:root {
    --primary-color: #00ff88;
    --bg-color: #0a0a0a;
    --panel-bg: rgba(20, 20, 20, 0.95);
    --text-color: #ffffff;
}

* {
    box-sizing: border-box;
    user-select: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    -webkit-tap-highlight-color: transparent; /* Disable touch highlight */
    outline: none; /* Disable default outline */
}

body {
    margin: 0;
    padding: 0;
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    overflow: hidden;
}

/* App Layout */
.app-container {
    display: flex;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
    position: relative;
}

/* Sidebar */
.sidebar {
    width: 280px;
    background: var(--panel-bg);
    border-right: 1px solid #333;
    display: flex;
    flex-direction: column;
    z-index: 100;
    transition: transform 0.3s ease, width 0.3s ease, margin-left 0.3s ease;
    flex-shrink: 0;
    position: relative;
}

.sidebar.collapsed {
    margin-left: -280px;
}

.sidebar-header {
    padding: 20px;
    border-bottom: 1px solid #333;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.2rem;
    font-weight: bold;
    color: #fff;
}

.neon-icon {
    color: var(--primary-color);
    filter: drop-shadow(0 0 5px var(--primary-color));
}

.close-btn {
    background: none;
    border: none;
    color: #888;
    cursor: pointer;
    padding: 5px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: color 0.2s;
}

.close-btn:hover {
    color: #fff;
}

.sidebar-content {
    padding: 20px;
    overflow-y: auto;
    flex: 1;
}

/* Scrollbar */
.sidebar-content::-webkit-scrollbar {
    width: 6px;
}

.sidebar-content::-webkit-scrollbar-track {
    background: transparent;
}

.sidebar-content::-webkit-scrollbar-thumb {
    background: rgba(128, 128, 128, 0.3);
    border-radius: 3px;
}

.sidebar-content::-webkit-scrollbar-thumb:hover {
    background: rgba(128, 128, 128, 0.5);
}

/* Tool Groups */
.tool-group {
    margin-bottom: 25px;
}

.tool-group h3 {
    font-size: 0.9rem;
    color: #888;
    margin-bottom: 12px; /* Slightly reduced */
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Sub-labels (like '画笔形状', '画笔大小') */
.slider-control label, 
.tool-group-sub label, 
.toggle-control label {
    display: block;
    margin-bottom: 8px;
    font-size: 0.85rem; /* Unified font size */
    color: #ccc; /* Unified color */
    font-weight: 500; /* Unified weight */
}
.color-picker-container {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    margin-bottom: 20px;
}

.color-option {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background-color: var(--color);
    cursor: pointer;
    border: 2px solid transparent;
    transition: transform 0.2s, box-shadow 0.2s;
}

.color-option.active {
    border-color: #fff;
    transform: scale(1.1);
    box-shadow: 0 0 10px var(--color);
}

.rainbow-option {
    background: linear-gradient(135deg, #ff0000, #ffff00, #00ff00, #00ffff, #0000ff, #ff00ff);
    display: flex;
    align-items: center;
    justify-content: center;
}

input[type="color"] {
    width: 32px;
    height: 32px;
    border: none;
    padding: 0;
    background: none;
    cursor: pointer;
    border-radius: 50%;
}

/* Sliders */
.slider-control {
    margin-bottom: 20px;
}

/* Label styling moved to unified block above */

input[type="range"] {
    width: 100%;
    accent-color: var(--primary-color);
}

/* Tool Buttons (Brush/Eraser) */
.tool-buttons {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

.tool-btn {
    flex: 1;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: #fff;
    padding: 10px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.tool-btn.active {
    background: var(--primary-color);
    color: #000;
    border-color: var(--primary-color);
    box-shadow: 0 0 10px rgba(0, 255, 136, 0.3);
}

/* Shape Options */
.shape-options, .symmetry-options {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 8px;
}

.shape-btn, .sym-btn {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: #fff;
    padding: 10px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.shape-btn:hover, .sym-btn:hover {
    background: rgba(255, 255, 255, 0.2);
}

.shape-btn.active, .sym-btn.active {
    background: var(--primary-color);
    color: #000;
    border-color: var(--primary-color);
    box-shadow: 0 0 10px rgba(0, 255, 136, 0.3);
}

/* Toggles */
.toggle-control {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.switch {
    position: relative;
    display: inline-block;
    width: 40px;
    height: 20px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #555;
    transition: .4s;
}

