:root {
    /* UI — Dark Mode (default)  c77830 */
    --primary-color: #f7941d;
    --primary-light: #ffb12b;
    --primary-dark: #d48a00;
    --secondary-color: #444;
    --color-bg: #1f1f1f;
    --color-bg-light: #2c2c2c;
    --color-bg-card: #333333;
    --color-bg-hover: #444444;
    --color-bg-inset: #0e0d0b;
    --color-fg: #edecec;
    --color-fg-subtle: rgba(237, 236, 236, 0.55);
    --color-fg-muted: rgba(237, 236, 236, 0.35);
    --color-border: rgba(237, 236, 236, 0.10);
    --color-border-strong: rgba(232, 229, 223, 0.16);
    --knob-size: 20px;
    --font-stack: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --groove-color: #b565d6;
    --groove-light: #a78bfa;

    /* 功能色 */
    --color-success: #10b981;
    --color-warning: #f59e0b;
    --color-danger: #e82020;
    --color-accent: #c77830;
    --color-accent-bg: rgba(199, 120, 48, 0.10);    
    --color-accent-soft: #d4956a;

    /* 动画变量 - 基于 arena.ai 流畅动画系统 */
    --animation-duration-fast: 0.15s;
    --animation-duration-normal: 0.3s;
    --animation-duration-slow: 0.5s;
    --animation-easing-default: cubic-bezier(0.4, 0, 0.2, 1);
    --animation-easing-in: cubic-bezier(0.4, 0, 1, 1);
    --animation-easing-out: cubic-bezier(0, 0, 0.2, 1);
    --animation-easing-in-out: cubic-bezier(0.4, 0, 0.2, 1);

    /* 过渡变量 */
    --transition-fast: var(--animation-duration-fast) var(--animation-easing-out);
    --transition-normal: var(--animation-duration-normal) var(--animation-easing-default);
    --transition-slow: var(--animation-duration-slow) var(--animation-easing-default);

    /* 阴影 */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

    /* 圆角 */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;
}

/* 亮色主题 — Cursor UI Light Mode */
:root[data-theme="light"] {
    --color-bg: #dedbd4;        /* 暖灰 */
    --color-bg-light: #e8e6e1;  /* 略深暖灰 */
    --color-fg: #2a2722;      /* 深褐文字 */
    --color-border: rgba(42, 39, 34, 0.12);
    --color-border-strong: rgba(45, 42, 36, 0.18);
    --color-bg-card: #e8e6e1;
    --color-bg-hover: #eceae4;
    --color-bg-inset: #ddd9cf;
    --color-fg-subtle: rgba(38, 37, 30, 0.55);
    --color-fg-muted: rgba(38, 37, 30, 0.35);
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.03);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.06);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.10);
}

:root[data-theme="light"] .beat-dot.active {
    box-shadow: 0 0 12px var(--primary-color), 0 0 24px rgba(245, 78, 0, 0.25); 
}

:root[data-theme="light"] .beat-dot.active.accent {
    box-shadow: 0 0 16px var(--primary-light), 0 0 32px rgba(245, 78, 0, 0.35);
}

:root[data-theme="light"] .poly-dot.active {
    box-shadow: 0 0 10px var(--groove-color), 0 0 20px rgba(181, 101, 214, 0.25); 
}

:root[data-theme="light"] .poly-dot.active.poly-accent { 
    box-shadow: 0 0 15px var(--groove-color), 0 0 30px rgba(181, 101, 214, 0.35); 
}

:root[data-theme="light"] .trainer-tab:hover { 
    background: var(--color-bg-card); 
}

:root[data-theme="light"] .subdiv-btn:hover { 
    background: var(--color-bg-card); 
}

* { box-sizing: border-box; user-select: none; }

body {
    font-family: var(--font-stack);
    background-color: var(--color-bg);
    color: var(--color-fg);
    /* display: flex; justify-content: center; align-items: center; */
    /* min-height: 100vh;  padding: 20px; */
    margin: 0;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: background-color var(--transition-slow), color var(--transition-slow);
}

body.is-scrubbing { cursor: ns-resize !important; }

.wrapper {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 8px;
  min-height: 90vh;
}

