:root {
    /* 🌞 Light Mode */
    --bg-color: #f8f9fa;
    --dot-color: #cbd5e1;

    --ui-bg: rgba(255, 255, 255, 0.85);
    --ui-border: rgba(255, 255, 255, 0.8);
    --ui-shadow: 0 8px 32px rgba(31, 38, 135, 0.08);
    --ui-text: #334155;
    --ui-text-dim: #64748b;
    --ui-hover-bg: rgba(0, 0, 0, 0.04);
    --ui-selection-bg: rgba(37, 130, 146, 0.1);

    --logo-gradient: linear-gradient(135deg, #258292 0%, #1a6b78 100%);
    --logo-text: #ffffff;

    --node-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --node-shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);

    --select-color: #258292;
    --group-bg: rgba(37, 130, 146, 0.05);
    --group-border: #258292;
    --link-color: #94a3b8;

    /* 节点配色 */
    --c-white-bg: #ffffff;
    --c-white-border: #e2e8f0;
    --c-white-text: #1e293b;

    --c-red-bg: #fee2e2;
    --c-red-border: #fecaca;
    --c-red-text: #991b1b;
    --c-yellow-bg: #fef3c7;
    --c-yellow-border: #fde68a;
    --c-yellow-text: #92400e;
    --c-green-bg: #d1fae5;
    --c-green-border: #a7f3d0;
    --c-green-text: #065f46;
    --c-blue-bg: #e0e7ff;
    --c-blue-border: #c7d2fe;
    --c-blue-text: #3730a3;
    --c-orange-bg: #ffedd5;
    --c-orange-border: #fed7aa;
    --c-orange-text: #9a3412;
    --c-purple-bg: #f3e8ff;
    --c-purple-border: #d8b4fe;
    --c-purple-text: #6b21a8;
    --c-pink-bg: #fce7f3;
    --c-pink-border: #fbcfe8;
    --c-pink-text: #9d174d;
    --c-cyan-bg: #cffafe;
    --c-cyan-border: #a5f3fc;
    --c-cyan-text: #155e75;

    --c-danger: #ef4444;
    --c-danger-text: #ffffff;
    --text-selection-bg: rgba(37, 130, 146, 0.3); /* 稍微透明的 --select-color */
}

/* 🌙 Dark Mode */
[data-theme="dark"] {
    --bg-color: #111827;
    --dot-color: #374151;

    --ui-bg: rgba(31, 41, 55, 0.85);
    --ui-border: rgba(255, 255, 255, 0.05);
    --ui-shadow: 0 10px 40px rgba(0, 0, 0, 0.4);
    --ui-text: #f1f5f9;
    --ui-text-dim: #94a3b8;
    --ui-hover-bg: rgba(255, 255, 255, 0.1);

    --logo-gradient: linear-gradient(135deg, #38b2ac 0%, #258292 100%);

    --node-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --node-shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.4);

    --select-color: #38b2ac;
    --group-bg: rgba(56, 178, 172, 0.1);
    --group-border: #258292;
    --link-color: #64748b;

    --c-white-bg: #1f2937;
    --c-white-border: #374151;
    --c-white-text: #f3f4f6;
    --c-red-bg: #450a0a;
    --c-red-border: #7f1d1d;
    --c-red-text: #fecaca;
    --c-yellow-bg: #451a03;
    --c-yellow-border: #78350f;
    --c-yellow-text: #fde68a;
    --c-green-bg: #064e3b;
    --c-green-border: #065f46;
    --c-green-text: #a7f3d0;
    --c-blue-bg: #1e1b4b;
    --c-blue-border: #312e81;
    --c-blue-text: #c7d2fe;
    --c-orange-bg: #431407;
    --c-orange-border: #7c2d12;
    --c-orange-text: #fdba74;
    --c-purple-bg: #3b0764;
    --c-purple-border: #6b21a8;
    --c-purple-text: #d8b4fe;
    --c-pink-bg: #500724;
    --c-pink-border: #831843;
    --c-pink-text: #fbcfe8;
    --c-cyan-bg: #083344;
    --c-cyan-border: #164e63;
    --c-cyan-text: #67e8f9;
    --text-selection-bg: rgba(56, 178, 172, 0.4);
}

/* --- 全局文本高亮优化 --- */
::selection {
    background-color: var(--text-selection-bg);
    color: inherit;
}

