/* ============================================
   BGRemover — macOS Bright Style (matching AnyAI Landing)
   ============================================ */

:root {
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans TC', sans-serif;
    --bg-primary: #f5f5f7;
    --bg-secondary: #ffffff;
    --bg-tertiary: #fafafa;
    --bg-hover: #f0f0f2;
    --text-primary: #1d1d1f;
    --text-secondary: #6e6e73;
    --text-tertiary: #aeaeb2;
    --accent-blue: #007aff;
    --accent-blue-light: rgba(0,122,255,0.08);
    --accent-purple: #af52de;
    --accent-green: #34c759;
    --accent-teal: #00bfa5;
    --accent-teal-light: rgba(0,191,165,0.08);
    --border-color: #d2d2d7;
    --border-light: #e5e5ea;
    --radius-sm: 10px;
    --radius-md: 14px;
    --radius-lg: 20px;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
    --shadow-lg: 0 8px 30px rgba(0,0,0,0.1);
    --transition: all 0.25s cubic-bezier(0.4,0,0.2,1);
}

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

body {
    font-family: var(--font-sans);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    min-height: 100vh;
}

.app { max-width: 1080px; margin: 0 auto; padding: 0 24px 60px; }

/* ── Top Bar ── */
.top-bar {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 12px;
    padding: 14px 0;
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(245,245,247,0.85);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    margin: 0 -24px;
    padding-left: 24px;
    padding-right: 24px;
}

.home-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 38px;
    height: 38px;
    border-radius: var(--radius-sm);
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.home-link:hover {
    color: var(--accent-blue);
    border-color: var(--accent-blue);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

/* Language Switcher */
.lang-switcher { position: relative; }

.lang-btn {
    display: flex;
    align-items: center;
    gap: 5px;
    padding: 6px 12px;
    font-size: 13px;
    font-weight: 500;
    font-family: var(--font-sans);
    color: var(--text-secondary);
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.lang-btn:hover {
    background: var(--bg-hover);
    border-color: var(--accent-blue);
    color: var(--accent-blue);
}

.lang-dropdown {
    display: none;
    position: absolute;
    top: calc(100% + 6px);
    right: 0;
    min-width: 140px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    z-index: 200;
}

.lang-dropdown.show { display: block; }

.lang-option {
    display: block;
    width: 100%;
    padding: 10px 16px;
    font-size: 13px;
    font-weight: 500;
    font-family: var(--font-sans);
    color: var(--text-primary);
    background: none;
    border: none;
    text-align: left;
    cursor: pointer;
    transition: var(--transition);
}

.lang-option:hover { background: var(--accent-blue-light); color: var(--accent-blue); }
.lang-option.active { color: var(--accent-blue); font-weight: 600; background: var(--accent-blue-light); }

/* ── Header ── */
.header {
    text-align: center;
    margin-bottom: 32px;
    animation: fadeInDown 0.6s ease-out;
}

@keyframes fadeInDown {
    from { opacity: 0; transform: translateY(-20px); }
    to { opacity: 1; transform: translateY(0); }
}

.logo-badge {
    display: inline-flex; align-items: center; gap: 8px;
    background: var(--accent-teal-light);
    border: 1px solid rgba(0,191,165,0.2);
    border-radius: 100px; padding: 5px 16px; margin-bottom: 14px;
    font-size: 11px; font-weight: 700; letter-spacing: 2px;
    text-transform: uppercase; color: var(--accent-teal);
}

.logo-badge .dot {
    width: 6px; height: 6px; border-radius: 50%;
    background: var(--accent-teal);
    box-shadow: 0 0 8px var(--accent-teal);
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse { 0%,100% { opacity:1; } 50% { opacity:0.3; } }

h1 {
    font-size: clamp(28px, 5vw, 42px);
    font-weight: 800;
    background: linear-gradient(135deg, var(--text-primary) 30%, var(--accent-teal));
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2; margin-bottom: 10px;
    letter-spacing: -1px;
}

.subtitle {
    color: var(--text-secondary); font-size: 15px; font-weight: 400;
}

.subtitle span { color: var(--accent-teal); font-weight: 600; }

/* ── Feature Highlights ── */
.feature-highlights {
    display: flex; gap: 10px; justify-content: center; flex-wrap: wrap;
    margin-bottom: 32px; animation: fadeInUp 0.6s ease-out 0.1s both;
}

.feature-chip {
    display: flex; align-items: center; gap: 6px;
    padding: 6px 14px; border-radius: 20px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    font-size: 12px; font-weight: 600; color: var(--text-secondary);
    box-shadow: var(--shadow-sm);
}

.feature-icon { font-size: 14px; }

/* ── Drop zone ── */
.dropzone-wrapper {
    animation: fadeInUp 0.6s ease-out 0.2s both;
}

@keyframes fadeInUp {
    from { opacity:0; transform: translateY(20px); }
    to { opacity:1; transform: translateY(0); }
}

.dropzone {
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-lg);
    background: var(--bg-secondary);
    padding: 56px 40px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    position: relative; overflow: hidden;
}

