/* ==========================================================================
   Hyper-Realistic 3D Rubik's Cube - Modern Glassmorphism Styling
   ========================================================================== */

:root {
    --bg-dark: #0f1117;
    --card-bg: rgba(22, 27, 38, 0.72);
    --card-border: rgba(255, 255, 255, 0.09);
    --card-hover: rgba(35, 42, 58, 0.85);
    --primary: #00f0ff;
    --primary-glow: rgba(0, 240, 255, 0.35);
    --accent: #ff0077;
    --accent-glow: rgba(255, 0, 119, 0.35);
    --text-main: #f0f4fc;
    --text-muted: #8e9bb2;
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    --radius-lg: 16px;
    --radius-md: 10px;
    --radius-sm: 6px;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    user-select: none;
    -webkit-user-select: none;
}

body, html {
    width: 100%;
    height: 100%;
    overflow: hidden;
    background-color: var(--bg-dark);
    font-family: var(--font-family);
    color: var(--text-main);
    touch-action: none;
}

#webgl-canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    display: block;
    z-index: 1;
}

/* ==========================================================================
   HUD & Overlay Container
   ========================================================================== */
.hud-layer {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 10;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    padding: 20px;
}

.hud-interactive {
    pointer-events: auto;
}

/* ==========================================================================
   Header & Navigation
   ========================================================================== */
.top-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    max-width: 1400px;
    margin: 0 auto;
    gap: 16px;
}

.brand-section {
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    padding: 8px 18px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--card-border);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
}

.brand-logo {
    width: 28px;
    height: 28px;
    filter: drop-shadow(0 0 8px var(--primary-glow));
}

.brand-title {
    font-size: 1.15rem;
    font-weight: 700;
    letter-spacing: 0.5px;
    background: linear-gradient(135deg, #ffffff 0%, var(--primary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Mode Navigation Pills */
.mode-tabs-container {
    display: flex;
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    padding: 5px;
    border-radius: 40px;
    border: 1px solid var(--card-border);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
    gap: 4px;
}

.mode-tab {
    background: transparent;
    border: none;
    color: var(--text-muted);
    font-size: 0.88rem;
    font-weight: 600;
    padding: 8px 16px;
    border-radius: 30px;
    cursor: pointer;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    align-items: center;
    gap: 6px;
}

.mode-tab:hover {
    color: var(--text-main);
}

.mode-tab.active {
    background: linear-gradient(135deg, rgba(0, 240, 255, 0.2), rgba(0, 240, 255, 0.05));
    color: var(--primary);
    border: 1px solid rgba(0, 240, 255, 0.35);
    box-shadow: 0 0 14px var(--primary-glow);
}

/* 模式还在，只是把设置面板收起来了 —— 淡一档，暗示再点一下能叫回来 */
.mode-tab.active.panel-collapsed {
    background: rgba(0, 240, 255, 0.07);
    border-color: rgba(0, 240, 255, 0.2);
    box-shadow: none;
    color: rgba(0, 240, 255, 0.72);
}

.mode-tab.active.panel-collapsed:hover {
    background: rgba(0, 240, 255, 0.14);
    color: var(--primary);
}

/* Theme Switcher */
.theme-selector {
    display: flex;
    align-items: center;
    gap: 6px;
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    padding: 5px 8px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--card-border);
}

.theme-btn {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    border: 2px solid transparent;
    cursor: pointer;
    transition: transform 0.2s, border-color 0.2s, box-shadow 0.2s;
}

.theme-btn:hover {
    transform: scale(1.15);
}

.theme-btn.active {
    border-color: #ffffff;
    box-shadow: 0 0 12px rgba(255, 255, 255, 0.6);
    transform: scale(1.15);
}

.theme-classic { background: linear-gradient(135deg, #cc0022 50%, #0051ba 50%); }
.theme-cyber { background: linear-gradient(135deg, #00f0ff 50%, #ff0077 50%); }
.theme-crystal { background: linear-gradient(135deg, #ffffff 50%, #48cae4 50%); }
.theme-luxury { background: linear-gradient(135deg, #d4af37 50%, #111113 50%); }

/* ==========================================================================
   Mode Floating Panels
   ========================================================================== */
.floating-panel {
    position: absolute;
    top: 90px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    padding: 16px 24px;
    box-shadow: 0 16px 40px rgba(0, 0, 0, 0.45);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.floating-panel.hidden {
    opacity: 0;
    pointer-events: none;
    transform: translateX(-50%) translateY(-20px);
}

