border);
}

.nav-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 600px;
    margin: 0 auto;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    background: linear-gradient(135deg, #fff 0%, rgba(255,255,255,0.7) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.new-post-btn {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: none;
    background: var(--glass-bg-strong);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border-strong);
    color: var(--text-light);
    font-size: 24px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    box-shadow: var(--glass-shadow);
}

.new-post-btn:active {
    transform: scale(0.92);
    background: rgba(255,255,255,0.35);
}

/* ========== 瀑布流布局 ========== */
.waterfall-container {
    padding: 90px 16px 24px;
    max-width: 600px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

@media (min-width: 768px) {
    .waterfall-container {
        grid-template-columns: repeat(3, 1fr);
        max-width: 900px;
    }
}

/* ========== 玻璃卡片 ========== */
.glass-card {
    border-radius: var(--radius-lg);
    background: var(--glass-bg);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border: 1px solid var(--glass-border);
    overflow: hidden;
    transition: all var(--transition-smooth);
    animation: cardAppear 0.6s var(--transition-spring) backwards;
    box-shadow: var(--glass-shadow);
}

.glass-card:hover {
    transform: translateY(-4px) scale(1.02);
    box-shadow: var(--glass-shadow-strong);
    border-color: var(--glass-border-strong);
    background: var(--glass-bg-strong);
}

@keyframes cardAppear {
    from {
        opacity: 0;
        transform: translateY(30px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.card-image {
    width: 100%;
    aspect-ratio: 1;
    object-fit: cover;
    display: block;
    cursor: pointer;
    transition: transform var(--transition-smooth);
}

.card-image:hover {
    transform: scale(1.05);
}

.card-content {
    padding: 16px;
}

.card-emoji {
    font-size: 28px;
    margin-bottom: 8px;
    display: block;
}

.card-text {
    font-size: 15px;
    line-height: 1.6;
    color: var(--text-primary);
    word-break: break-word;
    display: -webkit-box;
    -webkit-line-clamp: 4;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px solid var(--glass-border);
}

.card-time {
    font-size: 12px;
    color: var(--text-secondary);
}

.card-actions {
    display: flex;
    gap: 16px;
}

.action-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 14px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 4px;
    transition: all var(--transition-fast);
    padding: 4px 8px;
    border-radius: 12px;
}

.action-btn:active {
    background: rgba(255,255,255,0.2);
    transform: scale(0.95);
}

.action-btn.liked {
    color: #ff4757;
}

/* 纯文字卡片特殊样式 */
.text-only-card {
    padding: 20px;
    min-height: 150px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.text-only-card .card-text {
    -webkit-line-clamp: 8;
    font-size: 16px;
}

/* ========== 加载更多 ========== */
.load-more {
    display: flex;
    justify-content: center;
    padding: 24px;
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.load-more.visible {
    opacity: 1;
}

.loading-spinner {
    width: 32px;
    height: 32px;
    border: 3px solid var(--glass-border);
    border-top-color: var(--text-light);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* ========== 模态框 ========== */
.modal-overlay {
    position: fixed;
    inset: 0;
    z-index: 200;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    background: rgba(0,0,0,0.3);
    backdrop-filter: blur(4px);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-smooth);
    padding: 16px;
    padding-bottom: max(16px, env(safe-area-inset-bottom));
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-overlay.active .modal-glass {
    transform: translateY(0);
}

.modal-glass {
    width: 100%;
    max-width:500px;
    max-height: 90vh;
    border-radius: var(--radius-xl);
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: saturate(200%) blur(30px);
    -webkit-backdrop-filter: saturate(200%) blur(30px);
    border: 1px solid var(--glass-border-strong);
    box-shadow: 0 25px 50px rgba(0,0,0,0.2);
    transform: translateY(100%);
    transition: transform var(--transition-spring);
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 24px;
    border-bottom: 1px solid var(--glass-border);
}

.modal-header h3 {
    font-size: 18px;
    font-weight: 600;
}

.close-btn {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: none;
    background: var(--glass-bg);
    color: var(--text-secondary);
    font-size: 16px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.close-btn:active {
    background: rgba(0,0,0,0.1);
    transform: scale(0.9);
}

.modal-body {
    padding: 20px 24px;
    overflow-y: auto;
    flex: 1;
}

/* ========== 图片上传区 ========== */
.image-preview-area {
    position: relative;
    border-radius: var(--radius-md);
    overflow: hidden;
    margin-bottom: 20px;
    background: var(--glass-bg);
    border: 2px dashed var(--glass-border-strong);
    min-height: 200px;
}

.upload-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.upload-placeholder svg {
    margin-bottom: 12px;
    opacity: 0.6;
}

