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

:root {
    /* Claude AI / Warm Minimalist Palette */
    --primary: #c96442;
    --primary-hover: #b5573a;
    --primary-light: rgba(201, 100, 66, 0.1);
    --primary-text: #ffffff;
    
    --success: #2e7d32;
    --success-light: rgba(46, 125, 50, 0.08);
    --error: #c62828;
    --error-light: rgba(198, 40, 40, 0.08);

    /* Backgrounds & Surfaces */
    --bg: #f7f5f3;
    --surface: #ffffff;
    --sidebar-bg: #ffffff;
    --sidebar-border: #ebe7e4;

    /* Text colors */
    --text-primary: #1a1a1a;
    --text-secondary: #6b6560;
    --text-hint: #9e9790;

    /* Borders */
    --border: #e8e4e0;
    --border-hover: #d8d3cd;

    /* Radius */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;

    /* Transitions */
    --transition: 0.2s ease;
}

body.dark-mode {
    --bg: #1a1a1a;
    --surface: #242424;
    --sidebar-bg: #1f1f1f;
    --sidebar-border: #333333;
    --text-primary: #e4e4e4;
    --text-secondary: #9e9e9e;
    --text-hint: #666666;
    --border: #333333;
    --border-hover: #444444;
    --primary-light: rgba(201, 100, 66, 0.2);
    --success-light: rgba(46, 125, 50, 0.15);
    --error-light: rgba(198, 40, 40, 0.15);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg);
    color: var(--text-primary);
    line-height: 1.5;
    overflow-x: hidden;
    transition: background 0.3s ease, color 0.3s ease;
}

.app-container { display: flex; min-height: 100vh; }

/* Sidebar Overlay */
.sidebar-overlay {
    display: none; position: fixed; inset: 0;
    background: rgba(0, 0, 0, 0.4); z-index: 90; opacity: 0; transition: opacity 0.3s ease;
}
.sidebar-overlay.active { display: block; opacity: 1; }

/* Sidebar */
.sidebar {
    width: 260px; background: var(--sidebar-bg); border-right: 1px solid var(--sidebar-border);
    display: flex; flex-direction: column; padding: 24px 16px;
    position: fixed; left: 0; top: 0; bottom: 0; z-index: 100;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}
.sidebar-header { padding: 0 8px 32px 8px; }
.logo { display: flex; align-items: center; gap: 10px; color: var(--primary); }
.logo-text { font-size: 1.2rem; font-weight: 700; color: var(--text-primary); letter-spacing: -0.5px; }

.sidebar-nav { flex: 1; display: flex; flex-direction: column; gap: 4px; }
.nav-item {
    display: flex; align-items: center; gap: 12px; padding: 10px 12px;
    border-radius: var(--radius-md); text-decoration: none; color: var(--text-secondary);
    transition: var(--transition); font-weight: 500; font-size: 0.9rem;
}
.nav-item:hover { background: var(--primary-light); color: var(--text-primary); }
.nav-item.active { background: var(--primary-light); color: var(--primary); }

.sidebar-footer { padding: 16px 8px 0 0; border-top: 1px solid var(--border); margin-top: 16px; }
.status-badge { display: flex; align-items: center; gap: 8px; padding: 8px 12px; font-size: 0.8rem; color: var(--text-hint); }
.status-dot { width: 8px; height: 8px; background: var(--success); border-radius: 50%; }

/* Main Content */
.main-content { flex: 1; margin-left: 260px; display: flex; flex-direction: column; min-height: 100vh; }
.main-header {
    background: var(--surface); border-bottom: 1px solid var(--border); padding: 16px 32px;
    display: flex; justify-content: space-between; align-items: center; position: sticky; top: 0; z-index: 50;
}
.header-left { display: flex; align-items: center; gap: 16px; }
.header-left h1 { font-size: 1.2rem; font-weight: 600; }
.mobile-menu-btn { display: none; }

.icon-btn {
    width: 40px; height: 40px; border: none; background: transparent; border-radius: 50%;
    cursor: pointer; display: flex; align-items: center; justify-content: center;
    color: var(--text-secondary); transition: var(--transition);
}
.icon-btn:hover { background: var(--primary-light); color: var(--primary); }

.icon-btn-sm {
    width: 32px; height: 32px; border: none; background: transparent; border-radius: 50%;
    cursor: pointer; display: flex; align-items: center; justify-content: center;
    color: var(--text-hint); transition: var(--transition);
}
.icon-btn-sm:hover { background: var(--primary-light); color: var(--primary); }

