/* Core CSS Tokens & Theme Variables */
:root {
    --bg-base: #0f1115;
    --bg-surface: #171a21;
    
    /* Blue Theme Palette */
    --blue-main: #4da1f8;
    --blue-dark: #2b62aa;
    --blue-highlight: #b1fdfe;
    --blue-hover: #6db1f9;
    --blue-glow: rgba(77, 161, 248, 0.5);
    --blue-highlight-glow: rgba(177, 253, 254, 0.6);
    --blue-bg-glow: rgba(77, 161, 248, 0.08);
    --blue-surface-glow: rgba(77, 161, 248, 0.02);
    --blue-border-glow: rgba(77, 161, 248, 0.25);
    --blue-text-hud: #b1fdfe;

    /* Red/Amber Theme Palette */
    --red-main: #e53e3e;
    --red-dark: #9b2c2c;
    --red-highlight: #dd6b20;
    --red-hover: #fc8181;
    --red-glow: rgba(229, 62, 62, 0.5);
    --red-highlight-glow: rgba(221, 107, 32, 0.4);
    --red-bg-glow: rgba(229, 62, 62, 0.08);
    --red-surface-glow: rgba(229, 62, 62, 0.02);
    --red-border-glow: rgba(229, 62, 62, 0.25);
    --red-text-hud: #ff6b6b;

    --border-color: #2b303c;
    --text-primary: #f7fafc;
    --text-muted: #a0aec0;

    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
    --font-mono: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
    --font-display: 'Orbitron', sans-serif;
}

/* ==========================================================================
    Theme selection
   ========================================================================== */
:root { --accent-main: var(--blue-main); --accent-dark: var(--blue-dark); --accent-highlight: var(--blue-highlight); --accent-hover: var(--blue-hover); --accent-glow: var(--blue-glow); --accent-highlight-glow: var(--blue-highlight-glow); --accent-bg-glow: var(--blue-bg-glow); --bg-surface-glow: var(--blue-surface-glow); --border-glow: var(--blue-border-glow); --text-hud: var(--blue-text-hud); }
/* :root { --accent-main: var(--red-main); --accent-dark: var(--red-dark); --accent-highlight: var(--red-highlight); --accent-hover: var(--red-hover); --accent-glow: var(--red-glow); --accent-highlight-glow: var(--red-highlight-glow); --accent-bg-glow: var(--red-bg-glow); --bg-surface-glow: var(--red-surface-glow); --border-glow: var(--red-border-glow); --text-hud: var(--red-text-hud); } */

/* Dynamic Theme Override */
:root[data-theme="red"] {
    --accent-main: var(--red-main);
    --accent-dark: var(--red-dark);
    --accent-highlight: var(--red-highlight);
    --accent-hover: var(--red-hover);
    --accent-glow: var(--red-glow);
    --accent-highlight-glow: var(--red-highlight-glow);
    --accent-bg-glow: var(--red-bg-glow);
    --bg-surface-glow: var(--red-surface-glow);
    --border-glow: var(--red-border-glow);
    --text-hud: var(--red-text-hud);
}

/* Global Reset & Base Styles */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--bg-base);
    color: var(--text-primary);
    font-family: var(--font-sans);
    line-height: 1.5;
    background-image: 
        radial-gradient(circle at 50% 0%, var(--accent-bg-glow) 0%, transparent 60%),
        linear-gradient(rgba(15, 17, 21, 0.97), rgba(15, 17, 21, 0.97)),
        repeating-linear-gradient(0deg, rgba(0, 0, 0, 0.15) 0px, rgba(0, 0, 0, 0.15) 1px, transparent 1px, transparent 2px);
    background-size: 100% 100%, 100% 100%, 100% 2px;
    min-height: 100vh;
    padding: 20px;
    display: flex;
    justify-content: center;
}

