/* style.css (V4.2 - Usability Upgrade) */

/* ... 全局与基础设置 (保持不变) ... */
:root {
    --glow-color: #00e5ff;
    --spark-color: #fefefe;
    --bg-color: #010416;
    --text-light: #e0f7fa;
    --text-dark: #b0bec5;
}

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

body {
    font-family: "LXGW WenKai Screen", sans-serif;
    background-color: var(--bg-color);
    color: var(--text-light);
    overflow-x: hidden;
}

.scroll-container {
    height: 400vh;
}

.sticky-container {
    position: sticky;
    top: 0;
    width: 100%;
    height: 100vh;
    overflow: hidden;
}

#particle-canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    opacity: 0;
    transition: opacity 1s ease-in-out;
}

/* --- 页头与页脚 --- */
.main-header {
    position: absolute;
    width: 100%;
    z-index: 10;
    padding: 1.5rem 5%;
    top: 0;
    display: flex;
    justify-content: space-between;
    opacity: 1;
    /* ✨ 改动：初始可见 */
    transition: opacity 0.5s;
}

.logo {
    font-weight: bold;
}

.main-header nav {
    opacity: 0;
    transition: opacity 0.5s;
}

/* 导航链接初始不可见，滚动后出现 */
.main-footer {
    position: absolute;
    width: 100%;
    z-index: 10;
    padding: 1.5rem 5%;
    bottom: 0;
    text-align: center;
    opacity: 0;
}

/* ... 页脚其他样式保持不变 ... */

/* --- 叙事核心元素 --- */
.genesis-story {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
}

.genesis-core {
    position: absolute;
    width: 50vmax;
    height: 50vmax;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 2;
    transform: scale(0.1);
    /* ✨ 改动：初始为一个较小的可见尺寸 */
    opacity: 1;
    /* ✨ 改动：初始可见 */
}

/* ... .core-spark, .core-ring 样式保持不变 ... */
.core-spark {
    width: 8px;
    height: 8px;
    background: var(--spark-color);
    border-radius: 50%;
    box-shadow: 0 0 10px var(--spark-color), 0 0 20px var(--spark-color), 0 0 40px var(--glow-color);
    animation: spark-pulse 2s infinite alternate;
}

.core-ring {
    position: absolute;
    width: 100%;
    height: 100%;
    border: 1px solid rgba(0, 229, 255, 0.2);
    border-radius: 50%;
    animation: rotate 20s linear infinite;
}

.core-ring:nth-child(2) {
    animation-duration: 25s;
    animation-direction: reverse;
}

.core-ring:nth-child(3) {
    width: 70%;
    height: 70%;
    animation-duration: 30s;
}


/* ... h1, p, cta 等元素样式保持不变，初始为opacity:0 ... */
.main-headline {
    font-size: clamp(2.5rem, 8vw, 5rem);
    text-align: center;
    line-height: 1.3;
    z-index: 3;
    opacity: 0;
}

.main-headline span {
    display: inline-block;
    opacity: 0;
    transform: translateY(20px);
}

.main-subtitle {
    font-size: clamp(1rem, 3vw, 1.2rem);
    color: var(--text-dark);
    text-align: center;
    z-index: 3;
    opacity: 0;
}

.cta-container {
    position: absolute;
    z-index: 5;
    opacity: 0;
    transform: scale(0.5);
}

.cta-button {
    background: transparent;
    border: 2px solid var(--glow-color);
    color: var(--glow-color);
    padding: 1rem 2.5rem;
    border-radius: 50px;
    font-size: 1.2rem;
    font-weight: bold;
    transition: all 0.3s ease;
    cursor: pointer;
    box-shadow: inset 0 0 10px rgba(0, 229, 255, 0.5), 0 0 15px rgba(0, 229, 255, 0.5);
}

.cta-button:hover {
    background: rgba(0, 229, 255, 0.1);
    box-shadow: inset 0 0 15px rgba(0, 229, 255, 0.8), 0 0 25px rgba(0, 229, 255, 0.8);
    transform: scale(1.05);
}

/* ✨ 新增：滚动提示样式 ✨ */
.scroll-down-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    width: 24px;
    height: 40px;
    border: 2px solid var(--text-dark);
    border-radius: 20px;
    opacity: 1;
    transition: opacity 0.5s;
}

.scroll-down-indicator .arrow {
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 8px;
    height: 8px;
    background-color: var(--text-dark);
    border-radius: 50%;
    animation: scroll-hint 1.5s infinite;
}

body.scrolled .scroll-down-indicator {
    opacity: 0;
    /* 当body有scrolled类时，提示消失 */
}

/* --- 动画关键帧 --- */
@keyframes scroll-hint {
    0% {
        transform: translate(-50%, 0);
        opacity: 0;
    }

    50% {
        opacity: 1;
    }

    100% {
        transform: translate(-50%, 15px);
        opacity: 0;
    }
}

@keyframes spark-pulse {
    from {
        transform: scale(0.8);
        opacity: 0.7;
    }

    to {
        transform: scale(1.2);
        opacity: 1;
    }
}

@keyframes rotate {
    from {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }
}