.metronome-container {
    background-color: var(--color-bg-card);
    padding: 35px 40px;
    margin: 12px;
    border-radius: var(--radius-xl);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-2xl);
    width: 100%; max-width: 420px;
    text-align: center; position: relative;
    animation: slideUp var(--animation-duration-slow) var(--animation-easing-out);
}

/* --- 音量控制 --- */
.volume-control {
    position: absolute; top: 25px; right: 25px;
    width: 24px; height: 24px; cursor: ns-resize;
    color: var(--color-fg-subtle); 
    transition: opacity var(--transition-fast), transform var(--transition-fast), color var(--transition-fast); 
    z-index: 10;
}
.volume-control svg { width: 100%; height: 100%; fill: currentColor; display: block; }
.volume-control:hover { transform: scale(1.15); color: var(--primary-color); }
.volume-control.dragging { transform: scale(1.2); color: var(--primary-color); }

/* --- 核心显示 --- */
.bpm-display {
    font-family: var(--font-stack); font-size: 84px; font-weight: 800;
    color: var(--primary-color); margin: 5px 0 10px 0; line-height: 1;
    letter-spacing: -2px; font-variant-numeric: tabular-nums;
    transition: transform var(--transition-fast);
}
.bpm-label { 
    font-size: 12px; 
    color: var(--color-fg-muted); 
    letter-spacing: 2px; 
    font-weight: 600; 
    text-transform: uppercase; 
}

/* --- 主节拍点 --- */
.dots-wrapper { display: flex; flex-direction: column; align-items: center; justify-content: center; margin-bottom: 20px; }
.dots-container { display: flex; justify-content: center; align-items: center; gap: 14px; height: 30px; margin: 10px 0 5px 0 !important; }
.beat-dot {
    width: 10px; height: 10px; background-color: var(--color-bg-card); 
    border: 2px solid var(--color-border);
    border-radius: 50%; 
    transition: all var(--transition-fast);
    cursor: pointer;
}
.beat-dot:hover { background-color: var(--color-bg-hover); transform: scale(1.15); }
.beat-dot.accent { width: 14px; height: 14px; }

.beat-dot.active {
    background-color: var(--primary-color); border-color: var(--primary-color);
    box-shadow: 0 0 12px var(--primary-color), 0 0 24px rgba(245, 78, 0, 0.4); 
    transform: scale(1.35);
    animation: beatPulse 0.15s var(--animation-easing-out);
}
.beat-dot.active.accent {
    background-color: var(--primary-light); border-color: var(--primary-light);
    transform: scale(1.5); 
    box-shadow: 0 0 16px var(--primary-light), 0 0 32px rgba(245, 78, 0, 0.5);
}
.beat-dot.muted-active {
    background-color: transparent; border-color: var(--primary-color);
    box-shadow: 0 0 8px rgba(245, 78, 0, 0.4); transform: scale(1.2);
}
.beat-dot.accent.muted-active {
    border-color: var(--primary-light); 
    box-shadow: 0 0 12px rgba(245, 78, 0, 0.4); 
    transform: scale(1.4);
}

/* --- 复合节拍点 (Poly) --- */
.poly-dots-container { display: none; justify-content: center; align-items: center; gap: 10px; height: 15px; }
.poly-dots-container.active { display: flex; }
.poly-dot {
    width: 7px; height: 7px; background-color: var(--color-bg-card); 
    border: 2px solid var(--color-border);
    border-radius: 50%; 
    transition: all var(--transition-fast);
}
.poly-dot.poly-accent { width: 10px; height: 10px; }
.poly-dot.active {
    background-color: var(--groove-color); border-color: var(--groove-color);
    box-shadow: 0 0 10px var(--groove-color), 0 0 20px rgba(181, 101, 214, 0.4); 
    transform: scale(1.35);
}
.poly-dot.active.poly-accent { 
    transform: scale(1.5); 
    box-shadow: 0 0 15px var(--groove-color), 0 0 30px rgba(181, 101, 214, 0.5); 
}
.poly-dot.muted-active {
    background-color: transparent; border-color: var(--groove-color);
    box-shadow: 0 0 8px rgba(181, 101, 214, 0.4); transform: scale(1.2);
}

