/* Modern CSS Reset */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }
body { line-height: 1.5; }
img, picture, video, canvas, svg { display: block; max-width: 100%; }
input, button, textarea, select { font: inherit; }
p, h1, h2, h3, h4, h5, h6 { overflow-wrap: break-word; }

/* Variables & Theme */
:root {
    --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif;
    --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;

    --bg: #ffffff;
    --fg: #1f2937;
    --fg-muted: #6b7280;
    --border: #e5e7eb;
    --panel-bg: #ffffff;
    --input-bg: #f9fafb;
    --button-bg: #f3f4f6;
    --button-hover-bg: #e5e7eb;
    --accent: #3b82f6;
    --accent-fg: #ffffff;
    --error-bg: #fee2e2;
    --error-fg: #b91c1c;
    --error-border: #fca5a5;

    --sidebar-width: 280px;
    --header-height: 4rem;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #111827;
        --fg: #f3f4f6;
        --fg-muted: #9ca3af;
        --border: #374151;
        --panel-bg: #1f2937;
        --input-bg: #374151;
        --button-bg: #374151;
        --button-hover-bg: #4b5563;
        --accent: #60a5fa;
        --accent-fg: #1f2937;
        --error-bg: #450a0a;
        --error-fg: #fca5a5;
        --error-border: #b91c1c;
    }
    /* Add the rule specifically for dark mode */
    .history-item .meta .source {
            color: var(--fg);
    }
}

/* Base Body Styles */
body {
    font-family: var(--font-sans);
    background-color: var(--bg);
    color: var(--fg);
    display: flex;
    min-height: 100vh;
}

/* Layout: Sidebar + Main */
#history-panel {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: var(--sidebar-width);
    background-color: var(--bg); /* Match body bg, border provides separation */
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column; /* Allow header/content/footer structure */
    overflow-y: auto;
    z-index: 10;
    transition: transform 0.3s ease-in-out; /* Add transition for mobile */
}

main {
    flex-grow: 1;
    margin-left: var(--sidebar-width); /* Offset by sidebar */
    padding: 1.5rem 2rem;
    display: flex;
    flex-direction: column;
}

/* Main Header */
.main-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    /* Adjust height/padding as needed */
}

.main-header h1 {
    text-align: left;
    font-weight: 600;
    margin-bottom: 0; /* Remove bottom margin */
    color: var(--fg); /* Option 1: Standard text color */
    font-family: var(--font-mono); /* Option 1: Monospace font */
    flex-grow: 1; /* Allow title to take center space */
    font-size: 3rem; /* Option 1: Original size */
}

#history-toggle-mobile {
    display: none; /* Hidden by default on desktop */
    padding: 0.5rem; /* Make it easier to tap */
    line-height: 1; /* Prevent extra spacing */
    /* width: 40px; Match spacer */
    /* Let button size naturally */
    height: 40px;
    font-size: 0.875rem; /* Match other buttons */
    justify-content: center;
    align-items: center;
}

#history-toggle-mobile span {
    /* font-size: 1.5rem; /* Adjust icon size */
}

.main-header .spacer { /* Style the spacer div explicitly */
    width: 60px; /* Adjust as needed based on button width */
    flex-shrink: 0;
}

/* Error Banner */
.error-banner {
        background-color: var(--error-bg);
        color: var(--error-fg);
        padding: 0.75rem 1rem;
        border: 1px solid var(--error-border);
        border-radius: 0.375rem; /* 6px */
        margin-bottom: 1rem;
        font-size: 0.875rem; /* 14px */
}

/* Shared Link Banner */
.shared-link-banner {
    background-color: #dbeafe; /* Light blue background */
    color: #1e40af; /* Dark blue text */
    padding: 0.75rem 1rem;
    border: 1px solid #93c5fd; /* Blue border */
    border-radius: 0.375rem;
    margin-bottom: 1rem;
    font-size: 0.875rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