.slider:before {
    position: absolute;
    content: "";
    height: 16px;
    width: 16px;
    left: 2px;
    bottom: 2px;
    background-color: white;
    transition: .4s;
}

input:checked + .slider {
    background-color: var(--primary-color);
}

input:checked + .slider:before {
    transform: translateX(20px);
}

.slider.round {
    border-radius: 20px;
}

.slider.round:before {
    border-radius: 50%;
}

/* Canvas Area */
.canvas-area {
    flex: 1;
    position: relative;
    background-color: #000;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: width 0.3s ease;
}

.canvas-wrapper {
    flex: 1;
    width: 100%;
    height: 100%;
    position: relative;
    overflow: hidden;
}

canvas {
    display: block;
}

/* Top Bar (Base styles, might be overridden in responsive) */
.top-bar {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    padding: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    pointer-events: none;
    z-index: 50;
}

.top-bar > * {
    pointer-events: auto;
}

.top-bar-left {
    width: 40px;
}

.action-buttons {
    display: flex;
    gap: 15px;
    background: rgba(20, 20, 20, 0.8);
    padding: 8px 15px;
    border-radius: 30px;
    backdrop-filter: blur(5px);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.icon-btn {
    background: transparent;
    border: none;
    color: #fff;
    cursor: pointer;
    padding: 8px;
    border-radius: 50%;
    transition: background 0.2s, transform 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: scale(1.1);
}

.primary-btn {
    background: var(--primary-color);
    color: #000;
    border: none;
    padding: 10px 20px;
    border-radius: 20px;
    font-weight: bold;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.2s;
    box-shadow: 0 0 15px rgba(0, 255, 136, 0.3);
}

.primary-btn:hover {
    background: #fff;
    box-shadow: 0 0 20px rgba(255, 255, 255, 0.5);
    transform: translateY(-2px);
}

/* Sidebar Toggle (Floating) */
.sidebar-toggle {
    position: absolute;
    top: 20px;
    left: 20px;
    z-index: 90;
    background: rgba(20, 20, 20, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: #fff;
    padding: 8px;
    border-radius: 8px;
    cursor: pointer;
    backdrop-filter: blur(5px);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.3s, transform 0.3s;
}

.app-container:not(.mobile-view) .sidebar:not(.collapsed) ~ #sidebarToggle {
    opacity: 0;
    pointer-events: none;
    visibility: hidden;
}

.app-container:not(.mobile-view) .sidebar.collapsed ~ #sidebarToggle {
    opacity: 1;
    pointer-events: auto;
    visibility: visible;
    transform: translateX(0);
}

.mobile-icon { display: none; }
.desktop-icon { display: block; }

/* Music Floating Button */
.music-fab {
    position: absolute;
    bottom: 20px;
    left: 20px; 
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: rgba(20, 20, 20, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: #fff;
    cursor: pointer;
    backdrop-filter: blur(5px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 90; /* Lower than sidebar (100) but high enough to be clickable */
    transition: all 0.3s ease;
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.5);
}

/* Push FAB when sidebar is OPEN on desktop */
.app-container:not(.mobile-view) .sidebar:not(.collapsed) ~ .music-fab {
    left: 300px; /* 280px sidebar + 20px margin */
}

.music-fab:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: scale(1.1);
}

.music-fab.active {
    background: var(--primary-color);
    color: #000;
    border-color: var(--primary-color);
    box-shadow: 0 0 20px rgba(0, 255, 136, 0.4);
    animation: pulse-music 2s infinite;
}

@keyframes pulse-music {
    0% { box-shadow: 0 0 0 0 rgba(0, 255, 136, 0.4); }
    70% { box-shadow: 0 0 0 10px rgba(0, 255, 136, 0); }
    100% { box-shadow: 0 0 0 0 rgba(0, 255, 136, 0); }
}

/* Music Style Buttons */
.style-btn {
    flex: 1;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: #fff;
    padding: 8px 0;
    border-radius: 8px;
    cursor: pointer;
    font-size: 13px;
    transition: all 0.2s;
}

.style-btn.active {
    background: var(--primary-color);
    color: #000;
    border-color: var(--primary-color);
    box-shadow: 0 0 10px rgba(0, 255, 136, 0.3);
    font-weight: bold;
}

.style-btn:hover:not(.active) {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-1px);
}