/* Speedcube Timer Panel */
#panel-speedcube {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    min-width: 320px;
}

.timer-digits {
    font-size: 2.8rem;
    font-weight: 800;
    font-variant-numeric: tabular-nums;
    letter-spacing: 2px;
    color: #ffffff;
    text-shadow: 0 0 20px rgba(255, 255, 255, 0.3);
}

.timer-digits.inspecting {
    color: #ffd500;
    text-shadow: 0 0 20px rgba(255, 213, 0, 0.5);
}

.timer-digits.running {
    color: #00ff66;
    text-shadow: 0 0 20px rgba(0, 255, 102, 0.5);
}

.timer-stats {
    display: flex;
    gap: 20px;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.timer-stat-val {
    color: var(--primary);
    font-weight: 700;
}

/* Explode Slider Panel */
#panel-explode {
    display: flex;
    align-items: center;
    gap: 16px;
    min-width: 380px;
}

/* Reduced Color Panel */
#panel-reduced {
    top: 90px;
    left: 50%;
    transform: translateX(-50%);
    min-width: 420px;
    display: flex;
    flex-direction: column;
}

.color-count-selector {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.color-chip {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-muted);
    padding: 8px 14px;
    border-radius: 20px;
    font-size: 0.82rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    flex: 1 1 auto;
    text-align: center;
}

.color-chip:hover {
    background: rgba(255, 255, 255, 0.12);
    color: var(--text-main);
    transform: translateY(-1px);
}

.color-chip.active {
    background: linear-gradient(135deg, rgba(0, 240, 255, 0.25), rgba(0, 240, 255, 0.08));
    border-color: var(--primary);
    color: var(--primary);
    box-shadow: 0 0 14px var(--primary-glow);
}

.slider-container {
    display: flex;
    align-items: center;
    gap: 12px;
    width: 100%;
}

.custom-range {
    flex: 1;
    -webkit-appearance: none;
    height: 6px;
    border-radius: 4px;
    background: rgba(255, 255, 255, 0.15);
    outline: none;
}

.custom-range::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--primary);
    box-shadow: 0 0 10px var(--primary);
    cursor: pointer;
}

/* Patterns Showcase Panel */
#panel-patterns {
    top: 90px;
    right: 20px;
    left: auto;
    transform: none;
    max-width: 380px;
    max-height: 70vh;
    overflow-y: auto;
}

#panel-patterns.hidden {
    transform: translateY(-20px);
}

.patterns-grid {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-top: 10px;
}

.pattern-card {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-md);
    padding: 12px;
    transition: background 0.2s, border-color 0.2s;
}

.pattern-card:hover {
    background: var(--card-hover);
    border-color: var(--primary-glow);
}

.pattern-header h4 {
    font-size: 0.95rem;
    color: var(--text-main);
    margin-bottom: 4px;
}

.pattern-desc {
    font-size: 0.8rem;
    color: var(--text-muted);
    line-height: 1.4;
    margin-bottom: 8px;
}

.pattern-moves {
    font-family: monospace;
    font-size: 0.75rem;
    color: var(--primary);
    background: rgba(0, 0, 0, 0.25);
    padding: 4px 8px;
    border-radius: 4px;
    margin-bottom: 8px;
    word-break: break-all;
}

/* AI Solver Step Panel */
#panel-solver {
    top: 90px;
    right: 20px;
    left: auto;
    transform: none;
    width: 340px;
    max-height: 70vh;
    display: flex;
    flex-direction: column;
}

#panel-solver.hidden {
    transform: translateY(-20px);
}

.solver-steps-list {
    flex: 1;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 6px;
    margin: 12px 0;
    max-height: 320px;
    padding-right: 4px;
}

.solver-step-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 12px;
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.03);
    border-left: 3px solid transparent;
    font-size: 0.85rem;
    transition: all 0.2s;
}

.solver-step-item.active {
    background: rgba(0, 240, 255, 0.12);
    border-left-color: var(--primary);
    color: var(--primary);
    box-shadow: 0 0 10px rgba(0, 240, 255, 0.15);
}

.solver-step-item.completed {
    opacity: 0.4;
    text-decoration: line-through;
}

