:root {
        /* UI radius */
        --radius: 12px;
        /* Cyber Security Theme (Dark) */
        --primary: #00ff41; /* Terminal Green */
        --primary-dim: #008F11;
        --accent: #FFD700; /* System Gold */
        --alert: #ff003c; /* Critical Red */
        
        --bg-body: #020202;
        --bg-grid: #0a0a0a;
        --card-bg: rgba(5, 20, 10, 0.85); /* Darker, slightly transparent */
        --border-color: rgba(0, 255, 65, 0.3);
        
        --text-main: #ffffff;
        --text-highlight: #00ff41;
        --text-muted: #cccccc; /* Significantly brighter for visibility */
        
        --font-main: 'JetBrains Mono', monospace;
        --shadow-glow: 0 0 20px rgba(0, 255, 65, 0.2);

        /* Dynamic Component Backgrounds */
        --bg-panel: rgba(0, 0, 0, 0.3);
        --bg-input: rgba(0, 0, 0, 0.4);
        --bg-controls: rgba(255, 255, 255, 0.05);
        --bg-progress-track: rgba(255, 255, 255, 0.1);
        --bg-badge: rgba(125, 125, 125, 0.1);
        --bg-hover: rgba(255, 255, 255, 0.1);
        --bg-status: rgba(0, 255, 65, 0.1);
        --shadow-status: 0 0 5px rgba(0, 255, 65, 0.2);
        --focus-glow: rgba(0, 255, 65, 0.2);
        --text-shadow-brand: 0 0 10px rgba(255,255,255,0.3);
        --text-shadow-time: 0 0 10px rgba(255,255,255,0.2);
        --btn-active-text: #020202; /* readable text on bright active buttons in dark theme */
    }

    [data-theme="light"] {
        /* Clean Corporate (Light) */
        --primary: #0f172a; /* Dark Navy for high contrast */
        --primary-dim: #334155;
        --accent: #2563eb; /* Bright Blue */
        --alert: #dc2626;
        
        --bg-body: #cbd5e1; /* Slate 300 - Grey Background */
        --bg-grid: #94a3b8;
        --card-bg: #ffffff;
        --border-color: #94a3b8;
        
        --text-main: #020617; /* Almost Black */
        --text-highlight: #0f172a;
        --text-muted: #475569; /* Dark Slate */
        
        --shadow-glow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);

        /* Dynamic Component Backgrounds Light */
        --bg-panel: #f1f5f9; /* Light grey panel */
        --bg-input: #f8fafc;
        --bg-controls: #e2e8f0;
        --bg-progress-track: #cbd5e1;
        --bg-badge: #f1f5f9;
        --bg-hover: #cbd5e1;
        --bg-status: rgba(15, 23, 42, 0.05);
        --shadow-status: none;
        --focus-glow: rgba(37, 99, 235, 0.2);
        --text-shadow-brand: none;
        --text-shadow-time: none;
        --btn-active-text: #ffffff; /* white text for active buttons in light theme */
    }

    * { box-sizing: border-box; }

    body {
        margin: 0;
        background-color: var(--bg-body);
        color: var(--text-main);
        font-family: var(--font-main);
        overflow-x: hidden;
        min-height: 100vh;
        transition: all 0.3s ease;
    }

    /* Cyber Grid Background */
    body::before {
        content: "";
        position: fixed;
        top: 0; left: 0; width: 100%; height: 100%;
        background: 
            linear-gradient(var(--bg-grid) 1px, transparent 1px),
            linear-gradient(90deg, var(--bg-grid) 1px, transparent 1px);
        background-size: 50px 50px;
        z-index: -2;
        pointer-events: none;
        opacity: 0.15;
    }

    /* Vignette */
    body::after {
        content: "";
        position: fixed;
        top: 0; left: 0; width: 100%; height: 100%;
        background: radial-gradient(circle at center, transparent 0%, rgba(0,0,0,0.8) 100%);
        z-index: -1;
        pointer-events: none;
    }

    /* --- Layout --- */
    .container { max-width: 1200px; margin: 0 auto; padding: 24px 20px; }

