:root {
    --primary-color: #3b82f6;
    --bg-color: #f8fafc;
    --container-bg: #ffffff;
    --text-main: #1e293b;
    --text-sub: #64748b;
    --border-color: #e2e8f0;
    --badge-bg: #f1f5f9;
    --description-bg: #f1f5f9;
}

[data-theme='dark'] {
    --bg-color: #0f172a;
    --container-bg: #1e293b;
    --text-main: #f1f5f9;
    --text-sub: #94a3b8;
    --border-color: #334155;
    --badge-bg: #334155;
    --description-bg: #334155;
}

body {
    font-family: 'Pretendard', -apple-system, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    margin: 0;
    padding: 40px 20px;
    transition: background-color 0.3s, color 0.3s;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background: var(--container-bg);
    padding: 32px;
    border-radius: 12px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    position: relative;
    transition: background-color 0.3s;
}

/* Theme Toggle Button */
.theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    padding: 8px;
    border-radius: 50%;
    border: 1px solid var(--border-color);
    background: var(--container-bg);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: 0.2s;
}

.theme-toggle:hover {
    background: var(--badge-bg);
}

.theme-toggle svg {
    width: 20px;
    height: 20px;
    fill: var(--text-main);
}

/* Header Section */
.issue-header {
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 20px;
    margin-bottom: 24px;
}

.issue-id {
    color: var(--text-sub);
    font-size: 0.9rem;
    font-weight: 600;
}

.issue-title {
    font-size: 2rem;
    margin: 8px 0;
    color: var(--text-main);
}

.badge {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    margin-right: 8px;
}

.status-open { background: #dcfce7; color: #166534; }
[data-theme='dark'] .status-open { background: #064e3b; color: #dcfce7; }

.priority-high { background: #fee2e2; color: #991b1b; }
[data-theme='dark'] .priority-high { background: #7f1d1d; color: #fee2e2; }

/* Main Content */
.issue-content {
    margin-bottom: 32px;
}

.section-title {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
}

.description {
    background: var(--description-bg);
    padding: 20px;
    border-radius: 8px;
    white-space: pre-wrap;
    transition: background-color 0.3s;
}

/* Meta Information */
.meta-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-top: 24px;
    padding: 20px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
}

.meta-item label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-sub);
    margin-bottom: 4px;
}

.meta-item span {
    font-weight: 600;
}

/* Footer Actions */
.actions {
    display: flex;
    gap: 12px;
    margin-top: 32px;
}

.btn {
    padding: 10px 20px;
    border-radius: 6px;
    border: none;
    cursor: pointer;
    font-weight: 600;
    transition: 0.2s;
}

.btn-primary { background: var(--primary-color); color: white; }
.btn-outline { 
    background: var(--container-bg); 
    border: 1px solid var(--border-color); 
    color: var(--text-main); 
}
.btn:hover { opacity: 0.9; }