:root {
    --bg-main: #f9fafb;
    --bg-surface: #ffffff;
    --text-main: #111827;
    --text-muted: #6b7280;
    --border-color: #e5e7eb;
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --accent-color: #10b981;
    --danger-color: #ef4444;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

body {
    background-color: var(--bg-main);
    color: var(--text-main);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    min-height: 100vh;
}

/* Sidebar Layout */
.sidebar {
    width: 250px;
    background-color: var(--bg-surface);
    border-right: 1px solid var(--border-color);
    padding: 20px 0;
    display: flex;
    flex-direction: column;
}

.sidebar-logo {
    font-size: 1.25rem;
    font-weight: 700;
    padding: 0 20px 20px 20px;
    color: var(--text-main);
    display: flex;
    align-items: center;
    gap: 8px;
}

.sidebar-logo span {
    color: var(--primary-color);
}

.nav-link {
    display: block;
    padding: 12px 20px;
    color: var(--text-muted);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.2s;
    border-left: 3px solid transparent;
}

.nav-link:hover, .nav-link.active {
    background-color: #f3f4f6;
    color: var(--primary-color);
    border-left-color: var(--primary-color);
}

/* Main Content */
.main-content {
    flex: 1;
    padding: 40px;
    overflow-y: auto;
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 30px;
    gap: 20px;
}

.title {
    font-size: 1.875rem;
    font-weight: 700;
    margin: 0 0 8px 0;
}

.subtitle {
    color: var(--text-muted);
    margin: 0;
}

.credits {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    padding: 12px 18px;
    border-radius: 10px;
    text-align: right;
    box-shadow: var(--shadow-sm);
}

.credits-count {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.credits-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-weight: 500;
}

/* Cards */
.card {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    box-shadow: var(--shadow-sm);
    margin-bottom: 24px;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-top: 0;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
}

/* Forms & Inputs */
.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 6px;
    color: var(--text-main);
}

.form-control {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.875rem;
    box-sizing: border-box;
    transition: border-color 0.2s;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.btn {
    display: inline-block;
    padding: 10px 16px;
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: 6px;
    cursor: pointer;
    border: none;
    transition: all 0.2s;
}

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

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

.btn-outline {
    background-color: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-main);
}

.btn-outline:hover {
    background-color: #f3f4f6;
}

/* Tabs */
.tab-content {
    display: none;
}
.tab-content.active {
    display: block;
}

/* Gallery Grid */
.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 16px;
}

.gallery-item {
    border-radius: 8px;
    overflow: hidden;
    border: 1px solid var(--border-color);
    position: relative;
}

.gallery-item img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    display: block;
}

.qr-panel {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px;
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    background-color: #f9fafb;
}

.qr-image {
    width: 200px;
    height: 200px;
    border-radius: 8px;
    margin-bottom: 20px;
    box-shadow: var(--shadow-md);
}

.meta-button {
    background-color: #1877F2;
    color: white;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
}
.meta-button:hover {
    background-color: #166fe5;
}

/* Mobile Layout & Responsiveness */
.mobile-header {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 60px;
    background-color: var(--bg-surface);
    border-bottom: 1px solid var(--border-color);
    align-items: center;
    justify-content: space-between;
    padding: 0 16px;
    box-sizing: border-box;
    z-index: 999;
}

.mobile-logo {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-main);
}
.mobile-logo span {
    color: var(--primary-color);
}

.hamburger-btn {
    background: none;
    border: none;
    color: var(--text-main);
    cursor: pointer;
    padding: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    transition: background-color 0.2s;
}
.hamburger-btn:hover {
    background-color: #f3f4f6;
}

.sidebar-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: rgba(0, 0, 0, 0.4);
    z-index: 1001;
    backdrop-filter: blur(2px);
}

@media (max-width: 768px) {
    body {
        flex-direction: column;
    }
    
    .mobile-header {
        display: flex;
    }
    
    .sidebar {
        position: fixed;
        top: 0;
        left: -260px;
        width: 250px;
        height: 100vh;
        z-index: 1002;
        transition: left 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        box-shadow: 4px 0 10px rgba(0, 0, 0, 0.05);
    }
    
    .sidebar.open {
        left: 0;
    }
    
    .sidebar-overlay.active {
        display: block;
    }
    
    .main-content {
        padding: 20px;
        padding-top: 80px; /* Space for fixed mobile header */
        overflow-x: hidden;
    }
    
    .header {
        flex-direction: column;
        align-items: stretch;
        gap: 15px;
    }
    
    .credits {
        text-align: left;
    }
}