/* 针对节点编辑时的特定处理 */
.node.editing::selection {
    background-color: var(--text-selection-bg);
}

/* 确保 textarea 也遵循同样的风格 */
textarea::selection {
    background-color: var(--text-selection-bg);
}

body,
html {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    background-image: radial-gradient(var(--dot-color) 1.5px, transparent 1.5px);
    background-size: 24px 24px;
    color: var(--ui-text);
    user-select: none;
    transition: background-color 0.3s, color 0.3s;
}

body.mode-space {
    cursor: grab;
}

body.mode-pan {
    cursor: grabbing;
}

body.mode-space * {
    cursor: grab !important;
}

body.mode-pan * {
    cursor: grabbing !important;
}

/* --- UI Panel --- */
#ui-layer {
    position: absolute;
    top: 24px;
    left: 24px;
    z-index: 1000;
    /* 收起状态 */
    width: 48px;
    height: 48px;

    border-radius: 14px;
    background: var(--ui-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--ui-border);
    box-shadow: var(--ui-shadow);
    overflow: visible;
    display: flex;
    flex-direction: column;
    color: var(--ui-text);

    transition:
        width 0.3s cubic-bezier(0.16, 1, 0.3, 1) 0.15s,
        height 0.3s cubic-bezier(0.16, 1, 0.3, 1) 0.15s,
        border-radius 0.3s;
}

#ui-layer:hover,
#ui-layer:focus-within {
    width: 340px;
    height: auto;
    border-radius: 18px;
    transition:
        width 0.3s cubic-bezier(0.16, 1, 0.3, 1) 0s,
        height 0.3s cubic-bezier(0.16, 1, 0.3, 1) 0s;
}

/* ✨ 新增：移动端激活状态 (无动画，防止布局崩坏) */
#ui-layer.mobile-active {
    width: 340px;
    height: auto;
    border-radius: 18px;
    /* 关键：取消过渡，直接瞬开 */
    transition: none !important; 
}

/* 顶部栏容器 */
#ui-top-bar {
    height: 48px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    padding: 0 6px;
    /* 微调内边距 */
    box-sizing: border-box;
}

/* ✨ Logo 区域 - 重新设计 */
#ui-logo-box {
    width: 36px;
    height: 36px;
    /* border-radius: 10px;
    background: var(--logo-gradient); */
    display: flex;
    align-items: center;
    justify-content: center;
    /* color: var(--logo-text); */
    font-size: 18px;
    flex-shrink: 0;
    /* box-shadow: 0 2px 8px rgba(99, 102, 241, 0.3); */
    /* 默认在左上角 */
}

/* 标题和按钮容器 */
#ui-header-content {
    display: flex;
    align-items: center;
    flex-grow: 1;
    overflow: visible;
    opacity: 0;
    pointer-events: none;
    margin-left: 12px;
    transition: opacity 0.15s ease-out 0s;
}

#ui-layer:hover #ui-header-content,
#ui-layer:focus-within #ui-header-content {
    opacity: 1;
    pointer-events: auto;
    transition: opacity 0.3s ease-out 0.2s;
}

#ui-layer.mobile-active #ui-header-content {
    opacity: 1;
    pointer-events: auto;
    transition: none !important; /* 移动端瞬现 */
}


#ui-layer:hover #ui-content,
#ui-layer:focus-within #ui-content {
    opacity: 1;
    height: auto;
    overflow: visible;
    transition: opacity 0.3s ease-out 0.2s;
}

#ui-layer.mobile-active #ui-content {
    opacity: 1;
    height: auto;
    overflow: visible;
    transition: none !important; /* 移动端瞬现 */
}

/* Title - 重新设计 */
#ui-title {
    font-weight: 700;
    font-size: 15px;
    flex-grow: 1;
    white-space: nowrap;
    letter-spacing: -0.02em;
    color: var(--ui-text);
}

/* 顶部功能按钮 (Theme & Help) - 重新设计 */
.header-btn {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    border: none;
    background: transparent;
    color: var(--ui-text-dim);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
    margin-left: 4px;
    position: relative;
    /* For tooltip positioning */
}

.header-btn svg {
    width: 18px;
    height: 18px;
    fill: none;
    stroke: currentColor;
}

.header-btn:hover {
    background: var(--ui-hover-bg);
    color: var(--ui-text);
}

