/* ═══════════════════════════════════════════════════════════════
   MIDI Tools — Material 3 · Flexbox 加固版（修复手机重叠）
   ═══════════════════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@400;500;700&family=Roboto+Mono:wght@400;500&display=swap');

:root {
    --md-primary:                   #D0BCFF;
    --md-on-primary:                #381E72;
    --md-primary-container:         #4F378B;
    --md-on-primary-container:      #EADDFF;
    --md-secondary:                 #CCC2DC;
    --md-on-secondary:              #332D41;
    --md-secondary-container:       #4A4458;
    --md-on-secondary-container:    #E8DEF8;
    --md-tertiary:                  #EFB8C8;
    --md-on-tertiary:               #492532;
    --md-tertiary-container:        #633B48;
    --md-on-tertiary-container:     #FFD8E4;
    --md-error:                     #F2B8B5;
    --md-on-error:                  #601410;
    --md-error-container:           #8C1D18;
    --md-on-error-container:        #F9DEDC;
    --md-background:                #141218;
    --md-on-background:             #E6E0E9;
    --md-surface:                   #141218;
    --md-on-surface:                #E6E0E9;
    --md-surface-variant:           #49454F;
    --md-on-surface-variant:        #CAC4D0;
    --md-outline:                   #938F99;
    --md-outline-variant:           #49454F;
    --md-inverse-surface:           #E6E0E9;
    --md-inverse-on-surface:        #322F35;
    --md-inverse-primary:           #6750A4;
    --md-surface-container-lowest:  #0F0D13;
    --md-surface-container-low:     #1D1B20;
    --md-surface-container:         #211F26;
    --md-surface-container-high:    #2B2930;
    --md-surface-container-highest: #36343B;

    --md-elevation-1: 0 1px 2px rgba(0,0,0,.30), 0 1px 3px 1px rgba(0,0,0,.15);
    --md-elevation-2: 0 1px 2px rgba(0,0,0,.30), 0 2px 6px 2px rgba(0,0,0,.15);
    --md-elevation-3: 0 1px 3px rgba(0,0,0,.30), 0 4px 8px 3px rgba(0,0,0,.15);

    --radius-xs:    4px;
    --radius-sm:    8px;
    --radius-md:    12px;
    --radius-lg:    16px;
    --radius-xl:    28px;
    --radius-full:  9999px;

    --ease-standard:   cubic-bezier(0.2, 0, 0, 1);
    --ease-decelerate: cubic-bezier(0.05, 0.7, 0.1, 1);
    --ease-accelerate: cubic-bezier(0.3, 0, 0.8, 0.15);
    --ease-emphasized: cubic-bezier(0.2, 0, 0, 1);
    --dur-fast:        150ms;
    --dur-normal:      250ms;
    --dur-enter:       280ms;

    --font-mono:      'Roboto Mono', 'JetBrains Mono', 'Consolas', monospace;
    --font-sans:      'Roboto', system-ui, -apple-system, 'Segoe UI', 'Noto Sans Arabic', sans-serif;
    --editor-font:    0.8125rem;
    --editor-lh:      22px;
    --left-sidebar-w: 200px;

    --bg-base:            var(--md-surface);
    --bg-surface:         var(--md-surface-container-low);
    --bg-elevated:        var(--md-surface-container);
    --bg-elevated-2:      var(--md-surface-container-high);
    --bg-input:           var(--md-surface-container-highest);
    --bg-editor:          var(--md-surface-container-lowest);
    --ink-primary:        var(--md-on-surface);
    --ink-secondary:      var(--md-on-surface-variant);
    --ink-muted:          var(--md-outline);
    --accent:             var(--md-primary);
    --accent-on:          var(--md-on-primary);
    --accent-soft:        var(--md-primary-container);
    --accent-soft-text:   var(--md-on-primary-container);
    --accent2:            var(--md-tertiary);
    --accent2-on:         var(--md-on-tertiary);
    --accent2-soft:       var(--md-tertiary-container);
    --accent2-soft-text:  var(--md-on-tertiary-container);
    --shadow-raise-sm:    var(--md-elevation-1);
    --shadow-raise-md:    var(--md-elevation-2);
    --shadow-raise-lg:    var(--md-elevation-3);
    --bg:                 var(--bg-base);
    --bg2:                var(--bg-surface);
    --bg3:                var(--bg-elevated-2);
    --ink:                var(--ink-primary);
    --muted:              var(--ink-muted);
    --rule:               var(--md-outline-variant);
    --editor-bg:          var(--bg-editor);
    --gutter-bg:          var(--md-surface-container-low);
    --highlight:          rgba(208, 188, 255, 0.12);
    --playing:            rgba(239, 184, 200, 0.14);
    --chord-playing-bg:   rgba(208, 188, 255, 0.10);
    --error-color:        var(--md-error);
    --paused-color:       #F2B8B5;
    --select-chevron:     url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24'%3E%3Cpath d='M7 10l5 5 5-5' stroke='%23CAC4D0' stroke-width='2' fill='none'/%3E%3C/svg%3E");
}

