/* 基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #070a1a 0%, #10152b 50%, #181c2f 100%);
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
    color: #ffffff;
}

/* 星空背景动画 */
.starfield {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

/* 地球背景 */
/* 地球容器：用于在页面中居中显示 */
.earth-wrap {
    position: fixed;
    inset: 0; /* top:0; right:0; bottom:0; left:0 */
    display: flex;
    justify-content: center;
    align-items: center;
    pointer-events: none; /* 背景元素不阻塞交互 */
    z-index: -1;
}

.earth {
    display: block; /* 避免 inline 元素产生基线偏移 */
    width: 90vmin;
    height: auto; /* 保持原始纵横比 */
    max-width: 90%;
    max-height: 80vh;
    transform-origin: center center;
    filter: drop-shadow(0 20px 60px rgba(33, 150, 243, 0.25)) 
            drop-shadow(0 0 120px rgba(33, 150, 243, 0.18));
    animation: earthRotate 60s infinite linear;
    pointer-events: none;
    object-fit: contain; /* 保证在任何容器内都按比例展示 */
}

@keyframes earthRotate {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.star {
    position: absolute;
    width: 2px;
    height: 2px;
    background: #fff;
    border-radius: 50%;
    animation: twinkle 2s infinite;
}

.star:nth-child(1) { top: 20%; left: 20%; animation-delay: 0s; }
.star:nth-child(2) { top: 20%; left: 60%; animation-delay: 0.5s; }
.star:nth-child(3) { top: 20%; left: 90%; animation-delay: 1s; }
.star:nth-child(4) { top: 40%; left: 10%; animation-delay: 1.5s; }
.star:nth-child(5) { top: 40%; left: 40%; animation-delay: 0.2s; }
.star:nth-child(6) { top: 40%; left: 80%; animation-delay: 0.8s; }
.star:nth-child(7) { top: 60%; left: 30%; animation-delay: 1.2s; }
.star:nth-child(8) { top: 60%; left: 70%; animation-delay: 0.7s; }
.star:nth-child(9) { top: 80%; left: 15%; animation-delay: 1.8s; }
.star:nth-child(10) { top: 80%; left: 85%; animation-delay: 0.3s; }
.star:nth-child(11) { top: 10%; left: 50%; animation-delay: 1.3s; }
.star:nth-child(12) { top: 30%; left: 75%; animation-delay: 0.9s; }
.star:nth-child(13) { top: 50%; left: 25%; animation-delay: 1.7s; }
.star:nth-child(14) { top: 70%; left: 55%; animation-delay: 0.4s; }
.star:nth-child(15) { top: 90%; left: 45%; animation-delay: 1.1s; }
.star:nth-child(16) { top: 15%; left: 35%; animation-delay: 0.6s; }
.star:nth-child(17) { top: 35%; left: 65%; animation-delay: 1.4s; }
.star:nth-child(18) { top: 55%; left: 5%; animation-delay: 0.1s; }
.star:nth-child(19) { top: 75%; left: 95%; animation-delay: 1.6s; }
.star:nth-child(20) { top: 85%; left: 25%; animation-delay: 1.9s; }

@keyframes twinkle {
    0%, 100% { opacity: 0.3; transform: scale(1); }
    50% { opacity: 1; transform: scale(1.2); }
}

/* 容器和布局 */
.container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    position: relative;
    z-index: 1;
}

/* 头部样式 */
.main-header {
    text-align: center;
    padding: 40px 0;
    animation: fadeInDown 1s ease-out;
}

.game-title {
    margin-bottom: 20px;
}

.title-text {
    display: block;
    font-size: 3rem;
    font-weight: bold;
    margin-bottom: 10px;
    background: linear-gradient(45deg, #4fc3f7, #29b6f6, #03a9f4);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 0 30px rgba(79, 195, 247, 0.5);
    animation: glow 2s infinite alternate;
}

@keyframes glow {
    from { filter: drop-shadow(0 0 5px rgba(79, 195, 247, 0.8)); }
    to { filter: drop-shadow(0 0 20px rgba(79, 195, 247, 0.8)); }
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 主菜单样式 */
.main-menu {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 40px 0;
}

.menu-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
    width: 100%;
    max-width: 800px;
}

.menu-item {
    background: rgba(255, 255, 255, 0.1);
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 20px;
    padding: 40px 30px;
    text-align: center;
    transition: all 0.3s ease;
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    animation: fadeInUp 1s ease-out;
    position: relative;
    overflow: hidden;
}

.menu-item:hover {
    transform: translateY(-10px);
    border-color: #4fc3f7;
    box-shadow: 0 20px 40px rgba(79, 195, 247, 0.3);
    background: rgba(255, 255, 255, 0.15);
}

.menu-item:hover .menu-icon svg {
    transform: scale(1.1) rotate(5deg);
}

.menu-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    transition: transform 0.3s ease;
}

.menu-icon svg {
    width: 100%;
    height: 100%;
    filter: drop-shadow(0 5px 10px rgba(0, 0, 0, 0.3));
    transition: transform 0.3s ease;
}

.menu-item h2 {
    font-size: 1.8rem;
    margin-bottom: 10px;
    color: #4fc3f7;
    font-weight: 600;
}

.menu-item p {
    color: #b3c6f0;
    margin-bottom: 25px;
    font-size: 1rem;
    line-height: 1.5;
}

.menu-button {
    background: linear-gradient(45deg, #f7e34f, #7bf629);
    border: none;
    border-radius: 30px;
    padding: 15px 30px;
    color: white;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    position: relative;
    overflow: hidden;
}

.menu-button:hover {
    transform: scale(1.05);
    box-shadow: 0 10px 25px rgba(169, 247, 79, 0.405);
}

.menu-button:active {
    transform: scale(0.98);
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.rocket-builder {
    animation-delay: 0.2s;
}

.tracking-station {
    animation-delay: 0.4s;
}

/* 底部样式 */
.game-footer {
    padding: 30px 0;
    text-align: center;
}

@keyframes orbit {
    0% { transform: rotate(0deg) translateX(30px) rotate(0deg); }
    100% { transform: rotate(360deg) translateX(30px) rotate(-360deg); }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* 响应式设计 */
@media (max-width: 768px) {
    .title-text {
        font-size: 2.2rem;
    }
    
    .menu-container {
        grid-template-columns: 1fr;
        gap: 30px;
        padding: 0 10px;
    }
    
    .menu-item {
        padding: 30px 20px;
    }
    
    .menu-icon {
        width: 60px;
        height: 60px;
    }
    
    .menu-item h2 {
        font-size: 1.5rem;
    }
    
    .container {
        padding: 0 15px;
    }
    
    .main-header {
        padding: 30px 0;
    }
}

@media (max-width: 480px) {
    .title-text {
        font-size: 1.8rem;
    }
    
    .menu-item {
        padding: 25px 15px;
    }
    
    .menu-button {
        padding: 12px 25px;
        font-size: 1rem;
    }
}

/* 深色主题优化 */
@media (prefers-color-scheme: dark) {
    .menu-item {
        background: rgba(255, 255, 255, 0.08);
        border-color: rgba(255, 255, 255, 0.15);
    }
    
    .menu-item:hover {
        background: rgba(255, 255, 255, 0.12);
    }
}