/* ===== Reset & Base ===== */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --sidebar-width: 280px;
    --border-color: #e8e8e8;
    --bg-primary: #ffffff;
    --bg-sidebar: #fafafa;
    --bg-hover: #f2f2f2;
    --bg-active: #eef1f6;
    --text-primary: #1a1a1a;
    --text-secondary: #6b6b6b;
    --text-muted: #999;
    --accent: #4a6cf7;
    --accent-light: #eef1ff;
    --copy-success: #22c55e;
    --tag-orange-bg: #fff3e0;
    --tag-orange-text: #e67e22;
    --tag-blue-bg: #e3f2fd;
    --tag-blue-text: #2196f3;
    --tag-green-bg: #e8f5e9;
    --tag-green-text: #4caf50;
    --tag-purple-bg: #f3e5f5;
    --tag-purple-text: #9c27b0;
    --tag-red-bg: #fce4ec;
    --tag-red-text: #e53935;
    --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --radius: 6px;
    --transition: 0.2s ease;
}

html,
body {
    height: 100%;
    font-family: var(--font);
    font-size: 14px;
    color: var(--text-primary);
    background: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
}

/* ===== Layout ===== */
.app {
    display: flex;
    height: 100vh;
    overflow: hidden;
}

/* ===== Sidebar ===== */
.sidebar {
    width: var(--sidebar-width);
    min-width: var(--sidebar-width);
    background: var(--bg-sidebar);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.sidebar-header {
    padding: 20px 16px 12px;
    border-bottom: 1px solid var(--border-color);
}

.sidebar-header h1 {
    font-size: 15px;
    font-weight: 600;
    letter-spacing: -0.01em;
    color: var(--text-primary);
    margin-bottom: 14px;
    display: flex;
    align-items: center;
    gap: 6px;
}

.sidebar-header h1 span {
    font-size: 10px;
    background: var(--accent-light);
    color: var(--accent);
    padding: 2px 6px;
    border-radius: 4px;
    font-weight: 500;
}

/* Search */
.search-wrapper {
    position: relative;
}

.search-wrapper svg {
    position: absolute;
    left: 10px;
    top: 50%;
    transform: translateY(-50%);
    width: 14px;
    height: 14px;
    color: var(--text-muted);
    pointer-events: none;
}

.search-input {
    width: 100%;
    padding: 8px 10px 8px 32px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 13px;
    font-family: var(--font);
    color: var(--text-primary);
    background: var(--bg-primary);
    outline: none;
    transition: border-color var(--transition);
}

.search-input::placeholder {
    color: var(--text-muted);
}

.search-input:focus {
    border-color: var(--accent);
}

/* Folder Tree */
.folder-tree {
    flex: 1;
    overflow-y: auto;
    padding: 8px 0;
}

.folder-tree::-webkit-scrollbar {
    width: 4px;
}

.folder-tree::-webkit-scrollbar-thumb {
    background: #ddd;
    border-radius: 4px;
}

/* Folder Item */
.folder-item {
    user-select: none;
}

.folder-header {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 7px 16px;
    cursor: pointer;
    color: var(--text-primary);
    font-size: 13px;
    font-weight: 500;
    transition: background var(--transition);
    border: none;
    background: none;
    width: 100%;
    text-align: left;
    font-family: var(--font);
}

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

.folder-header .chevron {
    width: 16px;
    height: 16px;
    color: var(--text-muted);
    transition: transform var(--transition);
    flex-shrink: 0;
}

.folder-header .chevron.expanded {
    transform: rotate(90deg);
}

.folder-header .folder-icon {
    width: 16px;
    height: 16px;
    color: var(--text-secondary);
    flex-shrink: 0;
}

.folder-header .folder-name {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* Folder Children */
.folder-children {
    overflow: hidden;
    max-height: 0;
    transition: max-height 0.3s ease;
}

.folder-children.expanded {
    max-height: 2000px;
}

/* Sub-folder (layer 2) */
.subfolder-header {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 16px 6px 38px;
    cursor: pointer;
    color: var(--text-primary);
    font-size: 13px;
    font-weight: 500;
    transition: background var(--transition);
    border: none;
    background: none;
    width: 100%;
    text-align: left;
    font-family: var(--font);
}

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

.subfolder-header .chevron {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
    color: var(--text-muted);
    transition: transform var(--transition);
}

