:root {
    --primary-color: #639cf1;
    --primary-hover: #4686e5;
    --bg-overlay: rgba(58, 71, 99, 0.3);
    --card-bg: rgba(30, 41, 59, 0.5);
    --border-radius: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --text-white: #e2e8f0;
    --text-dark: #1e293b;
    --glass-white: rgba(255, 255, 255, 0.55);
    --glass-white-hover: rgba(255, 255, 255, 0.70);
    --shadow-sm: 0 8px 20px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 20px 40px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 20px 40px -12px rgba(0, 0, 0, 0.2);
}

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

/* ===== 主体、背景、分割线、内联积木 ===== */
body {
    position: relative;
    min-height: 100vh;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #1e293b, #1d1e20);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 2rem 1.5rem;
    color: var(--text-white);
    overflow-x: hidden;
    scrollbar-width: thin;
    scrollbar-color: rgba(255, 255, 255, 0.8);
}

.background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('../background.webp');
    background-size: cover;
    background-position: center;
    opacity: 0.2;
    z-index: -1;
}

hr {
    margin: 1rem auto 1.8rem auto;
    border: none;
    border-top: 1px solid rgba(255, 255, 255, 0.2);
    max-width: 100%;
    width: 100%;
}

code.inline {
    padding: 0.2rem 0.4rem;
    white-space: normal;
}

br {
    user-select: none;
    -webkit-user-drag: none;
    pointer-events: none;
}

.no-select {
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    pointer-events: none;
}

@media (max-width: 640px) {
    body {
        padding: 12px;
    }
}

/* 不允许底部页面的滚动条出现 */
::-webkit-scrollbar {
    width: 0px;
}