/* --- BPM 控制 --- */
.control-row { margin: 20px 0; display: flex; align-items: center; justify-content: space-between; gap: 15px; }
.btn-circle {
    width: 44px;
    height: 44px;
    border-radius: var(--radius-full);
    border: 2px solid var(--color-border);
    background: transparent;
    color: var(--color-fg-subtle);
    font-family: var(--font-stack);
    font-size: 24px;
    font-weight: 300;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    padding-bottom: 4px;
}
.btn-circle:hover { 
    border-color: var(--primary-color); 
    color: var(--primary-color); 
    transform: scale(1.08); 
}
.btn-circle:active { transform: scale(0.95); }

input[type="range"] { 
    -webkit-appearance: none; 
    appearance: none;
    width: 100%; 
    height: var(--knob-size);
    background: transparent; 
    outline: none;
    cursor: pointer;
    vertical-align: middle;
}
input[type="range"]::-webkit-slider-runnable-track {
    width: 100%;
    height: 4px;
    background: var(--color-border);
    border-radius: var(--radius-full);
}
input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none; 
    appearance: none;
    height: var(--knob-size); 
    width: var(--knob-size);
    border-radius: 50%; 
    background: var(--primary-color); 
    cursor: pointer; 
    margin-top: calc((var(--knob-size) - 4px) / -2);
    box-shadow: var(--shadow-md); 
    border: none;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}
input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.15);
    box-shadow: var(--shadow-lg);
}
/* Firefox */
input[type="range"]::-moz-range-thumb {
    height: var(--knob-size);
    width: var(--knob-size);
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    box-shadow: var(--shadow-md);
    border: none;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}
input[type="range"]::-moz-range-thumb:hover {
    transform: scale(1.15);
    box-shadow: var(--shadow-lg);
}

/* --- 网格系统 --- */
.settings-grid { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 15px; margin-bottom: 20px; align-items: start; }
.setting-item { 
    display: flex; 
    flex-direction: column; 
    align-items: center; 
    gap: 10px; 
    color: var(--color-fg-muted); 
    font-size: 12px; 
    font-weight: 600; 
    letter-spacing: 1px;
    text-transform: uppercase;
}

/* --- 下拉菜单 --- */
.custom-select-container { position: relative; width: 100%; max-width: 80px; }
.select-trigger {
    display: flex; justify-content: center; align-items: center; 
    background-color: var(--color-bg-light); 
    color: var(--color-fg);
    border: 1px solid var(--color-border); 
    padding: 0 25px 0 10px; 
    border-radius: var(--radius-md); 
    font-size: 16px; 
    font-weight: 600;
    cursor: pointer; 
    height: 38px; 
    transition: all var(--transition-fast); 
    position: relative;
}
.select-trigger:hover { 
    border-color: var(--primary-color); 
    box-shadow: var(--shadow-sm);
}
.custom-select-container.open .select-trigger { 
    border-color: var(--primary-color); 
    box-shadow: 0 0 8px rgba(245, 78, 0, 0.2);
}
.select-trigger::after {
    content: ''; position: absolute; right: 12px; top: 50%; transform: translateY(-20%);
    border-left: 4px solid transparent; border-right: 4px solid transparent; border-top: 5px solid var(--color-fg-muted); 
    transition: transform var(--transition-fast);
}
.custom-select-container.open .select-trigger::after { 
    transform: translateY(-20%) rotate(180deg); 
    border-top-color: var(--primary-color); 
}
.select-options {
    position: absolute; top: 115%; left: 0; right: 0; 
    background: var(--color-bg-light); 
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md); 
    display: none; flex-direction: column; z-index: 100;
    box-shadow: var(--shadow-xl); 
    max-height: 200px; overflow-y: auto;
    animation: slideDown var(--animation-duration-fast) var(--animation-easing-out);
}
.custom-select-container.open .select-options { display: flex; }
.option { 
    padding: 10px; 
    cursor: pointer; 
    color: var(--color-fg-subtle); 
    font-size: 15px; 
    font-weight: 500; 
    transition: all var(--transition-fast); 
}
.option:hover { 
    background-color: var(--color-bg-hover); 
    color: var(--color-fg); 
}
.option.selected { 
    color: var(--primary-color); 
    background-color: rgba(245, 78, 0, 0.1); 
    font-weight: 700; 
}

