/* ============================================================
   照片去背景工具 · tool.css
   页面结构：头部 / 上传区 / 结果区(对比滑杆) / 特性 / 步骤 / FAQ
   断点：1024px / 768px / 480px 全覆盖
   ============================================================ */

.tool-header {
    padding: 150px 0 56px;
    background: linear-gradient(180deg, #f0f5ff 0%, #ffffff 100%);
    text-align: center;
}

.tool-hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(22, 163, 74, 0.1);
    border: 1px solid rgba(22, 163, 74, 0.25);
    color: #16a34a;
    font-size: 13px;
    font-weight: 600;
    padding: 8px 18px;
    border-radius: 100px;
    margin-bottom: 20px;
}

.tool-header h1 {
    font-size: clamp(30px, 5vw, 44px);
    font-weight: 900;
    color: var(--text);
    margin-bottom: 14px;
    line-height: 1.2;
}

.tool-header h1 .hl {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.tool-header p {
    font-size: 16px;
    color: var(--text-secondary);
    max-width: 640px;
    margin: 0 auto;
    line-height: 1.8;
}

.tool-main { padding-top: 48px; }

/* ===== 本地运行提示条 ===== */
.privacy-banner {
    display: flex;
    align-items: flex-start;
    gap: 14px;
    background: linear-gradient(135deg, #e8f1ff 0%, #f0f5ff 100%);
    border: 1.5px solid rgba(26, 110, 255, 0.15);
    border-radius: var(--radius);
    padding: 20px 24px;
    margin-bottom: 28px;
}
.privacy-icon {
    width: 40px; height: 40px;
    background: var(--primary);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}
.privacy-icon svg { width: 22px; height: 22px; color: white; }
.privacy-banner h4 { font-size: 15px; font-weight: 700; color: var(--primary); margin-bottom: 4px; }
.privacy-banner p { font-size: 13px; color: var(--text-secondary); line-height: 1.7; margin: 0; }

/* ===== 上传区 ===== */
.upload-panel { margin-bottom: 8px; }

.dropzone {
    border: 2px dashed rgba(26, 110, 255, 0.35);
    border-radius: var(--radius);
    background: linear-gradient(180deg, #fafcff 0%, #f4f8ff 100%);
    padding: 56px 24px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    outline: none;
}
.dropzone:hover, .dropzone:focus-visible, .dropzone.dragging {
    border-color: var(--primary);
    background: var(--primary-light);
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}
.dropzone.dragging { border-style: solid; }

.dz-icon {
    width: 72px; height: 72px;
    background: var(--primary-gradient);
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    box-shadow: 0 10px 28px rgba(26, 110, 255, 0.35);
}
.dz-icon svg { width: 36px; height: 36px; color: white; }

.dropzone h3 { font-size: 18px; font-weight: 700; color: var(--text); margin-bottom: 8px; }
.dropzone p { font-size: 13px; color: var(--text-light); margin-bottom: 20px; }

.dz-actions {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 14px;
    flex-wrap: wrap;
}
.btn-pick {
    display: inline-flex;
    align-items: center;
    padding: 12px 32px;
    background: var(--primary-gradient);
    color: white;
    font-size: 15px;
    font-weight: 700;
    border-radius: 12px;
    box-shadow: 0 8px 24px rgba(26, 110, 255, 0.35);
    transition: var(--transition);
}
.dropzone:hover .btn-pick { transform: translateY(-2px); box-shadow: 0 12px 32px rgba(26, 110, 255, 0.45); }
.dz-paste-hint { font-size: 12px; color: var(--text-light); }

/* ===== 处理中遮罩 ===== */
.processing-overlay {
    position: fixed;
    inset: 0;
    z-index: 2000;
    background: rgba(7, 11, 20, 0.72);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
}
.proc-box {
    background: white;
    border-radius: var(--radius);
    padding: 44px 40px;
    max-width: 400px;
    width: 100%;
    text-align: center;
    box-shadow: 0 24px 80px rgba(0, 0, 0, 0.35);
}
.proc-ring { position: relative; width: 140px; height: 140px; margin: 0 auto 24px; }
.proc-ring svg { width: 100%; height: 100%; transform: rotate(-90deg); }
.proc-bg { fill: none; stroke: var(--border); stroke-width: 9; }
.proc-fill {
    fill: none;
    stroke: url(#procGrad);
    stroke: var(--primary);
    stroke-width: 9;
    stroke-linecap: round;
    stroke-dasharray: 326.7;
    stroke-dashoffset: 326.7;
    transition: stroke-dashoffset 0.3s ease;
}
.proc-pct {
    position: absolute; top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    font-size: 30px; font-weight: 900; color: var(--text);
    font-variant-numeric: tabular-nums;
}
.proc-box h3 { font-size: 18px; font-weight: 800; margin-bottom: 8px; }
.proc-box p { font-size: 13px; color: var(--text-secondary); line-height: 1.7; }

