:root {
    /* Dark Theme Colors */
    --primary: #6366F1;
    --primary-hover: #4F46E5;
    --bg-color: #111827;
    --card-bg: #1F2937;
    --text-main: #F9FAFB;
    --text-muted: #9CA3AF;
    --input-bg: #374151;
    --input-border: #4B5563;
    --result-bg: #030712;

    /* Highlight Colors */
    --color-number: #F472B6; /* Pink */
    --color-symbol: #4ADE80; /* Light Green */
}

* {
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 20px;
}

.card {
    background: var(--card-bg);
    width: 100%;
    max-width: 400px;
    padding: 24px;
    border-radius: 16px;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.5);
}

h2 {
    text-align: center;
    margin-top: 0;
    margin-bottom: 24px;
    font-size: 1.5rem;
}

.result-container {
    background-color: var(--result-bg);
    border-radius: 8px;
    padding: 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    word-break: break-all;
    min-height: 60px;
    border: 1px solid var(--input-border);
}

#result {
    font-size: 1.25rem;
    font-weight: bold;
    letter-spacing: 2px;
    color: var(--primary);
}

/* Color classes for better readability */
.num { color: var(--color-number); }
.sym { color: var(--color-symbol); }

.btn-copy {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--primary);
    padding: 8px;
    border-radius: 8px;
    transition: background 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    margin-left: 10px;
}

.btn-copy:hover {
    background: rgba(99, 102, 241, 0.2);
}

.form-group {
    margin-bottom: 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.form-group label {
    font-size: 1rem;
    display: flex;
    flex-direction: column;
}

.form-group label span {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 4px;
}

input[type="number"] {
    width: 80px;
    padding: 8px;
    background-color: var(--input-bg);
    color: var(--text-main);
    border: 1px solid var(--input-border);
    border-radius: 8px;
    font-size: 1rem;
    text-align: center;
}

input[type="number"]:focus {
    outline: none;
    border-color: var(--primary);
}

input[type="checkbox"] {
    width: 20px;
    height: 20px;
    accent-color: var(--primary);
    cursor: pointer;
}

.btn-generate {
    width: 100%;
    padding: 16px;
    background-color: var(--primary);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: bold;
    cursor: pointer;
    margin-top: 16px;
    transition: background 0.2s;
}

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

#toast {
    visibility: hidden;
    min-width: 200px;
    background-color: #374151;
    color: #fff;
    text-align: center;
    border-radius: 8px;
    padding: 12px;
    position: fixed;
    z-index: 1;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 0.9rem;
    opacity: 0;
    transition: opacity 0.3s, visibility 0.3s;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
}

#toast.show {
    visibility: visible;
    opacity: 1;
}