.step-num {
    font-weight: 700;
    opacity: 0.6;
    font-size: 0.75rem;
}

.step-notation {
    font-family: monospace;
    font-weight: 800;
    background: rgba(0, 0, 0, 0.3);
    padding: 2px 6px;
    border-radius: 4px;
    color: var(--primary);
}

.step-desc {
    flex: 1;
    font-size: 0.8rem;
    color: var(--text-muted);
}

.solver-controls {
    display: flex;
    gap: 8px;
}

.empty-hint {
    font-size: 0.82rem;
    color: var(--text-muted);
    line-height: 1.6;
    padding: 14px 12px;
    text-align: center;
    background: rgba(255, 255, 255, 0.03);
    border: 1px dashed rgba(255, 255, 255, 0.12);
    border-radius: var(--radius-md);
}

/* ==========================================================================
   Bottom Controls & Quick Toolbar
   ========================================================================== */
.bottom-dock {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    width: 100%;
    max-width: 900px;
    margin: 0 auto;
}

.quick-toolbar {
    display: flex;
    align-items: center;
    gap: 10px;
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    padding: 6px 14px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--card-border);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
}

.action-btn {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-main);
    padding: 8px 14px;
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.action-btn:hover {
    background: rgba(255, 255, 255, 0.12);
    border-color: rgba(255, 255, 255, 0.25);
    transform: translateY(-1px);
}

.action-btn.primary-highlight {
    background: linear-gradient(135deg, rgba(0, 240, 255, 0.3), rgba(0, 240, 255, 0.1));
    border-color: rgba(0, 240, 255, 0.5);
    color: var(--primary);
}

.action-btn.primary-highlight:hover {
    box-shadow: 0 0 16px var(--primary-glow);
}

.action-btn.icon-only {
    padding: 8px 10px;
    font-size: 1rem;
}

.action-btn.active {
    background: rgba(0, 240, 255, 0.25);
    color: var(--primary);
    border-color: var(--primary);
}

.action-btn:disabled {
    opacity: 0.35;
    cursor: not-allowed;
    transform: none;
}

.action-btn:disabled:hover {
    background: rgba(255, 255, 255, 0.06);
    border-color: rgba(255, 255, 255, 0.1);
    transform: none;
}

/* Notation Keys Strip */
.notation-strip {
    display: flex;
    gap: 6px;
    background: rgba(18, 22, 32, 0.6);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    padding: 4px 10px;
    border-radius: 30px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.notation-btn {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.08);
    color: var(--text-main);
    min-width: 32px;
    height: 32px;
    border-radius: 50%;
    font-size: 0.8rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.15s ease;
}

.notation-btn:hover {
    background: var(--primary);
    color: #000000;
    border-color: var(--primary);
    transform: scale(1.12);
}

.btn-primary-small {
    background: var(--primary);
    color: #000;
    border: none;
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    font-size: 0.8rem;
    font-weight: 700;
    cursor: pointer;
    transition: opacity 0.2s, transform 0.2s;
    width: 100%;
}

.btn-primary-small:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

.btn-primary-small:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

/* ==========================================================================
   Help & Instructions Modal
   ========================================================================== */
.modal-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.65);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.2s ease;
}

.modal-backdrop.hidden {
    opacity: 0;
    pointer-events: none;
}

.modal-content {
    background: #171b26;
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    padding: 24px 30px;
    max-width: 520px;
    width: 90%;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.6);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}

.modal-header h3 {
    font-size: 1.25rem;
    color: var(--text-main);
}

.close-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.5rem;
    cursor: pointer;
}

.modal-body {
    font-size: 0.9rem;
    line-height: 1.6;
    color: var(--text-muted);
}

.shortcut-grid {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 8px 16px;
    margin-top: 12px;
    background: rgba(0, 0, 0, 0.3);
    padding: 12px;
    border-radius: var(--radius-md);
}

.kbd {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: monospace;
    font-size: 0.8rem;
    color: var(--primary);
    text-align: center;
}

/* ==========================================================================
   Spatial 12-Direction Control Ring (3D Anchored)
   ========================================================================== */
.spatial-ring-wrapper {
    position: absolute;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    pointer-events: none;
    z-index: 8;
    transition: opacity 0.4s ease;
}

