/**
 * 一键上滑按钮样式
 * Enhanced Back to Top Button Styles
 */

/* 基础按钮样式 - 精致小巧版 */
#back-to-top {
    position: fixed;
    bottom: 24px;
    right: 24px;
    z-index: 999;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow:
        0 6px 24px rgba(0, 0, 0, 0.1),
        0 2px 6px rgba(0, 0, 0, 0.06),
        inset 0 1px 0 rgba(255, 255, 255, 0.8);

    display: flex;
    align-items: center;
    justify-content: center;

    opacity: 0;
    visibility: hidden;
    transform: translateY(20px) scale(0.8);

    transition: all 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
    cursor: pointer;
    text-decoration: none;

    /* 防止文本选择 */
    user-select: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;

    /* 触摸优化 */
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
}

/* 按钮显示状态 */
#back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0) scale(1);
}

/* 悬停效果 - 精致小巧版 */
#back-to-top:hover {
    transform: translateY(-6px) scale(1.08);
    box-shadow:
        0 12px 36px rgba(59, 130, 246, 0.2),
        0 6px 18px rgba(0, 0, 0, 0.12),
        inset 0 1px 0 rgba(255, 255, 255, 0.9);
    background: rgba(255, 255, 255, 1);
    border-color: rgba(59, 130, 246, 0.2);
}

/* 点击效果 - 精致小巧版 */
#back-to-top:active,
#back-to-top.clicking {
    transform: translateY(-4px) scale(1.03);
    transition: all 0.1s ease;
    box-shadow:
        0 8px 24px rgba(59, 130, 246, 0.25),
        0 4px 12px rgba(0, 0, 0, 0.15),
        inset 0 1px 0 rgba(255, 255, 255, 1);
}

/* 图标样式优化 - 完美居中 */
#back-to-top img {
    width: 16px;
    height: 16px;
    transition: all 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
    filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.1));

    /* 确保图标完美居中 */
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 2;
}

#back-to-top:hover img {
    transform: translate(-50%, -50%) translateY(-2px);
    filter: drop-shadow(0 2px 4px rgba(59, 130, 246, 0.3));
}

/* 脉冲动画效果 */
#back-to-top::before {
    content: '';
    position: absolute;
    top: -2px;
    left: -2px;
    right: -2px;
    bottom: -2px;
    border-radius: 50%;
    background: linear-gradient(45deg,
            rgba(59, 130, 246, 0.3),
            rgba(147, 197, 253, 0.2),
            rgba(59, 130, 246, 0.3));
    opacity: 0;
    animation: pulse-ring 2s cubic-bezier(0.455, 0.03, 0.515, 0.955) infinite;
    z-index: -1;
}

#back-to-top:hover::before {
    animation-duration: 1s;
    opacity: 1;
}

/* 内部光晕效果 */
#back-to-top::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.3) 0%, transparent 70%);
    transform: translate(-50%, -50%);
    transition: all 0.3s ease;
    z-index: -1;
}

#back-to-top:hover::after {
    width: 100%;
    height: 100%;
}

/* 进度环样式 - 精致小巧版 */
.back-to-top-progress {
    position: absolute;
    top: -2px;
    left: -2px;
    width: 48px;
    height: 48px;
    pointer-events: none;
    z-index: -1;
}

.progress-ring {
    width: 48px;
    height: 48px;
    transform: rotate(-90deg);
    transition: all 0.3s ease;
}

.progress-ring-circle {
    r: 22;
    cx: 24;
    cy: 24;
    fill: transparent;
    stroke: rgba(59, 130, 246, 0.3);
    stroke-width: 2;
    stroke-linecap: round;
    transition: stroke-dashoffset 0.1s ease, stroke 0.3s ease;
}

/* 涟漪效果 */
.ripple-effect {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(59, 130, 246, 0.3);
    transform: translate(-50%, -50%);
    pointer-events: none;
    z-index: -1;
}

.ripple-effect.active {
    animation: rippleExpand 0.6s ease-out;
}

/* 动画关键帧 */
@keyframes pulse-ring {
    0% {
        transform: scale(0.8);
        opacity: 1;
    }

    80% {
        transform: scale(1.2);
        opacity: 0;
    }

    100% {
        transform: scale(1.3);
        opacity: 0;
    }
}

@keyframes backToTopSlideIn {
    0% {
        opacity: 0;
        visibility: hidden;
        transform: translateY(20px) scale(0.8) rotate(180deg);
    }

    100% {
        opacity: 1;
        visibility: visible;
        transform: translateY(0) scale(1) rotate(0deg);
    }
}

@keyframes backToTopSlideOut {
    0% {
        opacity: 1;
        visibility: visible;
        transform: translateY(0) scale(1) rotate(0deg);
    }

    100% {
        opacity: 0;
        visibility: hidden;
        transform: translateY(20px) scale(0.8) rotate(-180deg);
    }
}

@keyframes backToTopBounce {

    0%,
    100% {
        transform: translateY(0) scale(1);
    }

    25% {
        transform: translateY(-8px) scale(1.1);
    }

    50% {
        transform: translateY(-4px) scale(1.05);
    }

    75% {
        transform: translateY(-2px) scale(1.02);
    }
}

@keyframes rippleExpand {
    0% {
        width: 0;
        height: 0;
        opacity: 0.8;
    }