.header-btn.active {
    background: var(--select-color);
    color: white;
}

/* 内容区域 */
#ui-content {
    padding: 0 16px 16px 16px;
    opacity: 0;
    display: flex;
    flex-direction: column;
    gap: 12px;
    transition: opacity 0.15s ease-out 0s;
    overflow: hidden;
    height: 0;
    /* 收起时高度为0，防止撑开 */
}

#ui-layer:hover #ui-content,
#ui-layer:focus-within #ui-content {
    opacity: 1;
    height: auto;
    overflow: visible;
    transition: opacity 0.3s ease-out 0.2s;
}

textarea {
    width: 100%;
    height: 80px;
    resize: none;
    border: 1px solid var(--dot-color);
    border-radius: 10px;
    padding: 12px;
    font-family: inherit;
    font-size: 14px;
    background: rgba(255, 255, 255, 0.05);
    color: inherit;
    outline: none;
    box-sizing: border-box;
    transition: border-color 0.2s, background-color 0.2s;
    line-height: 1.5;
}

textarea:focus {
    border-color: var(--select-color);
    background: var(--bg-color);
}

.btn-row {
    display: flex;
    gap: 10px;
    align-items: stretch;
    /* 确保所有元素高度一致 */
}

#export-container,
#btn-import,
#btn-clear {
    flex: 1;
    min-width: 0;
    /* 防止溢出 */
}

/* 统一内部按钮样式 */
.btn-row button.secondary {
    width: 100%;
    height: 100%;
    /* 填满父容器高度 */
    padding: 10px 0;
    font-size: 13px;
}

/* --- Toast 提示样式 --- */
#toast-container {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 9999;
    pointer-events: none;
}

.toast {
    background: var(--ui-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--ui-border);
    color: var(--select-color);
    padding: 10px 20px;
    border-radius: 12px;
    font-size: 14px;
    font-weight: 600;
    box-shadow: var(--ui-shadow);
    margin-top: 10px;
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    pointer-events: auto;
    display: flex;
    align-items: center;
    gap: 12px;
}

.toast.show {
    opacity: 1;
    transform: translateY(0);
}


.toast-actions {
    display: flex;
    gap: 8px;
    margin-left: 8px;
    border-left: 1px solid var(--dot-color);
    padding-left: 12px;
}

.btn-toast {
    background: transparent;
    border: 1px solid var(--select-color);
    color: var(--select-color);
    padding: 2px 8px;
    border-radius: 6px;
    font-size: 12px;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-toast:hover {
    background: var(--select-color);
    color: white;
}

button.primary {
    width: 100%;
    padding: 10px;
    cursor: pointer;
    background: var(--select-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    font-size: 13px;
    transition: transform 0.1s, opacity 0.2s;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

button.primary:active {
    transform: scale(0.98);
}

button.primary:hover {
    opacity: 0.9;
}

button.secondary {
    flex: 1;
    padding: 8px;
    cursor: pointer;
    background: transparent;
    color: var(--ui-text);
    border: 1px solid var(--dot-color);
    border-radius: 8px;
    font-size: 13px;
    font-weight: 500;
    transition: all 0.2s;
}

button.secondary:hover {
    background: var(--ui-hover-bg);
    border-color: var(--ui-text-dim);
}

button.btn-danger {
    background: var(--c-danger);
    color: var(--c-danger-text);
    border-color: var(--c-danger);
}

button.btn-danger:hover {
    background: #dc2626;
    opacity: 1;
}

/* 帮助菜单 */
#help-modal {
    position: absolute;
    top: 52px;
    right: 0;
    width: 280px;
    background: var(--ui-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--ui-border);
    box-shadow: var(--ui-shadow);
    border-radius: 14px;
    padding: 16px;
    opacity: 0;
    pointer-events: none;
    transform: translateY(-8px) scale(0.98);
    transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
    z-index: 2000;
    text-align: left;
    transform-origin: top right;
}

#help-modal.show {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0) scale(1);
}

.help-row {
    margin-bottom: 10px;
    font-size: 13px;
    color: var(--ui-text);
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    border-bottom: 1px dashed var(--dot-color);
    padding-bottom: 6px;
}

.help-row:last-of-type {
    border-bottom: none;
    margin-bottom: 16px;
}

.help-desc {
    opacity: 0.75;
    font-weight: 500;
}

.help-keys {
    font-family: monospace;
    font-size: 12px;
    background: var(--ui-hover-bg);
    padding: 2px 6px;
    border-radius: 4px;
    color: var(--ui-text);
}