@media (prefers-color-scheme: dark) {
    .shared-link-banner {
        background-color: #1e3a8a; /* Dark blue background for dark mode */
        color: #bfdbfe; /* Light blue text for dark mode */
        border-color: #3b82f6; /* Blue border for dark mode */
    }
}

.close-banner {
    background: none;
    border: none;
    font-size: 1.2rem;
    line-height: 1;
    color: inherit;
    cursor: pointer;
    padding: 0.25rem;
    opacity: 0.7;
    transition: opacity 0.2s;
}

.close-banner:hover {
    opacity: 1;
}

/* Main Content Panes */
#main-content {
    display: flex;
    flex-grow: 1;
    gap: 1.5rem;
    flex-wrap: wrap;
    min-height: 300px; /* Ensure panes don't collapse too small */
}

.pane {
    flex: 1 1 400px;
    border: 1px solid var(--border);
    border-radius: 0.5rem; /* 8px */
    background-color: var(--panel-bg);
    display: flex;
    flex-direction: column;
    position: relative; /* For copy button */
    overflow: hidden; /* Contain children */
}

.pane-header {
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.pane h2 {
    font-size: 1rem; /* 16px */
    font-weight: 500;
    margin: 0; /* Reset */
}

.stats-bar {
    font-size: 0.75rem; /* 12px */
    color: var(--fg-muted);
    display: flex;
    gap: 0.75rem;
}

.stats-bar span strong {
    color: var(--fg);
    font-weight: 500;
}

/* Link Controls */
.link-controls {
    padding: 0 1rem 0.5rem;
    display: flex;
    justify-content: flex-end;
}

.copy-link-button {
    padding: 0.3rem 0.6rem;
    font-size: 0.75rem;
    border: 1px solid var(--border);
    background-color: var(--button-bg);
    color: var(--fg-muted);
    border-radius: 0.25rem;
    cursor: pointer;
    transition: background-color 0.1s, color 0.1s;
    opacity: 0.8;
}

.copy-link-button:hover {
    opacity: 1;
    color: var(--fg);
    background-color: var(--button-hover-bg);
}

.copy-link-button.copied {
    background-color: var(--accent);
    color: var(--accent-fg);
    border-color: var(--accent);
    opacity: 1;
}

.pane .content {
    flex-grow: 1;
    padding: 1rem;
    display: flex; /* Use flex to make textarea grow */
    position: relative; /* For copy button positioning relative to content area */
}

.pane textarea {
    flex-grow: 1;
    width: 100%;
    border: none; /* Remove border, rely on pane border */
    border-radius: 0;
    font-family: var(--font-mono);
    font-size: 0.875rem; /* 14px */
    line-height: 1.5;
    resize: none;
    background-color: transparent; /* Inherit from pane */
    color: var(--fg);
    padding: 0; /* Padding applied to parent */
    height: 100%; /* Fill parent */
}

.pane textarea:focus {
    outline: none; /* Remove default focus outline */
}

/* Copy Button Refined */
.copy-button {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    padding: 0.25rem 0.5rem;
    font-size: 0.75rem;
    border: 1px solid var(--border);
    background-color: var(--button-bg);
    color: var(--fg-muted);
    border-radius: 0.25rem;
    cursor: pointer;
    opacity: 0;
    transition: opacity 0.2s ease-in-out, background-color 0.1s, color 0.1s;
    z-index: 5;
}

.pane .content:hover .copy-button,
.pane textarea:focus + .copy-button,
.copy-button:focus,
.copy-button:hover {
    opacity: 1;
    color: var(--fg);
    background-color: var(--button-hover-bg);
}

    .copy-button.copied {
        background-color: var(--accent);
        color: var(--accent-fg);
        border-color: var(--accent);
        opacity: 1;
    }

/* History Panel Styling */
#history-panel {
    padding: 1rem; /* Consistent padding */
}