.app-container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
}

header {
    text-align: center;
    margin-bottom: 30px;
    border-bottom: 2px solid var(--accent-main);
    padding-bottom: 15px;
    box-shadow: 0 4px 10px -5px var(--border-glow);
}

header h1 {
    font-family: var(--font-display);
    font-size: 2.8rem;
    font-weight: 900;
    letter-spacing: 4px;
    margin-bottom: 5px;
}

.glow-text {
    color: var(--text-primary);
    text-shadow: 
        0 0 10px var(--accent-glow),
        0 0 20px var(--accent-glow);
    animation: textPulse 4s infinite alternate;
}

.subtitle {
    font-family: var(--font-display);
    color: var(--text-muted);
    font-size: 0.9rem;
    letter-spacing: 8px;
    font-weight: 600;
}

/* Layout Grid */
.grid-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    align-items: start;
}

@media (max-width: 900px) {
    .grid-container {
        grid-template-columns: 1fr;
    }
}

/* Card Styling (HUD panels) */
.card {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 24px;
    box-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.7);
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-main), var(--accent-highlight));
}

.card:hover {
    border-color: var(--border-glow);
    box-shadow: 
        0 15px 35px -10px rgba(0, 0, 0, 0.8),
        0 0 15px var(--bg-surface-glow);
}

.card-header {
    margin-bottom: 20px;
}

.card-header h2 {
    font-family: var(--font-display);
    font-size: 1.1rem;
    letter-spacing: 2px;
    color: var(--text-primary);
    text-transform: uppercase;
    font-weight: 800;
    border-left: 3px solid var(--accent-main);
    padding-left: 10px;
}

.divider {
    height: 1px;
    background: linear-gradient(90deg, var(--border-color) 0%, rgba(43, 48, 60, 0.2) 100%);
    margin: 25px 0;
}

/* Forms & Fields */
.control-group h3 {
    font-family: var(--font-display);
    font-size: 0.9rem;
    letter-spacing: 1px;
    color: var(--text-muted);
    margin-bottom: 15px;
    text-transform: uppercase;
}

.row {
    display: flex;
    gap: 20px;
    margin-bottom: 15px;
}

.row:last-child {
    margin-bottom: 0;
}

.field {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

label {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
    display: flex;
    justify-content: space-between;
}

.hud-num {
    color: var(--text-hud);
    font-family: var(--font-display);
    font-size: 0.85rem;
}

select {
    background-color: var(--bg-base);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    padding: 10px 14px;
    border-radius: 4px;
    font-size: 0.9rem;
    font-weight: 500;
    outline: none;
    transition: border-color 0.2s;
    cursor: pointer;
}

select:focus {
    border-color: var(--accent-main);
}

/* Custom Range Sliders */
input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 6px;
    background: var(--border-color);
    border-radius: 3px;
    outline: none;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--accent-main);
    box-shadow: 0 0 6px var(--accent-glow);
    cursor: pointer;
    transition: transform 0.1s, background-color 0.1s;
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    background: var(--accent-hover);
}

/* Checkbox Grid */
.checkbox-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
    gap: 12px;
}

.checkbox-container {
    display: flex;
    align-items: center;
    position: relative;
    padding-left: 28px;
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-primary);
    user-select: none;
    height: 22px;
}

.checkbox-container input {
    position: absolute;
    opacity: 0;
    cursor: pointer;
    height: 0;
    width: 0;
}

.checkmark {
    position: absolute;
    top: 2px;
    left: 0;
    height: 18px;
    width: 18px;
    background-color: var(--bg-base);
    border: 1px solid var(--border-color);
    border-radius: 3px;
    transition: all 0.2s;
}

.checkbox-container:hover input ~ .checkmark {
    border-color: var(--accent-main);
}

.checkbox-container input:checked ~ .checkmark {
    background-color: var(--accent-main);
    border-color: var(--accent-main);
    box-shadow: 0 0 8px var(--accent-glow);
}

.checkmark::after {
    content: "";
    position: absolute;
    display: none;
}

.checkbox-container input:checked ~ .checkmark::after {
    display: block;
}

.checkbox-container .checkmark::after {
    left: 6px;
    top: 2px;
    width: 4px;
    height: 8px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