    /* --- Header --- */
    header { 
        margin-bottom: 30px; 
        display: flex; 
        justify-content: space-between; 
        align-items: center; 
        flex-wrap: wrap; 
        gap: 15px; 
        border-bottom: 1px solid var(--border-color);
        padding-bottom: 15px;
        position: relative;
    }
    
    .brand h1 {
        margin: 0; 
        font-size: 2rem; 
        text-transform: uppercase;
        color: var(--text-main);
        text-shadow: var(--text-shadow-brand);
        letter-spacing: 2px;
        font-weight: 800;
    }

    .subtitle { 
        color: var(--text-highlight); 
        font-size: 0.9rem; 
        margin-top: 8px; 
        display: flex; align-items: center; gap: 10px;
        font-weight: 600;
        text-transform: uppercase;
        letter-spacing: 2px;
    }
    .status-dot { 
        width: 10px; height: 10px; 
        background: var(--primary); 
        border-radius: 50%; 
        box-shadow: 0 0 10px var(--primary); 
        animation: blink 2s infinite;
    }
    @keyframes blink { 0%, 100% { opacity: 1; transform: scale(1); } 50% { opacity: 0.5; transform: scale(0.8); } }

    /* --- Controls --- */
    .controls { display: flex; gap: 5px; background: var(--bg-controls); padding: 4px; border-radius: calc(var(--radius) / 1.8); border: 1px solid var(--border-color); }
    .hud-btn {
        background: transparent; 
        border: none; 
        color: var(--text-muted);
        padding: 8px 16px; 
        font-family: var(--font-main); 
        font-size: 0.8rem; 
        cursor: pointer;
        text-transform: uppercase;
        transition: all 0.2s;
        border-radius: calc(var(--radius) / 2);
        font-weight: 700;
        letter-spacing: 1px;
    }
    .hud-btn:hover { color: var(--text-main); background: var(--bg-hover); text-shadow: 0 0 5px white; }
    .hud-btn.active { 
        background: var(--primary);
        color: var(--btn-active-text);
        border: 1px solid var(--primary-dim);
        box-shadow: 0 6px 18px rgba(0,255,65,0.12);
    }

    /* Search Input */
    .search-wrapper {
        position: relative;
        flex-grow: 1;
        max-width: 600px;
        margin: 0 20px;
    }
    .search-input {
        width: 100%;
        background: var(--bg-input);
        border: 1px solid var(--border-color);
        padding: 12px 15px 12px 45px;
        color: var(--text-main);
        font-family: var(--font-main);
        font-size: 1rem;
        outline: none;
        border-radius: calc(var(--radius) / 1.8);
        transition: all 0.3s;
    }
    .search-input:focus { 
        border-color: var(--primary); 
        box-shadow: 0 0 15px var(--focus-glow); 
    }
    .search-input::placeholder { color: var(--text-muted); opacity: 0.7; }
    .search-icon {
        position: absolute; left: 15px; top: 50%; transform: translateY(-50%);
        color: var(--primary);
        font-size: 1.1rem;
    }

    /* Theme Toggle */
    .theme-toggle {
        background: transparent;
        border: 1px solid var(--border-color);
        color: var(--text-main);
        width: 40px; height: 40px;
        cursor: pointer;
        display: flex; align-items: center; justify-content: center;
        border-radius: calc(var(--radius) / 2);
        transition: all 0.2s;
    }
    .theme-toggle:hover { 
        color: var(--accent); 
        border-color: var(--accent); 
        box-shadow: 0 0 10px var(--accent);
    }

    /* --- Grid --- */
    .card-grid { 
        display: grid; 
        grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); 
        gap: 24px; 
    }

    /* --- Cyber Cards --- */
    .hud-card {
        position: relative;
        background: var(--card-bg);
        border: 1px solid var(--border-color);
        padding: 18px;
        box-shadow: var(--shadow-glow);
        transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
        border-radius: var(--radius);
        backdrop-filter: blur(5px);
        -webkit-backdrop-filter: blur(5px);
        overflow: hidden;
        display: flex;
        flex-direction: column;
        height: 100%;
    }
    
