:root {
    /* Light Theme (Original) - Kept for reference or future theme switcher */
    --light-bg-primary: #f0f4f8;
    --light-bg-secondary: #fff;
    --light-text-primary: #333;
    --light-text-secondary: #2c3e50;
    --light-accent-primary: #007bff;
    --light-accent-hover: #0056b3;
    --light-border-color: #ccc;
    --light-input-bg: #fff;
    --light-input-text: #333;
    --light-button-bg: #3498db;
    --light-button-text: #ffffff;
    --light-button-hover-bg: #2980b9;
    --light-shadow-color: rgba(0, 0, 0, 0.1);
    --light-output-strong-color: #C0392B;
    --light-green-accent: #006400;
    --light-special-button-bg: #3A7BC2;
    --light-special-button-hover-bg: #2c6aa0;
    --light-decrypt-button-bg: #f44336;
    --light-decrypt-button-hover-bg: #e53935;

    /* Hacker Theme Palette (Dark) */
    --dark-bg-primary: #0f0f0f;
    --dark-bg-secondary: #1a1a1a;
    --dark-text-primary: #00ff99; /* Bright mint green */
    --dark-text-secondary: #00b36b; /* Dimmer green */
    --dark-accent-primary: #00cc7a; /* Accent green */
    --dark-accent-hover: #00995c;  /* Darker accent green for hover */
    --dark-border-color: #2a2a2a;
    --dark-input-bg: #1a1a1a;      /* Same as secondary bg */
    --dark-input-text: var(--dark-text-primary); /* Bright green text in inputs */
    --dark-button-bg: var(--dark-accent-primary);
    --dark-button-text: #0f0f0f; /* Very dark text for green buttons */
    --dark-button-hover-bg: var(--dark-accent-hover);
    --dark-shadow-color: rgba(0, 128, 85, 0.15); /* Subtle green shadow */
    --dark-output-strong-color: #ff6b6b; /* Contrasting red/pink */
    --dark-green-accent: var(--dark-text-primary); /* Use primary text for this specific green */
    --dark-special-button-bg: var(--dark-accent-primary);
    --dark-special-button-hover-bg: var(--dark-accent-hover);
    --dark-decrypt-button-bg: #c0392b; /* Keep a distinct warning/error red */
    --dark-decrypt-button-hover-bg: #a93226;
}

/* General Styles */
*,
*::before,
*::after {
    box-sizing: border-box;
}

#matrix-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1; /* Keep it in the background */
    /* Fallback background color if JS fails or for initial load */
    background-color: #0f0f0f;
}

body {
    font-family: 'Fira Code', 'Courier New', monospace; /* Updated font stack */
    background-color: transparent; /* Canvas will draw the background */
    color: var(--dark-text-primary);
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    border-radius: 8px;
    padding-top: 50px;
    line-height: 1.6;
}

/* .cipher-title class removed as it's no longer used */

.container {
    background-color: var(--dark-bg-secondary);
    border-radius: 10px;
    box-shadow: 0 4px 12px var(--dark-shadow-color); /* Enhanced shadow */
    padding: 40px;
    max-width: 800px;
    width: 100%;
    margin: 20px auto;
    border: 1px solid var(--dark-border-color); /* Added border for container */
}

h1, h2, h3 {
    font-weight: 600;
    color: var(--dark-text-primary);
    text-align: center;
    margin-top: 1.5em;
    margin-bottom: 0.75em;
    line-height: 1.2;
}

h1 {
    font-size: 2.5rem;
    margin-top: 0;
    color: var(--dark-accent-primary); /* Make H1 stand out */
}

h2 {
    font-size: 2rem;
}

h3 {
    font-size: 1.5rem;
}

p, label {
    font-size: 1rem;
    line-height: 1.6;
    margin-bottom: 0.5em;
    color: var(--dark-text-secondary);
}

label {
    font-weight: bold;
    margin-top: 10px;
    display: block;
    color: var(--dark-text-primary);
}

input[type="number"], input[type="text"], textarea, select {
    padding: 10px;
    font-size: 1rem;
    border-radius: 5px;
    background-color: var(--dark-input-bg);
    color: var(--dark-input-text);
    border: 1px solid var(--dark-border-color);
    margin-bottom: 10px;
    box-sizing: border-box;
    width: 100%;
    box-shadow: inset 0 1px 3px var(--dark-shadow-color); /* Inner shadow for inputs */
    transition: border-color 0.2s, box-shadow 0.2s;
    margin: 10px 0;
}

input[type="number"]:focus, input[type="text"]:focus, textarea:focus, select:focus {
    outline: none;
    border-color: var(--dark-accent-primary);
    box-shadow: 0 0 8px var(--dark-accent-primary), inset 0 1px 3px var(--dark-shadow-color);
}

textarea {
    resize: none;
}

button {
    background-color: var(--dark-button-bg);
    color: var(--dark-button-text);
    border: 1px solid var(--dark-button-bg);
    padding: 10px 20px;
    font-size: 1.1rem;
    border-radius: 5px;
    cursor: pointer;
    margin-top: 20px;
    width: 100%;
    font-weight: bold;
    transition: background-color 0.2s, transform 0.2s ease-out, box-shadow 0.2s ease-out, border-color 0.2s;
}