/* --- Checkbox --- */
.checkbox-wrapper { position: relative; display: inline-flex; align-items: center; cursor: pointer; }
.input-checkbox { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); border: 0; }
.custom-checkbox {
    display: inline-block; width: 22px; height: 22px; 
    border: 2px solid var(--color-border); 
    border-radius: var(--radius-md); 
    position: relative; 
    transition: all var(--transition-fast);
}
.checkbox-wrapper:hover .custom-checkbox { 
    border-color: var(--primary-color); 
}
.custom-checkbox::after {
    content: ""; position: absolute; top: 50%; left: 50%; 
    transform: translate(-50%, -50%) scale(0.5);
    width: 10px; height: 10px; 
    background-color: var(--primary-color); 
    border-radius: var(--radius-sm); 
    opacity: 0; 
    transition: all var(--transition-fast);
}
.input-checkbox:checked + .custom-checkbox { 
    border-color: var(--primary-color); 
    background-color: rgba(245, 78, 0, 0.1);
}
.input-checkbox:checked + .custom-checkbox::after { 
    opacity: 1; 
    transform: translate(-50%, -50%) scale(1); 
}

/* --- 通用输入框样式 --- */
input.scrubber-input {
    background: var(--color-bg-light); 
    color: var(--primary-color); 
    border: 1px solid var(--color-border);
    padding: 0; 
    border-radius: var(--radius-md); 
    font-size: 16px; font-weight: 600;
    outline: none; text-align: center; height: 38px; width: 100%;
    transition: all var(--transition-fast); 
    cursor: ns-resize; 
    font-family: var(--font-stack); 
    font-variant-numeric: tabular-nums;
}
input.scrubber-input:disabled { 
    opacity: 0.4; 
    cursor: not-allowed; 
    background: var(--color-bg); 
    border-color: transparent; 
    color: var(--color-fg-muted); 
}
input.scrubber-input:not(:disabled):hover, 
input.scrubber-input:focus { 
    border-color: var(--primary-color); 
    color: var(--color-fg); 
    box-shadow: 0 0 8px rgba(247, 148, 29, 0.3); 
}
input.scrubber-input.dragging { 
    border-color: var(--primary-color); 
    color: var(--primary-color); 
    background: var(--color-bg-light); 
}
.timer-controls { display: flex; align-items: center; flex-direction: column; gap: 6px; width: 100%; }
.timer-controls input.scrubber-input { width: 100%; max-width: 80px; }

/* === 进阶训练模块 (TRAINER / AUTOMATOR) === */
.trainer-container {
    background-color: var(--color-bg-light);
    border: 1px solid var(--color-border); 
    border-radius: var(--radius-lg);
    padding: 16px 20px; margin-bottom: 20px; text-align: left;
    animation: fadeIn var(--animation-duration-normal) var(--animation-easing-out);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.trainer-container:hover {
    border-color: var(--primary-color);
}
.trainer-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 12px; }
.trainer-title { 
    font-size: 12px; 
    color: var(--color-fg-muted); 
    letter-spacing: 2px; 
    font-weight: 600; 
    text-transform: uppercase; 
}
.trainer-body { transition: opacity var(--transition-normal), filter var(--transition-normal); }
.trainer-body.disabled { opacity: 0.3; filter: grayscale(100%); pointer-events: none; }