body.light-mode {
    --md-primary:                   #6750A4;
    --md-on-primary:                #FFFFFF;
    --md-primary-container:         #EADDFF;
    --md-on-primary-container:      #21005D;
    --md-secondary:                 #625B71;
    --md-on-secondary:              #FFFFFF;
    --md-secondary-container:       #E8DEF8;
    --md-on-secondary-container:    #1D192B;
    --md-tertiary:                  #7D5260;
    --md-on-tertiary:               #FFFFFF;
    --md-tertiary-container:        #FFD8E4;
    --md-on-tertiary-container:     #31111D;
    --md-error:                     #B3261E;
    --md-on-error:                  #FFFFFF;
    --md-error-container:           #F9DEDC;
    --md-on-error-container:        #410E0B;
    --md-background:                #FEF7FF;
    --md-on-background:             #1D1B20;
    --md-surface:                   #FEF7FF;
    --md-on-surface:                #1D1B20;
    --md-surface-variant:           #E7E0EC;
    --md-on-surface-variant:        #49454F;
    --md-outline:                   #79747E;
    --md-outline-variant:           #CAC4D0;
    --md-inverse-surface:           #322F35;
    --md-inverse-on-surface:        #F5EFF7;
    --md-inverse-primary:           #D0BCFF;
    --md-surface-container-lowest:  #FFFFFF;
    --md-surface-container-low:     #F7F2FA;
    --md-surface-container:         #F3EDF7;
    --md-surface-container-high:    #ECE6F0;
    --md-surface-container-highest: #E6E0E9;
    --gutter-bg:      var(--md-surface-container-low);
    --highlight:      rgba(103, 80, 164, 0.10);
    --playing:        rgba(125, 82, 96, 0.10);
    --chord-playing-bg: rgba(103, 80, 164, 0.08);
    --error-color:    var(--md-error);
    --paused-color:   #B8860B;
    --select-chevron: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24'%3E%3Cpath d='M7 10l5 5 5-5' stroke='%2349454F' stroke-width='2' fill='none'/%3E%3C/svg%3E");
}

*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-sans);
    background: var(--md-background);
    color: var(--md-on-background);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    font-size: 0.875rem;
    transition: background-color var(--dur-normal) var(--ease-standard), color var(--dur-normal) var(--ease-standard);
}

/* 顶栏 */
header {
    background: var(--md-surface-container);
    padding: 0 12px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    flex-shrink: 0;
    min-height: 56px;
    flex-wrap: nowrap;
    transition: background-color var(--dur-normal) var(--ease-standard);
    z-index: 10;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-shrink: 0;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 4px;
    flex-shrink: 0;
}

.header-center {
    display: flex;
    align-items: center;
    gap: 8px;
    flex: 1 1 auto;
    justify-content: center;
    flex-wrap: nowrap;
    overflow-x: auto;
    overflow-y: hidden;
    min-width: 0;
    scrollbar-width: none;
}
.header-center::-webkit-scrollbar {
    display: none;
}

/* 图标按钮 (规则3：显式宽高) */
.sidebar-toggle {
    background: transparent;
    border: none;
    border-radius: 50%;
    color: var(--md-on-surface-variant);
    cursor: pointer;
    width: 44px;
    height: 44px;
    min-width: 44px;
    flex: 0 0 auto;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color var(--dur-fast) var(--ease-standard), color var(--dur-fast) var(--ease-standard), transform var(--dur-fast) var(--ease-standard);
    outline: none;
}
.sidebar-toggle:hover {
    color: var(--md-on-surface);
    background: color-mix(in srgb, var(--md-on-surface-variant) 10%, transparent);
}
.sidebar-toggle:active {
    background: color-mix(in srgb, var(--md-on-surface-variant) 14%, transparent);
    transform: scale(0.90);
}
.sidebar-toggle:focus-visible {
    outline: 2px solid var(--md-primary);
    outline-offset: 2px;
}
.sidebar-toggle.active {
    color: var(--md-on-secondary-container);
    background: var(--md-secondary-container);
}

header .logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1rem;
    font-weight: 500;
    color: var(--md-on-surface);
    white-space: nowrap;
    flex-shrink: 0;
}
header .logo svg {
    width: 22px;
    height: 22px;
    flex-shrink: 0;
}
header .logo span {
    color: var(--md-primary);
}

