:root {
    --bg-main: #181516;
    --bg-card: #231c1d;
    --bg-input: #312829;
    --accent: #d84552;
    --accent-hover: #b83742;
    --text-main: #f0f0f0;
    --text-muted: #9c9293;
    --border-color: #3b3031;
    --radius: 8px;
    --btn-text: #ffffff;
}

[data-theme="neon"] {
    --bg-main: #0d0d0d;
    --bg-card: #161616;
    --bg-input: #222222;
    --text-main: #ffffff;
    --text-muted: #a0a0a0;
    --accent: #c6ff00;
    --accent-hover: #a4d800;
    --border-color: #333333;
    --btn-text: #000000;
}

[data-theme="catppuccin-mocha"] {
    --bg-main: #1e1e2e;
    --bg-card: #181825;
    --bg-input: #313244;
    --text-main: #cdd6f4;
    --text-muted: #a6adc8;
    --accent: #cba6f7;
    --accent-hover: #b4befe;
    --border-color: #45475a;
}

[data-theme="catppuccin-latte"] {
    --bg-main: #eff1f5;
    --bg-card: #e6e9ef;
    --bg-input: #ccd0da;
    --text-main: #4c4f69;
    --text-muted: #6c6f85;
    --accent: #1e66f5;
    --accent-hover: #7287fd;
    --border-color: #bcc0cc;
}

[data-theme="github-dark"] {
    --bg-main: #0d1117;
    --bg-card: #161b22;
    --bg-input: #21262d;
    --text-main: #c9d1d9;
    --text-muted: #8b949e;
    --accent: #58a6ff;
    --accent-hover: #79c0ff;
    --border-color: #30363d;
}

[data-theme="github-light"] {
    --bg-main: #ffffff;
    --bg-card: #f6f8fa;
    --bg-input: #eaecef;
    --text-main: #24292e;
    --text-muted: #586069;
    --accent: #0969da;
    --accent-hover: #0366d6;
    --border-color: #d0d7de;
}

[data-theme="nord"] {
    --bg-main: #2e3440;
    --bg-card: #3b4252;
    --bg-input: #434c5e;
    --text-main: #d8dee9;
    --text-muted: #e5e9f0;
    --accent: #88c0d0;
    --accent-hover: #81a1c1;
    --border-color: #4c566a;
    --btn-text: #1a1a1a;
}



body {
    font-family: 'Bahnschrift', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-main);
    color: var(--text-main);
    margin: 0;
    padding: 0;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: var(--bg-card);
    padding: 15px 30px;
    border-bottom: 1px solid var(--border-color);
}

.logo {
    font-size: 1.2rem;
    font-weight: bold;
    color: var(--text-main);
}

.logo span {
    color: var(--accent);
}

.nav-links {
    display: flex;
    gap: 10px;
}

.nav-btn {
    background: transparent;
    border: none;
    color: var(--text-muted);
    font-size: 0.95rem;
    font-weight: 500;
    padding: 8px 16px;
    border-radius: var(--radius);
    cursor: pointer;
    transition: all 0.2s;
}

.nav-btn:hover {
    color: var(--text-main);
    background-color: rgba(255, 255, 255, 0.05);
}

.nav-btn.active {
    background-color: var(--accent);
    color: var(--btn-text);
}

main {
    padding: 40px 20px;
    display: flex;
    justify-content: center;
}

.view {
    width: 96%;
    max-width: 1800px;
}

.active-view {
    display: block;
}

.hidden-view {
    display: none !important;
}

.masonry-layout {
    display: flex;
    gap: 25px;
    width: 100%;
    align-items: flex-start;
}

.layout-col {
    display: flex;
    flex-direction: column;
    gap: 25px;
    flex: 1;
    min-width: 0;
}

@media (max-width: 850px) {
    .masonry-layout {
        flex-direction: column;
    }
}

h1 {
    text-align: center;
    color: var(--text-main);
    margin-bottom: 30px;
    font-weight: 600;
    letter-spacing: -0.5px;
    width: 100%;
}

.card {
    background-color: var(--bg-card);
    padding: 30px;
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
    box-sizing: border-box;
    width: 100%;
}

.converter-container, .quiz-container {
    background-color: var(--bg-card);
    padding: 30px;
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
    box-sizing: border-box;
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
}

h2 {
    color: var(--text-main);
    margin-top: 0;
    font-size: 1.2rem;
    font-weight: 600;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 10px;
    margin-bottom: 15px;
}

p {
    line-height: 1.6;
    color: var(--text-muted);
    font-size: 0.95rem;
}

.input-group, .setting-group {
    margin-bottom: 20px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-muted);
}

input[type="number"], input[type="text"], .code-area {
    width: 100%;
    padding: 12px 15px;
    background-color: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    color: var(--text-main);
    font-size: 1rem;
    box-sizing: border-box;
    transition: border-color 0.2s;
    font-family: 'Bahnschrift', -apple-system, sans-serif;
}

.code-area {
    resize: none;
    font-family: 'Bahnschrift', sans-serif;
    font-size: 1.1rem;
    color: var(--accent);
}

input[type="number"]:focus, input[type="text"]:focus, .code-area:focus {
    outline: none;
    border-color: var(--accent);
}

.radio-group {
    display: flex;
    gap: 15px;
    margin-top: 10px;
}

.radio-group input[type="radio"] {
    display: none;
}

.radio-label {
    flex: 1;
    padding: 12px;
    background-color: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    text-align: center;
    color: var(--text-muted);
    cursor: pointer;
    transition: all 0.2s;
    text-transform: none;
    letter-spacing: normal;
    font-weight: 600;
    margin: 0;
}

.radio-group input[type="radio"]:checked + .radio-label {
    background-color: var(--accent);
    color: var(--btn-text);
    border-color: var(--accent);
}