/* GitHub Link */
.github-link {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    text-decoration: none;
    font-size: 13px;
    color: var(--ui-text);
    background: var(--ui-hover-bg);
    padding: 8px;
    border-radius: 8px;
    transition: background 0.2s;
    margin-top: 8px;
    font-weight: 500;
}

.github-link:hover {
    background: rgba(0, 0, 0, 0.08);
}

[data-theme="dark"] .github-link:hover {
    background: rgba(255, 255, 255, 0.15);
}

/* --- Canvas Elements --- */
#canvas-container {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    overflow: hidden;
    touch-action: none; 
}

#world {
    position: absolute;
    top: 0;
    left: 0;
    transform-origin: 0 0;
}

.node {
    position: absolute;
    border: 1px solid transparent;
    border-radius: 12px;
    padding: 12px 20px;
    min-width: 60px;
    text-align: center;
    box-shadow: var(--node-shadow);
    font-size: 14px;
    font-weight: 500;
    cursor: grab;
    white-space: nowrap;
    z-index: 10;
    transition: box-shadow 0.2s, transform 0.1s;
}

.node:hover {
    box-shadow: var(--node-shadow-hover);
}

.node.selected {
    border: 2px solid var(--select-color) !important;
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.2), var(--node-shadow) !important;
    z-index: 50;
}

.node.editing {
    cursor: text;
    border-color: var(--select-color) !important;
    outline: none;
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.2);
    user-select: text;
    -webkit-user-select: text;
}

.node.c-white {
    background: var(--c-white-bg);
    border-color: var(--c-white-border);
    color: var(--c-white-text);
}

.node.c-red {
    background: var(--c-red-bg);
    border-color: var(--c-red-border);
    color: var(--c-red-text);
}

.node.c-yellow {
    background: var(--c-yellow-bg);
    border-color: var(--c-yellow-border);
    color: var(--c-yellow-text);
}

.node.c-green {
    background: var(--c-green-bg);
    border-color: var(--c-green-border);
    color: var(--c-green-text);
}

.node.c-blue {
    background: var(--c-blue-bg);
    border-color: var(--c-blue-border);
    color: var(--c-blue-text);
}

.node.c-orange {
    background: var(--c-orange-bg);
    border-color: var(--c-orange-border);
    color: var(--c-orange-text);
}

.node.c-purple {
    background: var(--c-purple-bg);
    border-color: var(--c-purple-border);
    color: var(--c-purple-text);
}

.node.c-pink {
    background: var(--c-pink-bg);
    border-color: var(--c-pink-border);
    color: var(--c-pink-text);
}

.node.c-cyan {
    background: var(--c-cyan-bg);
    border-color: var(--c-cyan-border);
    color: var(--c-cyan-text);
}

.group {
    position: absolute;
    border: 2px dashed var(--group-border);
    background: var(--group-bg);
    border-radius: 20px;
    z-index: 5;
    pointer-events: all;
    transition: background 0.2s;
}

.group.selected {
    border-color: var(--select-color);
    background: rgba(99, 102, 241, 0.15);
}

svg.connections {
    position: absolute;
    top: 0;
    left: 0;
    overflow: visible;
    z-index: 1;
    pointer-events: none;
}

line.link {
    stroke: var(--link-color);
    stroke-width: 2;
    opacity: 0.5;
}

#selection-box {
    position: absolute;
    border: 1px solid var(--select-color);
    background: var(--ui-selection-bg);
    display: none;
    z-index: 999;
    border-radius: 4px;
    pointer-events: none;
}

/* 复用帮助面板的样式，增加一些设置专用的 */
.help-modal-style {
    position: absolute;
    top: 52px;
    right: 0;
    width: 220px;
    background: var(--ui-bg);
    backdrop-filter: blur(16px);
    border: 1px solid var(--ui-border);
    box-shadow: var(--ui-shadow);
    border-radius: 14px;
    padding: 12px;
    opacity: 0;
    pointer-events: none;
    transform: translateY(-8px) scale(0.98);
    transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
    z-index: 2000;
    transform-origin: top right;
}

#settings-modal.show {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0) scale(1);
}

.settings-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 13px;
    color: var(--ui-text);
    padding: 4px 0;
}