/* 工具栏组 */
.toolbar-group {
    display: flex;
    align-items: center;
    gap: 6px;
    flex-shrink: 0;
    white-space: nowrap;
}

.toolbar-group label {
    font-size: 0.6875rem;
    font-weight: 400;
    color: var(--md-on-surface-variant);
    white-space: nowrap;
    flex-shrink: 0;
}

/* 滑杆 */
.toolbar-group input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 64px;
    height: 3px;
    flex-shrink: 0;
    background: var(--md-surface-container-highest);
    border: none;
    border-radius: var(--radius-full);
    outline: none;
    cursor: pointer;
}
.toolbar-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--md-primary);
    border: none;
    cursor: pointer;
}

/* 数字输入框 (规则5/6：不写死52px，按字符数算) */
.toolbar-group input[type="number"] {
    box-sizing: border-box;
    width: auto;
    min-width: 8ch;
    height: 32px;
    flex-shrink: 0;
    background: var(--md-surface-container-highest);
    border: none;
    border-radius: var(--radius-xs);
    color: var(--md-on-surface);
    padding: 0 6px;
    font-size: 0.75rem;
    font-family: var(--font-mono);
    text-align: center;
    outline: none;
    transition: background-color var(--dur-fast) var(--ease-standard), box-shadow var(--dur-fast) var(--ease-standard);
}
.toolbar-group input[type="number"]:hover {
    background: var(--md-surface-container-high);
}
.toolbar-group input[type="number"]:focus {
    background: var(--md-surface-container-high);
    box-shadow: inset 0 0 0 2px var(--md-primary);
}

.toolbar-group select {
    height: 32px;
    flex-shrink: 0;
    max-width: 140px;
    background-color: var(--md-surface-container-highest);
    border: none;
    border-radius: var(--radius-xs);
    color: var(--md-on-surface);
    padding: 0 26px 0 10px;
    font-size: 0.75rem;
    font-family: var(--font-sans);
    cursor: pointer;
    outline: none;
    -webkit-appearance: none;
    appearance: none;
    background-image: var(--select-chevron);
    background-repeat: no-repeat;
    background-position: right 6px center;
    text-overflow: ellipsis;
    transition: background-color var(--dur-fast) var(--ease-standard), box-shadow var(--dur-fast) var(--ease-standard);
}
.toolbar-group select:hover {
    background-color: var(--md-surface-container-high);
}
.toolbar-group select:focus {
    background-color: var(--md-surface-container-high);
    box-shadow: inset 0 0 0 2px var(--md-primary);
}

.toolbar-group .value-display {
    font-size: 0.6875rem;
    font-weight: 500;
    color: var(--md-primary);
    font-family: var(--font-mono);
    min-width: 32px;
    text-align: center;
    flex-shrink: 0;
}

/* 语言切换 */
.lang-switch {
    display: inline-flex;
    gap: 2px;
    background: var(--md-surface-container-highest);
    border: none;
    border-radius: var(--radius-full);
    padding: 2px;
    flex-shrink: 0;
}
.lang-btn {
    width: 56px;
    height: 26px;
    padding: 0;
    border-radius: var(--radius-full);
    border: none;
    background: transparent;
    color: var(--md-on-surface-variant);
    font-size: 0.6875rem;
    font-weight: 500;
    cursor: pointer;
    outline: none;
    white-space: nowrap;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: background-color var(--dur-fast) var(--ease-standard), color var(--dur-fast) var(--ease-standard), transform var(--dur-fast) var(--ease-standard);
}
.lang-btn:hover {
    color: var(--md-on-surface);
}
.lang-btn.active {
    color: var(--md-on-secondary-container);
    background: var(--md-secondary-container);
}
.lang-btn:active {
    transform: scale(0.94);
}

/* 状态指示 */
.status-indicator {
    display: inline-block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--md-outline);
    flex-shrink: 0;
}
.status-indicator.ready {
    background: var(--md-primary);
}
.status-indicator.playing {
    background: var(--md-tertiary);
    animation: pulse 0.8s infinite;
}
.status-indicator.paused {
    background: var(--paused-color);
}
.status-text {
    font-size: 0.6875rem;
    color: var(--md-on-surface-variant);
    white-space: nowrap;
    flex-shrink: 0;
}
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.4;
    }
}

