:root {
    /* Base Variables */
    --font-ui: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-mono: "Fira Code", "SFMono-Regular", Consolas, "Liberation Mono", Menlo, Courier, monospace;

    /* LIGHT MODE: Linux Terminal Style (Solarized Light inspired) */
    --bg-color: #fdf6e3;
    --text-color: #657b83;
    --header-bg: #eee8d5;
    --header-text: #586e75;
    --panel-bg: #fdf6e3;
    --panel-header-bg: #eee8d5;
    --panel-header-border: #93a1a1;
    --line-num-bg: #eee8d5;
    --line-num-text: #93a1a1;
    --line-num-border: #93a1a1;
    --editor-text: #586e75;
    --output-bg: #002b36; /* Dark terminal for output contrast */
    --output-text: #839496;
    --button-bg: #2aa198;
    --button-hover: #268bd2;
    --scroll-track: transparent;
    --scroll-thumb: #93a1a1;
    --scroll-thumb-hover: #586e75;

    --selection-bg: rgba(38, 139, 210, 0.3); /* Solarized Blue with opacity */

    /* Syntax Highlighting Colors (Light/Solarized) */
    --token-keyword: #859900; /* Green */
    --token-builtin: #268bd2; /* Blue */
    --token-string: #2aa198; /* Cyan */
    --token-number: #d33682; /* Magenta */
    --token-comment: #93a1a1; /* Grey */
    --token-operator: #b58900; /* Yellow */
    --token-type: #6c71c4; /* Violet */

    /* Terminal Specifics (Light Mode) */
    --term-font: "Courier New", Courier, monospace;
    --term-success: #859900;
    --term-error: #dc322f;
    --term-info: #268bd2;
    --term-input: #b58900;
}

[data-theme="dark"] {
    /* DARK MODE: Cyberpunk (Neon / Dark) */
    --bg-color: #0b0c15; /* Deep dark blue/black */
    --text-color: #e0e6ed;
    --header-bg: #12141d;
    --panel-bg: #12141d;
    --panel-header-bg: #1a1c29;
    --panel-header-border: #ff0055; /* Neon Pink Border */
    --line-num-bg: #0b0c15;
    --line-num-text: #565b70;
    --line-num-border: #2a2d3e;
    --editor-text: #e0e6ed;
    --output-bg: #050505; /* Pitch black terminal */
    --output-text: #00ff9f; /* Cyber Green */
    --button-bg: #ff0055; /* Neon Pink */
    --button-hover: #ff2a75;
    --scroll-thumb: #ff0055;
    --scroll-thumb-hover: #ff2a75;

    --selection-bg: rgba(255, 0, 85, 0.3); /* Neon Pink with opacity */

    /* Syntax Highlighting Colors (Cyberpunk) */
    --token-keyword: #ff0055; /* Pink */
    --token-builtin: #00f3ff; /* Cyan */
    --token-string: #ffee00; /* Yellow */
    --token-number: #bd00ff; /* Purple */
    --token-comment: #565b70; /* Muted Blue */
    --token-operator: #00ff9f; /* Green */
    --token-type: #00f3ff;

    /* Terminal Specifics (Dark Mode) */
    --term-font: "Courier New", Courier, monospace;
    --term-success: #00ff9f;
    --term-error: #ff0055;
    --term-info: #00f3ff;
    --term-input: #ffee00;
}

