/* ===================================
   PDF Editor - Design System Styles
   =================================== */

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

:root {
    /* Color System */
    --primary-500: #005FF9;
    --primary-700: #0045B7;
    --primary-100: #E6F0FF;
    
    --page-bg: #F8F9FA;
    --canvas-bg: #FFFFFF;
    --text-primary: #1A1D21;
    --text-secondary: #69717C;
    --border-default: rgba(0, 0, 0, 0.1);
    
    --success-500: #22C55E;
    --warning-500: #F59E0B;
    --error-500: #EF4444;
    
    /* Glassmorphism */
    --glass-bg: rgba(248, 249, 250, 0.6);
    --glass-border: rgba(255, 255, 255, 0.5);
    
    /* Spacing */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-xxl: 48px;
    
    /* Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    
    /* Shadows */
    --shadow-modal: 0px 16px 48px rgba(26, 29, 33, 0.15);
    --shadow-dropdown: 0px 8px 16px rgba(26, 29, 33, 0.1);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 16px;
    line-height: 1.5;
    color: var(--text-primary);
    background-color: var(--page-bg);
    overflow-x: hidden;
}

/* === Typography === */
h1 {
    font-size: 24px;
    font-weight: 600;
    line-height: 1.4;
}

h2 {
    font-size: 18px;
    font-weight: 600;
    line-height: 1.4;
}

.body-text {
    font-size: 16px;
    font-weight: 400;
    line-height: 1.5;
}

.ui-text {
    font-size: 14px;
    font-weight: 500;
    line-height: 1.2;
}

.small-text {
    font-size: 12px;
    font-weight: 400;
    line-height: 1.2;
}

/* === Main Toolbar === */
.main-toolbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 64px;
    padding: 0 var(--space-lg);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-lg);
    background: var(--glass-bg);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border-bottom: 1px solid var(--glass-border);
    z-index: 100;
}

.toolbar-section {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.toolbar-btn {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    height: 36px;
    background: transparent;
    border: none;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 200ms ease-out, color 200ms ease-out;
    white-space: nowrap;
}

.toolbar-btn:hover {
    background-color: rgba(0, 0, 0, 0.05);
}

.toolbar-btn.active,
.toolbar-btn.tool-active {
    background-color: var(--primary-100);
    color: var(--primary-500);
}

.toolbar-btn.primary {
    background-color: var(--primary-500);
    color: white;
    padding: 0 var(--space-lg);
    height: 44px;
}

.toolbar-btn.primary:hover {
    background-color: var(--primary-700);
}

.toolbar-btn.primary:active {
    transform: scale(0.98);
}

.toolbar-btn svg {
    flex-shrink: 0;
}

.zoom-level {
    min-width: 50px;
    text-align: center;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-primary);
}

/* === Annotation Toolbar === */
.annotation-toolbar {
    position: fixed;
    top: 80px;
    left: 50%;
    transform: translateX(-50%);
    padding: var(--space-md);
    background: var(--canvas-bg);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-dropdown);
    z-index: 90;
    animation: slideDown 200ms ease-out;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translate(-50%, -8px);
    }
    to {
        opacity: 1;
        transform: translate(-50%, 0);
    }
}

.annotation-controls {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    flex-wrap: wrap;
}

.annotation-label {
    font-size: 12px;
    font-weight: 500;
    color: var(--text-secondary);
}

#colorPicker {
    width: 40px;
    height: 32px;
    border: 1px solid var(--border-default);
    border-radius: var(--radius-sm);
    cursor: pointer;
}

#sizePicker {
    width: 100px;
}

#sizeValue {
    font-size: 14px;
    font-weight: 500;
    min-width: 20px;
    text-align: center;
}

#fontSizePicker {
    padding: var(--space-sm);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-sm);
    font-size: 14px;
}

.annotation-btn {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    background: var(--error-500);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 12px;
    font-weight: 500;
    cursor: pointer;
    transition: opacity 200ms ease-out;
}

.annotation-btn:hover {
    opacity: 0.9;
}

/* === Main Container === */
.main-container {
    display: flex;
    margin-top: 64px;
    height: calc(100vh - 64px);
}

/* === Side Panel === */
.side-panel {
    width: 280px;
    background: var(--glass-bg);
    backdrop-filter: blur(24px);
    -webkit-backdrop-filter: blur(24px);
    border-right: 1px solid var(--glass-border);
    overflow-y: auto;
    transition: transform 300ms ease-out;
}

.side-panel.collapsed {
    transform: translateX(-100%);
}

.panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-md);
    border-bottom: 1px solid var(--border-default);
}

.panel-btn {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    cursor: pointer;
    transition: background-color 200ms ease-out;
}

.panel-btn:hover {
    background-color: rgba(0, 0, 0, 0.05);
}

.thumbnails-container {
    padding: var(--space-md);
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.thumbnail-item {
    position: relative;
    padding: var(--space-sm);
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    background: transparent;
    cursor: pointer;
    transition: border-color 250ms ease-in-out, background-color 250ms ease-in-out;
}