/* Content Area */
.content-area {
    flex: 1; padding: 32px; display: flex; flex-direction: column; gap: 20px;
    max-width: 800px; width: 100%; margin: 0 auto;
}

/* Cards Common */
.card {
    background: var(--surface); border-radius: var(--radius-lg); border: 1px solid var(--border);
    overflow: hidden; transition: border-color 0.2s ease;
}
.card:hover { border-color: var(--border-hover); }
.card-header {
    display: flex; justify-content: space-between; align-items: center;
    padding: 20px 24px; border-bottom: 1px solid var(--border);
}
.card-header h3 { font-size: 1rem; font-weight: 600; }
.badge { font-size: 0.8rem; color: var(--primary); background: var(--primary-light); padding: 4px 10px; border-radius: 20px; font-weight: 600; }
.card-content { padding: 24px; }

/* Upload & Drop Zone */
.drop-zone { padding: 56px 24px; text-align: center; cursor: pointer; transition: var(--transition); border-bottom: 1px solid var(--border); }
.drop-zone:hover { background: var(--bg); }
.drop-zone.drag-over { background: var(--primary-light); border-color: var(--primary); }
.drop-zone-content { display: flex; flex-direction: column; align-items: center; gap: 20px; color: var(--text-hint); }
.drop-text h2 { font-size: 1.1rem; font-weight: 600; color: var(--text-primary); margin-bottom: 4px; }
.drop-text p { font-size: 0.9rem; color: var(--text-secondary); }

/* File Preview */
.file-preview { padding: 16px 24px; animation: slideDown 0.3s ease; }
.file-card { display: flex; align-items: center; gap: 12px; background: var(--bg); padding: 12px 16px; border-radius: var(--radius-md); }
.file-icon-mini { color: var(--primary); flex-shrink: 0; }
.file-details { flex: 1; display: flex; flex-direction: column; min-width: 0; }
.file-name { font-weight: 500; font-size: 0.9rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.file-size { font-size: 0.8rem; color: var(--text-hint); }

/* Files List */
.files-list { max-height: 400px; overflow-y: auto; overflow-x: hidden; padding: 12px 16px; width: 100%; }
.files-list::-webkit-scrollbar { width: 6px; }
.files-list::-webkit-scrollbar-thumb { background: var(--border-hover); border-radius: 3px; }

.file-item { display: flex; align-items: center; padding: 10px 0; border-bottom: 1px solid var(--border); margin-bottom: 4px; width: 100%; overflow: hidden; }
.file-item-icon { width: 32px; height: 32px; border-radius: var(--radius-sm); display: flex; align-items: center; justify-content: center; margin-right: 12px; flex-shrink: 0; background: var(--bg); }
.file-item-info { flex: 1 1 0%; min-width: 0; overflow: hidden; }
.file-item-name { font-weight: 500; font-size: 0.9rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; display: block; }
.file-item-path { font-size: 0.8rem; color: var(--text-hint); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; display: block; }
.file-item-size { font-size: 0.8rem; color: var(--text-hint); margin-left: 16px; white-space: nowrap; align-self: center; flex-shrink: 0; }

/* Form & Inputs */
.form-group { margin-bottom: 20px; }
.form-group label { display: block; font-weight: 600; margin-bottom: 8px; font-size: 0.9rem; }

.input-group { position: relative; display: flex; align-items: center; }
.input-group input, .input-full {
    width: 100%; padding: 12px 16px; font-size: 0.9rem; font-family: inherit;
    border: 1px solid var(--border); border-radius: var(--radius-md);
    background: var(--bg); color: var(--text-primary); transition: var(--transition);
}
.input-group input { padding-right: 48px; }
input:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-light); background: var(--surface); }
.input-group .icon-btn-sm { position: absolute; right: 8px; }

.form-hint { display: block; margin-top: 8px; font-size: 0.8rem; color: var(--text-hint); }
.form-hint code { background: var(--primary-light); padding: 2px 6px; border-radius: 4px; color: var(--primary); font-weight: 600; }

/* Toggles */
.toggles-container { margin-bottom: 24px; border-top: 1px solid var(--border); padding-top: 20px; }
.toggle-group { display: flex; justify-content: space-between; align-items: center; margin-bottom: 16px; }
.toggle-group:last-child { margin-bottom: 0; }
.toggle-label span:first-child { font-weight: 600; font-size: 0.9rem; display: block; color: var(--text-primary); }
.toggle-label .form-hint { margin-top: 2px; }