/* 按钮 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    height: 32px;
    padding: 0 14px;
    border: none;
    border-radius: var(--radius-full);
    background: var(--md-surface-container-highest);
    color: var(--md-primary);
    font-size: 0.75rem;
    font-weight: 500;
    font-family: var(--font-sans);
    cursor: pointer;
    white-space: nowrap;
    flex-shrink: 0;
    outline: none;
    transition: background-color var(--dur-fast) var(--ease-standard), color var(--dur-fast) var(--ease-standard), transform var(--dur-fast) var(--ease-standard);
}
.btn:hover {
    background: var(--md-surface-container-high);
}
.btn:active {
    background: var(--md-secondary-container);
    color: var(--md-on-secondary-container);
    transform: scale(0.96);
}
.btn.primary {
    background: var(--md-primary);
    color: var(--md-on-primary);
}
.btn.primary:hover {
    background: color-mix(in srgb, var(--md-on-primary) 8%, var(--md-primary));
}
.btn.primary:active {
    background: color-mix(in srgb, var(--md-on-primary) 14%, var(--md-primary));
    transform: scale(0.96);
}
.btn.accent2 {
    background: var(--md-secondary-container);
    color: var(--md-on-secondary-container);
}
.btn.accent2:hover {
    background: color-mix(in srgb, var(--md-on-secondary-container) 8%, var(--md-secondary-container));
}
.btn.accent2:active {
    background: color-mix(in srgb, var(--md-on-secondary-container) 14%, var(--md-secondary-container));
    transform: scale(0.96);
}
.btn:disabled {
    opacity: 0.38;
    cursor: not-allowed;
    pointer-events: none;
}
.btn-sm {
    height: 26px;
    padding: 0 10px;
    font-size: 0.6875rem;
}

.loop-btn.loop-on {
    background: var(--md-tertiary-container);
    color: var(--md-on-tertiary-container);
}

/* 主题按钮 (规则3：44x44显式尺寸) */
.theme-btn {
    background: transparent;
    border: none;
    border-radius: 50%;
    width: 44px;
    height: 44px;
    min-width: 44px;
    flex: 0 0 auto;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--md-on-surface-variant);
    transition: background-color var(--dur-fast) var(--ease-standard), color var(--dur-fast) var(--ease-standard), transform var(--dur-fast) var(--ease-standard);
    outline: none;
}
.theme-btn:hover {
    background: color-mix(in srgb, var(--md-on-surface-variant) 10%, transparent);
}
.theme-btn:active {
    transform: scale(0.90);
}
.theme-btn svg {
    transition: transform 400ms var(--ease-emphasized);
}
/* 只有切换深浅模式的按钮（ID 为 modeBtn）才旋转 */
#modeBtn svg { transition: transform 400ms var(--ease-emphasized); }
body.light-mode #modeBtn svg { transform: rotate(180deg); }

/* 主题弹窗 */
.theme-popup {
    position: fixed;
    top: 60px;
    right: 12px;
    background: var(--md-surface-container);
    border-radius: var(--radius-xs);
    padding: 6px;
    z-index: 1000;
    box-shadow: var(--md-elevation-2);
    min-width: 200px;
    max-width: calc(100vw - 24px);
    visibility: hidden;
    opacity: 0;
    transform: translateY(-6px) scale(0.94);
    transform-origin: top right;
    transition: opacity var(--dur-fast), transform var(--dur-enter), visibility 0s var(--dur-enter);
    pointer-events: none;
}
.theme-popup.show {
    visibility: visible;
    opacity: 1;
    transform: translateY(0) scale(1);
    pointer-events: auto;
    transition: opacity var(--dur-fast), transform var(--dur-enter), visibility 0s;
}
.theme-popup-header {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--md-on-surface-variant);
    margin-bottom: 6px;
    padding: 8px 10px 4px;
}
.theme-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2px;
}
.theme-swatch {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 10px;
    border-radius: var(--radius-xs);
    border: none;
    background: transparent;
    cursor: pointer;
    outline: none;
    transition: background-color var(--dur-fast), transform var(--dur-fast);
}
.theme-swatch:hover {
    background: color-mix(in srgb, var(--md-on-surface) 8%, transparent);
}
.theme-swatch:active {
    transform: scale(0.97);
}
.theme-swatch.active {
    background: var(--md-secondary-container);
    color: var(--md-on-secondary-container);
}
.swatch-circle {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    flex-shrink: 0;
}
.swatch-circle + .swatch-circle {
    margin-left: -6px;
}
.swatch-label {
    font-size: 0.75rem;
    font-weight: 500;
    white-space: nowrap;
}

/* 主布局 */
.app-layout {
    display: flex;
    flex: 1;
    min-height: 0;
    overflow: hidden;
}

