/* Base Styles and Layout */
body, html {
    margin: 0; 
    padding: 0; 
    /* Use dynamic viewport units to avoid mobile browser chrome overlap */
    min-height: 100dvh; 
    height: 100%;
    font-family: 'Inter', sans-serif; 
    background-color: var(--primary-bg); 
    color: var(--text-primary); 
    overflow: hidden; 
    font-size: 14px;
}

/* Respect iOS safe-area insets so content doesn't sit under the URL bar */
@supports (padding: max(0px)) {
    body {
        padding-top: max(env(safe-area-inset-top), 0px);
        padding-left: max(env(safe-area-inset-left), 0px);
        padding-right: max(env(safe-area-inset-right), 0px);
        padding-bottom: max(env(safe-area-inset-bottom), 0px);
        box-sizing: border-box;
    }
}

/* App Container Layout */
.app-container { 
    display: grid; 
    grid-template-columns: var(--panel-width) 1fr;
    grid-template-areas: "control main";
    height: 100%; 
    transition: grid-template-columns 0.3s ease-in-out; 
}
.app-container.panel-collapsed { 
    grid-template-columns: var(--panel-width-collapsed) 1fr; 
}

.app-container.assistant-active {
    /* Resizer is 1px wide */
    grid-template-columns: var(--panel-width) 1fr 1px var(--assistant-panel-width);
    grid-template-areas: "control main assistant-resizer assistant";
}
.app-container.panel-collapsed.assistant-active {
    grid-template-columns: var(--panel-width-collapsed) 1fr 1px var(--assistant-panel-width);
    grid-template-areas: "control main assistant-resizer assistant";
}

.app-container.assistant-active.assistant-collapsed {
    grid-template-columns: var(--panel-width) 1fr 0 45px;
}

.app-container.panel-collapsed.assistant-active.assistant-collapsed {
    grid-template-columns: var(--panel-width-collapsed) 1fr 0 45px;
}

.control-panel {
    grid-area: control;
}
.right-container {
    grid-area: main;
}
.assistant-panel {
    grid-area: assistant;
}
#assistant-resizer {
    grid-area: assistant-resizer;    
}

/* Common resizer styles */
.resizer, #assistant-resizer {
    background-color: var(--border-color);
    cursor: ew-resize;
    position: relative;
    transition: background-color 0.2s ease-in-out;
}

/* Control Panel Layout */
.control-panel { 
    background-color: var(--secondary-bg); 
    border-right: 1px solid var(--border-color); 
    display: flex; 
    flex-direction: column; 
    overflow-y: auto; 
    overflow-x: hidden; 
    position: relative; 
}

.panel-header { 
    display: flex; 
    align-items: center; 
    padding: 12px 16px; 
    border-bottom: 1px solid var(--border-color); 
}
.panel-header h2 { 
    font-size: 1rem; 
    margin: 0; 
    font-weight: 600; 
    color: var(--text-primary); 
}

/* Right Container Layout */
.right-container { 
    display: flex; 
    flex-direction: row; 
    overflow: hidden;
    padding: 0;
}

/* Window Layout */
.window { 
    flex-grow: 1; 
    flex-basis: 0; 
    background-color: var(--secondary-bg); 
    margin: 0; 
    border: 1px solid var(--border-color); 
    box-shadow: var(--shadow); 
    overflow: hidden; 
    display: flex; 
    flex-direction: column; 
    transition: all 0.3s ease-in-out; 
}

#pdf-window { 
    border-radius: 0;
    border-right: none; 
    border-left: none;
    flex-grow: 3; 
}
#output-window { 
    border-radius: 0;
    flex-grow: 7; 
}
.resizer { 
    flex-basis: 1px; 
    flex-shrink: 0; 
    padding: 0 4px; 
    margin: 0 -4px; 
}
/* Make the assistant resizer's hit area slightly smaller for a more subtle feel */
#assistant-resizer {
    padding: 0 3px;
    margin: 0 -3px;
}
.resizer:hover, #assistant-resizer:hover,
.resizer.resizing-active, #assistant-resizer.resizing-active {
    background-color: var(--primary-accent-start);
}
.resizer.hidden { 
    flex-basis: 0; 
    padding: 0; 
    margin: 0; 
    border-width: 0; 
}

