/* Base Variables & Reset */
:root {
    --bg-main: #f3f4f6;
    --bg-panel: #ffffff;
    --text-main: #1f2937;
    --text-muted: #6b7280;
    --border-color: #e5e7eb;
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --ring-color: #3b82f6;
    --font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-main);
    color: var(--text-main);
    height: 100vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.hidden {
    display: none !important;
}

/* Header */
.app-header {
    background-color: var(--bg-panel);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    z-index: 10;
    box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
}

.header-title {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.header-title h1 {
    font-size: 1.25rem;
    font-weight: 700;
    color: #1f2937;
}

.header-icon {
    width: 2rem;
    height: 2rem;
    color: var(--primary);
}

.btn-reset {
    font-size: 0.875rem;
    color: var(--text-muted);
    background: none;
    border: none;
    cursor: pointer;
    font-weight: 500;
}

.btn-reset:hover {
    color: var(--text-main);
}

/* Layout Views */
.view-container {
    flex: 1;
    display: flex;
    overflow: hidden;
}

/* Upload View */
.upload-view {
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
}

.upload-text {
    text-align: center;
    margin-bottom: 1.5rem;
    max-width: 32rem;
}

.upload-text h2 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.upload-text p {
    color: var(--text-muted);
    font-size: 0.875rem;
}

.uppy-wrapper {
    width: 100%;
    max-width: 48rem;
}

/* Workspace Sidebar */
.sidebar {
    width: 20rem;
    background-color: var(--bg-panel);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    z-index: 10;
}

.sidebar-header {
    padding: 0.5rem;
    border-bottom: 1px solid var(--border-color);
    background-color: #f9fafb;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.sidebar-header h2 {
    font-weight: 700;
    font-size: 1rem;
    color: #374151;
}

.sidebar-instructions {
    padding: 0.5rem;
    font-size: 0.75rem;
    color: var(--text-muted);
    border-bottom: 1px solid var(--border-color);
}

.groups-container {
    flex: 1;
    overflow-y: auto;
    padding: 0.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.sidebar-footer {
    padding: 0.5rem;
    border-top: 1px solid var(--border-color);
    background-color: #f9fafb;
}

/* Group Cards */
.group-card {
    background-color: var(--bg-panel);
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    padding: 0.5rem;
    box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.group-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.color-dot {
    width: 1rem;
    height: 1rem;
    border-radius: 50%;
    flex-shrink: 0;
}

.group-input {
    flex: 1;
    font-size: 0.875rem;
    font-weight: 600;
    border: none;
    border-bottom: 1px solid transparent;
    background: transparent;
    padding: 2px 0;
    outline: none;
}

.group-input:hover {
    border-bottom-color: #d1d5db;
}

.group-input:focus {
    border-bottom-color: var(--primary);
}

.group-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 0.25rem;
}

.group-count {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-weight: 500;
}

/* Buttons */
.btn-icon {
    background-color: #dbeafe;
    color: #1d4ed8;
    border: none;
    padding: 0.375rem;
    border-radius: 0.375rem;
    cursor: pointer;
    transition: background-color 0.2s;
    display: inline-flex;
}

.btn-icon:hover {
    background-color: #bfdbfe;
}

.btn-icon svg {
    width: 1.25rem;
    height: 1.25rem;
}

.btn-add-selected {
    background-color: #f3f4f6;
    color: #374151;
    padding: 0.25rem 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: 0.25rem;
    font-size: 0.75rem;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.25rem;
    transition: background-color 0.2s;
}

.btn-add-selected:hover {
    background-color: #e5e7eb;
}

.btn-add-selected svg {
    width: 0.75rem;
    height: 0.75rem;
}

.btn-export {
    width: 100%;
    background-color: var(--primary);
    color: white;
    font-weight: 700;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 0.25rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    transition: background-color 0.2s;
}

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

.btn-export svg {
    width: 1.25rem;
    height: 1.25rem;
}

/* Workspace Grid */
.main-content {
    flex: 1;
    background-color: var(--bg-main);
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.grid-toolbar {
    padding: 0.5rem;
    border-bottom: 1px solid var(--border-color);
    background-color: var(--bg-panel);
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
    z-index: 0;
}

.toolbar-left {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.selection-status {
    font-size: 0.875rem;
    font-weight: 500;
    color: #4b5563;
}

.grid-size-ctrl {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    border-left: 1px solid var(--border-color);
    padding-left: 1rem;
}

.grid-size-ctrl label {
    font-size: 0.75rem;
    font-weight: 500;
    color: #4b5563;
}

.grid-size-ctrl input {
    width: 6rem;
    cursor: pointer;
}

.toolbar-hints {
    font-size: 0.75rem;
    color: #9ca3af;
}

.pages-grid {
    flex: 1;
    padding: 0.5rem;
    overflow-y: auto;
    display: grid;
    gap: 0.5rem;
    align-content: start;
    align-items: start;
}

.pages-grid::-webkit-scrollbar {
    display: none;
}

.pages-grid {
    -ms-overflow-style: none;
    scrollbar-width: none;
}

/* Thumbnail Containers */
.thumbnail-container {
    position: relative;
    cursor: pointer;
    background-color: var(--bg-panel);
    border-radius: 0.25rem;
    border: 2px solid var(--border-color);
    transition: transform 0.1s, box-shadow 0.1s;
    height: fit-content;
}

.thumbnail-container:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

.thumbnail-container.selected {
    border-color: transparent;
    box-shadow: 0 0 0 4px var(--ring-color);
}

.thumbnail-container.is-dragging {
    opacity: 0.4;
    transform: scale(0.95);
}

.thumbnail-container.drag-over-before::before,
.thumbnail-container.drag-over-after::after {
    content: '';
    position: absolute;
    top: -4px;
    bottom: -4px;
    width: 4px;
    background-color: #ef4444;
    /* red */
    z-index: 10;
    border-radius: 2px;
}

.thumbnail-container.drag-over-before::before {
    left: -4px;
}

.thumbnail-container.drag-over-after::after {
    right: -4px;
}

.thumbnail-canvas {
    width: 100%;
    height: auto;
    display: block;
    pointer-events: none;
    background-color: #ffffff;
    /* Make unrendered canvases look like blank pages */
}

.page-number {
    position: absolute;
    bottom: 0.25rem;
    right: 0.25rem;
    background-color: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    color: white;
    padding: 0.125rem 0.375rem;
    border-radius: 0.25rem;
    font-size: 10px;
    font-weight: 700;
    pointer-events: none;
}

.badge-container {
    position: absolute;
    top: 0.25rem;
    left: 0.25rem;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.group-badge {
    width: 1rem;
    height: 1rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    cursor: pointer;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}

.group-badge:hover {
    opacity: 0.8;
}

.group-badge svg {
    width: 0.75rem;
    height: 0.75rem;
    pointer-events: none;
}

/* Overlay */
.overlay {
    position: fixed;
    inset: 0;
    background-color: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(4px);
    z-index: 50;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.spinner {
    width: 4rem;
    height: 4rem;
    border: 4px solid transparent;
    border-top-color: var(--primary);
    border-bottom-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}

.overlay-text {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-main);
}