/* ===== App Layout ===== */
.app-container { display: flex; height: 100vh; width: 100vw; overflow: hidden; }

/* ===== Sidebar ===== */
.sidebar {
    width: 220px; min-width: 220px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border);
    display: flex; flex-direction: column;
    z-index: 100; transition: transform var(--transition);
}

.sidebar-header { padding: 20px 16px 12px; border-bottom: 1px solid var(--border); }
.sidebar-header h1 { font-size: 1.3rem; font-weight: 700; color: var(--accent); letter-spacing: 0.5px; }
.sidebar-header .subtitle { font-size: 0.75rem; color: var(--text-muted); margin-top: 2px; }

.sidebar-nav { flex: 1; padding: 8px; overflow-y: auto; }

.nav-item {
    display: flex; align-items: center; gap: 10px;
    padding: 10px 12px; border-radius: var(--radius);
    cursor: pointer; color: var(--text-secondary);
    font-size: 0.9rem; transition: all var(--transition);
    user-select: none; margin-bottom: 2px;
}
.nav-item:hover { background: var(--bg-hover); color: var(--text-primary); }
.nav-item.active { background: var(--accent); color: #ffffff; font-weight: 500; }
.nav-item .nav-icon { font-size: 1.15rem; width: 24px; text-align: center; flex-shrink: 0; }

.sidebar-footer {
    padding: 12px 16px; border-top: 1px solid var(--border);
    font-size: 0.75rem; color: var(--text-muted); text-align: center;
}

/* ===== Main Content ===== */
.main-content { flex: 1; display: flex; flex-direction: column; overflow: hidden; min-width: 0; }

.page-header {
    padding: 12px 24px; background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    display: flex; align-items: center; justify-content: space-between;
    min-height: 50px;
}
.page-header h2 { font-size: 1.1rem; font-weight: 600; }

.page-body { flex: 1; overflow: hidden; display: flex; }

.page-content { display: none; width: 100%; height: 100%; }
.page-content.active { display: flex; }

/* ===== Collapsible ===== */
.collapsible-section { margin-bottom: 14px; }

.collapsible-header {
    display: flex; align-items: center; gap: 8px;
    cursor: pointer; user-select: none; padding: 6px 0;
    border-radius: var(--radius); transition: color var(--transition);
}
.collapsible-header:hover { color: var(--accent); }

.collapsible-arrow {
    font-size: 0.7rem; color: var(--text-muted);
    transition: transform var(--transition);
    width: 14px; text-align: center; flex-shrink: 0;
}

.collapsible-content {
    max-height: 0; overflow: hidden;
    transition: max-height 0.35s ease, opacity 0.25s ease, padding 0.25s ease;
    opacity: 0; padding-top: 0;
}
.collapsible-content.open { max-height: 5000px; opacity: 1; padding-top: 12px; }

/* ===== Upload Dropzone ===== */
.upload-dropzone {
    border: 2px dashed var(--border); border-radius: var(--radius);
    padding: 16px; text-align: center; cursor: pointer;
    transition: all var(--transition); background: var(--bg-input);
}
.upload-dropzone:hover, .upload-dropzone.dragover {
    border-color: var(--accent); background: var(--bg-hover);
}
.upload-dropzone-text {
    display: flex; flex-direction: column; align-items: center;
    gap: 4px; color: var(--text-muted); font-size: 0.85rem;
}
.upload-icon { font-size: 1.5rem; opacity: 0.7; }
.upload-hint { font-size: 0.7rem; opacity: 0.6; }

/* ===== Queue Status ===== */
.queue-status {
    text-align: center; padding: 8px; font-size: 0.8rem;
    color: var(--text-muted); min-height: 30px;
    display: flex; align-items: center; justify-content: center; gap: 6px;
}
.queue-status .spinner {
    width: 14px; height: 14px;
    border: 2px solid var(--border); border-top-color: var(--accent);
    border-radius: 50%; animation: spin 0.8s linear infinite;
}

/* ===== Mobile ===== */
.mobile-menu-btn {
    display: none; background: none; border: none;
    color: var(--text-primary); font-size: 1.3rem;
    cursor: pointer; padding: 4px 8px;
}

.sidebar-overlay {
    display: none; position: fixed; inset: 0;
    background: rgba(0,0,0,0.5); z-index: 99;
}
.sidebar-overlay.active { display: block; }

@media (max-width: 768px) {
    .mobile-menu-btn { display: block; }
    .sidebar {
        position: fixed; left: 0; top: 0; height: 100%;
        transform: translateX(-100%);
    }
    .sidebar.open { transform: translateX(0); }
}

/* Dropzone focus for paste */
.upload-dropzone:focus {
    outline: 2px solid var(--accent);
    outline-offset: -2px;
    border-color: var(--accent);
}

.upload-dropzone .paste-hint {
    font-size: 0.65rem;
    opacity: 0.5;
    margin-top: 2px;
}

.header-logout-btn {
    text-decoration: none;
    font-size: 1rem;
    padding: 4px 8px;
    border-radius: var(--radius);
    transition: background var(--transition);
    cursor: pointer;
}

.header-logout-btn:hover {
    background: var(--bg-hover);
}