/* ================================================================
   components.css · 按钮、卡片、滑块、开关、挑战题等通用组件
   ================================================================ */

/* ========== 按钮 ========== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 20px;
    border: none;
    border-radius: var(--radius-md);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    font-family: inherit;
}

.btn-primary {
    background: var(--accent-blue);
    color: white;
}

.btn-primary:hover {
    background: #2563eb;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background: var(--bg-elevated);
}

.btn-lg {
    padding: 14px 28px;
    font-size: 15px;
}

/* ========== 概念卡片 ========== */
.concept-card {
    background: linear-gradient(135deg, var(--bg-secondary) 0%, #1a2744 100%);
    border: 1px solid var(--bg-tertiary);
    border-radius: var(--radius-lg);
    padding: 28px 32px;
    margin-bottom: 24px;
    position: relative;
    overflow: hidden;
}

.concept-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(180deg, var(--accent-cyan), var(--accent-blue));
}

.concept-card h2 {
    font-size: 22px;
    margin-bottom: 12px;
    color: var(--accent-cyan);
}

.concept-card p {
    color: var(--text-secondary);
    font-size: 15px;
    max-width: 900px;
}

.concept-card .analogy {
    display: inline-block;
    background: rgba(6, 182, 212, 0.15);
    color: var(--accent-cyan);
    padding: 6px 16px;
    border-radius: var(--radius-xl);
    font-size: 13px;
    margin-top: 12px;
    border: 1px solid rgba(6, 182, 212, 0.3);
}

/* ========== 舞台容器 ========== */
.stage-wrapper {
    background: var(--bg-secondary);
    border: 1px solid var(--bg-tertiary);
    border-radius: var(--radius-lg);
    padding: 24px;
}

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

.stage-label {
    font-size: 12px;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 600;
}

.stage {
    background: #0a0f1a;
    border-radius: 12px;
    min-height: 420px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px;
    position: relative;
    overflow: hidden;
    background-image:
        radial-gradient(circle at 20% 30%, rgba(59, 130, 246, 0.05) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(139, 92, 246, 0.05) 0%, transparent 50%);
}

/* ========== 控制面板 ========== */
.control-panel {
    background: var(--bg-secondary);
    border: 1px solid var(--bg-tertiary);
    border-radius: var(--radius-lg);
    padding: 24px;
    position: sticky;
    top: 88px;
}

.control-panel h3 {
    font-size: 15px;
    margin-bottom: 20px;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 8px;
}

.control-panel h3::before {
    content: '';
    width: 8px;
    height: 8px;
    background: var(--accent-blue);
    border-radius: 50%;
}

.control-group {
    margin-bottom: 20px;
}

.control-group label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 8px;
    font-weight: 500;
}

.value-display {
    color: var(--accent-cyan);
    font-weight: 700;
    font-family: var(--font-mono);
    font-size: 12px;
    background: rgba(6, 182, 212, 0.1);
    padding: 2px 8px;
    border-radius: 4px;
}

/* ========== 滑块 ========== */
input[type="range"] {
    width: 100%;
    height: 6px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--bg-tertiary);
    border-radius: 3px;
    outline: none;
    cursor: pointer;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--accent-blue);
    cursor: pointer;
    border: 3px solid var(--bg-primary);
    box-shadow: 0 0 0 2px var(--accent-blue);
    transition: transform var(--transition-fast);
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.15);
}

input[type="range"]::-moz-range-thumb {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--accent-blue);
    cursor: pointer;
    border: 3px solid var(--bg-primary);
    box-shadow: 0 0 0 2px var(--accent-blue);
}

/* ========== 开关 ========== */
.toggle-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 0;
    border-top: 1px solid var(--bg-tertiary);
}

.toggle-row span {
    font-size: 13px;
    color: var(--text-secondary);
}

.toggle-switch {
    position: relative;
    width: 44px;
    height: 24px;
    background: var(--bg-tertiary);
    border-radius: 12px;
    cursor: pointer;
    transition: background var(--transition-base);
    border: none;
    padding: 0;
}

.toggle-switch.active {
    background: var(--accent-blue);
}

.toggle-switch::after {
    content: '';
    position: absolute;
    top: 2px;
    left: 2px;
    width: 20px;
    height: 20px;
    background: white;
    border-radius: 50%;
    transition: transform var(--transition-base);
}