body { font-family: var(--font-ui); margin: 0; background-color: var(--bg-color); color: var(--text-color); display: flex; flex-direction: column; height: 100vh; overflow: hidden; transition: background-color 0.3s, color 0.3s; }
header {
    background-color: var(--header-bg);
    color: var(--header-text);
    padding: 0.75rem 1rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
    position: relative;
    border-bottom: 2px solid var(--panel-header-border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
    flex-shrink: 0;
}
h1 { margin: 0; font-size: 1.5rem; text-transform: uppercase; letter-spacing: 2px; }
main { flex: 1; display: flex; flex-direction: column; padding: 1rem; gap: 0.5rem; overflow: hidden; }
.container { display: flex; flex-direction: column; flex: 1; gap: 0.5rem; min-height: 0; overflow: hidden; }
.editor-container { flex: 1; display: flex; flex-direction: column; background-color: var(--panel-bg); border-radius: 4px; box-shadow: 0 0 10px rgba(0,0,0,0.5); overflow: hidden; transition: background-color 0.3s; border: 1px solid var(--panel-header-border); min-height: 200px; }
.output-container { height: 25vh; flex: none; display: flex; flex-direction: column; background-color: var(--panel-bg); border-radius: 4px; box-shadow: 0 0 10px rgba(0,0,0,0.5); overflow: hidden; transition: height 0.3s ease-out, background-color 0.3s; border: 1px solid var(--panel-header-border); min-height: 150px; }
.output-container.expanded { height: 50vh; }
.panel-header { padding: 0.5rem 1rem; background-color: var(--panel-header-bg); border-bottom: 1px solid var(--panel-header-border); font-weight: 600; display: flex; justify-content: space-between; align-items: center; text-transform: uppercase; font-size: 0.8rem; letter-spacing: 1px; color: var(--text-color); cursor: pointer; user-select: none; }
#example-selector { padding: 0.25rem 0.5rem; border-radius: 0; border: 1px solid var(--text-color); font-size: 0.85rem; background-color: var(--bg-color); color: var(--text-color); font-family: var(--font-mono); cursor: pointer;}
.editor-wrapper { display: flex; flex: 1; position: relative; overflow: hidden; }
#line-numbers { width: 40px; padding: 1rem 0.5rem; text-align: right; background-color: var(--line-num-bg); color: var(--line-num-text); border-right: 1px solid var(--line-num-border); font-family: var(--font-mono); font-size: 0.9rem; line-height: 1.5; user-select: none; overflow: hidden; transition: background-color 0.3s, color 0.3s, border-color 0.3s; }

/* Code Editor Area with Highlighting */
.code-area { position: relative; flex: 1; display: flex; overflow: hidden; }

textarea, pre {
    margin: 0;
    padding: 1rem;
    border: none;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    line-height: 1.5;
    vertical-align: top;
}

/* Ensure code inside pre inherits perfectly */
pre code {
    font-family: inherit;
    font-size: inherit;
    line-height: inherit;
    padding: 0;
    margin: 0;
    white-space: pre;
}

/* The highlighting pre element is behind */
#highlighting {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none; /* Let clicks pass through */
    z-index: 1;
    background-color: var(--panel-bg);
    color: var(--editor-text);
    overflow: auto; /* Match textarea scrolling */
    box-sizing: border-box; /* Important for padding match */
    white-space: pre; /* Should match textarea */
}

/* The textarea is transparent and on top */
#code-editor {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 2;
    background-color: transparent;
    color: transparent; /* Text is hidden, only caret visible */
    caret-color: var(--text-color); /* Caret color matches text */
    overflow: auto;
    box-sizing: border-box;
    white-space: pre;
    resize: none;
    outline: none;
}

#code-editor::selection {
    background-color: var(--selection-bg);
    color: transparent;
}

/* Terminal Styles */
#terminal-window {
    flex: 1;
    background-color: var(--output-bg);
    color: var(--output-text);
    padding: 1rem;
    font-family: var(--term-font);
    font-size: 0.9rem;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
}

#terminal-output { flex: 1; white-space: pre-wrap; word-wrap: break-word; }
#terminal-input-line { display: flex; align-items: center; margin-top: 5px; border-top: 1px dashed var(--line-num-border); padding-top: 5px; }
#terminal-prompt { color: var(--term-success); margin-right: 8px; font-weight: bold; }
#terminal-input { flex: 1; background: transparent; border: none; color: var(--term-input); font-family: var(--term-font); font-size: 1rem; outline: none; caret-color: var(--term-input); }

.term-info { color: var(--term-info); font-style: italic; opacity: 0.8; margin-bottom: 5px; }
.term-error { color: var(--term-error); font-weight: bold; margin-top: 5px; }
.term-success { color: var(--term-success); margin-top: 5px; }
.term-input-echo { color: var(--term-input); opacity: 0.7; }
.term-output { color: var(--output-text); }


button { background-color: var(--button-bg); color: white; border: none; padding: 0.5rem 1rem; cursor: pointer; font-size: 0.9rem; font-weight: bold; transition: all 0.2s; text-transform: uppercase; letter-spacing: 1px; border-radius: 4px; display: inline-flex; align-items: center; justify-content: center; gap: 0.5rem; }
button:hover { background-color: var(--button-hover); transform: translateY(-1px); box-shadow: 0 2px 5px rgba(0,0,0,0.2); }

