* { margin: 0; padding: 0; box-sizing: border-box; font-family: "Inter", "Microsoft Yahei", system-ui, -apple-system, sans-serif; }
:root {
    --primary: #2563eb;
    --primary-light: #3b82f6;
    --primary-dark: #1d4ed8;
    --bg: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #0f172a;
    --text-sub: #64748b;
    --border: #e2e8f0;
    --success: #059669;
    --danger: #dc2626;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --safe-bottom: env(safe-area-inset-bottom);
}
html { -webkit-text-size-adjust: 100%; }
body { background: var(--bg); color: var(--text-main); min-height: 100vh; line-height: 1.5; }
.container { max-width: 1280px; margin: 0 auto; padding: 0 16px; }

nav { 
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%); 
    box-shadow: 0 4px 24px rgba(37,99,235,0.15); 
    position: sticky; top:0; z-index:99;
    backdrop-filter: blur(10px);
}
.nav-wrap { display: flex; justify-content: space-between; align-items: center; padding: 12px 0; }
.logo { font-size: 22px; font-weight: 800; color: #fff; display: flex; align-items: center; gap: 8px; letter-spacing: -0.3px; }
.logo span { font-size: 26px; }
.user-bar { display: flex; align-items: center; gap: 12px; }
.credit-tag { 
    background: rgba(255,255,255,0.2); 
    color: #fff; padding: 8px 16px; 
    border-radius: 999px; 
    font-size: 12px; font-weight:600;
    backdrop-filter: blur(4px);
}
.user-btn { 
    background: rgba(255,255,255,0.2); 
    color: #fff; padding: 8px 16px; 
    border-radius: 999px; border: none; 
    cursor: pointer; font-size:12px; font-weight:600; 
    transition: all 0.3s ease;
    backdrop-filter: blur(4px);
}
.user-btn:hover { 
    background: rgba(255,255,255,0.35); 
    transform: translateY(-2px);
}

.tab-wrap { 
    background: var(--card-bg); 
    border-radius: var(--radius-lg) var(--radius-lg) 0 0; 
    display: flex; gap: 4px; 
    padding: 0 16px; 
    margin-top: 24px;
    box-shadow: 0 -4px 20px rgba(0,0,0,0.03);
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
}
.tab-wrap::-webkit-scrollbar { display: none; }
.tab-btn { 
    padding: 16px 20px; 
    border: none; background: transparent; 
    font-size: 14px; font-weight:600; 
    color: var(--text-sub); 
    cursor: pointer; 
    border-bottom: 3px solid transparent; 
    transition: all 0.3s ease;
    border-radius: var(--radius-sm) var(--radius-sm) 0 0;
    flex-shrink: 0;
    white-space: nowrap;
}
.tab-btn:hover { color: var(--primary-light); background: rgba(37,99,235,0.03); }
.tab-btn.active { 
    color: var(--primary); 
    border-bottom-color: var(--primary); 
    background: rgba(37,99,235,0.05);
}
.tab-content { 
    display: none; 
    background: var(--card-bg); 
    padding: 20px; 
    border-radius: 0 0 var(--radius-lg) var(--radius-lg); 
    box-shadow: 0 8px 32px rgba(0,0,0,0.04); 
    margin-bottom: 20px;
}
.tab-content.active { display: block; }

.grid-row { display: grid; grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); gap: 16px; }
.convert-card { 
    background: var(--bg); 
    padding: 24px 12px; 
    border-radius: var(--radius-lg); 
    text-align: center; 
    cursor: pointer; 
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1); 
    border: 1px solid var(--border);
    position: relative;
    overflow: hidden;
}
.convert-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--primary-light));
    transform: scaleX(0);
    transition: transform 0.3s ease;
}
.convert-card:hover,
.convert-card:active { 
    transform: translateY(-4px); 
    box-shadow: 0 12px 24px rgba(37,99,235,0.1); 
    border-color: var(--primary); 
    background: var(--card-bg);
}
.convert-card:hover::before,
.convert-card:active::before { transform: scaleX(1); }
.card-icon { font-size: 36px; margin-bottom: 12px; color: var(--primary); line-height: 1; }
.card-title { font-weight: 700; font-size:14px; color: var(--text-main); margin-bottom: 4px; }
.card-desc { font-size: 12px; color: var(--text-sub); font-weight:500; }

.progress-wrap { 
    background: var(--card-bg); 
    padding: 20px; 
    border-radius: var(--radius-lg); 
    box-shadow: 0 8px 32px rgba(0,0,0,0.04); 
    margin-bottom: 20px;
}
#progressTip { margin-bottom: 12px; color: var(--text-main); font-weight:600; font-size:14px; }
.progress-bar-bg { 
    width: 100%; height: 10px; 
    background: var(--bg); 
    border-radius: 999px; 
    overflow: hidden; 
    margin:12px 0;
}
.progress-bar { 
    height: 100%; width: 0%; 
    background: linear-gradient(90deg, var(--primary), var(--primary-light)); 
    transition: width 0.4s ease;
    border-radius: 999px;
}
.download-item { 
    padding: 12px 16px; 
    background: var(--bg); 
    border-radius: var(--radius-md); 
    margin-bottom: 10px; 
    display: flex; justify-content: space-between; align-items: center; 
    border:1px solid var(--border);
    transition: all 0.2s ease;
}
.download-item:hover,
.download-item:active { border-color: var(--primary); background: rgba(37,99,235,0.02); }
.download-btn { 
    padding: 8px 16px; 
    background: var(--primary); 
    color: #fff; 
    border-radius: var(--radius-sm); 
    text-decoration: none; 
    font-size: 13px; 
    font-weight:600; 
    transition: all 0.2s ease;
}
.download-btn:hover,
.download-btn:active { background: var(--primary-dark); transform: translateY(-1px); }
#downloadWrap h4 { font-size:16px; font-weight:700; margin-bottom:16px; color:var(--success); }

