/* login.css - 登录 / 注册页 */
#login-screen {
    position: fixed;
    inset: 0;
    z-index: 9999;
    display: none;
    align-items: center;
    justify-content: center;
    padding: 20px;
    background: linear-gradient(180deg, #0a0e17 0%, #0f2027 55%, #1b2a38 100%);
    overflow-y: auto;
}
#login-screen.show { display: flex; }
#login-screen .login-card {
    width: 100%;
    max-width: 380px;
    background: rgba(20, 32, 44, 0.9);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 18px;
    padding: 28px 26px 22px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(6px);
}
.login-brand {
    text-align: center;
    margin-bottom: 20px;
}
.login-brand .login-logo {
    font-size: 44px;
    line-height: 1;
}
.login-brand h1 {
    margin: 10px 0 4px;
    font-size: 20px;
    color: #e8f1f5;
}
.login-brand p {
    margin: 0;
    font-size: 12.5px;
    color: #8aa0ad;
}
.login-tabs {
    display: flex;
    background: rgba(0, 0, 0, 0.25);
    border-radius: 10px;
    padding: 4px;
    margin-bottom: 18px;
}
.login-tabs button {
    flex: 1;
    padding: 9px 0;
    border: none;
    border-radius: 8px;
    background: transparent;
    color: #9db3c0;
    font-size: 14px;
    cursor: pointer;
    transition: all .15s;
}
.login-tabs button.active {
    background: linear-gradient(135deg, #2c5364, #3a6a82);
    color: #fff;
    font-weight: 600;
}
.login-field {
    margin-bottom: 14px;
}
.login-field label {
    display: block;
    font-size: 12.5px;
    color: #a9bdc9;
    margin-bottom: 6px;
}
.login-field input {
    width: 100%;
    box-sizing: border-box;
    padding: 11px 13px;
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 9px;
    background: rgba(0, 0, 0, 0.28);
    color: #e8f1f5;
    font-size: 15px;
    outline: none;
    transition: border-color .15s;
}
.login-field input:focus { border-color: #4aa3cc; }
.login-field input::placeholder { color: #5f7684; }
.login-submit {
    width: 100%;
    margin-top: 6px;
    padding: 12px 0;
    border: none;
    border-radius: 10px;
    background: linear-gradient(135deg, #2c5364, #3a6a82);
    color: #fff;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: filter .15s, opacity .15s;
}
.login-submit:hover { filter: brightness(1.1); }
.login-submit:disabled { opacity: .6; cursor: not-allowed; }
.login-error {
    display: none;
    margin-top: 12px;
    padding: 9px 12px;
    border-radius: 8px;
    background: rgba(229, 57, 53, 0.15);
    border: 1px solid rgba(229, 57, 53, 0.4);
    color: #ff8a80;
    font-size: 13px;
}
.login-error.show { display: block; }
.login-hint {
    margin-top: 14px;
    text-align: center;
    font-size: 12px;
    color: #6f8794;
}
@media (max-width: 420px) {
    #login-screen { align-items: flex-start; padding-top: 9vh; }
}