.trainer-tabs { 
    display: flex; 
    background: var(--color-bg); 
    border-radius: var(--radius-md); 
    padding: 4px; 
    margin-bottom: 15px; 
}
.trainer-tab {
    flex: 1; text-align: center; font-size: 12px; font-weight: 700; 
    color: var(--color-fg-muted);
    padding: 8px 0; cursor: pointer; border-radius: var(--radius-md); 
    transition: all var(--transition-fast); 
    letter-spacing: 1px;
}
.trainer-tab:hover { 
    color: var(--color-fg-subtle); 
    background: rgba(255, 255, 255, 0.123); 
}
.trainer-tab.active { 
    background: var(--color-bg-light); 
    color: var(--primary-color); 
    box-shadow: var(--shadow-md); 
}

.trainer-content { display: none; }
.trainer-content.active { 
    display: block; 
    animation: fadeIn var(--animation-duration-fast) var(--animation-easing-out); 
}

.trainer-controls-row { display: flex; align-items: flex-end; justify-content: space-between; gap: 10px; }
.t-input-group { display: flex; flex-direction: column; align-items: center; gap: 5px; flex: 1; }
.t-input-group label { 
    font-size: 11px; 
    font-weight: 600; 
    color: var(--color-fg-muted); 
    letter-spacing: 1px; 
}

.t-unit-btn {
    flex: 1; 
    background: var(--color-bg); 
    color: var(--color-fg-subtle); 
    border: 1px solid var(--color-border); 
    border-radius: var(--radius-md);
    height: 38px; font-size: 13px; font-weight: 700; cursor: pointer; 
    transition: all var(--transition-fast); 
    font-family: var(--font-stack);
}
.t-unit-btn:hover { 
    border-color: var(--primary-color); 
    color: var(--primary-color); 
    transform: translateY(-1px); 
}
.t-unit-btn:active { transform: scale(0.96); }

/* --- Prob-Wrapper (带符号或受控输入的容器) --- */
.prob-wrapper {
    position: relative; display: flex; align-items: center; justify-content: center;
    height: 38px; 
    background: var(--color-bg-light); 
    border: 1px solid var(--color-border); 
    border-radius: var(--radius-md);
    box-sizing: border-box; 
    transition: all var(--transition-fast); 
    width: 100%; max-width: 65px;
}
.prob-wrapper:hover { 
    border-color: var(--primary-color); 
}
.prob-wrapper:focus-within { 
    border-color: var(--primary-color); 
}
.prob-wrapper input.scrubber-input {
    width: 100% !important; height: 100% !important; border: none !important;
    background: transparent !important; margin: 0 !important; max-width: none !important;
    text-align: center;
}
.prob-wrapper span { color: var(--primary-color); font-weight: 700; font-size: 14px; pointer-events: none; }

/* Random Mode 专属布局 */
#random-mode .t-input-group.horizontal {
    flex-direction: row; justify-content: center; align-items: center; gap: 12px; padding: 0; width: 100%;
}
#random-mode label { flex: 0 0 auto; width: auto; margin: 0; text-align: right; }
#random-mode .prob-wrapper { flex: 0 0 auto; width: 60px; max-width: none; padding: 0 5px; }
#random-mode .prob-wrapper input.scrubber-input { text-align: right; padding-right: 4px; margin-right: 4px !important; }

/* 统一输入框宽度限制 */
.trainer-content input.scrubber-input:not(.prob-wrapper input),
.trainer-controls-row .scrubber-input:not(.prob-wrapper input) {
    width: 100%; max-width: 65px;
}

/* Target Limit 禁用状态 */
#auto-target-wrapper.disabled { opacity: 0.3; pointer-events: none; border-color: transparent; background: var(--color-bg); }