.switch { position: relative; display: inline-block; width: 44px; height: 24px; flex-shrink: 0; margin-left: 16px; }
.switch input { opacity: 0; width: 0; height: 0; }
.slider {
    position: absolute; cursor: pointer; top: 0; left: 0; right: 0; bottom: 0;
    background-color: var(--border); transition: .3s; border-radius: 24px;
}
.slider:before {
    position: absolute; content: ""; height: 18px; width: 18px; left: 3px; bottom: 3px;
    background-color: white; transition: .3s; border-radius: 50%; box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}
input:checked + .slider { background-color: var(--primary); }
input:focus + .slider { box-shadow: 0 0 0 3px var(--primary-light); }
input:checked + .slider:before { transform: translateX(20px); }

/* Buttons */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 10px;
    padding: 14px 24px; font-size: 0.95rem; font-weight: 600; font-family: inherit;
    border: none; border-radius: var(--radius-md); cursor: pointer; transition: var(--transition); width: 100%;
}
.btn-primary { background: var(--primary); color: var(--primary-text); }
.btn-primary:hover:not(:disabled) { background: var(--primary-hover); transform: translateY(-1px); }
.btn-primary:active:not(:disabled) { transform: translateY(0); }
.btn-primary:disabled { background: var(--border); color: var(--text-hint); cursor: not-allowed; }

/* Progress */
.progress-header { display: flex; justify-content: space-between; margin-bottom: 12px; font-size: 0.9rem; font-weight: 500; }
.progress-count { color: var(--text-secondary); font-weight: 400; }
.progress-bar-container { height: 4px; background: var(--border); border-radius: 2px; overflow: hidden; }
.progress-bar { height: 100%; background: var(--primary); border-radius: 2px; transition: width 0.3s ease; width: 0%; }
.progress-status { margin-top: 12px; font-size: 0.8rem; color: var(--text-hint); font-family: monospace; }

/* Result */
.result-content { padding: 32px; text-align: center; }
.result-content.success { background: var(--success-light); border-left: 4px solid var(--success); border-radius: 0 var(--radius-lg) var(--radius-lg) 0; }
.result-content.error { background: var(--error-light); border-left: 4px solid var(--error); border-radius: 0 var(--radius-lg) var(--radius-lg) 0; }
.result-icon { width: 48px; height: 48px; border-radius: 50%; display: flex; align-items: center; justify-content: center; margin: 0 auto 20px; background: var(--surface); }
.result-title { font-size: 1.2rem; font-weight: 700; margin-bottom: 8px; }
.result-message { color: var(--text-secondary); margin-bottom: 24px; font-size: 0.9rem; line-height: 1.6; }
.result-link {
    display: inline-flex; align-items: center; gap: 8px; padding: 10px 20px;
    background: var(--primary); color: var(--primary-text); text-decoration: none;
    border-radius: var(--radius-md); font-weight: 600; font-size: 0.9rem; transition: var(--transition);
}
.result-link:hover { background: var(--primary-hover); }

/* Loading */
.loading-overlay {
    position: fixed; inset: 0; background: rgba(26, 26, 26, 0.85); display: flex;
    flex-direction: column; align-items: center; justify-content: center; gap: 20px;
    z-index: 1000; backdrop-filter: blur(4px); color: white;
}
.loading-spinner { width: 40px; height: 40px; border: 3px solid rgba(255, 255, 255, 0.2); border-top-color: var(--primary); border-radius: 50%; animation: spin 0.8s linear infinite; }

/* Animations */
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes slideDown { from { opacity: 0; transform: translateY(-10px); } to { opacity: 1; transform: translateY(0); } }

/* Responsive */
@media (max-width: 768px) {
    .sidebar { transform: translateX(-100%); width: 280px; background: var(--surface); }
    .sidebar.open { transform: translateX(0); }
    .main-content { margin-left: 0; }
    .mobile-menu-btn { display: flex; }
    .main-header { padding: 16px 20px; }
    .content-area { padding: 20px 16px; }
    .card-header, .card-content { padding: 16px; }
    .drop-zone { padding: 40px 16px; }
    .file-item { flex-wrap: wrap; }
    .file-item-size { margin-left: 44px; width: 100%; margin-top: 4px; }
}