.checkbox-container.disabled {
    cursor: not-allowed;
    opacity: 0.5;
}

.glow-box {
    border: 1px dashed var(--border-color);
    padding: 12px 16px 12px 38px;
    border-radius: 6px;
    background-color: var(--bg-surface-glow);
    width: 100%;
    height: auto;
}

.glow-box:hover {
    border-color: var(--border-glow);
}

.glow-box .checkmark {
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
}

/* Ammo Grid */
.ammo-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px 25px;
}

@media (max-width: 500px) {
    .ammo-grid {
        grid-template-columns: 1fr;
    }
}

/* Output Panel Elements */
.output-panel {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.passcode-card {
    text-align: center;
}

.passcode-container {
    background-color: var(--bg-base);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 30px 8px;
    margin: 20px 0;
    box-shadow: inset 0 2px 10px rgba(0,0,0,0.8);
    position: relative;
}

.passcode-container::before {
    content: "CRITICAL STORAGE DATA";
    position: absolute;
    top: 5px;
    left: 10px;
    font-size: 0.6rem;
    font-family: var(--font-display);
    letter-spacing: 2px;
    color: var(--text-muted);
    font-weight: bold;
}

.passcode-text {
    font-family: var(--font-display);
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--text-hud);
    letter-spacing: 1px;
    text-shadow: 0 0 10px var(--border-glow);
}

.hud-btn {
    width: 100%;
    background-color: var(--accent-main);
    color: var(--text-primary);
    border: none;
    font-family: var(--font-display);
    font-weight: 800;
    font-size: 0.95rem;
    letter-spacing: 2px;
    padding: 15px 20px;
    border-radius: 4px;
    cursor: pointer;
    box-shadow: 0 4px 15px var(--accent-glow);
    transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
    outline: none;
}

.hud-btn:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px var(--accent-glow);
}

.hud-btn:active {
    transform: translateY(0);
}

.hud-btn.success {
    background-color: #38a169;
    box-shadow: 0 4px 15px rgba(56, 161, 105, 0.5);
}

/* Diagnostics HUD */
.diagnostics-content {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.diag-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px dashed #20242e;
    padding-bottom: 8px;
}

.diag-row:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.diag-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    font-weight: 600;
    letter-spacing: 1px;
}

.diag-value {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--text-primary);
}

.diag-value.monospace {
    word-break: keep-all;
    text-align: right;
    max-width: 70%;
    line-height: 1.4;
}

/* Animations */
@keyframes textPulse {
    from {
        text-shadow: 0 0 10px var(--accent-glow), 0 0 20px var(--accent-glow);
    }
    to {
        text-shadow: 0 0 15px var(--accent-glow), 0 0 30px var(--accent-glow);
    }
}

/* Decrypt HUD Panel */
.decrypt-input-container {
    display: flex;
    flex-direction: column;
    gap: 10px;
    align-items: center;
}

.decrypt-textbox {
    width: 100%;
    background-color: var(--bg-base);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 12px 15px;
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 600;
    text-align: center;
    letter-spacing: 2px;
    outline: none;
    text-transform: uppercase;
    transition: all 0.2s;
}

.decrypt-textbox::placeholder {
    color: #4a5568;
    font-size: 0.85rem;
    letter-spacing: 1px;
}

.decrypt-textbox:focus {
    border-color: var(--accent-main);
    box-shadow: 0 0 10px var(--border-glow);
}

.feedback-msg {
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 1px;
    text-transform: uppercase;
    text-align: center;
    min-height: 18px;
}

.feedback-msg.error {
    color: #e53e3e;
}

.feedback-msg.success {
    color: #38a169;
}

.feedback-msg.warning {
    color: #dd6b20;
}

/* Out of Bounds fields validation warning states */
.field.out-of-bounds select {
    border-color: #e53e3e !important;
    box-shadow: 
        0 0 12px rgba(229, 62, 62, 0.7),
        0 0 4px rgba(229, 62, 62, 0.4) !important;
}