/* === Subdivisions === */
.subdivision-control {
    display: flex; 
    background: var(--color-bg); 
    border-radius: var(--radius-lg); 
    padding: 4px; gap: 2px;
    margin-bottom: 20px; 
    border: 1px solid var(--color-border); 
    transition: all var(--transition-normal);
}
.subdivision-control.disabled { opacity: 0.2; pointer-events: none; filter: grayscale(100%); }
.subdiv-btn {
    flex: 1; display: flex; justify-content: center; align-items: center;
    height: 40px; border-radius: var(--radius-md); cursor: pointer; 
    color: var(--color-fg-muted); 
    transition: all var(--transition-fast); 
    position: relative;
}
.subdiv-btn:hover { 
    color: var(--color-fg-subtle); 
    background: rgba(255,255,255,0.03); 
    transform: translateY(-1px); 
}
.subdiv-btn.active {
    background: var(--color-bg-light); 
    color: var(--primary-color);
    box-shadow: var(--shadow-md); 
    border: 1px solid var(--primary-color);
}
.subdiv-btn:active { transform: scale(0.96); }
.subdiv-btn svg { width: 22px; height: 22px; fill: currentColor; }

/* 动态图标隐藏/显示控制 */
.subdiv-btn.toggleable svg { display: none; }
.subdiv-btn.toggleable[data-state="straight"] .icon-straight { display: block; }
.subdiv-btn.toggleable[data-state="straight-16t"] .icon-straight-16t { display: block; }
.subdiv-btn.toggleable[data-state="swing"] .icon-swing { display: block; }
.subdiv-btn.toggleable[data-state="swing-4"] .icon-swing-4 { display: block; }
.subdiv-btn.toggleable[data-state="swing-5"] .icon-swing-5 { display: block; }
.subdiv-btn.toggleable[data-state="swing-6"] .icon-swing-6 { display: block; }

.subdivision-control.groove-active { 
    border-color: rgba(181, 101, 214, 0.5); 
    box-shadow: 0 0 20px rgba(181, 101, 214, 0.15); 
}
.subdivision-control.groove-active .subdiv-btn.active { 
    color: var(--groove-color); 
    border-color: rgba(181, 101, 214, 0.5); 
}

/* Poly Toggle 样式 */
.poly-toggle-label { 
    cursor: pointer; 
    transition: all var(--transition-fast); 
    position: relative; 
}
.poly-toggle-label:hover { color: var(--color-fg-subtle); }
.poly-toggle-label:active { transform: scale(0.9); }
.poly-toggle-label.active { 
    color: var(--groove-color); 
    text-shadow: 0 0 12px rgba(181, 101, 214, 0.5); 
}
#poly-select-wrapper.disabled { opacity: 0.3; pointer-events: none; }

/* Timer Toggle 样式 (主题橙色效果) */
.timer-toggle-label { 
    cursor: pointer; 
    transition: all var(--transition-fast); 
    position: relative; 
}
.timer-toggle-label:hover { color: var(--color-fg-subtle); }
.timer-toggle-label:active { transform: scale(0.9); }
.timer-toggle-label.active {
    color: var(--primary-color);
    text-shadow: 0 0 12px rgba(245, 78, 0, 0.5);
}

/* === Buttons === */
.action-area { display: flex; gap: 15px; margin-top: 15px; }
.btn-tap {
    flex: 1; 
    background-color: transparent; 
    color: var(--color-fg-subtle); 
    border: 2px solid var(--color-border); 
    padding: 16px 0;
    font-size: 15px; 
    border-radius: var(--radius-lg); 
    cursor: pointer; 
    font-weight: 700; 
    transition: all var(--transition-fast); 
    letter-spacing: 1px;
}
.btn-tap:hover { 
    border-color: var(--primary-color); 
    color: var(--primary-color); 
    transform: translateY(-2px); 
}
.btn-tap:active { transform: scale(0.98); }
.btn-main {
    flex: 2; 
    background: var(--primary-color);
    color: #fff; 
    border: none; 
    padding: 16px 0;
    font-size: 16px; 
    border-radius: var(--radius-lg); 
    cursor: pointer; 
    font-weight: 700; 
    text-transform: uppercase;
    letter-spacing: 1px; 
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-lg);
}
.btn-main:hover { 
    transform: translateY(-2px); 
    box-shadow: var(--shadow-xl);
    filter: brightness(1.1);
}
.btn-main:active { transform: scale(0.98); }
.btn-main.playing { 
    background: linear-gradient(135deg, var(--color-danger) 0%, #ff6b6b 100%);
    box-shadow: var(--shadow-lg);
}

