* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Courier New', 'Monaco', 'Menlo', monospace;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    overflow: hidden;
}

/* 返回按钮 */
.back-button {
    position: fixed;
    top: 20px;
    left: 20px;
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 20px;
    background: rgba(255, 215, 0, 0.1);
    border: 2px solid #FFD700;
    border-radius: 6px;
    color: #FFD700;
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    box-shadow: 0 0 20px rgba(255, 215, 0, 0.3);
}

.back-button:hover {
    background: rgba(255, 215, 0, 0.2);
    box-shadow: 0 0 30px rgba(255, 215, 0, 0.5);
    transform: translateY(-2px);
}

/* 星空背景 */
.starry-background {
    position: fixed;
    width: 100vw;
    height: 100vh;
    top: 0;
    left: 0;
    z-index: 0;
    background: radial-gradient(ellipse at bottom, #1B2735 0%, #090A0F 100%);
}

.stars-container {
    position: absolute;
    width: 100%;
    height: 100%;
}

.star {
    position: absolute;
    background: #FFD700;
    border-radius: 50%;
    animation: starTwinkle 3s ease-in-out infinite;
}

.star:nth-child(1) {
    width: 3px;
    height: 3px;
    top: 20%;
    left: 10%;
    animation-delay: 0s;
}

.star:nth-child(2) {
    width: 2px;
    height: 2px;
    top: 30%;
    left: 80%;
    animation-delay: 0.5s;
}

.star:nth-child(3) {
    width: 4px;
    height: 4px;
    top: 60%;
    left: 20%;
    animation-delay: 1s;
}

.star:nth-child(4) {
    width: 2px;
    height: 2px;
    top: 80%;
    left: 70%;
    animation-delay: 1.5s;
}

.star:nth-child(5) {
    width: 3px;
    height: 3px;
    top: 15%;
    left: 60%;
    animation-delay: 2s;
}

.star:nth-child(6) {
    width: 2px;
    height: 2px;
    top: 70%;
    left: 90%;
    animation-delay: 2.5s;
}

.star:nth-child(7) {
    width: 4px;
    height: 4px;
    top: 40%;
    left: 40%;
    animation-delay: 3s;
}

.star:nth-child(8) {
    width: 2px;
    height: 2px;
    top: 90%;
    left: 30%;
    animation-delay: 0.8s;
}

.star:nth-child(9) {
    width: 3px;
    height: 3px;
    top: 10%;
    left: 90%;
    animation-delay: 1.8s;
}

.star:nth-child(10) {
    width: 2px;
    height: 2px;
    top: 50%;
    left: 5%;
    animation-delay: 2.8s;
}

@keyframes starTwinkle {
    0%, 100% {
        opacity: 0.3;
        transform: scale(1);
        box-shadow: 0 0 5px #FFD700;
    }
    50% {
        opacity: 1;
        transform: scale(1.2);
        box-shadow: 0 0 15px #FFD700, 0 0 25px #FFD700;
    }
}

/* 流星效果 */
.meteors-container {
    position: absolute;
    width: 100%;
    height: 100%;
}

.meteor {
    position: absolute;
    width: 2px;
    height: 2px;
    background: linear-gradient(45deg, #FFD700, transparent);
    border-radius: 50%;
    animation: meteorFall 8s linear infinite;
}

.meteor:nth-child(1) {
    top: 10%;
    left: 80%;
    animation-delay: 0s;
    animation-duration: 8s;
}

.meteor:nth-child(2) {
    top: 30%;
    left: 60%;
    animation-delay: 3s;
    animation-duration: 10s;
}

.meteor:nth-child(3) {
    top: 50%;
    left: 90%;
    animation-delay: 6s;
    animation-duration: 7s;
}

@keyframes meteorFall {
    0% {
        transform: translateX(0) translateY(0);
        opacity: 1;
        box-shadow: 0 0 10px #FFD700;
    }
    70% {
        opacity: 1;
        box-shadow: 0 0 20px #FFD700, 0 0 40px #FFD700;
    }
    100% {
        transform: translateX(-300px) translateY(300px);
        opacity: 0;
    }
}