/* 简单的复选框样式 */
input[type="checkbox"] {
    cursor: pointer;
    width: 16px;
    height: 16px;
    accent-color: var(--select-color);
}

body.hide-grid {
    background-image: none !important;
}

/* --- 手写风格全局样式 --- */
.hand-drawn-style {
    /* 英文使用 Architects Daughter，中文自动回退到 LXGW WenKai Mono TC */
    font-family: 'Architects Daughter', 'LXGW WenKai Mono TC', cursive !important;
}

/* 配合手写字体，节点可以稍微增加一点点倾斜感 */
.hand-drawn-style .node {
    letter-spacing: 0.05em;
    /* 给边框增加一点点不规则圆角，增加“手绘感” */
    border-radius: 255px 15px 225px 15px/15px 225px 15px 255px !important;
}

/* 按钮也同步变换字体 */
.hand-drawn-style button,
.hand-drawn-style textarea {
    font-family: 'Architects Daughter', 'LXGW WenKai Mono TC', cursive !important;
}

/* --- 空状态引导样式 --- */
.empty-state {
    position: absolute;
    top: 70px;
    /* 位于 UI 面板下方 */
    left: 40px;
    z-index: 0;
    /* 放在节点底层 */
    color: var(--select-color);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.5s ease;
    display: none;
    /* 默认隐藏，由 JS 控制 */
}

/* 当画布为空时显示 */
body.is-empty .empty-state {
    display: block;
    opacity: 0.6;
}

.empty-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.arrow-svg {
    width: 80px;
    height: 80px;
    transform: rotate(-10deg);
    /* 增加一个微弱的呼吸动画 */
    animation: arrow-bob 2s infinite ease-in-out;
}

.empty-state p {
    font-size: 16px;
    font-weight: 500;
    margin: 0;
    white-space: nowrap;
}

/* 手绘风格适配 */
.hand-drawn-style .empty-state p {
    font-family: 'Architects Daughter', 'LXGW WenKai Mono TC', cursive !important;
    font-size: 18px;
}

@keyframes arrow-bob {

    0%,
    100% {
        transform: translate(0, 0) rotate(-10deg);
    }

    50% {
        transform: translate(-5px, -5px) rotate(-15deg);
    }
}

/* --- 动作堆叠容器 --- */
.action-stack {
    position: relative;
    height: 38px;
    overflow: hidden;
    perspective: 1000px;
}

.stack-front,
.stack-back {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    gap: 10px;
    transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

/* 初始状态：正面在场，反面在下方旋转 */
.stack-back {
    transform: translateY(100%) rotateX(-90deg);
    opacity: 0;
    pointer-events: none;
}

/* 激活导出状态 */
.action-stack.is-exporting .stack-front {
    transform: translateY(-100%) rotateX(90deg);
    opacity: 0;
    pointer-events: none;
}

.action-stack.is-exporting .stack-back {
    transform: translateY(0) rotateX(0deg);
    opacity: 1;
    pointer-events: auto;
}

/* --- 链接节点专用样式 --- */
.node.is-link {
    font-size: 12px; /* 字体变小 */
    padding: 8px 16px; /* 稍微减小内边距让它更紧凑 */
    max-width: 240px; /* 限制最大宽度，拒绝大胶囊 */
    color: var(--select-color); /* 使用主题色，或者保持默认色 */
}

/* 链接文本容器：负责截断长网址 */
.node-text {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    text-decoration: underline; /* 下划线 */
    text-decoration-color: rgba(0, 0, 0, 0.2);
    pointer-events: none; /* 让点击穿透到 node，保证拖拽体验 */
}

/* 跳转按钮：悬浮在右侧 */
.link-btn {
    position: absolute;
    right: -32px; /* 移出节点外部 */
    top: 50%;
    transform: translateY(-50%) scale(0.8);
    width: 24px;
    height: 24px;
    
    background: var(--bg-color); /* 遮挡背后的网格线 */
    border: 1px solid var(--select-color);
    border-radius: 50%;
    
    display: flex;
    align-items: center;
    justify-content: center;
    
    font-size: 12px;
    color: var(--select-color);
    cursor: pointer;
    
    opacity: 0;
    pointer-events: none;
    transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.1);
    z-index: 100;
}

/* 只有当节点被选中时，按钮才出现 */
.node.selected .link-btn {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(-50%) scale(1);
}

.link-btn:hover {
    background: var(--select-color);
    color: white;
    transform: translateY(-50%) scale(1.1);
}

