@import url('https://fonts.googleapis.com/css2?family=Exo+2:wght@300;400;500;600;700&family=Orbitron:wght@400;500;600;700&display=swap');

:root {
    --color-primary: #1E293B;
    --color-secondary: #334155;
    --color-cta: #22C55E;
    --color-background: #0F172A;
    --color-text: #F8FAFC;
    
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
    --shadow-xl: 0 20px 25px rgba(0,0,0,0.15);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Exo 2', 'Segoe UI', sans-serif;
    user-select: none;
}

body {
    background-color: var(--color-background);
    width: 100vw;
    height: 100vh;
    overflow-x: hidden;
    color: var(--color-text);
}

/* 落地页布局 */
.landing-page {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* 导航栏 */
nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-md) var(--space-xl);
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(10px);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.logo {
    font-family: 'Orbitron', sans-serif;
    font-weight: 700;
    font-size: 24px;
    color: var(--color-cta);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.nav-links a {
    color: var(--color-text);
    text-decoration: none;
    margin-left: var(--space-lg);
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links a:hover {
    color: var(--color-cta);
}

.github-btn {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    background: var(--color-secondary);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 14px;
}

/* 英雄区域 */
.hero-section {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 100px var(--space-xl) var(--space-xl);
    text-align: center;
    background: radial-gradient(circle at center, #1E293B 0%, #0F172A 100%);
}

.hero-title {
    font-family: 'Orbitron', sans-serif;
    font-size: 4rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
    background: linear-gradient(135deg, #fff 0%, #22C55E 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 0 30px rgba(34, 197, 94, 0.3);
}

.hero-subtitle {
    font-size: 1.5rem;
    color: #94A3B8;
    max-width: 600px;
    margin-bottom: var(--space-2xl);
    line-height: 1.6;
}

/* 游戏容器 */
.game-wrapper {
    position: relative;
    width: 100%;
    max-width: 1024px;
    aspect-ratio: 16/9;
    background: #000;
    border-radius: 16px;
    box-shadow: 0 0 50px rgba(34, 197, 94, 0.2);
    overflow: hidden;
    border: 1px solid rgba(255,255,255,0.1);
    margin-bottom: var(--space-3xl);
}

canvas {
    width: 100%;
    height: 100%;
    display: block;
    transform: scaleX(-1);
}

/* UI 层覆盖 */
#uiLayer {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

.overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    background: rgba(15, 23, 42, 0.85);
    backdrop-filter: blur(8px);
    z-index: 20;
    transition: opacity 0.3s ease;
}

.btn-start {
    background: var(--color-cta);
    color: white;
    padding: 16px 48px;
    border-radius: 30px;
    font-size: 20px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    margin-top: var(--space-xl);
    pointer-events: auto;
    box-shadow: 0 4px 15px rgba(34, 197, 94, 0.4);
    transition: transform 0.2s, box-shadow 0.2s;
    display: flex;
    align-items: center;
    gap: 10px;
}

.btn-start:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(34, 197, 94, 0.6);
}

.controls-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
    margin-top: var(--space-xl);
}

.control-item {
    background: rgba(255,255,255,0.05);
    padding: var(--space-md);
    border-radius: 12px;
    border: 1px solid rgba(255,255,255,0.1);
}

.control-icon {
    font-size: 24px;
    margin-bottom: var(--space-sm);
}

/* 特性展示区 */
.features-section {
    padding: var(--space-3xl) var(--space-xl);
    background: #0F172A;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-2xl);
    max-width: 1200px;
    margin: 0 auto;
}

.feature-card {
    background: #1E293B;
    padding: var(--space-xl);
    border-radius: 16px;
    border: 1px solid rgba(255,255,255,0.05);
    transition: transform 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-card h3 {
    font-family: 'Orbitron', sans-serif;
    color: var(--color-cta);
    margin-bottom: var(--space-md);
    font-size: 1.25rem;
}

.feature-card p {
    color: #94A3B8;
    line-height: 1.6;
}

/* 页脚 */
footer {
    padding: var(--space-xl);
    text-align: center;
    background: #020617;
    color: #64748B;
    margin-top: auto;
}

/* 响应式 */
@media (max-width: 768px) {
    .hero-title { font-size: 2.5rem; }
    .controls-grid { grid-template-columns: 1fr; }
    .game-wrapper { aspect-ratio: 3/4; } /* 移动端竖屏适配 */
    nav { padding: var(--space-md); }
    .nav-links { display: none; } /* 简化导航 */
}

/* 动画 */
@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

.pulse { animation: pulse 2s infinite; }