button:hover {
    background-color: var(--dark-button-hover-bg);
    border-color: var(--dark-button-hover-bg);
    transform: scale(1.03); /* Slightly reduced hover scale */
    box-shadow: 0 6px 12px var(--dark-shadow-color); /* Enhanced hover shadow */
}

button:active {
    transform: scale(0.97); /* Slightly reduced active scale */
    box-shadow: 0 2px 4px var(--dark-shadow-color);
}

button.decrypt-btn {
    background-color: var(--dark-decrypt-button-bg);
    border-color: var(--dark-decrypt-button-bg);
}

button.decrypt-btn:hover {
    background-color: var(--dark-decrypt-button-hover-bg);
    border-color: var(--dark-decrypt-button-hover-bg);
}

.expand-btn, .collapsible { /* Grouping similar special buttons */
    background-color: var(--dark-special-button-bg);
    border-color: var(--dark-special-button-bg);
}

.expand-btn:hover, .collapsible:hover {
    background-color: var(--dark-special-button-hover-bg);
    border-color: var(--dark-special-button-hover-bg);
}

/* Animation for general page content sections */
.content-fade-in {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInRise 0.6s ease-out forwards;
    animation-delay: 0.2s; /* Optional delay */
}

@keyframes fadeInRise {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Animation for dynamically loaded result sections */
.result-fade-in { /* Renamed from .fade-in for clarity */
    opacity: 0; /* Ensure initial state is set if class is added dynamically */
    animation: fadeInAnimation 0.5s ease-in-out forwards;
}

@keyframes fadeInAnimation { /* Kept if different, or could use fadeInRise too */
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.compact-button {
    width: auto;
    padding: 8px 12px;
    margin: 5px 1%;
}

.output {
    background-color: var(--dark-input-bg); /* Consistent with other input/data display areas */
    padding: 15px;
    border-radius: 5px;
    border-left: 5px solid var(--dark-accent-primary);
    margin-top: 20px;
    /* font-family will be inherited from body */
    line-height: 1.6;
    color: var(--dark-text-primary);
    border: 1px solid var(--dark-border-color);
    box-shadow: 0 2px 8px var(--dark-shadow-color);
    opacity: 0; /* Prepare for fade-in */
}

.output strong {
    color: var(--dark-output-strong-color);
}

hr {
    border: 0;
    border-top: 1px solid var(--dark-border-color);
    margin: 20px 0;
}

.matrix-cell {
    padding: 10px;
    font-size: 1rem;
    width: 60px; /* Increased from 50px for better touch target / visual */
    height: 50px; /* Increased from 40px */
    /* margin: 2px; /* Replaced by grid gap */
    text-align: center;
    border-radius: 5px;
    background-color: var(--dark-input-bg);
    color: var(--dark-input-text);
    border: 1px solid var(--dark-border-color);
    /* display: inline-block; /* No longer needed with CSS Grid */
    /* margin-bottom: 10px; /* Grid gap will handle spacing */
    /* margin: 2px; /* Replaced by grid-gap */
    transition: border-color 0.2s, box-shadow 0.2s, background-color 0.2s;
}

.matrix-cell:focus {
    outline: none;
    border-color: var(--dark-accent-primary);
    box-shadow: 0 0 8px var(--dark-accent-primary);
    background-color: var(--dark-bg-secondary);
}

#matrix-inputs { /* This is also .matrix-container */
    display: grid;
    grid-template-columns: repeat(var(--matrix-size, 3), 45px); /* Default to 3 if var not set */
    gap: 8px; /* Updated gap, preferred over cell margins */
    justify-content: center; /* Center the grid if narrower than container */
    margin-bottom: 20px; /* Consolidating margin from .matrix-container */
    /* Removed flex properties, text-align for child inputs (handled by cells) */
}

/* Redundant #matrix-inputs input and @media query can be removed if not needed for other purposes */
/* For now, keeping them but commenting out content of @media if it's flex specific */
#matrix-inputs input {
    text-align: center; /* This is fine, though .matrix-cell also has it */
}

@media (min-width: 768px) {
    #matrix-inputs {
        /* Flex-specific rules removed/commented if they were here */
        /* Grid layout might not need specific changes here unless column count changes */
    }
}

/* .matrix-container rule can be effectively merged into #matrix-inputs as they are the same element */
/* Removing the separate .matrix-container rule to avoid confusion if its properties are now in #matrix-inputs */


.result-section {
    background-color: var(--dark-input-bg);
    border: 1px solid var(--dark-border-color);
    border-radius: 4px;
    padding: 15px;
    margin-top: 20px;
    text-align: center;
    opacity: 0; /* Prepare for fade-in */
    color: var(--dark-text-primary);
}

.result-section h2 {
    color: var(--dark-accent-primary);
    margin-top: 0;
}

.collapse-section {
    margin-top: 20px;
}

.tables-container {
    display: flex;
    justify-content: space-between;
    margin-top: 20px;
}

