:root { 
    --bg: #f5f5f7; 
    --primary: #007aff; 
}
* { 
    margin: 0; 
    padding: 0; 
    box-sizing: border-box; 
    -webkit-tap-highlight-color: transparent; 
}

body {
    background-color: var(--bg);
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", sans-serif;
    height: 100vh;
    display: flex;
    flex-direction: column;
    overflow: hidden; /* 禁止 Body 滚动 */
}

/* 顶部导航 */
.chat-navbar {
    height: 50px; 
    background: #fff; 
    border-bottom: 1px solid rgba(0,0,0,0.05);
    display: flex; 
    align-items: center; 
    justify-content: space-between;
    padding: 0 15px; 
    flex-shrink: 0; 
    z-index: 10;
}
.back-btn { 
    font-size: 16px; 
    color: #333; 
    text-decoration: none; 
}
.chat-title { 
    font-weight: 600; 
    font-size: 16px; 
}
.placeholder { 
    width: 20px; 
}

/* 消息区域 */
.chat-container {
    flex: 1;
    padding: 15px;
    overflow-y: auto; /* 允许内部滚动 */
    display: flex;
    flex-direction: column;
    gap: 15px;
    background: #f5f5f7;
    scrollbar-width: none; 
    -ms-overflow-style: none;
}
.chat-container::-webkit-scrollbar { 
    display: none; 
}

/* 消息气泡 */
.chat-msg { 
    display: flex; 
    gap: 10px; 
    max-width: 85%; 
    animation: fadeIn 0.3s ease; 
}
.chat-msg.self { 
    align-self: flex-end; 
    flex-direction: row-reverse; 
}
.chat-avatar { 
    width: 36px; 
    height: 36px; 
    border-radius: 6px; 
    flex-shrink: 0; 
    background: #ddd; 
    object-fit: cover; 
}
.msg-content { 
    display: flex; 
    flex-direction: column; 
}
.chat-name { 
    font-size: 11px; 
    color: #999; 
    margin-bottom: 4px; 
}
.chat-msg.self .chat-name { 
    text-align: right; 
}
.chat-bubble {
    background: #fff; 
    padding: 10px 14px; 
    border-radius: 12px;
    font-size: 15px; 
    line-height: 1.5; 
    color: #333;
    box-shadow: 0 1px 2px rgba(0,0,0,0.05);
    word-wrap: break-word; 
    position: relative;
}
.chat-msg:not(.self) .chat-bubble { 
    border-top-left-radius: 2px; 
}
.chat-msg.self .chat-bubble { 
    background: #95ec69; 
    border-top-right-radius: 2px; 
}

/* 底部输入框 */
.input-area {
    background: #f7f7f7; 
    border-top: 1px solid #ddd;
    padding: 10px; 
    display: flex; 
    gap: 10px; 
    align-items: center;
    flex-shrink: 0; 
    position: relative; 
    z-index: 20;
}
.chat-input {
    flex: 1; 
    padding: 10px; 
    border: none; 
    border-radius: 4px;
    background: #fff; 
    font-size: 16px; 
    height: 40px;
}
.chat-input:focus { 
    outline: none; 
}
.send-btn {
    background: var(--primary); 
    color: #fff; 
    border: none;
    padding: 0 15px; 
    height: 40px; 
    border-radius: 4px;
    font-size: 14px; 
    font-weight: bold; 
    cursor: pointer;
}
.send-btn:disabled { 
    background: #ccc; 
}

.emoji-btn { 
    background: none; 
    border: none; 
    font-size: 24px; 
    color: #666; 
    padding: 0 5px; 
    display: flex; 
    align-items: center; 
}

.emoji-panel {
    height: 0; 
    overflow-y: auto; 
    background: #f0f0f0; 
    transition: height 0.3s ease;
    display: grid; 
    grid-template-columns: repeat(8, 1fr); 
    gap: 5px; 
    padding: 0;
}
.emoji-panel.open { 
    height: 200px; 
    padding: 10px; 
    border-top: 1px solid #ddd; 
}
.emoji-item { 
    font-size: 22px; 
    text-align: center; 
    padding: 5px; 
    cursor: pointer;
}

@keyframes fadeIn { 
    from { 
        opacity: 0; 
        transform: translateY(10px); 
    } 
    to { 
        opacity: 1; 
        transform: translateY(0); 
    } 
}