.left-sidebar {
    width: 0;
    overflow: hidden;
    background: var(--md-surface-container-low);
    flex-shrink: 0;
    z-index: 5;
    transition: width 0.3s var(--ease-emphasized);
}
.left-sidebar.open {
    width: var(--left-sidebar-w);
}
.left-sidebar-inner {
    width: var(--left-sidebar-w);
    padding: 10px 0;
    display: flex;
    flex-direction: column;
}
.left-sidebar-header {
    padding: 0 24px 10px;
    font-size: 0.6875rem;
    font-weight: 500;
    color: var(--md-on-surface-variant);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.left-nav-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding: 0 10px;
}
.left-nav-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 9px 14px;
    border-radius: var(--radius-full);
    cursor: pointer;
    color: var(--md-on-surface-variant);
    font-size: 0.8125rem;
    font-weight: 500;
    user-select: none;
    transition: background-color var(--dur-fast);
}
.left-nav-item > span:not(.nav-icon) {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    flex: 1 1 auto;
}
.left-nav-item:hover {
    background: color-mix(in srgb, var(--md-on-surface-variant) 10%, transparent);
}
.left-nav-item:active {
    transform: scale(0.97);
}
.left-nav-item.active {
    background: var(--md-secondary-container);
    color: var(--md-on-secondary-container);
}
.nav-icon {
    font-size: 0.95rem;
    flex-shrink: 0;
}

.main-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
    min-height: 0;
    overflow: hidden;
}

.tab-content {
    display: none;
    flex: 1;
    min-height: 0;
    flex-direction: column;
}
.tab-content.active {
    display: flex;
    animation: tab-enter var(--dur-enter) var(--ease-decelerate) both;
}
@keyframes tab-enter {
    from {
        opacity: 0;
        transform: translateY(8px) scale(0.995);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

/* 编辑器 */
.main-container {
    display: flex;
    flex: 1;
    min-height: 0;
    overflow: hidden;
    background: var(--md-surface-container-lowest);
}
.editor-wrapper {
    flex: 1 1 auto;
    display: flex;
    overflow: hidden;
    position: relative;
    min-width: 0;
}
.resize-handle {
    width: 5px;
    cursor: col-resize;
    flex-shrink: 0;
    z-index: 5;
    transition: background var(--dur-fast);
}
.resize-handle:hover, .resize-handle.active {
    background: color-mix(in srgb, var(--md-primary) 12%, transparent);
}
.resize-handle::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 2px;
    height: 22px;
    background: var(--md-outline-variant);
    border-radius: 2px;
    opacity: 0.6;
}
.resize-handle:hover::after, .resize-handle.active::after {
    opacity: 1;
    background: var(--md-primary);
}

.gutter {
    background: var(--md-surface-container-low);
    color: var(--md-outline);
    font-family: var(--font-mono);
    font-size: var(--editor-font);
    padding: 10px 6px 10px 8px;
    text-align: right;
    user-select: none;
    overflow-y: auto;
    scrollbar-width: none;
    min-width: 48px;
    flex-shrink: 0;
}
.gutter::-webkit-scrollbar {
    display: none;
}
.gutter-line {
    line-height: var(--editor-lh);
    height: var(--editor-lh);
    padding: 0 2px;
    overflow: hidden;
}
.gutter-line.error {
    color: var(--md-error);
}
.gutter-line.playing {
    color: var(--md-tertiary);
    font-weight: 700;
}
.gutter-line.chord-marker {
    color: var(--md-primary);
    font-weight: 700;
}

.editor-area {
    flex: 1 1 auto;
    position: relative;
    overflow: hidden;
    min-width: 0;
}
.editor-area textarea {
    width: 100%;
    height: 100%;
    background: transparent;
    color: var(--md-on-surface);
    font-family: var(--font-mono);
    font-size: var(--editor-font);
    line-height: var(--editor-lh);
    padding: 10px 14px;
    border: none;
    outline: none;
    resize: none;
    white-space: pre;
    overflow-wrap: normal;
    overflow-x: auto;
    overflow-y: auto;
}
.editor-area textarea::placeholder {
    color: var(--md-on-surface-variant);
    opacity: 0.6;
}

.highlight-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    pointer-events: none;
    z-index: 2;
    overflow-y: auto;
    scrollbar-width: none;
}
.highlight-overlay::-webkit-scrollbar {
    display: none;
}
.highlight-row {
    position: absolute;
    left: 0;
    right: 0;
    height: var(--editor-lh);
}
.highlight-row.playing {
    background: var(--playing);
}
.highlight-row.chord-playing {
    background: var(--chord-playing-bg);
}

