:root {
    --bg-body: #f7f7f8;
    --bg-card: #ffffff;
    --text-main: #202123;
    --text-muted: #6e6e80;
    --border-color: #d9d9e3;
    --input-bg: #ffffff;
    --btn-bg: #202123;
    --btn-hover: #343541;
    --radius-sm: 6px;
    --radius-md: 12px;
}

body, html {
    margin: 0;
    padding: 0;
    height: 100vh;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
    background-color: var(--bg-body); 
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-main);
}

.container {
    background: var(--bg-card);
    width: 460px;
    max-width: 90vw;
    padding: 40px;
    border-radius: var(--radius-md);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.02), 0 10px 15px rgba(0, 0, 0, 0.03);
    border: 1px solid rgba(0, 0, 0, 0.05);
    box-sizing: border-box;
    text-align: center;
}

h1 {
    font-size: 2.2rem;
    font-weight: 600;
    margin: 0 0 8px 0;
    letter-spacing: -0.5px;
    color: var(--text-main); 
}

p.subtitle {
    font-size: 0.95rem;
    margin: 0 0 30px 0;
    color: var(--text-muted);
}

.tabs {
    display: flex;
    background: #f3f3f3;
    padding: 4px;
    border-radius: 8px;
    margin-bottom: 24px;
}

.tab-btn {
    flex: 1;
    padding: 10px 0;
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-muted);
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.2s ease;
    font-family: inherit;
}

.tab-btn.active {
    background: var(--bg-card);
    color: var(--text-main);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.panel {
    display: none;
    min-height: 220px; 
    width: 100%;
    flex-direction: column;
    animation: fadeIn 0.3s ease-in-out;
}

.panel.active {
    display: flex;
}

.panel-content {
    flex: 1; 
    display: flex;
    flex-direction: column;
    text-align: left;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(5px); }
    to { opacity: 1; transform: translateY(0); }
}

.input-group {
    margin-bottom: 1.2rem;
}

.input-hint {
    display: block;
    font-size: 0.82rem;
    color: var(--text-muted);
    margin-top: 20px;
    line-height: 1.5;
    white-space: nowrap;
    letter-spacing: -0.2px;
}

input[type="text"] {
    width: 100%;
    padding: 14px 16px;
    font-family: inherit;
    font-size: 1rem;
    color: var(--text-main);
    background-color: var(--input-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    box-sizing: border-box;
    outline: none;
    transition: border-color 0.2s ease;
}

input[type="text"]::placeholder { color: #acacbe; }

input[type="text"]:focus {
    border-color: var(--text-main);
    box-shadow: 0 0 0 1px var(--text-main);
}

.radio-group {
    display: flex;
    flex-direction: row;
    gap: 60px;
    margin-bottom: 1.5rem;
}

.radio-group label {
    display: flex;
    align-items: center;
    font-size: 0.95rem;
    cursor: pointer;
    color: var(--text-main);
}

.radio-group input[type="radio"] {
    margin: 0 10px 0 0;
    width: 16px;
    height: 16px;
    accent-color: var(--text-main);
    cursor: pointer;
}

.btn-submit {
    width: 100%;
    background: var(--btn-bg);
    color: white;
    border: none;
    padding: 14px;
    font-size: 1rem;
    font-weight: 500;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-family: inherit;
    transition: background-color 0.2s ease;
    margin-top: auto; 
}

.btn-submit:hover {
    background: var(--btn-hover);
}

#output {
    background: #202123;
    color: #ececf1;
    padding: 1rem;
    border-radius: var(--radius-sm);
    margin-top: 1.5rem;
    font-family: Consolas, Monaco, monospace;
    font-size: 0.85rem;
    line-height: 1.5;
    white-space: pre-wrap;
    word-wrap: break-word;
    max-height: 150px;
    overflow-y: auto;
    display: none;
    text-align: left;
}

#output::-webkit-scrollbar { width: 6px; }
#output::-webkit-scrollbar-track { background: #202123; border-radius: 8px; }
#output::-webkit-scrollbar-thumb { background: #565869; border-radius: 8px; }