/* ===== 结果区 ===== */
.result-panel {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
}

.result-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 14px 18px;
    border-bottom: 1px solid var(--border);
    background: var(--bg-warm);
    flex-wrap: wrap;
}

.mode-switch {
    display: flex;
    background: var(--border);
    border-radius: 10px;
    padding: 4px;
    gap: 4px;
}
.mode-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    border: none;
    background: transparent;
    font-family: inherit;
    font-size: 13px;
    font-weight: 600;
    color: var(--text-secondary);
    padding: 7px 16px;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
}
.mode-btn.active { background: white; color: var(--primary); box-shadow: 0 2px 8px rgba(0,0,0,0.08); }

.zoom-controls {
    display: flex;
    align-items: center;
    gap: 6px;
}
.zoom-controls button {
    width: 34px; height: 34px;
    border: 1.5px solid var(--border);
    background: white;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 700;
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}
.zoom-controls button:hover { border-color: var(--primary); color: var(--primary); }
#zoomLabel {
    min-width: 52px;
    text-align: center;
    font-size: 12px;
    font-weight: 700;
    color: var(--text);
    font-variant-numeric: tabular-nums;
}

/* 对比舞台 */
.compare-stage {
    position: relative;
    height: 520px;
    overflow: hidden;
    background: #dfe5ee;
    cursor: grab;
    touch-action: none;
}
.compare-stage:active { cursor: grabbing; }

.checker-bg {
    position: absolute; inset: 0;
    background-image:
        linear-gradient(45deg, #c9d2e0 25%, transparent 25%),
        linear-gradient(-45deg, #c9d2e0 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, #c9d2e0 75%),
        linear-gradient(-45deg, transparent 75%, #c9d2e0 75%);
    background-size: 24px 24px;
    background-position: 0 0, 0 12px, 12px -12px, -12px 0;
    background-color: #eef2f8;
}

.compare-stage canvas {
    position: absolute;
    top: 50%; left: 50%;
    transform-origin: center center;
    will-change: transform;
    image-rendering: auto;
}
#beforeCanvas { z-index: 1; }
.after-clip {
    position: absolute;
    inset: 0;
    z-index: 2;
    overflow: hidden;
    pointer-events: none;
}
#afterCanvas { z-index: 2; }

.compare-handle {
    position: absolute;
    top: 0; bottom: 0;
    left: 50%;
    width: 0;
    z-index: 5;
    pointer-events: none;
}
.handle-line {
    position: absolute;
    top: 0; bottom: 0;
    left: -1.5px;
    width: 3px;
    background: white;
    box-shadow: 0 0 12px rgba(0,0,0,0.35);
}
.handle-knob {
    position: absolute;
    top: 50%; left: 0;
    transform: translate(-50%, -50%);
    width: 40px; height: 40px;
    background: white;
    border-radius: 50%;
    box-shadow: 0 4px 16px rgba(0,0,0,0.3);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
}

.stage-hint {
    position: absolute;
    left: 50%; bottom: 12px;
    transform: translateX(-50%);
    z-index: 6;
    font-size: 12px;
    color: rgba(30, 41, 59, 0.65);
    background: rgba(255,255,255,0.75);
    backdrop-filter: blur(6px);
    padding: 5px 14px;
    border-radius: 100px;
    pointer-events: none;
    white-space: nowrap;
}

/* 结果选项 */
.result-options {
    display: flex;
    gap: 24px;
    padding: 18px 20px;
    border-bottom: 1px solid var(--border);
    flex-wrap: wrap;
    align-items: center;
}
.opt-group { display: flex; align-items: center; gap: 12px; }
.opt-label { font-size: 13px; font-weight: 700; color: var(--text); white-space: nowrap; }

.seg-control {
    display: flex;
    background: var(--bg-warm);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 3px;
    gap: 3px;
    flex-wrap: wrap;
}
.seg-control button {
    border: none;
    background: transparent;
    font-family: inherit;
    font-size: 12px;
    font-weight: 600;
    color: var(--text-secondary);
    padding: 6px 14px;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
}
.seg-control button.active { background: var(--primary-gradient); color: white; box-shadow: 0 3px 10px rgba(26,110,255,0.3); }