/* 侧栏 */
.sidebar {
    width: 280px;
    min-width: 180px;
    max-width: 500px;
    flex-shrink: 0;
    background: var(--md-surface-container-low);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}
.sidebar-tabs {
    display: flex;
    flex-shrink: 0;
    padding: 0 6px;
}
.sidebar-tab {
    flex: 1 1 0;
    min-width: 0;
    position: relative;
    padding: 0 6px;
    height: 40px;
    border: none;
    border-radius: 0;
    background: transparent;
    color: var(--md-on-surface-variant);
    font-size: 0.75rem;
    font-weight: 500;
    cursor: pointer;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    transition: color var(--dur-fast), background-color var(--dur-fast);
}
.sidebar-tab::after {
    content: '';
    position: absolute;
    left: 12px;
    right: 12px;
    bottom: 0;
    height: 3px;
    border-radius: 3px 3px 0 0;
    background: var(--md-primary);
    transform: scaleX(0);
    transition: transform var(--dur-enter) var(--ease-emphasized);
}
.sidebar-tab:hover {
    background: color-mix(in srgb, var(--md-on-surface) 8%, transparent);
}
.sidebar-tab.active {
    color: var(--md-primary);
}
.sidebar-tab.active::after {
    transform: scaleX(1);
}

.sidebar-panel {
    display: none;
    flex: 1;
    overflow-y: auto;
    padding: 12px;
    flex-direction: column;
    gap: 10px;
    min-width: 0;
}
.sidebar-panel.active {
    display: flex;
    animation: panel-enter var(--dur-enter) var(--ease-decelerate) both;
}
@keyframes panel-enter {
    from {
        opacity: 0;
        transform: translateY(6px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}
.sidebar-panel h3 {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--md-on-surface-variant);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.speed-panel, .note-info-card, .help-box, .about-card {
    background: var(--md-surface-container-highest);
    border-radius: var(--radius-md);
    padding: 12px;
    min-width: 0;
}
.speed-panel .speed-row {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 6px;
}
.speed-panel input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    flex: 1 1 auto;
    min-width: 40px;
    height: 3px;
    background: var(--md-surface-container);
    border-radius: var(--radius-full);
    outline: none;
}
.speed-panel input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--md-primary);
}
.speed-panel .speed-val {
    font-family: var(--font-mono);
    font-size: 0.8125rem;
    color: var(--md-primary);
    flex-shrink: 0;
}
.speed-panel .speed-bpm {
    font-size: 0.6875rem;
    color: var(--md-on-surface-variant);
    text-align: center;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.speed-presets {
    display: flex;
    gap: 4px;
    flex-wrap: wrap;
}
.speed-presets .btn {
    flex: 1 1 0;
    min-width: 34px;
    height: 28px;
    padding: 0 8px;
    font-size: 0.6875rem;
}

.note-info-card .row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 8px;
    padding: 3px 0;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    min-width: 0;
}
.note-info-card .row .label {
    color: var(--md-on-surface-variant);
    flex: 1 1 auto;
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.note-info-card .row .val {
    color: var(--md-on-surface);
    font-weight: 500;
    flex: 0 0 auto;
    max-width: 60%;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    text-align: right;
}
.note-info-card .row .val.freq {
    color: var(--md-tertiary);
}

.help-box {
    font-size: 0.75rem;
    color: var(--md-on-surface-variant);
    line-height: 1.6;
    word-break: break-word;
}
.help-box code {
    background: var(--md-surface-container);
    padding: 1px 5px;
    border-radius: var(--radius-xs);
    color: var(--md-primary);
}

.sidebar-stats {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    padding: 8px 0 0;
    font-family: var(--font-mono);
    font-size: 0.6875rem;
    color: var(--md-on-surface-variant);
}
.sidebar-stats > span {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    min-width: 0;
}

.about-card {
    display: flex;
    flex-direction: column;
    gap: 6px;
}
.about-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 8px;
    font-size: 0.75rem;
    min-width: 0;
}
.about-label {
    color: var(--md-on-surface-variant);
    font-size: 0.6875rem;
    flex: 1 1 auto;
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.about-val {
    color: var(--md-on-surface);
    font-weight: 500;
    font-family: var(--font-mono);
    font-size: 0.6875rem;
    flex: 0 0 auto;
    max-width: 60%;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    text-align: right;
}

