:root {
    --bg-color: #f4f4f9;
    --container-bg: #ffffff;
    --text-color: #333333;
    --primary-color: #4a90e2;
    --btn-hover: #357abd;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

body.dark-mode {
    --bg-color: #1a1a1a;
    --container-bg: #2d2d2d;
    --text-color: #f0f0f0;
    --primary-color: #61afef;
    --btn-hover: #4b89c3;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.5);
}

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

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

.container {
    background-color: var(--container-bg);
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow);
    text-align: center;
    max-width: 600px;
    width: 95%;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.logo-area {
    text-align: left;
}

.subtitle {
    font-size: 0.85rem;
    opacity: 0.8;
    margin-top: 0.3rem;
}

.site-nav {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-bottom: 2rem;
    padding: 0.8rem;
    background-color: rgba(0,0,0,0.02);
    border-radius: 0.5rem;
}

body.dark-mode .site-nav {
    background-color: rgba(255,255,255,0.05);
}

.site-nav a {
    text-decoration: none;
    color: var(--text-color);
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.2s;
}

.site-nav a:hover {
    color: var(--primary-color);
}

.info-section {
    margin-top: 3rem;
    text-align: left;
    line-height: 1.6;
}

.info-section h2 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--primary-color);
    display: inline-block;
}

.info-section p {
    font-size: 1rem;
    opacity: 0.9;
}

.tip-card {
    background-color: rgba(0,0,0,0.02);
    padding: 1.2rem;
    border-radius: 0.8rem;
    margin-bottom: 1rem;
}

body.dark-mode .tip-card {
    background-color: rgba(255,255,255,0.05);
}

.tip-card h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.tip-card p {
    font-size: 0.9rem;
}

h1 {
    font-size: 1.5rem;
}

.theme-btn {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 0.5rem;
    background-color: var(--primary-color);
    color: white;
    cursor: pointer;
    font-size: 0.9rem;
    transition: opacity 0.2s;
}

.theme-btn:hover {
    opacity: 0.9;
}

.numbers-container {
    display: flex;
    flex-direction: column;
    gap: 15px;
    min-height: 80px;
    margin-bottom: 2rem;
}

.number-row {
    display: flex;
    justify-content: center;
    gap: 10px;
    padding: 10px;
    background-color: rgba(0,0,0,0.03);
    border-radius: 0.5rem;
}

body.dark-mode .number-row {
    background-color: rgba(255,255,255,0.05);
}

.ball {
    width: 45px;
    height: 45px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: bold;
    font-size: 1.1rem;
    color: white;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
    animation: bounce 0.5s ease;
}

/* Lotto Ball Colors */
.ball-1 { background-color: #fbc400; } /* 1-10: Yellow */
.ball-2 { background-color: #69c8f2; } /* 11-20: Blue */
.ball-3 { background-color: #ff7272; } /* 21-30: Red */
.ball-4 { background-color: #aaa; }    /* 31-40: Gray */
.ball-5 { background-color: #b0d840; } /* 41-45: Green */

@keyframes bounce {
    0% { transform: scale(0); }
    70% { transform: scale(1.1); }
    100% { transform: scale(1); }
}

.placeholder {
    color: #888;
    font-style: italic;
}

.generate-btn {
    width: 100%;
    padding: 1rem;
    font-size: 1.1rem;
    font-weight: bold;
    border: none;
    border-radius: 0.5rem;
    background-color: var(--primary-color);
    color: white;
    cursor: pointer;
    transition: background-color 0.2s;
}

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

.partnership-section {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid rgba(0,0,0,0.1);
    text-align: left;
}

body.dark-mode .partnership-section {
    border-top-color: rgba(255,255,255,0.1);
}

.partnership-section h2 {
    font-size: 1.2rem;
    margin-bottom: 1.5rem;
    text-align: center;
}

.partnership-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-size: 0.9rem;
    font-weight: bold;
}

.form-group input, 
.form-group textarea {
    padding: 0.8rem;
    border: 1px solid #ccc;
    border-radius: 0.5rem;
    background-color: var(--container-bg);
    color: var(--text-color);
    font-family: inherit;
}

body.dark-mode .form-group input,
body.dark-mode .form-group textarea {
    border-color: #444;
}

.form-group textarea {
    min-height: 100px;
    resize: vertical;
}

.submit-btn {
    padding: 0.8rem;
    border: none;
    border-radius: 0.5rem;
    background-color: #28a745;
    color: white;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.2s;
}

.submit-btn:hover {
    background-color: #218838;
}

.comments-section {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid rgba(0,0,0,0.1);
}

body.dark-mode .comments-section {
    border-top-color: rgba(255,255,255,0.1);
}

.comments-section h2 {
    font-size: 1.2rem;
    margin-bottom: 1.5rem;
    text-align: center;
}

footer {
    margin-top: 2rem;
    font-size: 0.8rem;
    opacity: 0.7;
}

footer a {
    color: var(--text-color);
    text-decoration: none;
    margin-left: 10px;
}

footer a:hover {
    text-decoration: underline;
}