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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    min-height: 100vh;
    color: #e4e4e4;
    line-height: 1.6;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    padding: 2rem 1rem;
}

h1 {
    text-align: center;
    font-size: 1.8rem;
    margin-bottom: 0.5rem;
    color: #fff;
}

.subtitle {
    text-align: center;
    color: #888;
    margin-bottom: 2rem;
}

section {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

h2 {
    font-size: 1.1rem;
    color: #aaa;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.input-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
}

.input-group {
    display: flex;
    flex-direction: column;
}

.input-group label {
    font-size: 0.85rem;
    color: #ccc;
    margin-bottom: 0.3rem;
}

.input-group input {
    padding: 0.75rem;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    background: rgba(0, 0, 0, 0.3);
    color: #fff;
    font-size: 1.1rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.input-group input:focus {
    outline: none;
    border-color: #4a9eff;
    box-shadow: 0 0 0 3px rgba(74, 158, 255, 0.2);
}

.input-group input:invalid {
    border-color: #ff6b6b;
}

.hint {
    font-size: 0.75rem;
    color: #666;
    margin-top: 0.25rem;
}

.results-grid {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.result-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem 1rem;
    background: rgba(0, 0, 0, 0.2);
    border-radius: 8px;
    flex-wrap: wrap;
}

.result-label {
    color: #ccc;
    font-size: 0.95rem;
}

.result-value {
    font-size: 1.1rem;
    font-weight: 600;
    color: #4a9eff;
    font-family: 'SF Mono', 'Monaco', 'Consolas', monospace;
}

.result-row .hint {
    width: 100%;
    margin-top: 0.25rem;
}

.error {
    color: #ff6b6b;
    text-align: center;
    padding: 1rem;
    background: rgba(255, 107, 107, 0.1);
    border-radius: 8px;
    display: none;
}

.error.visible {
    display: block;
}

/* Distribution Chart */
.chart-container {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.chart {
    display: flex;
    align-items: flex-end;
    justify-content: center;
    gap: 4px;
    height: 180px;
    padding: 1rem 0.5rem;
    background: rgba(0, 0, 0, 0.2);
    border-radius: 8px;
}

.chart-bar {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-end;
    flex: 1;
    max-width: 60px;
    height: 100%;
}

.chart-bar-fill {
    width: 100%;
    border-radius: 4px 4px 0 0;
    transition: height 0.3s ease, background-color 0.3s ease;
    min-height: 2px;
}

.chart-bar-value {
    font-size: 0.7rem;
    color: #aaa;
    margin-bottom: 4px;
    font-family: 'SF Mono', 'Monaco', 'Consolas', monospace;
}

.chart-labels {
    display: flex;
    justify-content: center;
    gap: 4px;
    padding: 0 0.5rem;
}

.chart-label {
    flex: 1;
    max-width: 60px;
    text-align: center;
    font-size: 0.85rem;
    color: #888;
}

@media (max-width: 480px) {
    .input-grid {
        grid-template-columns: 1fr;
    }

    h1 {
        font-size: 1.5rem;
    }

    .container {
        padding: 1rem;
    }
}