.color-chips { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.chip {
    width: 28px; height: 28px;
    border-radius: 50%;
    border: 2px solid white;
    box-shadow: 0 0 0 1.5px var(--border), 0 2px 6px rgba(0,0,0,0.12);
    cursor: pointer;
    transition: var(--transition);
    padding: 0;
}
.chip:hover { transform: scale(1.12); }
.chip.active { box-shadow: 0 0 0 2.5px var(--primary), 0 2px 8px rgba(26,110,255,0.3); transform: scale(1.12); }
.chip-transparent {
    background-image:
        linear-gradient(45deg, #c9d2e0 25%, transparent 25%),
        linear-gradient(-45deg, #c9d2e0 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, #c9d2e0 75%),
        linear-gradient(-45deg, transparent 75%, #c9d2e0 75%);
    background-size: 12px 12px;
    background-position: 0 0, 0 6px, 6px -6px, -6px 0;
    background-color: #fff;
}
.chip-custom {
    background: conic-gradient(#ff5e5e, #ffb84d, #f7e463, #6fe08a, #4dc3ff, #a78bfa, #ff7ad9, #ff5e5e);
    position: relative;
}

/* 结果操作按钮 */
.result-actions {
    display: flex;
    gap: 12px;
    padding: 18px 20px;
    flex-wrap: wrap;
}
.btn-tool {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 26px;
    border-radius: 12px;
    font-family: inherit;
    font-size: 14px;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition);
    border: none;
}
.btn-primary-tool {
    background: var(--primary-gradient);
    color: white;
    box-shadow: 0 8px 24px rgba(26, 110, 255, 0.35);
}
.btn-primary-tool:hover { transform: translateY(-2px); box-shadow: 0 12px 32px rgba(26, 110, 255, 0.45); }
.btn-ghost-tool {
    background: white;
    color: var(--text-secondary);
    border: 1.5px solid var(--border);
}
.btn-ghost-tool:hover { border-color: var(--primary); color: var(--primary); }

/* ===== 特性 ===== */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}
.feature-card {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 28px 24px;
    transition: var(--transition);
}
.feature-card:hover { box-shadow: var(--shadow-hover); transform: translateY(-4px); border-color: rgba(26,110,255,0.2); }
.f-icon {
    width: 52px; height: 52px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
}
.f-icon svg { width: 26px; height: 26px; color: var(--primary); }
.feature-card h3 { font-size: 16px; font-weight: 700; margin-bottom: 8px; }
.feature-card p { font-size: 13px; color: var(--text-secondary); line-height: 1.8; }

/* ===== 步骤 ===== */
.steps-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}
.step-card {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 30px 26px;
    text-align: center;
    transition: var(--transition);
}
.step-card:hover { box-shadow: var(--shadow-hover); border-color: rgba(26,110,255,0.2); transform: translateY(-4px); }
.step-num {
    width: 46px; height: 46px;
    background: var(--primary-gradient);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    font-weight: 900;
    margin: 0 auto 16px;
    box-shadow: 0 6px 16px rgba(26,110,255,0.3);
}
.step-card h4 { font-size: 16px; font-weight: 700; margin-bottom: 8px; }
.step-card p { font-size: 13px; color: var(--text-secondary); line-height: 1.8; }

/* ===== FAQ ===== */
.faq-list { max-width: 780px; margin: 0 auto; }
.faq-item {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    margin-bottom: 12px;
    overflow: hidden;
    transition: var(--transition);
}
.faq-item[open] { border-color: rgba(26,110,255,0.25); box-shadow: var(--shadow); }
.faq-item summary {
    list-style: none;
    cursor: pointer;
    padding: 18px 22px;
    font-size: 15px;
    font-weight: 700;
    color: var(--text);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    user-select: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
    content: '+';
    font-size: 20px;
    font-weight: 400;
    color: var(--primary);
    flex-shrink: 0;
    transition: transform 0.3s ease;
}
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item p { padding: 0 22px 18px; font-size: 14px; color: var(--text-secondary); line-height: 1.9; }

/* ============================================================
   响应式：1024px
   ============================================================ */
@media (max-width: 1024px) {
    .tool-header { padding: 130px 0 44px; }
    .feature-grid { grid-template-columns: repeat(2, 1fr); }
    .steps-grid { grid-template-columns: 1fr; max-width: 560px; margin: 0 auto; }
    .compare-stage { height: 440px; }
}

/* ============================================================
   响应式：768px
   ============================================================ */
@media (max-width: 768px) {
    .tool-header { padding: 118px 0 36px; }
    .tool-header p { font-size: 14px; padding: 0 8px; }
    .tool-hero-badge { font-size: 12px; padding: 6px 14px; }

