:root {
    --primary-color: #4a90e2;
    --background-color: #f0f2f5;
    --container-bg: #ffffff;
    --text-color: #333333;
    --white: #ffffff;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --slider-bg: #ccc;
}

[data-theme="dark"] {
    --background-color: #1a1a1a;
    --container-bg: #2d2d2d;
    --text-color: #f0f2f5;
    --shadow-color: rgba(0, 0, 0, 0.5);
    --slider-bg: #4a90e2;
}

body {
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, sans-serif;
    background-color: var(--background-color);
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    background-color: var(--container-bg);
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 10px 30px var(--shadow-color);
    text-align: center;
    width: 100%;
    max-width: 500px;
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

h1 {
    color: var(--text-color);
    margin-bottom: 30px;
    font-size: 2em;
}

.numbers-container {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-bottom: 40px;
    flex-wrap: wrap;
    min-height: 60px;
}

.number-ball {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    color: white;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.4em;
    font-weight: bold;
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
    animation: bounceIn 0.5s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

@keyframes bounceIn {
    0% { transform: scale(0.1); opacity: 0; }
    60% { transform: scale(1.2); }
    100% { transform: scale(1); opacity: 1; }
}

#generate-btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 16px 32px;
    border-radius: 12px;
    font-size: 1.1em;
    font-weight: bold;
    cursor: pointer;
    transition: transform 0.2s, background-color 0.3s;
    box-shadow: 0 4px 15px rgba(74, 144, 226, 0.3);
}

#generate-btn:hover {
    transform: translateY(-2px);
    filter: brightness(1.1);
}

#generate-btn:active {
    transform: translateY(0);
}

/* 테마 스위치 스타일 */
.theme-switch-wrapper {
    position: fixed;
    top: 20px;
    right: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-color);
}

.theme-switch {
    display: inline-block;
    height: 26px;
    position: relative;
    width: 50px;
}

.theme-switch input {
    display: none;
}

.slider {
    background-color: var(--slider-bg);
    bottom: 0;
    cursor: pointer;
    left: 0;
    position: absolute;
    right: 0;
    top: 0;
    transition: .4s;
    border-radius: 34px;
}

.slider:before {
    background-color: #fff;
    bottom: 4px;
    content: "";
    height: 18px;
    left: 4px;
    position: absolute;
    transition: .4s;
    width: 18px;
    border-radius: 50%;
}

input:checked + .slider:before {
    transform: translateX(24px);
}

/* 공 색상 */
.color-1 { background: linear-gradient(135deg, #f6d365 0%, #fda085 100%); }
.color-2 { background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%); }
.color-3 { background: linear-gradient(135deg, #5ee7df 0%, #b490ca 100%); }
.color-4 { background: linear-gradient(135deg, #a1c4fd 0%, #c2e9fb 100%); }
.color-5 { background: linear-gradient(135deg, #84fab0 0%, #8fd3f4 100%); }
.color-6 { background: linear-gradient(135deg, #ff9a9e 0%, #fecfef 100%); }