.spatial-btn.btn-anchor {
    position: absolute;
    transform: translate(-50%, -50%);
    pointer-events: auto;
    background: rgba(22, 27, 38, 0.85);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border: 1px solid rgba(0, 240, 255, 0.4);
    color: var(--primary);
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 4px 18px rgba(0, 0, 0, 0.5), inset 0 0 8px rgba(0, 240, 255, 0.2);
    transition: background 0.18s, border-color 0.18s, color 0.18s,
                box-shadow 0.18s, opacity 0.3s ease, transform 0.14s ease;
    /* 注意：left / top 绝不能参与过渡，否则按钮会拖在视角后面追不上魔方 */
    outline: none;
    will-change: left, top;
}

.spatial-btn .arrow {
    font-size: 1.1rem;
    font-weight: 900;
    line-height: 1;
    pointer-events: none;
}

.spatial-btn:hover {
    background: var(--primary);
    color: #0b0e14;
    border-color: #ffffff;
    transform: translate(-50%, -50%) scale(1.22);
    box-shadow: 0 0 24px var(--primary-glow), inset 0 0 12px rgba(255, 255, 255, 0.7);
}

.spatial-btn:active {
    transform: translate(-50%, -50%) scale(0.92);
}

/* Immersive Mode Styles */
.spatial-ring-wrapper.immersive-mode .spatial-btn {
    opacity: 0.18;
    border-color: rgba(255, 255, 255, 0.15);
    color: rgba(255, 255, 255, 0.5);
    background: rgba(15, 18, 26, 0.35);
    box-shadow: none;
}

.spatial-ring-wrapper.immersive-mode.active-bright .spatial-btn,
.spatial-ring-wrapper.immersive-mode .spatial-btn:hover {
    opacity: 0.95;
    border-color: var(--primary);
    color: var(--primary);
    background: rgba(22, 27, 38, 0.9);
    box-shadow: 0 0 20px var(--primary-glow);
}

body.immersive-active .top-nav,
body.immersive-active .bottom-dock,
body.immersive-active .floating-panel {
    opacity: 0 !important;
    pointer-events: none !important;
    transform: translateY(-20px) !important;
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.exit-immersive-btn {
    position: fixed;
    top: 24px;
    right: 24px;
    z-index: 50;
    background: rgba(22, 27, 38, 0.85);
    backdrop-filter: blur(14px);
    border: 1px solid rgba(0, 240, 255, 0.3);
    color: var(--text-muted);
    padding: 8px 18px;
    border-radius: 30px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    display: none;
    align-items: center;
    gap: 6px;
    transition: all 0.2s ease;
}

.exit-immersive-btn:hover {
    color: var(--text-main);
    border-color: var(--primary);
    box-shadow: 0 0 16px var(--primary-glow);
}

body.immersive-active .exit-immersive-btn {
    display: flex;
}

/* Scrollbar customization */
::-webkit-scrollbar {
    width: 5px;
}
::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.15);
    border-radius: 10px;
}

/* ==========================================================================
   窄屏 / 触屏适配
   一份代码同时服务桌面和手机：靠断点重排，不做第二套页面。
   ========================================================================== */

/* 平板与窄桌面：先把最挤的地方让出来 */
@media (max-width: 900px) {
    .top-nav { gap: 10px; }
    .mode-tab { padding: 8px 12px; font-size: 0.82rem; }
    .action-btn { padding: 7px 11px; font-size: 0.8rem; }
}

@media (max-width: 700px) {
    .hud-layer { padding: 10px; }

    /* ---- 顶栏重排成两行：品牌 + 皮肤一行，模式标签独占一行 ---- */
    .top-nav {
        flex-wrap: wrap;
        gap: 8px;
    }

    .brand-section {
        order: 1;
        flex: 0 0 auto;
        padding: 6px 12px;
        gap: 8px;
    }
    .brand-logo { width: 22px; height: 22px; }
    .brand-title { font-size: 0.95rem; }

    .theme-selector {
        order: 2;
        flex: 0 0 auto;
        margin-left: auto;      /* 顶到右边，和品牌分列两端 */
        padding: 4px 6px;
    }
    .theme-btn { width: 24px; height: 24px; }

