* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

main {
    flex: 1;
    padding: 20px;
}

main.container {
    display: block;
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
    padding: 40px 20px;
    background-color: var(--primary-bg-color);
    border-radius: 12px;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
}

main h1 {
    color: var(--primary-text-color);
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-align: center;
}

main .subtitle {
    color: var(--secondary-text-color);
    text-align: center;
    margin-bottom: 30px;
    font-size: 1.1rem;
}

/* Mode Selector */
.mode-selector {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 30px;
}

.mode-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 30px;
    background: var(--input-bg-color);
    color: var(--primary-text-color);
    border: 2px solid var(--input-border-color);
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
}

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

.mode-btn.active {
    background: var(--button-bg-color);
    color: var(--button-text-color);
    border-color: var(--button-bg-color);
}

/* Tool Layout */
.tool-layout {
    margin-bottom: 40px;
}

.mode-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.input-panel,
.output-panel {
    background: var(--input-bg-color);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    display: flex;
    flex-direction: column;
    border: 1px solid var(--input-border-color);
}

.panel-header {
    background: var(--header-bg-color);
    padding: 15px 20px;
    border-bottom: 1px solid var(--input-border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.panel-header h3 {
    font-size: 1.1rem;
    color: var(--primary-text-color);
    font-weight: 600;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 10px;
}

.char-count {
    font-size: 0.85rem;
    color: var(--secondary-text-color);
}

.icon-btn {
    background: transparent;
    border: none;
    color: var(--button-bg-color);
    cursor: pointer;
    padding: 5px;
    display: flex;
    align-items: center;
    transition: all 0.2s;
}

.icon-btn:hover {
    color: var(--button-hover-bg-color);
    transform: scale(1.1);
}

/* Textareas */
textarea {
    flex: 1;
    width: 100%;
    min-height: 250px;
    padding: 20px;
    border: none;
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.95rem;
    line-height: 1.6;
    resize: vertical;
    background: var(--input-bg-color);
    color: var(--input-text-color);
}

textarea:focus {
    outline: none;
}

textarea[readonly] {
    background: var(--input-bg-color);
}

.panel-footer {
    padding: 15px 20px;
    background: var(--header-bg-color);
    border-top: 1px solid var(--input-border-color);
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    align-items: center;
}

.encoding-options {
    display: flex;
    gap: 15px;
    flex: 1;
}

.radio-label {
    display: flex;
    align-items: center;
    gap: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    color: var(--primary-text-color);
}

.radio-label input[type="radio"] {
    cursor: pointer;
}

.action-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    border: 1px solid var(--input-border-color);
    background: var(--input-bg-color);
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    color: var(--primary-text-color);
}

.action-btn:hover {
    background: var(--button-hover-bg-color);
    border-color: var(--button-bg-color);
    transform: translateY(-2px);
}

.action-btn.primary {
    background: var(--button-bg-color);
    color: var(--button-text-color);
    border: none;
}

.action-btn.primary:hover {
    background: var(--button-hover-bg-color);
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.feature-card {
    background: var(--input-bg-color);
    padding: 25px;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    border: 1px solid var(--input-border-color);
}

.feature-card svg {
    stroke: var(--button-bg-color);
    margin-bottom: 15px;
}

.feature-card h4 {
    color: var(--primary-text-color);
    font-size: 1.1rem;
    margin-bottom: 10px;
}

.feature-card p {
    color: var(--secondary-text-color);
    font-size: 0.9rem;
    line-height: 1.5;
}

/* Info Section */
.info-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.info-box {
    display: flex;
    gap: 12px;
    padding: 16px;
    background: var(--input-bg-color);
    border-radius: 12px;
    font-size: 0.9rem;
    color: var(--primary-text-color);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    border: 1px solid var(--input-border-color);
}

.info-box svg {
    flex-shrink: 0;
    stroke: var(--button-bg-color);
}

.info-box strong {
    color: var(--button-bg-color);
}

.info-box ul {
    margin: 10px 0;
    padding-left: 20px;
}

.info-box code {
    background: var(--header-bg-color);
    padding: 2px 6px;
    border-radius: 3px;
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.85rem;
}

.examples-box {
    padding: 20px;
    background: var(--input-bg-color);
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    border: 1px solid var(--input-border-color);
}

.examples-box h4 {
    color: var(--primary-text-color);
    margin-bottom: 15px;
}

.encoding-examples {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 10px;
}

.example-item {
    background: var(--header-bg-color);
    padding: 10px;
    border-radius: 6px;
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.85rem;
    color: var(--primary-text-color);
}

.example-item code {
    color: var(--button-bg-color);
}

/* Responsive Design */
@media (max-width: 1024px) {
    .mode-section {
        grid-template-columns: 1fr;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 600px) {
    main h1 {
        font-size: 2rem;
    }

    main .subtitle {
        font-size: 1rem;
    }

    .mode-selector {
        flex-direction: column;
    }

    .panel-footer {
        flex-direction: column;
        align-items: stretch;
    }

    .encoding-options {
        flex-direction: column;
    }

    .action-btn {
        width: 100%;
        justify-content: center;
    }

    .encoding-examples {
        grid-template-columns: 1fr 1fr;
    }
}