/* Window Collapse States */
.window.collapsed { 
    flex-grow: 0; 
    flex-basis: 45px; 
}
.window.collapsed .window-top-bar { 
    padding: 8px; 
    height: 100%; 
    align-items: center; 
    justify-content: center; 
}
.window.collapsed .tabs-container, 
.window.collapsed .window-content { 
    display: none; 
}
.window.collapsed #textbook-zoom-controls {
    display: none !important;
}
.window.collapsed #textbook-toc-toggle {
    display: none !important;
}
.window.collapsed #textbook-highlight,
.window.collapsed #textbook-save {
    display: none !important;
}

/* Ensure only hover styles apply and click is not swallowed by overlapping elements */
.toc-toggle-button {
    background: none;
    border: 1px solid transparent;
    cursor: pointer;
    color: var(--text-secondary);
    font-size: 1rem;
    width: 28px;
    height: 28px;
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.toc-toggle-button:hover { 
    background-color: var(--hover-bg); 
    color: var(--text-primary); 
}

/* Window Top Bar */
.window-top-bar { 
    display: flex; 
    align-items: center; 
    padding: 8px 8px 0 16px; 
    border-bottom: 1px solid var(--border-color); 
    flex-shrink: 0; 
    gap: 16px; 
}
.window-top-bar .tabs-container { 
    display: flex; 
    gap: 16px; 
}

.tab-item { 
    font-size: 0.9rem; 
    font-weight: 500; 
    color: var(--text-secondary); 
    padding-bottom: 8px; 
    background: none; 
    border: none; 
    cursor: pointer; 
    border-bottom: 2px solid transparent;
    display: flex;
    align-items: center;
    gap: 8px;
}
.tab-item.active { 
    color: var(--primary-accent-start); 
    font-weight: 600; 
    border-bottom-color: var(--primary-accent-start); 
}

.tab-close {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 2px;
    border-radius: 3px;
    font-size: 0.8rem;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 18px;
    height: 18px;
    transition: all 0.2s ease;
}

.tab-close:hover {
    background-color: var(--hover-bg);
    color: var(--error-text);
}

.window-top-bar .window-controls { 
    margin-left: auto; 
    display: flex; 
    align-items: center; 
    gap: 4px; 
}
.window-controls button {
    background: none; 
    border: 1px solid transparent; 
    cursor: pointer; 
    color: var(--text-secondary); 
    font-size: 1rem;
    width: 28px; 
    height: 28px; 
    border-radius: 6px;
    display: flex; 
    align-items: center; 
    justify-content: center;
    transition: all 0.2s ease;
}
.window-controls button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    filter: grayscale(0.8);
}
.window-controls button:hover { 
    background-color: var(--hover-bg); 
    color: var(--text-primary); 
}

.window-controls .highlight-controls-container {
    display: inline-flex;
    align-items: center;
    gap: 2px;
}

.window-controls button.active {
    background-color: var(--primary-accent-light);
    color: var(--primary-accent-start);
    border-color: var(--primary-accent-start);
}

.window-controls button.remove-mode {
    background-color: var(--error-bg);
    color: var(--error-text);
    border-color: var(--error-border);
}

.window-controls button.remove-mode:hover {
    background-color: #fecaca; /* A slightly darker red */
    color: var(--danger-secondary);
    border-color: var(--error-text);
}