.dropzone:hover, .dropzone.drag-over {
    border-color: var(--accent-teal);
    background: var(--accent-teal-light);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.dropzone-icon {
    width: 72px; height: 72px; margin: 0 auto 18px;
    border-radius: 50%;
    background: var(--accent-teal-light);
    display: flex; align-items: center; justify-content: center;
    font-size: 32px;
    border: 1px solid rgba(0,191,165,0.15);
}

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

.dropzone p { color: var(--text-secondary); font-size: 13px; }
.dropzone p .highlight { color: var(--accent-teal); font-weight: 600; cursor: pointer; }
.dropzone p .highlight:hover { text-decoration: underline; }

.file-types {
    display: flex; gap: 8px; justify-content: center; margin-top: 14px;
}
.file-types span {
    font-size: 11px; font-weight: 600;
    padding: 4px 12px; border-radius: 100px;
    background: var(--bg-tertiary); border: 1px solid var(--border-light);
    color: var(--text-secondary); letter-spacing: 0.5px;
}

#fileInput { display: none; }

/* ── Workspace ── */
.workspace {
    display: none;
    margin-top: 32px;
    animation: fadeInUp 0.5s ease-out;
}

.workspace.active { display: block; }

.panels {
    display: grid; grid-template-columns: 1fr 1fr;
    gap: 20px; margin-bottom: 20px;
}

@media (max-width: 768px) {
    .panels { grid-template-columns: 1fr; }
}

.panel {
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.panel:hover { border-color: var(--accent-teal); box-shadow: var(--shadow-md); }

.panel-header {
    padding: 12px 18px;
    display: flex; align-items: center; justify-content: space-between;
    border-bottom: 1px solid var(--border-light);
    background: var(--bg-tertiary);
}

.panel-title {
    display: flex; align-items: center; gap: 8px;
    font-size: 13px; font-weight: 700; letter-spacing: 0.5px;
    text-transform: uppercase;
}

.panel-title .tag {
    font-size: 9px; font-weight: 700;
    padding: 3px 8px; border-radius: 4px;
    letter-spacing: 1px;
}

.panel-title .tag.original {
    background: rgba(255,149,0,0.1); color: #ff9500;
    border: 1px solid rgba(255,149,0,0.2);
}

.panel-title .tag.result {
    background: var(--accent-teal-light); color: var(--accent-teal);
    border: 1px solid rgba(0,191,165,0.2);
}

.panel-body {
    position: relative; min-height: 300px;
    display: flex; align-items: center; justify-content: center;
    padding: 16px;
    background-image:
        linear-gradient(45deg, rgba(0,0,0,0.03) 25%, transparent 25%),
        linear-gradient(-45deg, rgba(0,0,0,0.03) 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, rgba(0,0,0,0.03) 75%),
        linear-gradient(-45deg, transparent 75%, rgba(0,0,0,0.03) 75%);
    background-size: 20px 20px;
    background-position: 0 0, 0 10px, 10px -10px, -10px 0;
}

.panel-body img {
    max-width: 100%; max-height: 450px;
    object-fit: contain; border-radius: var(--radius-sm);
}

/* ── Reupload button ── */
.btn-reupload {
    display: inline-flex; align-items: center; gap: 5px;
    padding: 5px 14px; border-radius: 8px;
    font-family: var(--font-sans);
    font-size: 12px; font-weight: 600;
    background: rgba(255,149,0,0.08);
    color: #ff9500;
    border: 1px solid rgba(255,149,0,0.2);
    cursor: pointer;
    transition: var(--transition);
}

.btn-reupload:hover {
    background: rgba(255,149,0,0.15);
    border-color: rgba(255,149,0,0.4);
    box-shadow: var(--shadow-sm);
    transform: translateY(-1px);
}

/* ── Progress ── */
.progress-overlay {
    display: none; position: absolute; inset: 0;
    background: rgba(255,255,255,0.92);
    backdrop-filter: blur(8px);
    flex-direction: column; align-items: center; justify-content: center;
    gap: 18px; z-index: 10;
    border-radius: var(--radius-lg);
}

.progress-overlay.active { display: flex; }

.spinner {
    width: 48px; height: 48px;
    border: 3px solid var(--border-light);
    border-top-color: var(--accent-teal);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

.progress-text {
    font-size: 14px; color: var(--accent-teal);
    font-weight: 600; text-align: center;
}

.progress-bar-track {
    width: 200px; height: 4px;
    background: var(--border-light);
    border-radius: 100px; overflow: hidden;
}

.progress-bar-fill {
    height: 100%; width: 0%;
    background: linear-gradient(90deg, var(--accent-teal), var(--accent-blue));
    border-radius: 100px;
    transition: width 0.3s ease;
}

/* ── Controls ── */
.controls {
    display: flex; gap: 12px; justify-content: center; flex-wrap: wrap;
}

.btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 12px 28px; border-radius: 50px;
    font-family: var(--font-sans);
    font-size: 14px; font-weight: 700;
    border: none; cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-teal), #00897b);
    color: #fff;
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0,191,165,0.3);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-light);
}
.btn-secondary:hover {
    background: var(--bg-hover);
    border-color: var(--accent-blue);
    transform: translateY(-2px);
}