.upload-placeholder span {
    font-size: 14px;
}

.upload-placeholder:active {
    background: rgba(255,255,255,0.2);
}

#previewImg {
    width: 100%;
    height: 100%;
    object-fit: cover;
    position: absolute;
    inset: 0;
}

.remove-img {
    position: absolute;
    top: 12px;
    right: 12px;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: none;
    background: rgba(0,0,0,0.5);
    color: white;
    font-size: 14px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(4px);
    transition: all var(--transition-fast);
}

.remove-img:active {
    transform: scale(0.9);
    background: rgba(0,0,0,0.7);
}

/* ========== Emoji 选择器 ========== */
.emoji-section {
    margin-bottom: 20px;
}

.emoji-section label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 12px;
}

.emoji-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 8px;
}

.emoji-btn {
    aspect-ratio: 1;
    border-radius: var(--radius-sm);
    border: 2px solid transparent;
    background: var(--glass-bg);
    font-size: 24px;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.emoji-btn:hover {
    background: var(--glass-bg-strong);
    transform: scale(1.1);
}

.emoji-btn.active {
    border-color: var(--accent-1);
    background: rgba(102, 126, 234, 0.15);
}

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

/* ========== 输入框 ========== */
.input-section {
    position: relative;
}

textarea {
    width: 100%;
    padding: 16px;
    border-radius: var(--radius-md);
    border: 1px solid var(--glass-border);
    background: var(--glass-bg);
    font-size: 16px;
    line-height: 1.6;
    resize: none;
    outline: none;
    transition: all var(--transition-fast);
    font-family: inherit;
}

textarea:focus {
    border-color: var(--accent-1);
    background: var(--glass-bg-strong);
}

.char-count {
    position: absolute;
    bottom: 12px;
    right: 12px;
    font-size: 12px;
    color: var(--text-secondary);
}

/* ========== 底部按钮 ========== */
.modal-footer {
    display: flex;
    gap: 12px;
    padding: 16px 24px 24px;
    border-top: 1px solid var(--glass-border);
}

.modal-footer button {
    flex: 1;
    padding: 14px 24px;
    border-radius: var(--radius-md);
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    border: none;
}

.cancel-btn {
    background: var(--glass-bg);
    color: var(--text-secondary);
}

.cancel-btn:active {
    background: rgba(0,0,0,0.1);
}

.submit-btn {
    background: linear-gradient(135deg, var(--accent-1) 0%, var(--accent-2) 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.submit-btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.submit-btn:not(:disabled):active {
    transform: scale(0.98);
}

.btn-loader {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-loader::after {
    content: '';
    width: 20px;
    height: 20px;
    border: 2px solid transparent;
    border-top-color: white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

/* ========== 图片灯箱 ========== */
.lightbox {
    position: fixed;
    inset: 0;
    z-index: 300;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0,0,0,0.9);
    backdrop-filter: blur(20px);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-smooth);
    padding: 20px;
}

.lightbox.active {
    opacity: 1;
    visibility: visible;
}

.lightbox img {
    max-width: 100%;
    max-height: 90vh;
    border-radius: var(--radius-md);
    transform: scale(0.9);
    transition: transform var(--transition-spring);
}

.lightbox.active img {
    transform: scale(1);
}

/* ========== Toast ========== */
.toast {
    position: fixed;
    top: 100px;
    left: 50%;
    transform: translateX(-50%) translateY(-20px);
    padding: 14px 28px;
    border-radius: var(--radius-md);
    background: var(--glass-bg-strong);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border-strong);
    color: var(--text-primary);
    font-size: 14px;
    font-weight: 500;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-smooth);
    z-index: 400;
    box-shadow: var(--glass-shadow-strong);
}

.toast.show {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

/* ========== 空状态 ========== */
.empty-state {
    grid-column: 1 / -1;
    text-align: center;
    padding: 60px 20px;
    color: var(--text-light);
}

.empty-state-icon {
    font-size: 64px;
    margin-bottom: 16px;
    opacity: 0.8;
}

.empty-state-text {
    font-size: 16px;
    opacity: 0.9;
}

/* ========== 响应式优化 ========== */
@media (max-width: 380px) {
    .waterfall-container {
        grid-template-columns: 1fr;
    }
    
    .emoji-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

/* 深色模式支持 */
@media (prefers-color-scheme: dark) {
    :root {
        --glass-bg: rgba(30, 30, 50, 0.4);
        --glass-bg-strong: rgba(30, 30, 50, 0.6);
        --glass-border: rgba(255, 255, 255, 0.1);
        --glass-border-strong: rgba(255, 255, 255, 0.2);
        --text-primary: #f0f0f5;
        --text-secondary: rgba(240, 240, 245, 0.6);
    }
    
    body {
        background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    }
    
    .modal-glass {
        background: rgba(30, 30, 50, 0.9);
    }
}