:root {
    --bg-dark: #0A0A0B;
    --logo-cyan: #00E5FF;
    --logo-magenta: #FF00E5;
    --logo-orange: #FF9100;
    --logo-gold: #FFD600;
    --text-white: #FFFFFF;
    --text-dim: rgba(255, 255, 255, 0.6);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body { 
    background-color: var(--bg-dark);
    color: var(--text-white);
    font-family: 'Plus Jakarta Sans', sans-serif;
    overflow: hidden;
}

/* --- 背景层设计 --- */
.bg-wrapper {
    position: fixed;
    top: 0; left: 0; width: 100%; height: 100%;
    z-index: -1;
}

.static-bg {
    position: absolute;
    width: 100%; height: 100%;
    background-image: url('background.png');
    background-size: cover;
    background-position: center;
    opacity: 0.25; /* 重点：降低背景图亮度，为文字留出空间 */
    filter: blur(2px) saturate(1.2);
}

#particles-bg {
    position: absolute;
    top: 0; left: 0;
}

/* --- 滑屏效果 --- */
.scroller {
    height: 100vh;
    scroll-snap-type: y mandatory;
    overflow-y: scroll;
    scroll-behavior: smooth;
}

section {
    height: 100vh;
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    scroll-snap-align: start;
    position: relative;
    padding: 0 10%;
}

/* --- 导航栏 --- */
header {
    position: fixed; top: 0; width: 100%; z-index: 100;
    padding: 30px 50px; display: flex; justify-content: space-between; align-items: center;
    background: linear-gradient(to bottom, rgba(10,10,11,0.8), transparent);
}

.brand { display: flex; align-items: center; text-decoration: none; color: #fff; gap: 15px; }
.breathe-logo { width: 45px; height: 45px; animation: breathe 4s ease-in-out infinite; }
.brand-name { display: flex; flex-direction: column; }
.brand-name .cn { font-size: 1.1rem; font-weight: 800; letter-spacing: 2px; }
.brand-name .en { font-size: 0.7rem; opacity: 0.7; }

.nav-links { display: flex; gap: 30px; align-items: center; }
.nav-links a { color: var(--text-dim); text-decoration: none; transition: 0.3s; font-size: 0.9rem; }
.nav-links a:hover { color: var(--logo-cyan); }
.nav-btn { padding: 8px 20px; border: 1px solid var(--logo-magenta); border-radius: 50px; color: var(--logo-magenta) !important; }

/* --- 核心组件 --- */
.hero-content { text-align: center; max-width: 900px; }
h1 { font-size: clamp(2.5rem, 5vw, 4.5rem); font-weight: 800; line-height: 1.1; margin-bottom: 25px; }
.glitch-text {
    background: linear-gradient(90deg, #fff, var(--logo-cyan), var(--logo-magenta), #fff);
    background-size: 200% auto;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: shine 8s linear infinite;
}

.hero-sub { font-size: 1.2rem; color: var(--text-dim); margin-bottom: 40px; }

.btn { padding: 15px 35px; border-radius: 50px; text-decoration: none; font-weight: bold; transition: 0.4s; display: inline-block; }
.btn-primary { background: var(--logo-cyan); color: #000; box-shadow: 0 10px 30px rgba(0, 229, 255, 0.3); }
.btn-secondary { border: 1px solid var(--text-dim); color: #fff; margin-left: 15px; }
.btn:hover { transform: translateY(-3px); }

/* --- 装饰分隔线 --- */
.section-separator {
    position: absolute; bottom: 0; left: 0; width: 100%; height: 1px;
    background: linear-gradient(90deg, transparent, var(--logo-cyan), var(--logo-magenta), transparent);
    opacity: 0.5;
}

/* --- 卡片设计 --- */
.pillars, .course-flex { display: flex; gap: 30px; margin-top: 50px; width: 100%; }
.pillar-card, .c-card {
    flex: 1; padding: 40px; border-radius: 20px; 
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: 0.4s;
}
.pillar-card:hover, .c-card:hover { border-color: var(--logo-cyan); transform: scale(1.05); }