.thumbnail-item:hover {
    background-color: rgba(0, 0, 0, 0.03);
}

.thumbnail-item.selected {
    border-color: var(--primary-500);
    background-color: var(--primary-100);
}

.thumbnail-page-number {
    font-size: 12px;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: var(--space-xs);
}

.thumbnail-preview {
    width: 100%;
    border: 1px solid var(--border-default);
    border-radius: var(--radius-sm);
}

/* === Canvas Area === */
.canvas-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    overflow: auto;
    background-color: var(--page-bg);
}

/* === Welcome Screen === */
.welcome-screen {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    text-align: center;
    padding: var(--space-xxl);
}

.welcome-screen svg {
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
}

.welcome-screen h1 {
    margin-bottom: var(--space-md);
    color: var(--text-primary);
}

.welcome-screen p {
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
}

.primary-btn {
    padding: 0 var(--space-lg);
    height: 44px;
    background-color: var(--primary-500);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 200ms ease-out, transform 150ms ease-out;
}

.primary-btn:hover {
    background-color: var(--primary-700);
}

.primary-btn:active {
    transform: scale(0.98);
}

.secondary-btn {
    padding: 0 var(--space-lg);
    height: 44px;
    background-color: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 200ms ease-out;
}

.secondary-btn:hover {
    background-color: rgba(0, 0, 0, 0.05);
}

/* === PDF Viewer === */
.pdf-viewer {
    width: 100%;
    max-width: 1400px;
    padding: var(--space-xl);
}

.page-navigation {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-md);
    margin-bottom: var(--space-lg);
    padding: var(--space-md);
    background: var(--canvas-bg);
    border-radius: var(--radius-md);
}

.nav-btn {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: 1px solid var(--border-default);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    cursor: pointer;
    transition: background-color 200ms ease-out;
}

.nav-btn:hover:not(:disabled) {
    background-color: rgba(0, 0, 0, 0.05);
}

.nav-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

.page-info {
    font-size: 14px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

#currentPageInput {
    width: 50px;
    padding: var(--space-xs) var(--space-sm);
    text-align: center;
    border: 1px solid var(--border-default);
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 500;
}

/* === Canvas Wrapper === */
.canvas-wrapper {
    position: relative;
    display: inline-block;
    background: var(--canvas-bg);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    margin: 0 auto;
}

#pdfCanvas,
#annotationCanvas {
    display: block;
}

#annotationCanvas {
    position: absolute;
    top: 0;
    left: 0;
    cursor: crosshair;
}

/* === Modals === */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(26, 29, 33, 0.5);
    z-index: 200;
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--canvas-bg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-modal);
    width: 90%;
    max-width: 500px;
    max-height: 80vh;
    overflow: auto;
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-lg);
    border-bottom: 1px solid var(--border-default);
}

.close-btn {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    cursor: pointer;
    transition: background-color 200ms ease-out;
}

.close-btn:hover {
    background-color: rgba(0, 0, 0, 0.05);
}

.modal-body {
    padding: var(--space-lg);
}

.modal-body p {
    margin-bottom: var(--space-md);
    color: var(--text-secondary);
}

.modal-input {
    width: 100%;
    padding: var(--space-md);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-md);
    font-size: 16px;
    font-family: inherit;
    margin-bottom: var(--space-sm);
}

.helper-text {
    font-size: 12px;
    color: var(--text-secondary);
}

.modal-footer {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: var(--space-md);
    padding: var(--space-lg);
    border-top: 1px solid var(--border-default);
}

/* === Toast Notification === */
.toast {
    position: fixed;
    bottom: var(--space-lg);
    right: var(--space-lg);
    padding: var(--space-md) var(--space-lg);
    background: var(--text-primary);
    color: white;
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 500;
    box-shadow: var(--shadow-dropdown);
    transform: translateY(100px);
    opacity: 0;
    transition: transform 300ms ease-out, opacity 300ms ease-out;
    z-index: 300;
    max-width: 400px;
}

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

.toast.success {
    background: var(--success-500);
}

.toast.error {
    background: var(--error-500);
}

.toast.warning {
    background: var(--warning-500);
}

/* === Responsive === */
@media (max-width: 1200px) {
    .side-panel {
        position: fixed;
        left: 0;
        top: 64px;
        height: calc(100vh - 64px);
        z-index: 90;
    }
    
    .toolbar-btn span {
        display: none;
    }
}

@media (max-width: 768px) {
    .main-toolbar {
        padding: 0 var(--space-md);
    }
    
    .toolbar-section {
        gap: var(--space-xs);
    }
    
    .pdf-viewer {
        padding: var(--space-md);
    }
    
    .annotation-toolbar {
        left: var(--space-md);
        right: var(--space-md);
        transform: translateX(0);
    }
    
    .annotation-controls {
        gap: var(--space-sm);
    }
}

/* === Drag and Drop === */
.canvas-area.drag-over {
    background-color: var(--primary-100);
    border: 2px dashed var(--primary-500);
}

/* === Animations === */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* === Loading Spinner === */
.spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}