.modal-mask { 
    position: fixed; inset: 0; 
    background: rgba(15,23,42,0.7); 
    display: flex; align-items: flex-end; justify-content: center; 
    z-index: 999; padding: 0; 
    backdrop-filter: blur(6px);
    animation: fadeIn 0.2s ease;
}
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}
.modal-box { 
    background: var(--card-bg); 
    border-radius: var(--radius-xl) var(--radius-xl) 0 0; 
    width: 100%; max-width: 480px; 
    padding: 24px; 
    padding-bottom: calc(24px + var(--safe-bottom));
    position: relative; 
    box-shadow: 0 -8px 32px rgba(0,0,0,0.1);
    animation: slideUp 0.3s ease;
    max-height: 80vh;
    overflow-y: auto;
}
@keyframes slideUp {
    from { transform: translateY(100%); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}
.close-modal { 
    position: absolute; top: 16px; right: 16px; 
    width: 36px; height: 36px; 
    border-radius: 50%; 
    border: none; 
    background: var(--bg); 
    cursor: pointer; 
    font-size: 20px; 
    color:var(--text-sub); 
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}
.close-modal:hover,
.close-modal:active { background: var(--border); color: var(--text-main); transform: rotate(90deg); }
.hidden { display: none !important; }

.set-row { margin: 14px 0; }
.set-label { display: block; margin-bottom: 8px; font-weight: 600; color: var(--text-main); font-size:14px; }
.set-input { 
    width: 100%; padding: 14px 16px; 
    border: 1px solid var(--border); 
    border-radius: var(--radius-md); 
    font-size: 15px;
    transition: all 0.2s ease;
    -webkit-appearance: none;
    appearance: none;
}
.set-input:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(37,99,235,0.1); }
.set-select { 
    width: 100%; padding: 14px 16px; 
    border: 1px solid var(--border); 
    border-radius: var(--radius-md); 
    font-size: 15px;
    transition: all 0.2s ease;
    -webkit-appearance: none;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='%2364748b' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 16px;
}
.set-select:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(37,99,235,0.1); }

.btn-primary { 
    width: 100%; padding: 16px; 
    background: linear-gradient(90deg, var(--primary), var(--primary-light)); 
    color: #fff; 
    border: none; 
    border-radius: var(--radius-md); 
    font-size: 15px; 
    font-weight:700; 
    cursor: pointer; 
    transition: all 0.3s ease;
}
.btn-primary:hover,
.btn-primary:active { opacity: 0.92; transform: translateY(-1px); box-shadow: 0 8px 20px rgba(37,99,235,0.2); }

#renderTempBox { position: fixed; left: -9999px; top: 0; background: #fff; z-index: -999; visibility: visible; }

footer { 
    text-align: center; 
    padding: 24px 0 calc(24px + var(--safe-bottom)); 
    color: var(--text-sub); 
    font-size: 13px; 
    line-height: 1.6;
    border-top: 1px solid var(--border);
    margin-top: 16px;
}
.footer-links {
    margin-bottom: 10px;
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}
.footer-links a {
    color: var(--text-sub);
    text-decoration: none;
    transition: color 0.2s ease;
    font-size: 12px;
}
.footer-links a:hover,
.footer-links a:active {
    color: var(--primary);
}

@media screen and (min-width: 768px) {
    .container { padding: 0 20px; }
    .nav-wrap { padding: 16px 0; }
    .logo { font-size: 28px; }
    .logo span { font-size: 32px; }
    .credit-tag { padding: 10px 20px; font-size: 14px; }
    .user-btn { padding: 10px 22px; font-size: 14px; }
    
    .tab-wrap { padding: 0 24px; margin-top: 32px; }
    .tab-btn { padding: 20px 28px; font-size: 16px; }
    .tab-content { padding: 36px; margin-bottom: 28px; }
    
    .grid-row { grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 24px; }
    .convert-card { padding: 32px 20px; }
    .card-icon { font-size: 44px; margin-bottom: 16px; }
    .card-title { font-size: 16px; }
    .card-desc { font-size: 13px; }
    
    .progress-wrap { padding: 28px; margin-bottom: 28px; }
    #progressTip { font-size: 15px; }
    
    .modal-box { 
        max-width: 400px; 
        border-radius: var(--radius-xl); 
        padding-bottom: 24px;
        max-height: none;
    }
    .modal-mask { align-items: center; }
    @keyframes slideUp {
        from { transform: translateY(20px); opacity: 0; }
        to { transform: translateY(0); opacity: 1; }
    }
    
    footer { padding: 40px 0 30px; font-size: 14px; }
    .footer-links { gap: 24px; }
    .footer-links a { font-size: 14px; }
}

@media screen and (min-width: 1024px) {
    .grid-row { grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); }
}