/* ============================================
 * 课粒工坊 · 氛围增强层 v4（Ambient Enhance v4）
 *
 * v4 变更（双模式卡片玻璃）：
 *  - 日间模式：动态聚光跟随鼠标（明亮、有互动感）
 *  - 夜间模式：静止玻璃 + 菲涅尔边缘反光（沉稳、高级）
 *
 * 本文件职责：极光 / 双模式玻璃效果 / 导航底线 / reduced-motion
 *
 * 已移至 handdrawn-enhance.css（唯一来源）：
 *   四角装饰(.corner-ornament) / 漂浮碎片(.floating-doodle) / 滚动条 / 选中文字 / Focus
 * handdrawn-enhance.css 职责：下划线 / 徽章 / 按钮 / 分隔线 / 标题装饰 / 加载动画 / 滚动条 / 选中 / focus
 * ============================================ */

/* ========== 极光微光（夜间顶部，纯 CSS 动画） ========== */
.aurora-layer {
    position: fixed;
    top: 0; left: 0;
    width: 100%; height: 35vh;
    pointer-events: none;
    z-index: 0;
    opacity: 0;
    transition: opacity 3s ease;
    overflow: hidden;
}
body:not([data-theme="day"]) .aurora-layer { opacity: 1; }
.aurora-layer::before {
    content: '';
    position: absolute; inset: 0;
    background: linear-gradient(180deg,
        rgba(124,58,237,0.04) 0%, rgba(99,102,241,0.03) 30%,
        rgba(56,189,248,0.02) 55%, transparent 100%);
    animation: auroraShift 20s ease-in-out infinite alternate;
}
@keyframes auroraShift {
    0%   { transform: translateX(-5%) skewX(-3deg); filter: hue-rotate(0deg); }
    33%  { transform: translateX(3%) skewX(2deg);   filter: hue-rotate(15deg); }
    66%  { transform: translateX(-2%) skewX(-1deg);  filter: hue-rotate(-10deg); }
    100% { transform: translateX(5%) skewX(3deg);   filter: hue-rotate(5deg); }
}
.aurora-wave {
    position: absolute; width: 200%; height: 100%;
    left: -50%; top: 0;
    background: repeating-linear-gradient(95deg,
        transparent 0px, rgba(168,139,250,0.015) 80px,
        rgba(56,189,248,0.01) 160px, transparent 240px);
    animation: auroraWaveDrift 30s linear infinite;
}
@keyframes auroraWaveDrift {
    from { transform: translateX(0); }
    to   { transform: translateX(50%); }
}

/* ========== 纸张纹理（白天） — 极简处理 ========== */
[data-theme="day"] body::after {
    content: ''; position:fixed; top:0; left:0;
    width:100%; height:100%;
    pointer-events:none; z-index:0;
    opacity: 0;
}

/* ========== 导航栏底部紫黄渐变线（复用登录卡片设计） ========== */
.navbar::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 8%;
    right: 25%;
    height: 1px;
    background: linear-gradient(90deg,
        transparent,
        rgba(167, 139, 250, 0.55) 30%,
        rgba(251, 191, 36, 0.45) 70%,
        transparent
    );
    opacity: 0.75;
    pointer-events: none;
}
/* 日间模式：靛蓝→金黄渐变（与登录卡片 .login-card::before 统一） */
[data-theme="day"] .navbar::after {
    background: linear-gradient(90deg,
        transparent,
        var(--primary-light, rgba(123, 150, 255, 0.5)) 30%,
        var(--accent-light, rgba(251, 191, 36, 0.5)) 70%,
        transparent
    );
    opacity: 0.55;
}

/* ========== 减少动画偏好适配 ========== */
@media (prefers-reduced-motion: reduce) {
    .aurora-layer::before,
    .aurora-wave,
    .card-shine {
        animation: none !important;
        display: none !important;
    }
    .aurora-layer { display: none !important; }
    #mouse-glow { display: none !important; }
}