.btn-accent {
    background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
    color: #fff;
}
.btn-accent:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0,122,255,0.3);
}

.btn:disabled {
    opacity: 0.4; cursor: not-allowed; transform: none !important;
    box-shadow: none !important;
}

.btn .icon { font-size: 16px; }

/* ── Settings bar ── */
.settings-bar {
    display: flex; gap: 16px; justify-content: center;
    align-items: center; flex-wrap: wrap;
    margin-bottom: 20px;
    padding: 14px 22px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.setting-group {
    display: flex; align-items: center; gap: 8px;
    font-size: 13px; color: var(--text-secondary);
}

.setting-group label { font-weight: 600; white-space: nowrap; }

.setting-group select {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-light);
    color: var(--text-primary);
    padding: 6px 12px; border-radius: 8px;
    font-family: inherit; font-size: 13px;
    cursor: pointer;
    transition: var(--transition);
}

.setting-group select:hover { border-color: var(--accent-teal); }

/* ── Image info ── */
.image-info {
    display: flex; gap: 12px; justify-content: center;
    margin-bottom: 20px; flex-wrap: wrap;
}

.info-chip {
    display: flex; align-items: center; gap: 6px;
    padding: 5px 14px; border-radius: 100px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    font-size: 12px; color: var(--text-secondary);
    box-shadow: var(--shadow-sm);
}

.info-chip .val { color: var(--text-primary); font-weight: 600; }

/* ── How-to Section ── */
.how-to-section {
    margin-top: 56px;
    text-align: center;
    animation: fadeInUp 0.5s ease-out 0.3s both;
}

.how-to-section h2 {
    font-size: 24px; font-weight: 700;
    margin-bottom: 28px; letter-spacing: -0.5px;
}

.how-to-grid {
    display: grid; grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.how-to-step {
    text-align: center;
    padding: 28px 20px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.how-to-step:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--accent-teal);
}

.step-number {
    width: 40px; height: 40px; margin: 0 auto 12px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent-teal), var(--accent-blue));
    color: #fff; font-weight: 800; font-size: 18px;
    display: flex; align-items: center; justify-content: center;
}

.how-to-step h3 { font-size: 15px; font-weight: 600; margin-bottom: 6px; }
.how-to-step p { font-size: 13px; color: var(--text-secondary); line-height: 1.6; }

/* ── FAQ Section ── */
.faq-section {
    margin-top: 48px;
    animation: fadeInUp 0.5s ease-out 0.4s both;
}

.faq-section h2 {
    text-align: center;
    font-size: 24px; font-weight: 700;
    margin-bottom: 20px; letter-spacing: -0.5px;
}

.faq-item {
    background: var(--bg-secondary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: var(--transition);
    margin-bottom: 10px;
}

.faq-item:hover { border-color: var(--accent-teal); box-shadow: var(--shadow-sm); }

.faq-item summary {
    padding: 16px 18px;
    font-size: 14px; font-weight: 600;
    cursor: pointer; list-style: none;
    display: flex; align-items: center; justify-content: space-between;
    gap: 12px; transition: var(--transition);
}

.faq-item summary::-webkit-details-marker { display: none; }

.faq-item summary::after {
    content: '+'; font-size: 18px; font-weight: 400;
    color: var(--text-tertiary); flex-shrink: 0; transition: var(--transition);
}

.faq-item[open] summary::after { content: '−'; color: var(--accent-teal); }
.faq-item summary:hover { background: var(--accent-teal-light); color: var(--accent-teal); }
.faq-item[open] summary { border-bottom: 1px solid var(--border-light); color: var(--accent-teal); }

.faq-item div { padding: 14px 18px; }
.faq-item p { font-size: 13px; color: var(--text-secondary); line-height: 1.7; }

/* ── Toast ── */
.toast {
    position: fixed; bottom: 30px; left: 50%; transform: translateX(-50%) translateY(100px);
    background: var(--bg-secondary); border: 1px solid var(--accent-teal);
    color: var(--text-primary); padding: 14px 28px; border-radius: 50px;
    font-size: 14px; font-weight: 600; z-index: 999;
    box-shadow: var(--shadow-lg);
    transition: transform 0.4s cubic-bezier(0.4,0,0.2,1);
    pointer-events: none;
}

.toast.show { transform: translateX(-50%) translateY(0); }

/* ── Footer ── */
.footer {
    text-align: center; margin-top: 48px;
    color: var(--text-tertiary); font-size: 12px;
}

.footer-seo {
    font-size: 11px; color: var(--text-tertiary);
    max-width: 600px; margin: 8px auto 0;
    line-height: 1.5; opacity: 0.7;
}

/* ── Responsive ── */
@media (max-width: 768px) {
    .how-to-grid { grid-template-columns: 1fr; }
    .app { padding: 0 16px 40px; }
    .top-bar { margin: 0 -16px; padding-left: 16px; padding-right: 16px; }
}

@media (max-width: 480px) {
    h1 { font-size: 26px; }
    .dropzone { padding: 40px 20px; }
    .feature-highlights { gap: 6px; }
    .feature-chip { padding: 5px 10px; font-size: 11px; }
}