/* --- 动画 --- */
@keyframes breathe { 0%, 100% { transform: scale(1); filter: brightness(1); } 50% { transform: scale(1.05); filter: brightness(1.3) drop-shadow(0 0 10px var(--logo-cyan)); } }
@keyframes shine { 0% { background-position: 0% center; } 100% { background-position: 200% center; } }

/* 响应式调整 */
@media (max-width: 768px) {
    header { padding: 20px; }
    .nav-links { display: none; }
    .pillars, .course-flex { flex-direction: column; }
    section { height: auto; min-height: 100vh; padding: 100px 5%; }
}


/* --- Service 核心：50%透明底色与中心弥散 --- */
.service-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
    padding: 20px;
}

.s-item {
    position: relative;
    padding: 45px 30px;
    height: 350px;
    border-radius: 20px;
    display: flex;
    flex-direction: column;
    overflow: hidden; /* 确保弥散不超出圆角 */
    transition: all 0.5s cubic-bezier(0.2, 0.8, 0.2, 1);
    cursor: pointer;
    
    /* 基础毛玻璃 */
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(15px);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

/* 独立定义每个卡片的颜色变量 (50% 透明度底色) */
.s-item.cyan { 
    --neon-color: #00E5FF; 
    --bg-diffuse: rgba(0, 229, 255, 0.15); /* 初始较淡的底色 */
}
.s-item.magenta { 
    --neon-color: #FF00E5; 
    --bg-diffuse: rgba(255, 0, 229, 0.15); 
}
.s-item.orange { 
    --neon-color: #FF9100; 
    --bg-diffuse: rgba(255, 145, 0, 0.15); 
}
.s-item.gold { 
    --neon-color: #FFD600; 
    --bg-diffuse: rgba(255, 214, 0, 0.15); 
}

/* 实现“两边深、中间亮”的霓虹边框 */
.s-item::before {
    content: "";
    position: absolute;
    inset: 0;
    border-radius: 20px;
    padding: 2px; /* 边框厚度 */
    background: linear-gradient(135deg, 
        rgba(255,255,255,0.1) 0%, 
        var(--neon-color) 20%, 
        #ffffff 50%, 
        var(--neon-color) 80%, 
        rgba(255,255,255,0.1) 100%
    );
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    pointer-events: none;
}

/* 实现卡片内部 80% 透明度的弥散背景 */
.s-item::after {
    content: "";
    position: absolute;
    inset: 0;
    z-index: -1;
    /* 核心：径向渐变模拟弥散感 */
    background: radial-gradient(
        circle at 80% 80%, 
        var(--bg-diffuse) 0%, 
        rgba(0, 0, 0, 0) 80%
    );
    opacity: 0.6;
    transition: opacity 0.5s ease;
}

/* Hover 状态：底色加深至 50% 透明度，弥散感增强 */
.s-item:hover {
    transform: translateY(-15px) scale(1.02);
    border-color: rgba(255, 255, 255, 0.3);
}

.s-item:hover::after {
    opacity: 1;
    /* Hover时底色变得更浓郁 (接近50%透明) */
    background: radial-gradient(
        circle at 50% 40%, 
        var(--bg-diffuse) 0%, 
        var(--bg-diffuse) 30%, 
        rgba(0, 0, 0, 0) 80%
    );
}

/* 外发光弥散 (Box Shadow) */
.s-item.cyan:hover { box-shadow: 0 0 50px rgba(0, 229, 255, 0.3); }
.s-item.magenta:hover { box-shadow: 0 0 50px rgba(255, 0, 229, 0.3); }
.s-item.orange:hover { box-shadow: 0 0 50px rgba(255, 145, 0, 0.3); }
.s-item.gold:hover { box-shadow: 0 0 50px rgba(255, 214, 0, 0.3); }

/* 文字处理 */
.s-item h4 {
    font-size: 1.6rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 20px;
    z-index: 1;
    line-height: 1.2;
}

.s-item p {
    font-size: 1rem;
    color: rgba(255, 255, 255, 0.8);
    z-index: 1;
    line-height: 1.5;
}
/* 响应式 */
@media (max-width: 1024px) {
    .service-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 600px) {
    .service-grid { grid-template-columns: 1fr; }
}