/* 手写模式适配：下划线改为波浪线可能更有趣，或者保持简单 */
.hand-drawn-style .node-text {
    text-decoration-style: solid; 
}

.help-footer-row {
    display: flex;
    gap: 8px;
    margin-top: 12px;
    padding-top: 12px;
    border-top: 1px dashed var(--dot-color);
}

.help-action-btn {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    font-size: 12px;
    color: var(--ui-text);
    background: var(--ui-hover-bg);
    padding: 8px 0;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.2s;
    font-family: inherit; /* 继承手写字体 */
}

.help-action-btn:hover {
    background: rgba(0, 0, 0, 0.08);
    transform: translateY(-1px);
}
[data-theme="dark"] .help-action-btn:hover {
    background: rgba(255, 255, 255, 0.15);
}

/* --- About Overlay & Card --- */
.modal-overlay {
    position: fixed;
    top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(0, 0, 0, 0.2);
    backdrop-filter: blur(4px);
    z-index: 3000;
    display: flex;
    align-items: center;
    justify-content: center;
    
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s;
}

.modal-overlay.show {
    opacity: 1;
    pointer-events: auto;
}

#about-card {
    width: 320px;
    background: var(--ui-bg);
    border: 1px solid var(--ui-border);
    box-shadow: 0 20px 50px rgba(0,0,0,0.2);
    border-radius: 24px;
    padding: 32px 24px;
    text-align: center;
    position: relative;
    transform: scale(0.95) translateY(10px);
    transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.modal-overlay.show #about-card {
    transform: scale(1) translateY(0);
}

.about-logo { font-size: 48px; margin-bottom: 8px; }
.about-title { font-size: 24px; font-weight: 800; color: var(--select-color); margin-bottom: 4px; }
.about-version { font-size: 12px; color: var(--ui-text-dim); margin-bottom: 24px; font-family: monospace; }

.about-desc {
    font-size: 14px;
    line-height: 1.6;
    color: var(--ui-text);
    margin-bottom: 24px;
    opacity: 0.9;
}

.about-stats {
    font-size: 12px;
    color: var(--ui-text-dim);
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
}

.heart-icon { color: var(--c-danger); animation: heartbeat 1.5s infinite; }

.about-links {
    display: flex;
    gap: 12px;
    justify-content: center;
}

.about-link-item {
    padding: 8px 16px;
    border-radius: 20px;
    background: var(--ui-hover-bg);
    color: var(--ui-text);
    text-decoration: none;
    font-size: 13px;
    font-weight: 600;
    transition: all 0.2s;
}

.about-link-item:hover {
    background: var(--select-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(37, 130, 146, 0.2);
}

#btn-close-about {
    position: absolute;
    top: 16px; right: 16px;
    background: transparent; border: none;
    color: var(--ui-text-dim);
    cursor: pointer;
    font-size: 18px;
    padding: 4px;
    border-radius: 50%;
    width: 32px; height: 32px;
    display: flex; align-items: center; justify-content: center;
    transition: background 0.2s;
}
#btn-close-about:hover { background: var(--ui-hover-bg); color: var(--ui-text); }

@keyframes heartbeat {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.2); }
}

.about-title { 
    font-size: 24px; 
    font-weight: 800; 
    color: var(--select-color); 
    margin-bottom: 4px;
    font-family: inherit; /* 关键修改 */
}

/* Star 引导按钮 */
.about-stars {
    margin-bottom: 24px;
    display: flex;
    justify-content: center;
}

.btn-star {
    display: flex;
    align-items: center;
    padding: 8px 16px;
    background: var(--ui-bg);
    border: 1px solid var(--ui-border);
    border-radius: 8px;
    color: var(--ui-text);
    text-decoration: none;
    font-size: 13px;
    font-weight: 600;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
    transition: all 0.2s;
}

.btn-star:hover {
    background: #fffbeb; /* 极淡的黄色背景 */
    border-color: #fcd34d;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(251, 191, 36, 0.2);
}

[data-theme="dark"] .btn-star:hover {
    background: #422006;
    border-color: #f59e0b;
}

/* 博客链接样式 */
.about-link-item {
    font-size: 13px;
    color: var(--ui-text-dim); /* 低调处理 */
    text-decoration: none;
    padding: 4px 8px;
    border-radius: 6px;
    transition: color 0.2s;
}

.about-link-item:hover {
    color: var(--select-color);
    background: var(--ui-hover-bg);
}