.window-content { 
    padding: 20px; 
    overflow: auto; 
    flex-grow: 1; 
}

/* Performance Optimizations */
body.resizing { 
    cursor: ew-resize !important; 
    user-select: none !important; 
}
body.resizing * { 
    pointer-events: none !important; 
}
body.resizing .app-container {
    transition: none !important;
}
body.resizing .window { 
    transition: none !important; 
}

/* Desktop-specific border adjustments for when assistant is active */
@media (min-width: 1025px) {
    .app-container.assistant-active #output-window {
        border-right: none;
    }
}

/* Settings Menu Styles */
.settings-menu {
    position: absolute;
    top: 100%;
    right: 8px;
    background: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    box-shadow: var(--shadow);
    padding: 8px;
    min-width: 200px;
    z-index: 1000;
    display: none;
    flex-direction: column;
    gap: 12px;
}

.settings-menu-item {
    display: flex;
    flex-direction: column;
    gap: 4px;
    align-items: flex-start;
}

.settings-menu-item label {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-primary);
    text-align: left;
    align-self: flex-start;
}

.settings-menu-item select {
    padding: 6px 8px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background: var(--primary-bg);
    color: var(--text-primary);
    font-size: 0.85rem;
    cursor: pointer;
    width: 100%;
    text-align: left;
}

.settings-menu-item select:focus {
    outline: none;
    border-color: var(--primary-accent-start);
    box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.1);
}

/* Highlight color dropdown styling */
.highlight-color-select {
    font-family: monospace; /* Better circle rendering */
    font-size: 0.9rem;
}

.highlight-color-select option[value="yellow"] {
    color: #d97706; /* Darker yellow for visibility */
}

.highlight-color-select option[value="blue"] {
    color: #2563eb; /* Blue */
}

.highlight-color-select option[value="green"] {
    color: #16a34a; /* Green */
}

.highlight-color-select option[value="orange"] {
    color: #ea580c; /* Orange */
}

.highlight-color-select option[value="pink"] {
    color: #db2777; /* Pink */
}

/* NEW: Compact Color Picker for Highlights */
.color-picker {
    position: relative;
    display: flex;
    align-items: center;
}

#highlight-color-btn {
    width: 28px;
    height: 28px;
    padding: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 4px;
}

#highlight-color-btn .color-swatch {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    border: 1px solid rgba(0,0,0,0.2);
    display: inline-block;
}

#highlight-color-btn .fa-caret-down {
    font-size: 0.7rem;
    color: var(--text-secondary);
    transition: transform 0.2s ease;
}

.color-palette {
    position: absolute;
    top: 110%;
    right: 0;
    background-color: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    box-shadow: var(--shadow);
    padding: 6px;
    z-index: 1001;
    display: none; /* Toggled by JS */
    flex-wrap: wrap;
    width: 80px; /* 2 columns of swatches */
    gap: 4px;
}

.color-option {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: 2px solid transparent;
    background: none;
    cursor: pointer;
    padding: 2px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.color-option:hover {
    border-color: var(--primary-accent-start);
}

.color-option .color-swatch {
    width: 100%;
    height: 100%;
    border-radius: 50%;
    border: 1px solid rgba(0,0,0,0.1);
}

/* Responsive Layout */
@media (max-width: 1024px) {
    /* On smaller screens, the grid layout is maintained. The assistant panel
       will "squeeze" the main content area by remaining in the grid. */
    .app-container {
        grid-template-columns: var(--panel-width) 1fr;
        grid-template-areas: "control main";
    }
    .app-container.panel-collapsed {
        grid-template-columns: var(--panel-width-collapsed) 1fr;
    }
}

@media (max-width: 768px) {
    .window.collapsed {
        /* Make the collapsed bar thinner on mobile */
        flex-basis: 35px;
    }

    #pdf-viewer-toolbar {
        /* Allow PDF controls to wrap on small screens */
        flex-wrap: wrap;
    }
    .window-controls {
        /* Ensure controls within the top bar can also wrap */
        flex-wrap: wrap;
        justify-content: flex-end;
    }
}