/* 星云效果 */
.nebula {
    position: absolute;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 30% 70%, rgba(138, 43, 226, 0.1) 0%, transparent 50%),
                radial-gradient(circle at 70% 30%, rgba(75, 0, 130, 0.1) 0%, transparent 50%);
    animation: nebulaShift 20s ease-in-out infinite;
}

@keyframes nebulaShift {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 0.6; }
}

/* 粒子效果 */
.particles-container {
    position: absolute;
    width: 100%;
    height: 100%;
}

.particle {
    position: absolute;
    width: 1px;
    height: 1px;
    background: #FFD700;
    border-radius: 50%;
    animation: particleFloat 15s linear infinite;
}

.particle:nth-child(1) {
    left: 20%;
    animation-delay: 0s;
}

.particle:nth-child(2) {
    left: 40%;
    animation-delay: 3s;
}

.particle:nth-child(3) {
    left: 60%;
    animation-delay: 6s;
}

.particle:nth-child(4) {
    left: 80%;
    animation-delay: 9s;
}

.particle:nth-child(5) {
    left: 10%;
    animation-delay: 12s;
}

@keyframes particleFloat {
    0% {
        bottom: -10px;
        opacity: 0;
        transform: translateX(0);
    }
    10% {
        opacity: 1;
    }
    90% {
        opacity: 1;
    }
    100% {
        bottom: 100vh;
        opacity: 0;
        transform: translateX(50px);
    }
}

/* 科幻卡片容器 */
.login-container {
    position: relative;
    z-index: 10;
    width: 100%;
    max-width: 400px;
    margin: 0 20px;
}

.scifi-card {
    background: rgba(20, 20, 30, 0.9);
    backdrop-filter: blur(15px);
    border: 2px solid #FFD700;
    border-radius: 12px;
    padding: 40px 30px;
    box-shadow: 
        0 0 30px rgba(255, 215, 0, 0.3),
        inset 0 0 30px rgba(255, 215, 0, 0.1);
    animation: cardMaterialize 1s ease-out;
    position: relative;
}

.scifi-card::before {
    content: '';
    position: absolute;
    top: -2px;
    left: -2px;
    right: -2px;
    bottom: -2px;
    background: linear-gradient(45deg, #c7b761, #000000, #FFD700);
    border-radius: 12px;
    z-index: -1;
    animation: borderGlow 3s ease-in-out infinite;
}

@keyframes cardMaterialize {
    from {
        opacity: 0;
        transform: translateY(50px) scale(0.8);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

@keyframes borderGlow {
    0%, 100% { opacity: 0.5; }
    50% { opacity: 1; }
}

.card-header {
    text-align: center;
    margin-bottom: 30px;
}

.galaxy-icon {
    font-size: 3rem;
    margin-bottom: 15px;
    animation: galaxySpin 4s linear infinite;
}

@keyframes galaxySpin {
    0% { transform: rotate(0deg) scale(1); }
    50% { transform: rotate(180deg) scale(1.1); }
    100% { transform: rotate(360deg) scale(1); }
}

.card-header h2 {
    color: #FFD700;
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 2px;
    text-shadow: 0 0 10px #FFD700;
}

.subtitle {
    color: rgba(255, 215, 0, 0.7);
    font-size: 0.8rem;
    margin-bottom: 20px;
    font-weight: 300;
    letter-spacing: 3px;
    text-transform: uppercase;
}

.laser-divider {
    width: 80px;
    height: 2px;
    background: linear-gradient(90deg, transparent, #FFD700, transparent);
    margin: 0 auto;
    animation: laserPulse 2s ease-in-out infinite;
}

@keyframes laserPulse {
    0%, 100% { 
        box-shadow: 0 0 5px #FFD700; 
        opacity: 0.7; 
    }
    50% { 
        box-shadow: 0 0 20px #FFD700, 0 0 40px #FFD700; 
        opacity: 1; 
    }
}

