* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    background: #101522;
    color: #e8edf7;
    font-family: Arial, "Microsoft YaHei", sans-serif;
}

.container {
    width: 100%;
    max-width: 760px;
    margin: 50px auto;
    padding: 20px;
}

.login-card {
    max-width: 420px;
    margin: 100px auto;
    padding: 38px;
    background: #1b2434;
    border: 1px solid #303d53;
    border-radius: 16px;
    text-align: center;
}

.logo {
    width: 60px;
    height: 60px;
    margin: 0 auto;
    border-radius: 16px;
    background: #4778ed;
    color: white;
    font-size: 36px;
    line-height: 60px;
    font-weight: bold;
}

h1 {
    margin-bottom: 8px;
}

p, small {
    color: #96a4bb;
}

input {
    width: 100%;
    padding: 14px;
    margin: 10px 0;
    color: white;
    background: #111a29;
    border: 1px solid #344158;
    border-radius: 8px;
    outline: none;
}

input:focus {
    border-color: #5786f4;
}

button {
    padding: 12px 20px;
    color: white;
    background: #4778ed;
    border: 0;
    border-radius: 8px;
    cursor: pointer;
}

button:hover {
    background: #3566dc;
}

.login-card button {
    width: 100%;
    margin-top: 12px;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 18px;
    background: #1b2434;
    border: 1px solid #303d53;
    border-radius: 12px;
}

header strong, header small {
    display: block;
}

header a {
    color: #83a7ff;
    text-decoration: none;
}

main {
    margin-top: 30px;
    padding: 25px;
    background: #1b2434;
    border: 1px solid #303d53;
    border-radius: 12px;
}

.search-box {
    display: flex;
    gap: 10px;
}

.search-box input {
    flex: 1;
    min-width: 0;
}

.search-box button {
    margin: 10px 0;
}

#message, #loginMessage {
    margin: 15px 0;
    color: #aab8cf;
    font-size: 14px;
}

.user-item {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 15px 0;
    border-bottom: 1px solid #303d53;
}

.user-item img {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    object-fit: cover;
    background: #344158;
}

.user-info {
    flex: 1;
    min-width: 0;
}

.user-info strong, .user-info small {
    display: block;
    margin-bottom: 4px;
}

.user-info .status {
    color: #55c99b;
}

@media (max-width: 520px) {
    .container {
        margin: 10px auto;
        padding: 12px;
    }

    .login-card {
        margin: 60px auto;
        padding: 25px;
    }

    main {
        padding: 16px;
    }

    .user-item {
        gap: 10px;
    }

    .user-item button {
        padding: 10px;
    }
}