* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: -apple-system, "Microsoft YaHei", sans-serif;
    background: #0d0d0d;
    color: #ddd;
    height: 100vh;
}

/* 登录页 */
.login-box {
    max-width: 360px;
    margin: 100px auto;
    background: #1a1a1a;
    padding: 40px 30px;
    border-radius: 8px;
    border: 1px solid #2a2a2a;
}
.login-box h2 { text-align: center; margin-bottom: 30px; color: #eee; font-weight: 500; font-size: 20px; }
.login-box input {
    width: 100%;
    padding: 12px;
    margin: 8px 0;
    border: 1px solid #333;
    border-radius: 6px;
    background: #111;
    color: #eee;
    font-size: 15px;
    outline: none;
}
.login-box input:focus { border-color: #555; }
.login-box button {
    width: 100%;
    padding: 12px;
    margin-top: 15px;
    background: #e0e0e0;
    color: #111;
    border: none;
    border-radius: 6px;
    font-size: 15px;
    cursor: pointer;
}
.login-box button:hover { background: #fff; }
.error { color: #cc6666; text-align: center; margin-top: 10px; font-size: 14px; }
.tip { text-align:center; margin-top:15px; font-size:13px; color:#666; }
.tip a { color: #999; text-decoration: none; }

/* 聊天页 */
.chat-layout { display: flex; height: 100vh; }
.chat-sidebar {
    width: 260px;
    background: #141414;
    border-right: 1px solid #2a2a2a;
    display: flex;
    flex-direction: column;
}
.chat-sidebar .header {
    padding: 15px;
    background: #1a1a1a;
    border-bottom: 1px solid #2a2a2a;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 14px;
}
.conv-list { flex: 1; overflow-y: auto; }
.conv-item {
    padding: 14px 15px;
    cursor: pointer;
    border-bottom: 1px solid #1e1e1e;
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 14px;
}
.conv-item:hover { background: #1a1a1a; }
.conv-item.active { background: #222; }
.status-dot { width: 8px; height: 8px; border-radius: 50%; }
.status-online { background: #888; }
.status-offline { background: #333; }

.chat-main { flex: 1; display: flex; flex-direction: column; background: #0d0d0d; }
.chat-topbar {
    padding: 12px 20px;
    background: #141414;
    border-bottom: 1px solid #2a2a2a;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 14px;
}
.online-text { color: #aaa; }
.offline-text { color: #555; }

.msg-area { flex: 1; overflow-y: auto; padding: 20px; }
.msg {
    max-width: 60%;
    margin-bottom: 10px;
    padding: 10px 14px;
    border-radius: 8px;
    word-break: break-word;
    font-size: 14px;
    line-height: 1.5;
}
.msg.me { background: #2a2a2a; margin-left: auto; }
.msg.other { background: #1a1a1a; margin-right: auto; border: 1px solid #2a2a2a; }
.msg img, .msg video { max-width: 100%; border-radius: 6px; margin-top: 5px; }
.msg a { color: #ccc; }
.msg .time { font-size: 11px; opacity: 0.4; margin-top: 4px; }

.input-area {
    padding: 12px 15px;
    background: #141414;
    border-top: 1px solid #2a2a2a;
    display: flex;
    gap: 10px;
    align-items: flex-end;
}
.input-area textarea {
    flex: 1;
    padding: 10px;
    border-radius: 6px;
    border: 1px solid #2a2a2a;
    background: #0d0d0d;
    color: #eee;
    resize: none;
    height: 40px;
    font-size: 14px;
    outline: none;
}
.input-area textarea:focus { border-color: #444; }
.input-area button {
    padding: 10px 16px;
    background: #e0e0e0;
    color: #111;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
}
.input-area .upload-btn { background: #2a2a2a; color: #ccc; padding: 10px 12px; }

/* 管理后台 */
.admin-box { max-width: 800px; margin: 30px auto; padding: 20px; }
.admin-box h1 { color: #eee; margin-bottom: 20px; font-weight: 500; font-size: 22px; }
.admin-section {
    background: #141414;
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 16px;
    border: 1px solid #2a2a2a;
}
.admin-section h3 { margin-bottom: 15px; color: #ccc; font-weight: 500; font-size: 16px; }
.admin-section input, .admin-section select {
    padding: 8px 10px;
    margin: 0 5px 8px 0;
    background: #0d0d0d;
    border: 1px solid #2a2a2a;
    color: #eee;
    border-radius: 4px;
    outline: none;
}
.admin-section button {
    padding: 8px 16px;
    background: #e0e0e0;
    color: #111;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}
table { width: 100%; border-collapse: collapse; margin-top: 10px; }
th, td { padding: 10px; text-align: left; border-bottom: 1px solid #222; font-size: 14px; }
th { color: #888; font-weight: normal; }
.btn-small { padding: 4px 12px; font-size: 13px; background: #2a2a2a; color: #ccc; }