:root {
    --primary-color: #10b981;
    /* Emerald Green */
    --secondary-color: #047857;
    /* Dark Forest Green */
    --accent-color: #f59e0b;
    /* Gold/Amber */
    --bg-color: #f4f7f6;
    --card-bg: #ffffff;
    --text-color: #333333;
    --text-muted: #6c757d;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --radius: 15px;
}

body {
    background: linear-gradient(135deg, #fdfbfb 0%, #ebedee 100%);
    font-family: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    color: var(--text-color);
    min-height: 100vh;
}

/* Navbar */
.navbar-custom {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    box-shadow: var(--shadow);
    padding: 1rem 2rem;
}

.navbar-custom .navbar-brand {
    color: white;
    font-weight: bold;
    font-size: 1.5rem;
}

.navbar-custom .nav-link {
    color: rgba(255, 255, 255, 0.9);
    font-weight: 500;
    transition: color 0.3s;
}

.navbar-custom .nav-link:hover {
    color: #ffcc00;
}

/* Card */
.content-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 2rem;
    margin-bottom: 2rem;
    border: none;
}

/* Ball Styles */
.ball_645 {
    display: inline-block;
    border-radius: 50%;
    text-align: center;
    vertical-align: middle;
    color: #fff;
    font-weight: 600;
    margin: 5px;
    box-shadow: 0 3px 5px rgba(0, 0, 0, 0.2);
}

.ball_645.lrg {
    width: 60px;
    height: 60px;
    line-height: 60px;
    font-size: 28px;
}

.ball_645.sml {
    width: 30px;
    height: 30px;
    line-height: 30px;
    font-size: 14px;
}

/* Ball Colors */
.ball_645.ball1 {
    background: #fbc400;
    text-shadow: 0px 1px 2px rgba(0, 0, 0, 0.3);
}

/* 1-10 */
.ball_645.ball2 {
    background: #69c8f2;
    text-shadow: 0px 1px 2px rgba(0, 0, 0, 0.3);
}

/* 11-20 */
.ball_645.ball3 {
    background: #ff7272;
    text-shadow: 0px 1px 2px rgba(0, 0, 0, 0.3);
}

/* 21-30 */
.ball_645.ball4 {
    background: #aaaaaa;
    text-shadow: 0px 1px 2px rgba(0, 0, 0, 0.3);
}

/* 31-40 */
.ball_645.ball5 {
    background: #b0d840;
    text-shadow: 0px 1px 2px rgba(0, 0, 0, 0.3);
}

/* 41-45 */

/* Buttons */
.btn-custom {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    border: none;
    color: white;
    padding: 10px 30px;
    border-radius: 50px;
    font-weight: bold;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2);
    transition: transform 0.2s, box-shadow 0.2s;
}

.btn-custom:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 8px rgba(0, 0, 0, 0.3);
    color: white;
}

.btn-outline-custom {
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
    border-radius: 50px;
    padding: 8px 25px;
    font-weight: bold;
    background: transparent;
    transition: all 0.3s;
}

.btn-outline-custom:hover {
    background: var(--primary-color);
    color: white;
}

/* List Group */
.list-group-item {
    border: none;
    border-bottom: 1px solid #eee;
    padding: 1rem 1.5rem;
}

.list-group-item.active {
    background-color: #fff3cd;
    /* Warning light */
    color: #856404;
    border-color: #ffeeba;
    font-weight: bold;
}

/* Media Queries */
@media (max-width: 576px) {
    .ball_645.lrg {
        width: 35px;
        height: 35px;
        line-height: 35px;
        font-size: 16px;
        margin: 2px;
    }


    .navbar-brand {
        font-size: 1.2rem;
    }

    .content-card {
        padding: 1.5rem;
    }
}

/* OMR Card Styles */
.omr-card {
    background: #fff0f0;
    /* Light reddish/pinkish background typical for OMR */
    border: 2px solid #ff9999;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    position: relative;
}

.omr-card::before {
    content: "LOTTO 6/45";
    position: absolute;
    top: -15px;
    left: 20px;
    background: #d9534f;
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-weight: bold;
    font-size: 0.9rem;
}

.omr-row {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
    margin-top: 15px;
}

/* Vertical marking style for OMR */
.omr-number {
    position: relative;
    width: 30px;
    height: 50px;
    /* Tall rectangle */
    border: 1px solid #d9534f;
    /* Reddish border */
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: bold;
    color: #d9534f;
    cursor: pointer;
    background: white;
    transition: all 0.1s;
}

.omr-number:hover {
    background-color: #ffe6e6;
}

/* Marking effect - simulates a pen mark */
.omr-number.marked {
    background-color: #000;
    /* Black pen mark */
    color: #000;
    /* Hide number */
    border-color: #000;
}

.omr-number.marked::after {
    content: "";
    /* Or a diagonal line */
    position: absolute;
    width: 6px;
    height: 30px;
    background: white;
    /* Simulating the gap in the mark? Or actually solid black is better for simulation */
    display: none;
}

/* Except number - maybe red mark? */
.omr-number.except-mark {
    background-color: #d9534f;
    /* Red pen mark */
    color: #d9534f;
    border-color: #d9534f;
}

.omr-section-label {
    writing-mode: vertical-rl;
    text-orientation: upright;
    font-weight: bold;
    color: #d9534f;
    margin-right: 10px;
    border-right: 2px solid #d9534f;
    padding-right: 5px;
}