:root {
    --font:
        "San Francisco", "SF Pro Display", "Helvetica Neue", system-ui,
        sans-serif;
    --accent: #00000080;
    --bg-start: #00eaff;
    --bg-middle: #7e7ef2;
    --bg-end: #ff0000;
    --text-color: #404046;
    --subtitle-color: #0000ff59;
}

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

body {
    font-family: var(--font);
    color: var(--text-color);
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    background: linear-gradient(
        135deg,
        var(--bg-start),
        var(--bg-middle),
        var(--bg-end)
    );
    background-size: 400% 400%;
    animation: subtlePulse 15s ease-in-out infinite alternate;
}

@keyframes subtlePulse {
    0% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
    100% {
        background-position: 0% 50%;
    }
}

/* ---------- 主容器 ---------- */
main {
    width: 90%;
    max-width: 700px;
    padding: 3rem 2rem;
    background: rgba(255, 255, 255, 0.55);
    backdrop-filter: blur(65px);
    border-radius: 10px;
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.08);
    box-sizing: border-box;
}

/* ---------- 文字样式 ---------- */
h1 {
    font-weight: 700;
    font-size: clamp(2rem, 6vw, 2.8rem);
    margin-bottom: 0.5em;
    letter-spacing: clamp(0.5px, 2vw, 1px);
}

.subtitle {
    font-weight: 400;
    font-size: clamp(1rem, 4vw, 1.2rem);
    color: var(--subtitle-color);
    margin-bottom: 1.5em;
    letter-spacing: clamp(1px, 4vw, 3.5px);
}

.intro {
    font-size: clamp(0.9rem, 3vw, 1.05rem);
    line-height: 1.6;
    color: #2c2c2e;
    margin-bottom: 2em;
    letter-spacing: 0.5px;
}

/* ---------- 导航链接 ---------- */
nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
}

nav a {
    font-weight: 500;
    font-size: clamp(0.9rem, 3vw, 1rem);
    color: var(--accent);
    text-decoration: none;
    transition:
        color 0.3s,
        transform 0.3s;
}

nav a:hover {
    color: #000;
    transform: translateY(-2px);
}

/* ---------- 动态立体文字效果 ---------- */
.floating-text {
    text-shadow:
        0 2px 4px rgba(0, 0, 0, 0.1),
        0 4px 8px rgba(0, 0, 0, 0.08),
        0 8px 16px rgba(0, 0, 0, 0.06);
    animation: floatText 4s ease-in-out infinite alternate;
}

@keyframes floatText {
    0% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-4px);
    }
    100% {
        transform: translateY(0px);
    }
}

/* ---------- 媒体查询优化 ---------- */
@media (max-width: 480px) {
    main {
        padding: 2rem 1rem;
        border-radius: 12px;
    }

    h1 {
        font-size: 2rem;
        letter-spacing: 0.5px;
    }

    .subtitle {
        font-size: 1rem;
        letter-spacing: 1px;
    }

    .intro {
        font-size: 0.95rem;
        line-height: 1.5;
    }

    nav a {
        font-size: 0.9rem;
    }
}