:root {
    --bg-main: #F8FAFC;
    --bg-surface: #FFFFFF;
    --bg-surface-hover: #F1F5F9;
    --bg-sidebar: #F1F5F9;
    --bg-preview: #FFFFFF;
    
    --text-primary: #0F172A;
    --text-secondary: #475569;
    --text-muted: #94A3B8;
    
    --primary: #3B82F6;
    --primary-hover: #2563EB;
    --success: #10B981;
    --danger: #EF4444;
    --warning: #F59E0B;
    
    --border-color: #E2E8F0;
    --border-light: #F1F5F9;
    --border-radius: 8px;
    --radius-sm: 4px;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    
    --slack-bg: #FFFFFF;
    --slack-text: #1d1c1d;
    --slack-meta: #616061;
}

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

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-main);
    color: var(--text-primary);
    line-height: 1.5;
    height: 100vh;
    display: flex;
    overflow: hidden;
}

.app-container {
    display: flex;
    width: 100%;
    height: 100%;
}

/* Base Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    border: 1px solid transparent;
}

.btn-primary {
    background-color: var(--primary);
    color: white;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
}

.btn-outline {
    background-color: transparent;
    border-color: var(--border-color);
    color: var(--text-primary);
}

.btn-outline:hover {
    background-color: var(--bg-surface-hover);
}

.btn-text {
    background: transparent;
    color: var(--text-secondary);
    padding: 0.25rem 0.5rem;
}

.btn-text:hover {
    color: var(--text-primary);
    background-color: var(--bg-surface-hover);
}

.btn-full {
    width: 100%;
}

/* Sidebar */
.sidebar {
    width: 280px;
    background-color: var(--bg-sidebar);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    padding: 1.5rem;
    gap: 2rem;
    overflow-y: auto;
}

.sidebar-header h2 {
    font-size: 1.25rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.sidebar-section h3 {
    font-size: 0.75rem;
    text-transform: uppercase;
    font-weight: 600;
    color: var(--text-secondary);
    letter-spacing: 0.05em;
    margin-bottom: 0.75rem;
}

.profile-section {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.profile-section label {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--text-secondary);
}

input[type="text"], select {
    width: 100%;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-family: inherit;
    font-size: 0.875rem;
    transition: border-color 0.2s;
}

input[type="text"]:focus, select:focus {
    outline: none;
    border-color: var(--primary);
}

/* Templates list */
.template-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 0.75rem;
}

.template-item {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.875rem;
    group: relative;
}

.template-text {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    flex: 1;
}

.template-actions {
    display: flex;
    gap: 0.25rem;
    opacity: 0;
    transition: opacity 0.2s;
}

.template-item:hover .template-actions {
    opacity: 1;
}

.btn-quick-add, .btn-remove-template {
    background: transparent;
    border: none;
    cursor: pointer;
    color: var(--text-secondary);
    border-radius: 4px;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-quick-add:hover { background-color: var(--border-light); color: var(--primary); }
.btn-remove-template:hover { background-color: rgba(239, 68, 68, 0.1); color: var(--danger); }

.add-template {
    display: flex;
    gap: 0.5rem;
}

/* History list */
.history-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    margin-bottom: 1rem;
}

.history-item {
    font-size: 0.875rem;
    padding: 0.5rem;
    border-radius: var(--radius-sm);
    cursor: pointer;
    color: var(--text-secondary);
}

.history-item:hover {
    background-color: var(--border-light);
    color: var(--text-primary);
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 2rem;
    overflow-y: auto;
    background-color: var(--bg-main);
}

.main-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.main-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.save-status {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-style: italic;
    opacity: 0;
    transition: opacity 0.3s;
}

.save-status.visible {
    opacity: 1;
}

.sections-container {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    max-width: 800px;
}

/* Cards */
.card-section {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow-sm);
}

.card-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.card-header h2 {
    font-size: 1.125rem;
    font-weight: 600;
}

.item-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 1rem;
    min-height: 10px;
}

.list-item {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 0.5rem;
    border: 1px solid transparent;
    border-radius: var(--radius-sm);
    background-color: var(--bg-surface-hover);
    animation: fadeIn 0.2s ease-out;
}

.list-item.dragging {
    opacity: 0.5;
    background-color: var(--bg-sidebar);
}

.drag-handle {
    color: var(--text-muted);
    cursor: grab;
    user-select: none;
    line-height: 1.2;
}

.item-text {
    flex: 1;
    font-size: 0.875rem;
    word-break: break-word;
}

.btn-remove {
    background: transparent;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 1.25rem;
    line-height: 1;
    padding: 0 0.25rem;
    opacity: 0;
    transition: opacity 0.2s, color 0.2s;
}

.list-item:hover .btn-remove {
    opacity: 1;
}

.btn-remove:hover {
    color: var(--danger);
}

.item-input {
    border-color: transparent;
    background-color: var(--bg-main);
}

.item-input:hover {
    border-color: var(--border-color);
}

/* Preview Sidebar */
.preview-sidebar {
    width: 400px;
    background-color: var(--bg-preview);
    border-left: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
}

.preview-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.preview-header h2 {
    font-size: 1rem;
    font-weight: 600;
}

.preview-actions {
    display: flex;
    gap: 0.5rem;
}

select {
    width: auto;
}

.slack-preview-container {
    padding: 1.5rem;
    flex: 1;
    overflow-y: auto;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

.slack-message {
    display: flex;
    gap: 0.75rem;
}

.slack-avatar {
    width: 36px;
    height: 36px;
    border-radius: 4px;
    background-color: var(--primary);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 1rem;
    flex-shrink: 0;
}

.slack-content {
    flex: 1;
}

.slack-meta {
    margin-bottom: 0.25rem;
}

.slack-meta strong {
    color: var(--slack-text);
    font-weight: 900;
    font-size: 0.95rem;
}

.slack-time {
    color: var(--slack-meta);
    font-size: 0.75rem;
    margin-left: 0.5rem;
}

.slack-body {
    color: var(--slack-text);
    font-size: 0.95rem;
    line-height: 1.46;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.slack-body strong {
    font-weight: 700;
}

.slack-body ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
}

.slack-body li {
    position: relative;
    padding-left: 1rem;
    margin-bottom: 0.1rem;
}

.slack-body li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--slack-meta);
}

#hidden-copy-area {
    position: absolute;
    left: -9999px;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-5px); }
    to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 1024px) {
    .app-container {
        flex-direction: column;
        overflow-y: auto;
    }
    
    .sidebar, .preview-sidebar {
        width: 100%;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        max-height: none;
    }
    
    .preview-sidebar {
        border-left: none;
        border-top: 1px solid var(--border-color);
    }
    
    body {
        overflow-y: auto;
    }
}