.field.out-of-bounds input[type="range"] {
    background: rgba(229, 62, 62, 0.3) !important;
    box-shadow: 0 0 10px rgba(229, 62, 62, 0.4) !important;
}

.field.out-of-bounds label span.hud-num {
    color: #e53e3e !important;
    text-shadow: 
        0 0 6px rgba(229, 62, 62, 0.9),
        0 0 12px rgba(229, 62, 62, 0.6) !important;
}

/* Documentation & Info Card */
.info-card {
    margin-top: 30px;
}

.info-content section {
    margin-bottom: 20px;
}

.info-content section:last-child {
    margin-bottom: 0;
}

.info-content h3 {
    font-family: var(--font-display);
    font-size: 0.95rem;
    letter-spacing: 1.5px;
    color: var(--text-primary);
    margin-bottom: 12px;
    text-transform: uppercase;
}

.info-content p {
    font-size: 0.9rem;
    line-height: 1.65;
    color: var(--text-muted);
    margin-bottom: 14px;
}

.info-content p:last-child {
    margin-bottom: 0;
}

.info-content strong {
    color: var(--text-primary);
}

.info-content em {
    color: var(--accent-hover);
    font-style: normal;
}

.info-content ul {
    list-style: none;
    padding-left: 0;
    margin-bottom: 16px;
}

.info-content ul li {
    font-size: 0.88rem;
    line-height: 1.6;
    color: var(--text-muted);
    position: relative;
    padding-left: 20px;
    margin-bottom: 8px;
}

.info-content ul li::before {
    content: '►';
    position: absolute;
    left: 0;
    top: 0;
    color: var(--accent-main);
    font-size: 0.65rem;
    line-height: 1.6;
}

.info-content code {
    font-family: var(--font-mono);
    font-size: 0.82rem;
    background-color: var(--bg-base);
    color: var(--accent-hover);
    padding: 2px 6px;
    border-radius: 4px;
    border: 1px solid var(--border-color);
}

.info-content a {
    color: var(--accent-hover);
    text-decoration: none;
    border-bottom: 1px dashed var(--accent-main);
    transition: all 0.2s;
}

.info-content a:hover {
    color: var(--text-primary);
    border-bottom-style: solid;
    text-shadow: 0 0 8px var(--accent-glow);
}

/* Payload Bit Table */
.payload-table {
    width: 100%;
    max-width: 440px;
    border-collapse: collapse;
    margin: 18px 0;
    font-size: 0.88rem;
    background-color: var(--bg-base);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    overflow: hidden;
}

.payload-table th {
    font-family: var(--font-display);
    font-size: 0.8rem;
    letter-spacing: 1.5px;
    text-transform: uppercase;
    color: var(--text-primary);
    background-color: rgba(43, 48, 60, 0.4);
    border-bottom: 2px solid var(--accent-main);
    padding: 10px 16px;
    text-align: left;
}

.payload-table td {
    padding: 8px 16px;
    border-bottom: 1px solid rgba(43, 48, 60, 0.4);
    color: var(--text-muted);
}

.payload-table tr:last-child td {
    border-bottom: none;
}

.payload-table tr:hover {
    background-color: var(--bg-surface-glow);
}

.payload-table .bit-range {
    font-family: var(--font-mono);
    font-weight: 700;
    color: var(--accent-hover);
    width: 120px;
}

.payload-table .text-dim {
    color: #4a5568;
}

/* Footer HUD Style */
footer {
    text-align: center;
    margin-top: 40px;
    padding: 15px 0;
    border-top: 1px dashed var(--border-color);
}

footer p {
    font-family: var(--font-display);
    font-size: 0.75rem;
    letter-spacing: 2px;
    color: var(--text-muted);
}

.easter-egg-brand {
    cursor: pointer;
    user-select: none;
    transition: color 0.2s, text-shadow 0.2s;
}

.easter-egg-brand:hover {
    color: var(--accent-highlight);
    text-shadow: 0 0 8px var(--accent-highlight-glow);
}