    .hud-card::before {
        content: '';
        position: absolute;
        top: 0; left: 0; width: 100%; height: 2px;
        background: linear-gradient(90deg, transparent, var(--primary), transparent);
        transform: translateX(-100%);
        transition: transform 0.5s;
    }

    .hud-card:hover { 
        transform: translateY(-3px);
        border-color: var(--primary);
        box-shadow: 0 0 22px rgba(0, 255, 65, 0.12); 
    }
    .hud-card:hover::before { transform: translateX(100%); }

    /* Card Typography */
    .paper-meta { 
        display: flex; justify-content: center; gap: 12px; align-items: center;
        margin-bottom: 10px; border-bottom: 1px solid var(--border-color); padding-bottom: 8px;
    }
    .paper-code { 
        font-size: 0.85rem; color: var(--accent); font-weight: 800; letter-spacing: 1px;
        text-shadow: 0 0 5px rgba(255, 215, 0, 0.3);
    }
    .paper-name { 
        font-size: 1.15rem; color: var(--text-main); margin: 12px 0; 
        text-transform: uppercase; letter-spacing: 0.28px; line-height: 1.25;
        font-weight: 700;
        text-align: center; /* Centered Title */
        min-height: 2.8em; 
        display: block;
        padding: 6px 8px;
        white-space: normal;
        word-spacing: 0.1ch;
        overflow-wrap: anywhere;
        word-break: break-word;
    }

    /* Ensure a small gap between the two title spans so words don't concatenate */
    .paper-name .title-left { display: inline-block; margin-right: 0.25ch; }
    .paper-name .title-right { display: inline-block; }

    /* Ensure titles wrap and resemble OOP multi-line style on small screens */
    @media (max-width: 480px) {
            .paper-name {
            font-size: 1rem;
            letter-spacing: 0.6px;
            line-height: 1.2;
            min-height: 3.6em;
            padding: 0 6px;
            white-space: normal;
            overflow-wrap: anywhere;
            word-break: break-word;
        }
        /* Constrain title width so long names wrap consistently like OOP on mobile */
        .paper-name {
            max-width: 82%;
            margin-left: auto;
            margin-right: auto;
        }
    }
    
    /* Timer Display */
    .timer-section {
        background: var(--bg-panel);
        border: 1px solid var(--border-color);
        padding: 14px;
        margin-bottom: 14px;
        border-radius: calc(var(--radius) * 0.9);
        position: relative;
    }

    .timer-display {
        display: grid; grid-template-columns: repeat(4, 1fr); gap: 5px; text-align: center;
    }
    
    .time-val { 
        font-size: 1.6rem; color: var(--text-main); display: block; font-weight: 800;
        text-shadow: var(--text-shadow-time);
    }
    .time-label { 
        font-size: 0.65rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: 1px; margin-top: 4px;
    }

    /* Progress Bar */
    .progress-container { 
        width: 100%; height: 6px; background: var(--bg-progress-track); margin-bottom: 12px; border-radius: calc(var(--radius) / 2); overflow: hidden;
    }
    .progress-bar { 
        height: 100%; background: var(--primary); width: 100%; 
        box-shadow: 0 0 15px var(--primary);
        transition: width 1s linear;
    }

    /* Footer Details */
    .details-row { 
        display: flex; justify-content: space-between;
        font-size: 0.85rem; color: var(--text-muted);
        font-weight: 500;
    }
    .details-row span { display: flex; align-items: center; gap: 8px; }
    .details-row i { color: var(--primary); }

    /* Status Colors */
    .status-urgent .time-val { color: var(--alert); text-shadow: 0 0 15px var(--alert); }
    .status-urgent .progress-bar { background: var(--alert); box-shadow: 0 0 15px var(--alert); }
    .status-urgent .status-badge { color: var(--alert); border-color: var(--alert); background: rgba(255, 0, 60, 0.1); box-shadow: 0 0 10px rgba(255,0,60,0.2); }

    .status-done .time-val { color: var(--text-muted); text-shadow: none; }
    .status-done .progress-bar { background: var(--text-muted); box-shadow: none; }
    .status-done .paper-name { text-decoration: line-through; opacity: 0.5; }

