* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background: linear-gradient(135deg, #0b0b2b, #1a1a40, #0d0d21);
    color: #e0e0ff;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
}

.header {
    text-align: center;
    padding: 25px 0;
    background: rgba(10, 10, 35, 0.8);
    border-bottom: 1px solid rgba(100, 150, 255, 0.3);
    z-index: 10;
}

h1 {
    font-size: 3.2rem;
    margin-bottom: 15px;
    background: linear-gradient(90deg, #4facfe, #00f2fe);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    text-shadow: 0 0 20px rgba(79, 172, 254, 0.4);
}

.subtitle {
    font-size: 1.4rem;
    opacity: 0.9;
    max-width: 1000px;
    margin: 0 auto;
    line-height: 1.6;
    color: #aab6fe;
}

.tabs {
    display: flex;
    justify-content: center;
    margin: 20px 0;
    gap: 20px;
}

.tab-btn {
    background: rgba(15, 15, 45, 0.6);
    border: 2px solid #4facfe;
    border-radius: 50px;
    color: #e0e0ff;
    padding: 15px 40px;
    font-size: 1.3rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.tab-btn.active {
    background: linear-gradient(90deg, #4facfe, #00f2fe);
    color: #0b0b2b;
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(79, 172, 254, 0.6);
}

.tab-btn:hover:not(.active) {
    background: rgba(30, 30, 70, 0.8);
}

.container {
    display: flex;
    flex: 1;
    gap: 30px;
    padding: 0 30px 30px;
    max-width: 2000px;
    margin: 0 auto;
    width: 100%;
}

.simulation-panel {
    flex: 1;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.5);
    background: rgba(5, 5, 25, 0.6);
    border: 1px solid rgba(100, 150, 255, 0.2);
    height: 70vh;
    position: relative;
}

#solar-system {
    width: 100%;
    height: 100%;
}

#gravity-sim {
    width: 100%;
    height: 100%;
    display: none;
}

.controls {
    width: 400px;
    background: rgba(15, 15, 45, 0.85);
    padding: 25px;
    border-radius: 20px;
    overflow-y: auto;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.5);
    border: 1px solid rgba(100, 150, 255, 0.2);
    height: 70vh;
}

.control-section {
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 1px solid rgba(100, 150, 255, 0.2);
}

.control-section h2 {
    font-size: 1.7rem;
    margin-bottom: 20px;
    color: #64a6ff;
    display: flex;
    align-items: center;
    gap: 10px;
}

.slider-container {
    margin-bottom: 20px;
}

.slider-label {
    display: flex;
    justify-content: space-between;
    margin-bottom: 12px;
    font-size: 1.1rem;
    color: #aab6fe;
}

.slider {
    width: 100%;
    height: 8px;
    -webkit-appearance: none;
    background: rgba(100, 150, 255, 0.2);
    border-radius: 4px;
    outline: none;
}

.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: #4facfe;
    cursor: pointer;
    box-shadow: 0 0 8px rgba(79, 172, 254, 0.8);
    transition: all 0.2s ease;
}

.slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    background: #00f2fe;
}

button {
    background: linear-gradient(90deg, #4facfe, #00f2fe);
    border: none;
    border-radius: 12px;
    color: #0b0b2b;
    padding: 14px 20px;
    font-weight: 600;
    font-size: 1.1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 100%;
    margin: 10px 0;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    box-shadow: 0 4px 15px rgba(79, 172, 254, 0.3);
}

button:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(79, 172, 254, 0.6);
}

.button-group {
    display: flex;
    gap: 15px;
}

.button-group button {
    flex: 1;
}

.stats {
    position: absolute;
    bottom: 20px;
    left: 20px;
    background: rgba(10, 10, 35, 0.7);
    padding: 15px 20px;
    border-radius: 12px;
    font-size: 1.1rem;
    border: 1px solid rgba(100, 150, 255, 0.2);
    display: flex;
    gap: 20px;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.stat-value {
    font-weight: bold;
    font-size: 1.3rem;
    color: #4facfe;
}

.instructions {
    position: absolute;
    top: 20px;
    right: 20px;
    background: rgba(10, 10, 35, 0.7);
    padding: 20px;
    border-radius: 12px;
    font-size: 1rem;
    max-width: 280px;
    border: 1px solid rgba(100, 150, 255, 0.2);
}

.instructions h3 {
    margin-bottom: 15px;
    color: #64a6ff;
    display: flex;
    align-items: center;
    gap: 10px;
}

.instructions ul {
    padding-left: 25px;
}

.instructions li {
    margin-bottom: 12px;
    line-height: 1.5;
}

.footer {
    text-align: center;
    padding: 25px;
    margin-top: 30px;
    background: rgba(10, 10, 35, 0.7);
    border-radius: 15px;
    font-size: 1.1rem;
    border: 1px solid rgba(100, 150, 255, 0.2);
}

@media (max-width: 1200px) {
    .container {
        flex-direction: column;
    }
    
    .controls {
        width: 100%;
        max-height: 400px;
    }
    
    .simulation-panel {
        height: 60vh;
    }
}

/* 3D效果数字 */
.featured-numbers {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    display: flex;
    gap: 30px;
    z-index: 5;
    pointer-events: none;
}

.featured-number {
    font-size: 10rem;
    font-weight: 900;
    color: rgba(79, 172, 254, 0.1);
    text-shadow: 0 0 30px rgba(79, 172, 254, 0.5);
    transform: translateZ(100px);
}

/* 动画效果 */
@keyframes float {
    0% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
    100% { transform: translateY(0); }
}

.floating {
    animation: float 8s ease-in-out infinite;
}