/* 表单样式 */
.form-group {
    position: relative;
    margin-bottom: 30px;
}

.form-group input {
    width: 100%;
    padding: 15px 0;
    background: transparent;
    border: none;
    border-bottom: 1px solid rgba(255, 215, 0, 0.3);
    color: #FFD700;
    font-size: 16px;
    font-family: inherit;
    outline: none;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.form-group input:focus {
    border-bottom-color: #FFD700;
    text-shadow: 0 0 5px #FFD700;
}

.form-group input::placeholder {
    color: transparent;
}

.form-group label {
    position: absolute;
    left: 0;
    top: 15px;
    color: rgba(255, 215, 0, 0.6);
    font-size: 14px;
    pointer-events: none;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.form-group input:focus + label,
.form-group input:valid + label {
    top: -5px;
    font-size: 11px;
    color: #FFD700;
    text-shadow: 0 0 5px #FFD700;
}

.laser-line {
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: #FFD700;
    transition: all 0.3s ease;
    transform: translateX(-50%);
    box-shadow: 0 0 10px #FFD700;
}

.form-group input:focus ~ .laser-line {
    width: 100%;
}

/* 验证码组 */
.verification-group {
    display: flex;
    align-items: flex-end;
    gap: 15px;
}

.verification-group input {
    flex: 1;
}

.verify-btn, .scifi-btn-small {
    padding: 12px 20px;
    background: rgba(255, 215, 0, 0.1);
    border: 1px solid #FFD700;
    border-radius: 6px;
    color: #FFD700;
    font-size: 12px;
    font-family: inherit;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    white-space: nowrap;
}

.verify-btn:hover:not(:disabled), .scifi-btn-small:hover:not(:disabled) {
    background: rgba(255, 215, 0, 0.2);
    box-shadow: 0 0 15px rgba(255, 215, 0, 0.5);
    transform: translateY(-2px);
}

.verify-btn:disabled, .scifi-btn-small:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* 登录按钮 */
.login-btn, .scifi-btn {
    width: 100%;
    padding: 15px;
    background: rgba(255, 215, 0, 0.1);
    border: 2px solid #FFD700;
    border-radius: 6px;
    color: #FFD700;
    font-size: 16px;
    font-family: inherit;
    font-weight: 600;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    transition: all 0.3s ease;
    margin: 25px 0;
    text-transform: uppercase;
    letter-spacing: 2px;
}

.login-btn:hover, .scifi-btn:hover {
    background: rgba(255, 215, 0, 0.2);
    box-shadow: 
        0 0 20px rgba(255, 215, 0, 0.5),
        inset 0 0 20px rgba(255, 215, 0, 0.1);
    transform: translateY(-2px);
}

.btn-text {
    position: relative;
    z-index: 2;
}

.btn-glow {
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 215, 0, 0.3), transparent);
    transition: left 0.5s ease;
}

.login-btn:hover .btn-glow, .scifi-btn:hover .btn-glow {
    left: 100%;
}

/* 附加链接 */
.additional-links {
    text-align: center;
    margin-top: 25px;
}

.scifi-link {
    color: rgba(255, 215, 0, 0.7);
    text-decoration: none;
    font-size: 12px;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.scifi-link:hover {
    color: #FFD700;
    text-shadow: 0 0 10px #FFD700;
}

.divider {
    color: rgba(255, 215, 0, 0.4);
    margin: 0 15px;
}

/* 隐藏和显示动画 */
.hidden {
    display: none;
}

.fade-out {
    opacity: 0;
    transform: translateY(-20px);
    transition: all 0.3s ease;
}

/* 响应式设计 */
@media (max-width: 480px) {
    .scifi-card {
        padding: 30px 20px;
        margin: 0 15px;
    }
    
    .back-button {
        top: 15px;
        left: 15px;
        padding: 10px 16px;
        font-size: 12px;
    }
    
    .verification-group {
        gap: 8px;
    }

    .verification-group .form-group {
        flex: 1;
        min-width: 0;
    }

    .verify-btn, .scifi-btn-small {
        flex-shrink: 0;
        padding: 12px 10px;
        font-size: 11px;
        min-width: 75px;
        letter-spacing: 0.5px;
    }
    
    .galaxy-icon {
        font-size: 2.5rem;
    }
    
    .card-header h2 {
        font-size: 1.5rem;
    }
}