/* ==================== 关键帧动画 ==================== */

/* 淡入动画 */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* 向上滑入动画 */
@keyframes slideUp {
  from { transform: translateY(20px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

/* 向下滑入动画 */
@keyframes slideDown {
  from { transform: translateY(-20px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

/* 缩放淡入动画 */
@keyframes scaleIn {
  from { transform: scale(0.95); opacity: 0; }
  to { transform: scale(1); opacity: 1; }
}

/* 弹跳动画 */
@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

/* 脉冲动画 */
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

/* 旋转动画 */
@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

/* 摇晃动画 */
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-5px); }
  75% { transform: translateX(5px); }
}

/* 发光动画 */
@keyframes glow {
  0%, 100% {
    box-shadow: 0 0 5px var(--primary-color),
                0 0 10px var(--primary-color);
  }
  50% {
    box-shadow: 0 0 10px var(--primary-color),
                0 0 20px var(--primary-color),
                0 0 30px var(--primary-color);
  }
}

/* 渐变流动动画 */
@keyframes gradientFlow {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

/* 节拍闪烁动画 */
@keyframes beatPulse {
  0% { transform: scale(1); box-shadow: 0 0 0 rgba(245, 78, 0, 0); }
  50% { transform: scale(1.3); box-shadow: 0 0 20px rgba(245, 78, 0, 0.6); }
  100% { transform: scale(1); box-shadow: 0 0 0 rgba(245, 78, 0, 0); }
}

/* 数字变化动画 */
@keyframes countUp {
  from { transform: translateY(100%); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

/* ==================== 动画类 ==================== */

/* 淡入 */
.animate-fade-in {
  animation: fadeIn var(--animation-duration-normal) var(--animation-easing-out);
}

/* 向上滑入 */
.animate-slide-up {
  animation: slideUp var(--animation-duration-normal) var(--animation-easing-out);
}

/* 缩放淡入 */
.animate-scale-in {
  animation: scaleIn var(--animation-duration-normal) var(--animation-easing-out);
}

/* 弹跳 */
.animate-bounce {
  animation: bounce 1s ease-in-out infinite;
}

/* 脉冲 */
.animate-pulse {
  animation: pulse 2s ease-in-out infinite;
}

/* 旋转 */
.animate-spin {
  animation: spin 1s linear infinite;
}

/* 摇晃 */
.animate-shake {
  animation: shake 0.5s ease-in-out;
}

/* 发光 */
.animate-glow {
  animation: glow 2s ease-in-out infinite;
}

/* ==================== 主题切换按钮 ==================== */

.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    background-color: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    cursor: pointer;
    z-index: 1000;
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-md);
}

.theme-toggle:hover {
    transform: scale(1.08);
    border-color: var(--primary-color);
    box-shadow: var(--shadow-lg);
}

.theme-toggle:active {
    transform: scale(0.95);
}

.theme-toggle svg {
    width: 22px;
    height: 22px;
    fill: var(--color-fg-subtle);
    transition: all var(--transition-fast);
}

.theme-toggle:hover svg {
    fill: var(--primary-color);
}

/* 亮色主题下的切换按钮 */
:root[data-theme="light"] .theme-toggle {
    background-color: var(--color-bg-light);
}

.theme-toggle .icon-sun {
    display: none;
}

.theme-toggle .icon-moon {
    display: block;
}

:root[data-theme="light"] .theme-toggle .icon-sun {
    display: block;
}

:root[data-theme="light"] .theme-toggle .icon-moon {
    display: none;
}

/* ==================== 减少动画偏好 ==================== */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}