    .privacy-banner { flex-direction: column; gap: 12px; padding: 16px 18px; }
    .privacy-icon { width: 36px; height: 36px; }

    .dropzone { padding: 40px 18px; }
    .dz-icon { width: 60px; height: 60px; border-radius: 16px; }
    .dz-icon svg { width: 30px; height: 30px; }
    .dropzone h3 { font-size: 16px; }
    .dz-actions { flex-direction: column; gap: 10px; }

    .compare-stage { height: 340px; }
    .result-toolbar { padding: 10px 12px; gap: 8px; }
    .mode-switch { flex: 1; }
    .mode-btn { flex: 1; justify-content: center; padding: 7px 8px; font-size: 12px; }
    .zoom-controls button { width: 32px; height: 32px; }
    #zoomLabel { min-width: 44px; font-size: 11px; }
    .stage-hint { font-size: 11px; bottom: 8px; }

    .result-options { flex-direction: column; align-items: stretch; gap: 14px; padding: 14px; }
    .opt-group { flex-direction: column; align-items: flex-start; gap: 8px; }
    .seg-control { width: 100%; }
    .seg-control button { flex: 1; padding: 8px 6px; }

    .result-actions { flex-direction: column; padding: 14px; }
    .btn-tool { width: 100%; justify-content: center; padding: 13px 20px; }

    .feature-grid { grid-template-columns: 1fr; }
    .proc-box { padding: 32px 24px; }
    .proc-ring { width: 120px; height: 120px; }
    .proc-pct { font-size: 26px; }
}

/* ============================================================
   响应式：480px
   ============================================================ */
@media (max-width: 480px) {
    .compare-stage { height: 280px; }
    .handle-knob { width: 34px; height: 34px; }
    .tool-header h1 { font-size: 26px; }
}

/* ===== 抠图精度选择 ===== */
.quality-bar {
    display: flex;
    align-items: center;
    gap: 14px;
    margin-top: 16px;
    padding: 14px 18px;
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    flex-wrap: wrap;
}
.quality-hint { font-size: 12px; color: var(--text-light); flex: 1; min-width: 200px; }
@media (max-width: 768px) {
    .quality-bar { flex-direction: column; align-items: stretch; gap: 10px; }
    .quality-bar .seg-control button { flex: 1; }
}


/* ===== 引擎状态卡片（与 audio-convert 工具同款） ===== */
.engine-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 14px 18px;
    margin-bottom: 16px;
}
.engine-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    flex-wrap: wrap;
}
.engine-title {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 13px;
    font-weight: 600;
    color: var(--text);
}
.engine-dot {
    width: 10px; height: 10px;
    border-radius: 50%;
    background: #f59e0b;
    flex-shrink: 0;
    animation: engine-pulse 1.6s infinite;
}
.engine-dot.ready { background: #16a34a; animation: none; }
.engine-dot.error { background: #dc2626; animation: none; }
@keyframes engine-pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.4; transform: scale(0.8); }
}
.engine-retry {
    padding: 6px 14px;
    border: 1.5px solid var(--primary);
    background: var(--primary-light);
    color: var(--primary);
    font-family: inherit;
    font-size: 12px;
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
}
.engine-retry:hover { background: var(--primary); color: white; }
.engine-progress {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-top: 10px;
}
.engine-progress-bar {
    flex: 1;
    height: 6px;
    background: var(--bg-warm);
    border-radius: 100px;
    overflow: hidden;
}
.engine-progress-bar span {
    display: block;
    height: 100%;
    width: 0%;
    background: var(--primary-gradient);
    border-radius: 100px;
    transition: width 0.3s ease;
}
.engine-progress-text {
    font-size: 12px;
    font-weight: 700;
    color: var(--primary);
    min-width: 38px;
    text-align: right;
    font-variant-numeric: tabular-nums;
}
.engine-detail {
    margin-top: 10px;
    font-size: 12px;
    color: var(--text-secondary);
    line-height: 1.9;
    background: var(--bg-warm);
    border-radius: 8px;
    padding: 10px 14px;
    word-break: break-all;
}


/* ===== 修复：hidden 属性必须优先于组件 display 样式 =====
   .processing-overlay 的 display:flex 会覆盖浏览器原生 [hidden] 隐藏规则，
   导致浮窗永久显示、"取消处理" seemingly 失效。此处用 !important 根治。 */
.processing-overlay[hidden] { display: none !important; }
.result-panel[hidden] { display: none !important; }