.table-wrapper {
    width: 48%;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 10px;
}

th, td {
    border: 1px solid var(--dark-border-color);
    padding: 10px;
    text-align: center;
    background-color: var(--dark-input-bg);
    color: var(--dark-text-primary);
}

th { /* Table headers distinct */
    background-color: var(--dark-bg-secondary);
    color: var(--dark-accent-primary);
    font-weight: bold;
}

.collapse-content {
    padding: 15px;
    display: none;
    overflow: hidden;
    background-color: var(--dark-bg-secondary);
    border-radius: 5px;
    margin-top: 10px;
    border: 1px solid var(--dark-border-color);
}

.matrix, .ciphertext, .digraphs {
    /* font-family will be inherited from body */
    white-space: pre;
    background-color: var(--dark-input-bg);
    color: var(--dark-text-primary);
    padding: 10px;
    border: 1px solid var(--dark-border-color);
    border-radius: 4px;
    display: inline-block;
    margin-top: 10px;
}

.result-box {
    background-color: var(--dark-input-bg);
    border: 1px solid var(--dark-border-color);
    border-radius: 4px;
    padding: 15px;
    margin-top: 20px;
    opacity: 0; /* Prepare for fade-in */
    color: var(--dark-text-primary);
}

.ciphertext {
    font-weight: bold;
    color: var(--dark-green-accent);
    margin-top: 10px;
    /* font-family will be inherited */
}

.rail {
    /* font-family will be inherited */
    white-space: pre;
    margin-bottom: 5px;
    color: var(--dark-text-secondary);
}

/* Responsiveness - keeping the most encompassing ones from original Hii.css */
@media (max-width: 768px) {
    .container {
        padding: 20px;
    }

    input[type="number"], input[type="text"], textarea, select, button {
        font-size: 0.9rem;
    }

    h1 {
        font-size: 2rem;
    }
    h2 {
        font-size: 1.75rem;
    }
    h3 {
        font-size: 1.25rem;
    }
    .tables-container {
        flex-direction: column;
    }
    .table-wrapper {
        width: 100%;
        margin-bottom: 15px;
    }
}

@media (max-width: 500px) {
    h1 {
        font-size: 1.75rem;
    }
    h2 {
        font-size: 1.5rem;
    }
    h3 {
        font-size: 1.15rem;
    }
    input[type="number"], input[type="text"], textarea, select {
        width: 100%;
    }

    button {
        font-size: 1rem;
        padding: 15px;
    }
    .compact-button {
        width: 100%; /* Make compact buttons full width on small mobile */
        margin: 5px 0;
    }
}

/* Hill Cipher Page Specific Layout */
.hill-main-wrapper {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    padding: 0 20px 20px 20px;
}

.hill-section {
    background-color: var(--dark-bg-secondary); /* Should match .container or be distinct if preferred */
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px var(--dark-shadow-color);
    width: 100%;
    border: 1px solid var(--dark-border-color);
}

.hill-section h3 {
    margin-top: 0;
    margin-bottom: 15px;
    color: var(--dark-accent-primary);
    font-size: 1.3rem; /* Specific font size for section titles */
}
.hill-section h2 { /* For the output section title */
    margin-top: 0;
    margin-bottom: 15px;
    color: var(--dark-accent-primary);
    font-size: 1.3rem; /* Consistent with h3 in other sections */
}

.hill-config-section {
    flex: 1 1 100%;
}

.hill-plaintext-section,
.hill-ciphertext-section {
    flex: 1 1 calc(50% - 10px); /* Each takes half minus gap */
    min-width: 280px; /* Ensure they don't get too squished */
}

.hill-actions-section {
    flex-basis: 100%;
    text-align: center;
}

.hill-actions-section button {
    margin: 5px 10px; /* More horizontal margin */
    width: auto;
    padding: 10px 25px; /* More padding for primary actions */
}

.hill-output-section {
    flex-basis: 100%;
}

/* Responsive adjustments for Hill layout */
@media (max-width: 767px) { /* Max for typical mobile portrait */
    .hill-plaintext-section,
    .hill-ciphertext-section {
        flex: 1 1 100%; /* Stack them on smaller screens */
    }
}

/* Styling for matrix inputs (div#matrix-inputs) already has some styles */
/* Ensure .matrix-container (which is #matrix-inputs) specific styles are good */
.matrix-container { /* This is #matrix-inputs */
    justify-content: flex-start; /* Align cells to the left */
    gap: 8px; /* Slightly larger gap for matrix cells */
}
/* .matrix-cell styles are defined earlier, this is an override/adjustment for Hill Cipher page context */
.matrix-cell {
    width: 45px;    /* New width */
    height: 45px;   /* New height - same as width */
    padding: 5px;   /* Reduced padding for more input space */
    line-height: normal; /* Ensure text is centered vertically */
    /* font-size, margin, text-align, border-radius, border, background-color, color, box-sizing, display, transition
       are inherited from the earlier .matrix-cell rule or global styles */
}