#history-panel h2 {
    font-size: 1.125rem; /* 18px */
    text-align: left;
    margin-bottom: 1rem;
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border);
}

.action-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    padding: 0; /* Remove default padding */
    gap: 0.5rem;
}

/* Style buttons consistently */
button, .button {
    padding: 0.4rem 0.8rem;
    font-size: 0.8rem;
    border: 1px solid var(--border);
    background-color: var(--button-bg);
    color: var(--fg);
    border-radius: 0.375rem; /* 6px */
    cursor: pointer;
    transition: background-color 0.1s;
    white-space: nowrap;
}

button:hover, .button:hover {
    background-color: var(--button-hover-bg);
}

button:focus, .button:focus {
        outline: 2px solid transparent;
        outline-offset: 2px;
        box-shadow: 0 0 0 2px var(--accent);
}

.action-bar button {
    flex-shrink: 0; /* Prevent button shrinking */
}

.auto-save-indicator {
    font-size: 0.75rem;
    opacity: 0.8;
    color: var(--accent);
    text-align: right;
    flex-grow: 1; /* Allow indicator to take space */
}

.history-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.history-item {
    border-bottom: 1px solid var(--border);
    padding: 0.75rem 0.25rem;
    cursor: pointer;
    font-size: 0.8rem;
    border-radius: 0.25rem;
    transition: background-color 0.1s;
}

.history-item:hover {
    background-color: var(--input-bg); /* Use input background for hover */
}

.history-item:last-child {
    border-bottom: none;
}

.history-item .meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.7rem;
    color: var(--fg-muted);
    margin-bottom: 0.4rem;
}

.history-item .meta .source {
    font-weight: 500;
    background-color: var(--button-bg);
    padding: 0.1rem 0.3rem;
    border-radius: 0.2rem;
}

.history-item .preview {
    display: block;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    font-family: var(--font-mono);
    font-size: 0.75rem; /* Slightly smaller */
    line-height: 1.3;
    color: var(--fg-muted);
    max-width: 100%;
}

/* Responsive Overrides */
@media (max-width: 768px) {
    body {
        /* Optional: Prevent horizontal scroll if needed */
        /* overflow-x: hidden; */
    }
    #history-panel {
        z-index: 30; /* Higher z-index for overlay */
        transform: translateX(-100%); /* Hide off-screen */
        box-shadow: 4px 0 15px rgba(0,0,0,0.2); /* Stronger shadow for overlay */
    }
    #history-panel.history-visible {
        transform: translateX(0); /* Slide in */
    }

    main {
        margin-left: 0; /* Main content takes full width */
        padding: 1rem; /* Reduce padding on mobile */
    }

    #history-toggle-mobile {
        display: flex; /* Show mobile toggle button */
    }

    #main-content {
        gap: 1rem; /* Reduce gap between panes */
    }

    .pane {
        flex-basis: 100%; /* Stack panes vertically */
    }

    .main-header .spacer {
        width: auto; /* Allow spacer to adjust if needed */
    }

    .close-history-mobile {
        display: block; /* Show close button on mobile */
    }
}

.history-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    /* Uses history-panel padding */
    padding-bottom: 0.75rem;
    border-bottom: 1px solid var(--border);
    margin-bottom: 1rem; /* Consistent margin below header */
}

.close-history-mobile {
    display: none; /* Hidden by default on desktop */
    background: none;
    border: none;
    font-size: 1.75rem;
    padding: 0 0.5rem;
    line-height: 1;
    color: var(--fg-muted);
    cursor: pointer;
}

.close-history-mobile:hover {
    color: var(--fg);
}

.mobile-backdrop {
    position: fixed;
    inset: 0; /* Cover entire viewport */
    background-color: rgba(0, 0, 0, 0.5); /* Semi-transparent black */
    z-index: 25; /* Below history panel, above main */
    transition: opacity 0.3s ease-in-out;
    opacity: 1;
}