    /* Status Badge */
    .status-badge {
        font-size: 0.85rem; padding: 5px 10px;
        border: 1px solid var(--primary);
        color: var(--primary);
        background: var(--bg-status);
        text-transform: uppercase;
        border-radius: calc(var(--radius) / 2);
        font-weight: 700;
        letter-spacing: 1px;
        box-shadow: var(--shadow-status);
    }

    /* Detailed Schedule Table */
    .schedule-info {
        margin-top: 12px;
        border-top: 1px solid var(--border-color);
        padding-top: 10px;
        font-size: 0.75rem;
        margin-top: auto;
    }
    .schedule-row {
        display: flex; justify-content: space-between;
        margin-bottom: 4px;
        color: var(--text-muted);
        font-family: 'Inter', sans-serif;
        font-weight: 600;
    }
    .schedule-row span:last-child {
        color: var(--text-main);
        font-family: var(--font-main);
        text-align: right;
    }
    .meta-badge {
        display: inline-block;
        padding: 5px 8px;
        border: 1px solid var(--border-color);
        border-radius: calc(var(--radius) / 2);
        font-size: 0.75rem;
        font-weight: 600;
        color: var(--text-muted);
        background: var(--bg-badge);
    }

    .meta-info {
        margin-bottom: 12px; 
        font-size: 0.75rem; 
        color: var(--text-muted);
        display: flex;
        justify-content: center;
        align-items: center;
        gap: 10px;
        flex-wrap: wrap;
    }

    /* Subtle site credit (integrated, not a footer) */
    .site-credit {
        margin-top: 8px;
        text-align: center;
        font-size: 0.95rem;
        color: var(--text-muted);
        opacity: 0.98;
        letter-spacing: 0px;
        text-transform: uppercase;
        font-weight: 800;
        padding: 4px 0 6px 0;
        line-height: 1;
        transition: color 0.18s ease, opacity 0.18s ease, text-shadow 0.18s ease;
        text-shadow: var(--text-shadow-brand);
        display: inline-block;
    }

    /* Slightly increase contrast for the credit in dark theme */
    [data-theme="dark"] .site-credit {
        color: rgba(255,255,255,0.85);
        opacity: 0.9;
    }

    /* Ensure credit remains readable in light theme */
    [data-theme="light"] .site-credit {
        color: var(--text-muted);
        text-shadow: none;
        opacity: 0.95;
    }

    /* Copyright symbol styling - subtle outlined badge */
    /* Copyright symbol: plain glyph (no box) */
    .site-credit .site-symbol {
        display: inline-block;
        font-weight: 900;
        font-size: 1.3rem;
        margin-right: 2px; /* tightened gap between symbol and text */
        vertical-align: middle;
        line-height: 1;
        transition: color 0.12s ease, text-shadow 0.12s ease, transform 0.12s ease;
    }

    /* Dark theme: bright green glyph with subtle glow, credit text bright for contrast */
    [data-theme="dark"] .site-credit {
        color: rgba(255,255,255,0.92);
        text-shadow: none;
    }
    [data-theme="dark"] .site-credit .site-symbol {
        color: var(--primary);
        text-shadow: 0 6px 22px rgba(0,255,65,0.18);
    }

    /* Light theme: dark credit text and solid-symbol color for contrast */
    [data-theme="light"] .site-credit {
        color: var(--text-main);
        text-shadow: none;
    }
    [data-theme="light"] .site-credit .site-symbol {
        color: var(--primary-dim);
    }

    /* Slight lift on hover */
    .site-credit .site-symbol:hover { transform: translateY(-1px); }

    /* Footer container (visually integrated, not a separate band) */
    .site-footer {
        max-width: 1200px;
        margin: 6px auto 28px auto;
        padding: 0 20px;
        text-align: center;
        pointer-events: none; /* non-interactive */
    }

    .site-footer .site-credit { pointer-events: auto; }


    @media (max-width: 600px) {
        header { flex-direction: column; align-items: center; text-align: center; }
        .brand { display: flex; flex-direction: column; align-items: center; width: 100%; }
        .subtitle { justify-content: center; }
        .search-wrapper { margin: 15px 0; max-width: 100%; width: 100%; }
        .controls { justify-content: center; width: auto; }
        .brand h1 { font-size: 1.8rem; }
    }