.controls { display: flex; justify-content: space-between; align-items: center; gap: 1rem; flex-shrink: 0; padding: 0 0.5rem; }
.secondary-controls { display: flex; gap: 0.5rem; }

#run-button { padding: 0.5rem 1.5rem; font-size: 1rem; clip-path: polygon(10% 0, 100% 0, 100% 90%, 90% 100%, 0 100%, 0 10%); border-radius: 0; }
#save-button, #clear-button { background-color: var(--panel-header-border); color: var(--bg-color); }
#save-button:hover, #clear-button:hover { background-color: var(--text-color); }

/* Syntax Highlighting Tokens */
.token-keyword { color: var(--token-keyword); font-weight: bold; }
.token-builtin { color: var(--token-builtin); }
.token-string { color: var(--token-string); }
.token-number { color: var(--token-number); }
.token-comment { color: var(--token-comment); font-style: italic; }
.token-operator { color: var(--token-operator); }
.token-type { color: var(--token-type); }

/* Theme Toggle Button */
#theme-toggle {
    background: transparent;
    border: 1px solid var(--text-color);
    color: var(--text-color);
    padding: 0.5rem;
    font-size: 0.8rem;
    margin: 0;
    position: static; /* Removed absolute positioning */
    transform: none;
    opacity: 0.8;
    clip-path: none;
    border-radius: 4px;
}
#theme-toggle:hover { background: rgba(255,255,255,0.1); opacity: 1; color: var(--button-bg); border-color: var(--button-bg); }

footer { text-align: center; padding: 1rem; color: var(--line-num-text); font-size: 0.8rem; }
@media (max-width: 800px) {
    body { height: auto; overflow-y: auto; }
    main { overflow: visible; }
    .container { flex-direction: column; height: auto; overflow: visible; }
    .editor-container { height: 60vh; min-height: 400px; flex: none; }
    .output-container { height: auto; min-height: 300px; flex: none; }
}

/* Home Link Base Style */
.home-link {
    color: inherit;
    text-decoration: none;
    font-size: 1.2rem;
    border: 1px solid currentColor;
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
    display: inline-block;
}

@media (max-width: 600px) {
    /* Mobile Optimization for Buttons and Controls */
    button {
        padding: 0.4rem 0.8rem;
        font-size: 0.75rem;
        letter-spacing: 0.5px;
    }

    .controls {
        gap: 0.5rem;
        flex-wrap: wrap; /* Allow wrapping if needed on very small screens */
        justify-content: center; /* Center controls if wrapped */
    }

    #run-button {
        padding: 0.4rem 1rem;
        font-size: 0.8rem;
        width: 100%; /* Make run button full width on small screens for easier tapping */
        margin-bottom: 0.5rem;
    }

    .secondary-controls {
        width: 100%;
        justify-content: space-between;
    }

    .secondary-controls button {
        flex: 1; /* Distribute space evenly */
    }

    /* Header adjustments */
    header {
        padding: 0.5rem;
        gap: 0.5rem;
    }

    h1 {
        font-size: 1rem;
        width: 100%;
        text-align: center;
        order: -1; /* Move title to top if wrapping occurs */
    }

    #theme-toggle, .home-link {
        padding: 0.3rem 0.6rem;
        font-size: 0.75rem;
    }
}

@media (max-width: 500px) {
    h1 { font-size: 1.1rem; }
    /* header padding already handled in 600px block, but keeping this doesn't hurt */
}

/* Error line highlighting */
.error-line {
    background-color: rgba(255, 0, 85, 0.2);
    border-right: 3px solid var(--term-error) !important;
}

/* Scrollbars */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--scroll-track); }
::-webkit-scrollbar-thumb { background: var(--scroll-thumb); border-radius: 5px; }
::-webkit-scrollbar-thumb:hover { background: var(--scroll-thumb-hover); }