.subfolder-header .chevron.expanded {
    transform: rotate(90deg);
}

.subfolder-header svg {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
}

.subfolder-header .folder-name {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.subfolder-children {
    overflow: hidden;
    max-height: 0;
    transition: max-height 0.3s ease;
}

.subfolder-children.expanded {
    max-height: 2000px;
}

/* Prompt Item */
.prompt-item {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 16px 6px 38px;
    cursor: pointer;
    color: var(--text-secondary);
    font-size: 13px;
    font-weight: 400;
    transition: all var(--transition);
    border: none;
    background: none;
    width: 100%;
    text-align: left;
    font-family: var(--font);
    border-left: 2px solid transparent;
}

.prompt-item.nested {
    padding-left: 56px;
}

.prompt-item:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.prompt-item.active {
    background: var(--bg-active);
    color: var(--accent);
    border-left-color: var(--accent);
    font-weight: 500;
}

.prompt-item .prompt-icon {
    width: 14px;
    height: 14px;
    flex-shrink: 0;
    opacity: 0.5;
}

.prompt-item.active .prompt-icon {
    opacity: 1;
}

.prompt-item .prompt-name {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* ===== Content Area ===== */
.content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* Content Header */
.content-header {
    padding: 20px 32px 16px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 16px;
}

.content-title {
    font-size: 20px;
    font-weight: 600;
    letter-spacing: -0.02em;
    color: var(--text-primary);
}

.content-meta {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 8px;
    flex-wrap: wrap;
}

/* Tags */
.tag {
    display: inline-flex;
    align-items: center;
    padding: 3px 10px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 500;
    letter-spacing: 0.01em;
}

.tag-orange {
    background: var(--tag-orange-bg);
    color: var(--tag-orange-text);
}

.tag-blue {
    background: var(--tag-blue-bg);
    color: var(--tag-blue-text);
}

.tag-green {
    background: var(--tag-green-bg);
    color: var(--tag-green-text);
}

.tag-purple {
    background: var(--tag-purple-bg);
    color: var(--tag-purple-text);
}

.tag-red {
    background: var(--tag-red-bg);
    color: var(--tag-red-text);
}

/* Copy Button */
.copy-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    background: var(--accent);
    color: #fff;
    border: none;
    border-radius: var(--radius);
    font-size: 13px;
    font-weight: 500;
    font-family: var(--font);
    cursor: pointer;
    transition: all var(--transition);
    white-space: nowrap;
    flex-shrink: 0;
}

.copy-btn:hover {
    background: #3b5de7;
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(74, 108, 247, 0.3);
}

.copy-btn:active {
    transform: translateY(0);
}

.copy-btn.copied {
    background: var(--copy-success);
}

.copy-btn svg {
    width: 14px;
    height: 14px;
}

/* Content Body */
.content-body {
    flex: 1;
    overflow-y: auto;
    padding: 24px 32px 40px;
}

.content-body::-webkit-scrollbar {
    width: 6px;
}

.content-body::-webkit-scrollbar-thumb {
    background: #ddd;
    border-radius: 4px;
}

.prompt-text {
    font-size: 14px;
    line-height: 1.75;
    color: var(--text-primary);
    white-space: pre-wrap;
    word-wrap: break-word;
}

/* Character Count */
.char-count {
    margin-top: 20px;
    font-size: 12px;
    color: var(--text-muted);
}

/* Empty State */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    color: var(--text-muted);
    gap: 12px;
}

.empty-state svg {
    width: 48px;
    height: 48px;
    opacity: 0.3;
}

.empty-state p {
    font-size: 14px;
}

/* ===== Toast ===== */
.toast {
    position: fixed;
    bottom: 24px;
    right: 24px;
    background: #333;
    color: #fff;
    padding: 10px 20px;
    border-radius: var(--radius);
    font-size: 13px;
    font-family: var(--font);
    opacity: 0;
    transform: translateY(10px);
    transition: all 0.3s ease;
    pointer-events: none;
    z-index: 100;
}

.toast.show {
    opacity: 1;
    transform: translateY(0);
}

/* ===== No Results ===== */
.no-results {
    padding: 20px 16px;
    text-align: center;
    color: var(--text-muted);
    font-size: 13px;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .sidebar {
        width: 240px;
        min-width: 240px;
    }

    .content-header {
        padding: 16px 20px 12px;
    }

    .content-body {
        padding: 16px 20px 32px;
    }

    .content-title {
        font-size: 18px;
    }
}