.advanced-group-inline {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-bottom: 4px;
    min-width: 0;
}
.advanced-group-inline label {
    font-size: 0.625rem;
    font-weight: 500;
    color: var(--md-on-surface-variant);
    min-width: 42px;
    max-width: 58px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.advanced-group-inline input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    flex: 1 1 auto;
    min-width: 60px;
    height: 3px;
    background: var(--md-surface-container);
    border-radius: var(--radius-full);
    outline: none;
}
.advanced-group-inline input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 13px;
    height: 13px;
    border-radius: 50%;
    background: var(--md-primary);
}
.adv-val {
    font-family: var(--font-mono);
    font-size: 0.6875rem;
    color: var(--md-primary);
    flex-shrink: 0;
}

/* 导出页 */
#tab-dir {
    overflow-y: auto;
    padding: 32px 20px;
    align-items: center;
    background: var(--md-surface);
}
#tab-dir .dir-container {
    max-width: 840px;
    width: 100%;
    min-width: 0;
}
#tab-dir .dir-container h1 {
    font-size: 1.5rem;
    font-weight: 400;
    display: flex;
    align-items: center;
    gap: 10px;
    min-width: 0;
}
#tab-dir .dir-container h1 span {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    color: var(--md-primary);
}
#tab-dir .subtitle {
    font-size: 0.8125rem;
    margin-bottom: 24px;
    color: var(--md-on-surface-variant);
    word-break: break-word;
}
#tab-dir .actions {
    display: flex;
    gap: 8px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}
#tab-dir .options {
    display: flex;
    gap: 12px;
    margin-bottom: 16px;
    flex-wrap: wrap;
    align-items: center;
}

#tab-dir .options select, #tab-dir .options input[type="number"] {
    height: 32px;
    flex-shrink: 0;
    background: var(--md-surface-container-highest);
    border: none;
    border-radius: var(--radius-xs);
    color: var(--md-on-surface);
    padding: 0 26px 0 10px;
    font-size: 0.75rem;
    outline: none;
}
#tab-dir .options select {
    -webkit-appearance: none;
    appearance: none;
    background-image: var(--select-chevron);
    background-repeat: no-repeat;
    background-position: right 6px center;
}
#tab-dir .options input[type="number"] {
    box-sizing: border-box;
    width: auto;
    min-width: 8ch;
    text-align: center;
    padding: 0 6px;
}

#tab-dir .stats {
    display: none;
    gap: 10px;
    flex-wrap: wrap;
    margin-bottom: 16px;
}
#tab-dir .stats.show {
    display: flex;
}
#tab-dir .stat-card {
    background: var(--md-surface-container-highest);
    border-radius: var(--radius-md);
    padding: 12px 16px;
    text-align: center;
    flex: 1 1 140px;
    min-width: 0;
}
#tab-dir .stat-card .stat-num {
    font-size: 1.25rem;
    color: var(--md-primary);
    font-family: var(--font-mono);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
#tab-dir .stat-card .stat-label {
    font-size: 0.6875rem;
    color: var(--md-on-surface-variant);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

#tab-dir .preview-box {
    background: var(--md-surface-container);
    border-radius: var(--radius-md);
    padding: 0;
    margin-bottom: 16px;
    display: none;
    overflow: hidden;
}
#tab-dir .preview-box.show {
    display: block;
}
#tab-dir .preview-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 14px;
    font-size: 0.75rem;
    color: var(--md-on-surface-variant);
    gap: 8px;
}
#tab-dir .preview-header > span {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    min-width: 0;
}
#tab-dir .preview-content {
    max-height: 420px;
    overflow-y: auto;
    overflow-x: auto;
    padding: 14px;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    white-space: pre;
    background: var(--md-surface-container-lowest);
}

/* SSTV 页面 */
#tab-sstv {
    overflow-y: auto;
    background: var(--md-surface);
}
#tab-sstv .sstv-container {
    padding: 24px 20px;
    max-width: 900px;
    margin: 0 auto;
    gap: 16px;
    min-width: 0;
}
#tab-sstv textarea {
    width: 100%;
    height: 150px;
    background: var(--md-surface-container-highest);
    border: none;
    border-radius: var(--radius-xs);
    color: var(--md-on-surface);
    font-family: var(--font-mono);
    font-size: 0.8125rem;
    padding: 12px 14px;
    resize: vertical;
    outline: none;
}
#tab-sstv .sstv-options {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    align-items: center;
    min-width: 0;
}
#tab-sstv .sstv-options label {
    font-size: 0.75rem;
    flex-shrink: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
#tab-sstv .sstv-options input[type="range"] {
    width: 100px;
    flex-shrink: 1;
    min-width: 50px;
    height: 3px;
    background: var(--md-surface-container-highest);
    border-radius: var(--radius-full);
    outline: none;
    -webkit-appearance: none;
}
#tab-sstv .sstv-options input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--md-primary);
}
#tab-sstv .sstv-options input[type="number"] {
    box-sizing: border-box;
    width: auto;
    min-width: 8ch;
    flex-shrink: 0;
    height: 32px;
    background: var(--md-surface-container-highest);
    border-radius: var(--radius-xs);
    text-align: center;
    border: none;
    color: var(--md-on-surface);
    outline: none;
}
#tab-sstv .sstv-val {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--md-primary);
    flex-shrink: 0;
}
#tab-sstv .sstv-controls {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}
#tab-sstv .sstv-controls .btn {
    flex: 0 1 auto;
}