    /* 模式标签：整行横向滚动。
       white-space: nowrap 是关键 —— 没有它，中文会被挤成一列竖排。 */
    .mode-tabs-container {
        order: 3;
        flex: 1 0 100%;
        overflow-x: auto;
        overflow-y: hidden;
        scrollbar-width: none;
        -webkit-overflow-scrolling: touch;
        padding: 4px;
        gap: 2px;
    }
    .mode-tabs-container::-webkit-scrollbar { display: none; }

    .mode-tab {
        flex: 0 0 auto;
        white-space: nowrap;
        padding: 7px 12px;
        font-size: 0.8rem;
    }

    /* ---- 底部工具条：同样横向滚动，绝不换行 ---- */
    .bottom-dock { max-width: 100%; }

    .quick-toolbar {
        max-width: 100%;
        overflow-x: auto;
        overflow-y: hidden;
        scrollbar-width: none;
        -webkit-overflow-scrolling: touch;
        padding: 6px 10px;
        gap: 7px;
    }
    .quick-toolbar::-webkit-scrollbar { display: none; }

    .action-btn {
        flex: 0 0 auto;
        white-space: nowrap;
        padding: 8px 11px;
        font-size: 0.78rem;
    }
    /* 手机上按钮的英文括号注释太占地方，只留中文 */
    .action-btn .btn-en { display: none; }

    /* ---- 浮动面板改为贴边全宽 ---- */
    .floating-panel,
    #panel-patterns,
    #panel-solver,
    #panel-reduced {
        top: auto;
        bottom: 74px;
        left: 10px;
        right: 10px;
        width: auto;
        min-width: 0;
        max-width: none;
        max-height: 46vh;
        overflow-y: auto;
        transform: none;
        padding: 14px 16px;
    }

    .floating-panel.hidden,
    #panel-patterns.hidden,
    #panel-solver.hidden {
        transform: translateY(14px);
    }

    #panel-speedcube { min-width: 0; }
    .timer-digits { font-size: 2.1rem; }
    .timer-stats { gap: 12px; font-size: 0.78rem; flex-wrap: wrap; justify-content: center; }

    #panel-explode { min-width: 0; }
    .solver-steps-list { max-height: 30vh; }
    .color-count-selector { gap: 6px; }
    .color-chip { padding: 7px 10px; font-size: 0.76rem; }

    /* ---- 空间控制环：缩小按钮，扩大触摸热区 ---- */
    .spatial-btn.btn-anchor {
        width: 34px;
        height: 34px;
    }
    .spatial-btn .arrow { font-size: 1rem; }

    /* 手指比鼠标粗：给按钮一圈看不见的外扩热区，好按不少 */
    .spatial-btn.btn-anchor::after {
        content: "";
        position: absolute;
        inset: -7px;
        border-radius: 50%;
    }

    .exit-immersive-btn {
        top: 12px;
        right: 12px;
        padding: 7px 13px;
        font-size: 0.78rem;
    }

    .modal-content { padding: 18px 18px; max-height: 82vh; overflow-y: auto; }
    .modal-header h3 { font-size: 1.05rem; }
    .shortcut-grid { grid-template-columns: 1fr; gap: 4px 0; }
    .shortcut-grid .kbd { justify-self: start; margin-top: 6px; }
}

/* 横屏手机：高度紧张，把上下两条压薄，给魔方腾地方 */
@media (max-height: 480px) and (orientation: landscape) {
    .hud-layer { padding: 8px; }
    .brand-section { display: none; }
    .mode-tab { padding: 5px 10px; font-size: 0.75rem; }
    .action-btn { padding: 6px 9px; font-size: 0.75rem; }
    .quick-toolbar { padding: 4px 8px; }
    .floating-panel { max-height: 60vh; bottom: 56px; }
}

/* 触屏设备去掉 hover 效果：手指没有"悬停"，
   留着会让按钮在点完之后一直卡在高亮态 */
@media (hover: none) {
    .action-btn:hover,
    .mode-tab:hover,
    .color-chip:hover {
        transform: none;
    }
    .spatial-btn:hover {
        background: rgba(22, 27, 38, 0.85);
        color: var(--primary);
        border-color: rgba(0, 240, 255, 0.4);
        transform: translate(-50%, -50%);
        box-shadow: 0 4px 18px rgba(0, 0, 0, 0.5), inset 0 0 8px rgba(0, 240, 255, 0.2);
    }
    .spatial-btn:active {
        background: var(--primary);
        color: #0b0e14;
        transform: translate(-50%, -50%) scale(1.1);
    }
}