.cb-container {
    display: flex;
    gap: 10px;
    margin-top: 10px;
}

.custom-cb {
    flex: 1;
}

.cb-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 55px;
    font-size: 0.9rem;
    font-weight: bold;
    background-color: var(--bg-input);
    color: var(--text-muted);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    cursor: pointer;
    transition: all 0.2s;
    box-sizing: border-box;
    text-transform: none;
    letter-spacing: normal;
    margin: 0;
}

.cb-btn:hover {
    border-color: var(--text-muted);
}

input[type="checkbox"]:checked + .cb-btn {
    background-color: var(--accent);
    color: var(--btn-text);
    border-color: var(--accent);
}

.warning-text {
    color: var(--accent);
    font-size: 0.85rem;
    margin: 5px 0 0 0;
    min-height: 20px;
    font-weight: 600;
}

.action-buttons {
    display: flex;
    gap: 10px;
    margin-top: 15px;
}

.primary-btn {
    flex: 1;
    padding: 12px;
    background-color: var(--accent);
    color: var(--btn-text);
    border: none;
    border-radius: var(--radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s;
}

.primary-btn:hover {
    background-color: var(--accent-hover);
}

.primary-btn:disabled {
    background-color: var(--bg-input);
    color: var(--text-muted);
    cursor: not-allowed;
}

.secondary-btn {
    flex: 1;
    padding: 12px;
    background-color: var(--bg-input);
    color: var(--text-main);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.secondary-btn:hover:not(:disabled) {
    background-color: var(--border-color);
}

.secondary-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.help-box {
    background: var(--bg-main);
    padding: 15px;
    border-radius: var(--radius);
    margin-top: 15px;
    border: 1px solid var(--border-color);
    border-left: 4px solid var(--accent);
}

.help-divider {
    border-top: 1px solid var(--border-color);
    margin: 12px 0;
}

.hex-table, .bin-table {
    display: flex;
    justify-content: space-around;
    font-weight: bold;
    font-size: 1rem;
}

.bin-table {
    color: var(--accent);
}

.hex-table {
    font-family: 'Bahnschrift', sans-serif;
    color: var(--text-main);
}

#quizFeedback {
    text-align: center;
    font-weight: bold;
    margin-top: 20px;
    margin-bottom: 5px;
    min-height: 24px;
}

.explanation-text {
    text-align: center;
    font-size: 0.95rem;
    color: var(--text-muted);
    margin-top: 0;
    min-height: 48px;
}

.bit-container {
    display: flex;
    justify-content: space-between;
    margin-top: 20px;
    background: var(--bg-main);
    padding: 20px 15px;
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
}

.nibble-wrapper {
    display: flex;
    gap: 15px;
    margin-top: 15px;
}

.nibble-section {
    flex: 1;
    background: var(--bg-main);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 15px;
}

.nibble-container {
    margin-top: 0;
    padding: 0;
    border: none;
    background: transparent;
}

.bit-box {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.bit-label {
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-muted);
}

.bit-btn, .hex-bit-btn {
    width: 45px;
    height: 55px;
    font-size: 1.5rem;
    font-weight: bold;
    background-color: var(--bg-input);
    color: var(--text-muted);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    cursor: pointer;
    transition: all 0.2s;
}

.bit-btn:hover, .hex-bit-btn:hover {
    border-color: var(--text-muted);
}

.bit-btn.active-bit, .hex-bit-btn.active-bit {
    background-color: var(--accent);
    color: var(--btn-text);
    border-color: var(--accent);
}

.bit-total {
    text-align: center;
    font-size: 1.2rem;
    margin-top: 20px;
    font-weight: bold;
    color: var(--text-main);
}

.nibble-result {
    text-align: center;
    font-weight: bold;
    font-size: 1.1rem;
    margin-top: 15px;
    color: var(--text-main);
}

.nibble-result span {
    color: var(--accent);
}

.ascii-table-container {
    max-height: 400px;
    overflow-y: auto;
    margin-top: 15px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
}

.ascii-table {
    width: 100%;
    border-collapse: collapse;
    text-align: center;
    font-size: 0.9rem;
}

.ascii-table th {
    background-color: var(--bg-input);
    color: var(--text-muted);
    padding: 10px;
    position: sticky;
    top: 0;
    z-index: 1;
    border-bottom: 2px solid var(--border-color);
}

.ascii-table td {
    padding: 8px;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-main);
    font-family: 'Bahnschrift', sans-serif;
}

.ascii-table tr:hover {
    background-color: rgba(255, 255, 255, 0.05);
}

.ascii-table td:last-child {
    color: var(--accent);
    font-weight: bold;
    font-size: 1rem;
}

input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}
input[type=number] {
    -moz-appearance: textfield;
}

@media (max-width: 600px) {
    nav {
        flex-direction: column;
        gap: 15px;
        padding: 15px;
    }
    .nav-links {
        flex-wrap: wrap;
        justify-content: center;
        width: 100%;
    }
    .nav-btn {
        flex: 1 1 calc(50% - 10px);
        text-align: center;
    }
    main {
        padding: 20px 10px;
    }
    .card, .converter-container, .quiz-container {
        padding: 20px 15px;
    }
    .bit-container {
        flex-wrap: wrap;
        justify-content: center;
        gap: 10px;
    }
    .nibble-wrapper {
        flex-direction: column;
    }
    .nibble-section {
        width: 100%;
        box-sizing: border-box;
    }
    .nibble-container {
        flex-wrap: nowrap;
        justify-content: space-between;
    }
    .bit-btn, .hex-bit-btn {
        width: 35px;
        height: 45px;
        font-size: 1.2rem;
    }
    .radio-group {
        flex-direction: column;
    }
    .cb-container {
        flex-direction: column;
    }
}