    100% {
        width: 88px;
        height: 88px;
        opacity: 0;
    }
}

/* 增强版按钮特殊状态 */
#back-to-top[data-enhanced="true"].hover-active .progress-ring-circle {
    stroke: rgba(59, 130, 246, 0.8);
    stroke-width: 3;
}

#back-to-top[data-enhanced="true"].touch-active {
    transform: translateY(-4px) scale(0.95);
}

#back-to-top[data-enhanced="true"].clicking {
    transform: translateY(-6px) scale(1.05);
}

/* 移动端隐藏一键上滑按钮 */
@media (max-width: 768px) {
    #back-to-top {
        display: none !important;
        visibility: hidden !important;
        opacity: 0 !important;
        pointer-events: none !important;
    }

    #back-to-top img {
        width: 16px;
        height: 16px;
    }

    #back-to-top:hover {
        transform: translateY(-3px) scale(1.05);
    }

    #back-to-top:active,
    #back-to-top.clicking {
        transform: translateY(-2px) scale(1.02);
    }

    /* 移动端进度条优化 */
    .back-to-top-progress {
        width: 48px;
        height: 48px;
        top: -2px;
        left: -2px;
    }

    .progress-ring {
        width: 48px;
        height: 48px;
    }

    .progress-ring-circle {
        r: 22;
        cx: 24;
        cy: 24;
        stroke-width: 2.5;
        stroke: rgba(59, 130, 246, 0.4);
    }

    /* 移动端进度条激活状态 */
    #back-to-top[data-enhanced="true"].hover-active .progress-ring-circle {
        stroke: rgba(59, 130, 246, 0.8);
        stroke-width: 3;
    }

    /* 移动端涟漪效果调整 */
    .ripple-effect.active {
        animation: rippleExpandMobile 0.5s ease-out;
    }

    @keyframes rippleExpandMobile {
        0% {
            width: 0;
            height: 0;
            opacity: 0.6;
        }

        100% {
            width: 80px;
            height: 80px;
            opacity: 0;
        }
    }
}

/* 小屏幕设备 - 精致小巧版 */
@media (max-width: 480px) {
    #back-to-top {
        width: 36px;
        height: 36px;
        bottom: 14px;
        right: 14px;
    }

    #back-to-top img {
        width: 12px;
        height: 12px;
    }

    #back-to-top:hover {
        transform: translateY(-2px) scale(1.03);
    }

    #back-to-top:active,
    #back-to-top.clicking {
        transform: translateY(-1px) scale(1.01);
    }

    .back-to-top-progress {
        width: 40px;
        height: 40px;
    }

    .progress-ring {
        width: 40px;
        height: 40px;
    }

    .progress-ring-circle {
        r: 18;
        cx: 20;
        cy: 20;
    }
}

/* 高对比度模式支持 */
@media (prefers-contrast: high) {
    #back-to-top {
        background: #ffffff;
        border: 2px solid #000000;
        box-shadow: 0 4px 8px rgba(0, 0, 0, 0.3);
    }

    #back-to-top:hover {
        background: #f0f0f0;
        border-color: #333333;
    }
}

/* 减少动画偏好支持 */
@media (prefers-reduced-motion: reduce) {
    #back-to-top {
        transition: opacity 0.2s ease, visibility 0.2s ease;
    }

    #back-to-top::before {
        animation: none;
    }

    #back-to-top:hover {
        transform: none;
    }

    .progress-ring-circle {
        transition: none;
    }

    .ripple-effect.active {
        animation: none;
    }

    #back-to-top[data-enhanced="true"] {
        animation: none !important;
    }
}

/* 暗色主题支持 */
@media (prefers-color-scheme: dark) {
    #back-to-top {
        background: rgba(30, 30, 30, 0.95);
        border-color: rgba(255, 255, 255, 0.1);
        box-shadow:
            0 8px 32px rgba(0, 0, 0, 0.3),
            0 2px 8px rgba(0, 0, 0, 0.2),
            inset 0 1px 0 rgba(255, 255, 255, 0.1);
    }

    #back-to-top:hover {
        background: rgba(40, 40, 40, 1);
        border-color: rgba(59, 130, 246, 0.4);
        box-shadow:
            0 16px 48px rgba(59, 130, 246, 0.2),
            0 8px 24px rgba(0, 0, 0, 0.3),
            inset 0 1px 0 rgba(255, 255, 255, 0.2);
    }

    #back-to-top img {
        filter: invert(1) drop-shadow(0 1px 2px rgba(255, 255, 255, 0.1));
    }

    #back-to-top:hover img {
        filter: invert(1) drop-shadow(0 2px 4px rgba(59, 130, 246, 0.3));
    }
}

/* 键盘导航支持 */
#back-to-top:focus {
    outline: 2px solid #3b82f6;
    outline-offset: 2px;
}

#back-to-top:focus:not(:focus-visible) {
    outline: none;
}

/* 打印样式 */
@media print {
    #back-to-top {
        display: none !important;
    }
}

/* 横屏模式优化 */
@media (orientation: landscape) and (max-height: 500px) {
    #back-to-top {
        bottom: 10px;
        right: 10px;
        width: 40px;
        height: 40px;
    }

    #back-to-top img {
        width: 16px;
        height: 16px;
    }
}