.toggle-switch.active::after {
    transform: translateX(20px);
}

/* ========== 预设按钮组 ========== */
.preset-btns {
    display: flex;
    gap: 6px;
    margin-top: 6px;
}

.preset-btn {
    flex: 1;
    padding: 6px 0;
    border: 1px solid var(--bg-tertiary);
    background: transparent;
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    font-size: 11px;
    font-weight: 600;
    transition: all var(--transition-base);
}

.preset-btn:hover {
    border-color: var(--accent-cyan);
    color: var(--accent-cyan);
}

.preset-btn.active {
    background: var(--accent-cyan);
    border-color: var(--accent-cyan);
    color: #0a0f1a;
}

/* ========== 提示框 ========== */
.hint-box {
    background: rgba(139, 92, 246, 0.1);
    border: 1px solid rgba(139, 92, 246, 0.3);
    border-radius: var(--radius-md);
    padding: 14px 18px;
    margin-top: 16px;
    font-size: 13px;
    color: #c4b5fd;
    line-height: 1.7;
    min-height: 60px;
}

.hint-box strong {
    color: var(--accent-purple);
}

/* ========== 播放控制 ========== */
.play-controls {
    display: flex;
    gap: 10px;
    margin-top: 16px;
    flex-wrap: wrap;
}

/* ========== 步骤指示器 ========== */
.step-indicator {
    display: flex;
    gap: 8px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.step-dot {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    border-radius: var(--radius-xl);
    background: var(--bg-tertiary);
    font-size: 12px;
    color: var(--text-secondary);
    transition: all var(--transition-base);
    border: 1px solid transparent;
}

.step-dot.active {
    background: rgba(59, 130, 246, 0.15);
    border-color: var(--accent-blue);
    color: var(--accent-blue);
}

.step-dot.done {
    background: rgba(16, 185, 129, 0.15);
    border-color: var(--accent-green);
    color: var(--accent-green);
}

.step-dot .num {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--bg-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 10px;
    font-weight: 700;
}

/* ========== 代码输出面板 ========== */
.code-output {
    background: #0a0f1a;
    border: 1px solid var(--bg-tertiary);
    border-radius: var(--radius-md);
    padding: 16px;
    margin-top: 16px;
    font-family: var(--font-mono);
    font-size: 13px;
    line-height: 1.8;
    overflow-x: auto;
}

.code-output .code-line { display: block; }
.code-output .prop { color: var(--accent-cyan); }
.code-output .val { color: var(--accent-orange); }
.code-output .sel { color: var(--accent-pink); }
.code-output .brace { color: var(--text-secondary); }
.code-output .comment { color: var(--text-muted); font-style: italic; }

/* ========== 挑战题 ========== */
.challenge-card {
    background: var(--bg-secondary);
    border: 1px solid var(--bg-tertiary);
    border-radius: var(--radius-lg);
    padding: 28px;
    margin-bottom: 20px;
}

.challenge-card h3 {
    font-size: 17px;
    margin-bottom: 12px;
    color: var(--accent-orange);
}

.challenge-card .question {
    font-size: 15px;
    color: var(--text-primary);
    margin-bottom: 20px;
    line-height: 1.7;
}

.options-grid {
    display: grid;
    gap: 10px;
}

.option-btn {
    padding: 14px 20px;
    border: 2px solid var(--bg-tertiary);
    background: var(--bg-primary);
    color: var(--text-primary);
    border-radius: var(--radius-md);
    font-size: 14px;
    transition: all var(--transition-base);
    text-align: left;
    line-height: 1.5;
}

.option-btn:hover:not(.disabled) {
    border-color: var(--accent-blue);
    background: rgba(59, 130, 246, 0.08);
}

.option-btn.correct {
    border-color: var(--accent-green);
    background: rgba(16, 185, 129, 0.12);
}

.option-btn.wrong {
    border-color: var(--accent-red);
    background: rgba(239, 68, 68, 0.12);
}

.option-btn.disabled {
    cursor: not-allowed;
    opacity: 0.7;
}

.feedback {
    margin-top: 16px;
    padding: 14px 18px;
    border-radius: var(--radius-md);
    font-size: 14px;
    line-height: 1.6;
    display: none;
}

.feedback.show {
    display: block;
    animation: fadeInFast 0.3s ease;
}

.feedback.success {
    background: rgba(16, 185, 129, 0.12);
    border: 1px solid rgba(16, 185, 129, 0.3);
    color: var(--accent-green);
}