#tab-sstv .sstv-hex-preview, #tab-sstv .sstv-freq-table, #tab-sstv .sstv-info-card {
    background: var(--md-surface-container-highest);
    border-radius: var(--radius-md);
    padding: 14px;
    display: none;
}
#tab-sstv .sstv-hex-preview.show, #tab-sstv .sstv-freq-table.show {
    display: block;
}
#tab-sstv .sstv-freq-table table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.75rem;
    table-layout: fixed;
}
#tab-sstv .sstv-freq-table th {
    background: var(--md-surface-container);
    color: var(--md-on-surface-variant);
    text-align: left;
    padding: 10px 12px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
#tab-sstv .sstv-freq-table td {
    padding: 8px 12px;
    border-top: 1px solid var(--md-outline-variant);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
#tab-sstv .sstv-info-card {
    font-size: 0.75rem;
    color: var(--md-on-surface-variant);
    line-height: 1.6;
    display: block;
    word-break: break-word;
}
#tab-sstv .sstv-info-card code {
    background: var(--md-surface-container);
    padding: 1px 5px;
    border-radius: var(--radius-xs);
    color: var(--md-primary);
}

/* Toast */
.toast {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%) translateY(16px);
    background: var(--md-inverse-surface);
    color: var(--md-inverse-on-surface);
    padding: 12px 18px;
    border-radius: var(--radius-xs);
    z-index: 100;
    opacity: 0;
    pointer-events: none;
    transition: all 0.3s;
    max-width: calc(100vw - 32px);
    text-align: center;
    word-break: break-word;
}
.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* 响应式布局：解决手机端挤压重叠 */
@media (max-width: 900px) {
    header {
        flex-wrap: wrap;
        padding: 6px 10px;
        row-gap: 6px;
        min-height: auto;
    }
    .header-left {
        order: 1;
        flex: 1 1 auto;
    }
    .header-right {
        order: 2;
        flex: 0 0 auto;
    }
    .header-center {
        order: 3;
        flex-basis: 100%;
        justify-content: flex-start;
        padding: 2px 0 4px;
        scrollbar-width: none;
    }
    .header-center::-webkit-scrollbar {
        display: none;
    }

  /* 手机端控件：浮动按钮仍保持 44px 防误触，其他缩小 */
  .sidebar-toggle, .theme-btn {
        width: 44px;
        height: 44px;
        min-width: 44px;
        flex: 0 0 auto;
    }
    .lang-btn {
        width: 46px;
        height: 24px;
        font-size: 0.65rem;
    }
    .toolbar-group input[type="range"] {
        width: 56px;
    }
    .toolbar-group input[type="number"] {
        box-sizing: border-box;
        width: auto;
        min-width: 8ch;
        height: 28px;
        font-size: 0.7rem;
    }
    .toolbar-group select {
        height: 28px;
        font-size: 0.7rem;
        padding: 0 22px 0 8px;
        background-position: right 4px center;
    }
    .toolbar-group .btn {
        height: 28px;
        padding: 0 10px;
        font-size: 0.7rem;
    }
    .toolbar-group .btn-sm {
        height: 24px;
        padding: 0 8px;
        font-size: 0.65rem;
    }

    .sidebar {
        width: 220px;
        min-width: 160px;
    }
    .left-sidebar.open {
        width: 168px;
    }
    .left-sidebar-inner {
        width: 168px;
    }
}

@media (max-width: 600px) {
    .sidebar {
        display: none;
    }
    .left-sidebar.open {
        width: 148px;
    }
    .left-sidebar-inner {
        width: 148px;
    }

    #tab-dir {
        padding: 16px 10px;
    }
    #tab-dir .actions {
        flex-direction: column;
    }
    #tab-dir .actions .btn {
        width: 100%;
    }
    #tab-dir .options {
        flex-direction: column;
        align-items: stretch;
    }

    #tab-sstv .sstv-container {
        padding: 16px 10px;
    }
    #tab-sstv .sstv-controls {
        flex-direction: column;
    }
    #tab-sstv .sstv-controls .btn {
        width: 100%;
    }
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}