.feedback.error {
    background: rgba(239, 68, 68, 0.12);
    border: 1px solid rgba(239, 68, 68, 0.3);
    color: #f87171;
}

/* ========== 视图切换 ========== */
.view-toggle {
    display: flex;
    gap: 4px;
    background: var(--bg-primary);
    padding: 3px;
    border-radius: var(--radius-sm);
}

.view-toggle button {
    padding: 5px 12px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-size: 11px;
    font-weight: 600;
    border-radius: var(--radius-sm);
    transition: all var(--transition-base);
}

.view-toggle button.active {
    background: var(--accent-blue);
    color: white;
}

/* ========== 图层栈面板 ========== */
.layer-stack-panel {
    background: var(--bg-secondary);
    border: 1px solid var(--bg-tertiary);
    border-radius: var(--radius-lg);
    padding: 24px;
    position: sticky;
    top: 88px;
}

.layer-stack-panel h3 {
    font-size: 15px;
    margin-bottom: 6px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.layer-stack-panel h3::before {
    content: '';
    width: 8px;
    height: 8px;
    background: var(--accent-cyan);
    border-radius: 50%;
}

.layer-stack-panel .subtitle {
    font-size: 12px;
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.layer-card {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px;
    background: var(--bg-primary);
    border: 1px solid var(--bg-tertiary);
    border-radius: var(--radius-md);
    margin-bottom: 8px;
    transition: all 0.5s cubic-bezier(0.34, 1.2, 0.64, 1);
}

.layer-card .layer-thumb {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    font-size: 15px;
    color: white;
    flex-shrink: 0;
    transition: all 0.5s ease;
}

.layer-card .layer-info { flex: 1; min-width: 0; }
.layer-card .layer-name { font-size: 13px; font-weight: 600; }
.layer-card .layer-meta { font-size: 11px; color: var(--text-secondary); margin-top: 2px; }

.layer-card .layer-badge {
    font-size: 10px;
    padding: 2px 8px;
    border-radius: 10px;
    font-weight: 700;
    letter-spacing: 0.3px;
    white-space: nowrap;
}

.layer-card .layer-badge.flow-badge {
    background: rgba(59, 130, 246, 0.15);
    color: var(--accent-blue);
}

.layer-card .layer-badge.float-badge {
    background: rgba(6, 182, 212, 0.2);
    color: var(--accent-cyan);
}

.layer-card.is-floating {
    border-color: rgba(6, 182, 212, 0.5);
    background: rgba(6, 182, 212, 0.06);
    transform: translateX(6px);
    box-shadow: -4px 0 0 0 var(--accent-cyan);
}

/* ========== Z 轴深度指示 ========== */
.depth-indicator {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 16px;
    padding: 12px 14px;
    background: var(--bg-primary);
    border: 1px solid var(--bg-tertiary);
    border-radius: var(--radius-md);
}

.depth-indicator .depth-label {
    font-size: 11px;
    color: var(--text-secondary);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    flex-shrink: 0;
}

.depth-bar {
    flex: 1;
    height: 6px;
    background: var(--bg-tertiary);
    border-radius: 3px;
    position: relative;
    overflow: hidden;
}

.depth-bar .depth-fill {
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    background: linear-gradient(90deg, var(--accent-blue), var(--accent-cyan));
    border-radius: 3px;
    transition: width 0.8s ease;
}

.depth-value {
    font-size: 11px;
    font-weight: 700;
    color: var(--accent-cyan);
    font-family: var(--font-mono);
    flex-shrink: 0;
}

/* ========== 响应式 ========== */
@media (max-width: 1024px) {
    .control-panel,
    .layer-stack-panel {
        position: static;
    }
}

@media (max-width: 640px) {
    .concept-card { padding: 20px; }
    .stage { padding: 20px; min-height: 320px; }
    .challenge-card { padding: 20px; }
}

/* 多选选中状态 */
.option-btn.selected {
    border-color: var(--accent-blue);
    background: rgba(59, 130, 246, 0.15);
    color: var(--accent-blue);
    font-weight: bold;
}

/* AI 返回的代码块样式美化 */
.question pre {
    background: #0a0f1a;
    padding: 12px;
    border-radius: 6px;
    border: 1px solid var(--bg-tertiary);
    overflow-x: auto;
    margin: 10px 0;
}
.question code {
    font-family: var(--font-mono);
    color: var(--accent-cyan);
}