/* ------------------------------------
   CSS Variables & Theming
------------------------------------ */
:root {
    --primary-color: #1a365d;
    --primary-light: #2b528a;
    --accent-color: #0064ff;
    --bg-color: #ffffff;
    --surface-color: #ffffff;
    --text-main: #111827;
    --text-muted: #6b7280;
    --border-color: #e5e7eb;
    --success-color: #10b981;
    --danger-color: #ef4444;
    
    --glass-bg: rgba(255, 255, 255, 0.75);
    --glass-border: rgba(255, 255, 255, 0.3);
    --glass-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.07);
    
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --radius-md: 12px;
    --radius-lg: 20px;
}

/* ------------------------------------
   Reset & Base Styles
------------------------------------ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

/* ------------------------------------
   Typography & Utilities
------------------------------------ */
h1, h2, h3 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--primary-color);
}

.text-gray { color: var(--text-muted); }
.font-semibold { font-weight: 600; }
.text-danger { color: var(--danger-color); }
.w-100 { width: 100%; }
.mt-4 { margin-top: 1.5rem; }
.hidden { display: none !important; }

/* ------------------------------------
   Glassmorphism Components
------------------------------------ */
.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
    border-radius: var(--radius-lg);
}

/* ------------------------------------
   Buttons & Inputs
------------------------------------ */
.btn-primary {
    background-color: var(--primary-color);
    color: #fff;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.btn-primary:hover {
    background-color: var(--primary-light);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(26, 54, 93, 0.2);
}

.btn-text {
    background: none;
    border: none;
    font-weight: 600;
    cursor: pointer;
    transition: color var(--transition-fast);
}

.btn-text:hover {
    opacity: 0.8;
}

.form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-family: var(--font-family);
    font-size: 0.95rem;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
    background: var(--surface-color);
}

.form-control:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

.form-group {
    margin-bottom: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--primary-color);
}

/* ------------------------------------
   Layout - Header
------------------------------------ */
.glass-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 100;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* Onoffmix Style Header */
.onoff-header {
    width: 100%;
    background: #fff;
    border-bottom: 1px solid var(--border-color);
}

.gnb-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1.5rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.onoff-logo-text {
    font-size: 2rem;
    font-weight: 800;
    color: var(--accent-color);
    letter-spacing: -1px;
}

.search-bar {
    display: flex;
    align-items: center;
    border: 2px solid var(--accent-color);
    border-radius: 8px;
    overflow: hidden;
    width: 450px;
    height: 45px;
}

.search-bar input {
    flex-grow: 1;
    border: none;
    padding: 0 1rem;
    font-size: 1rem;
    outline: none;
}

.search-bar .search-btn {
    background: none;
    border: none;
    padding: 0 1rem;
    cursor: pointer;
    font-size: 1.2rem;
}

.util-links {
    display: flex;
    align-items: center;
    gap: 0.8rem;
    font-size: 0.85rem;
    color: #555;
}

.util-links a {
    color: #555;
    transition: color 0.2s;
}

.util-links a:hover {
    color: var(--text-main);
}

.util-links .divider {
    color: #ddd;
}

.lnb-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0.5rem 2rem 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.lnb-left {
    display: flex;
    align-items: center;
    gap: 1rem;
    font-weight: 600;
    font-size: 0.95rem;
}

.lnb-left a {
    color: #333;
    transition: color 0.2s;
}

.lnb-left a:hover {
    color: var(--accent-color);
}

.lnb-left .dot {
    color: #ccc;
    font-size: 1.2rem;
}

.lnb-right {
    display: flex;
    gap: 0.5rem;
}

.btn-outline {
    border: 1px solid #ddd;
    background: #fff;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    font-weight: 600;
    font-size: 0.9rem;
    color: #333;
}

.btn-solid {
    background: var(--accent-color);
    color: #fff;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    font-weight: 600;
    font-size: 0.9rem;
    border: 1px solid var(--accent-color);
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-icon {
    color: var(--accent-color);
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    font-weight: 600;
    color: var(--text-muted);
    transition: color var(--transition-fast);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--primary-color);
}

/* ------------------------------------
   Hero Section
------------------------------------ */
.hero {
    position: relative;
    padding: 10rem 2rem 6rem;
    text-align: center;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 60vh;
}

.hero-bg-shapes {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background: linear-gradient(135deg, #f3f4f6 0%, #e2e8f0 100%);
}

.shape {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.5;
}

.shape-1 {
    width: 400px;
    height: 400px;
    background: var(--accent-color);
    top: -100px;
    left: -100px;
}

.shape-2 {
    width: 500px;
    height: 500px;
    background: #93c5fd;
    bottom: -150px;
    right: -100px;
}

.hero-content {
    max-width: 700px;
    padding: 3rem;
    z-index: 1;
}

.hero-title {
    font-size: 3rem;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--text-muted);
    margin-bottom: 2rem;
}

/* ------------------------------------
   Banner Section (Onoffmix Style)
------------------------------------ */
.banner-section {
    padding-top: 2rem !important;
    padding-bottom: 2rem !important;
}

.main-banners {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
    height: 380px;
}

.main-banner-left {
    flex: 7;
    background: linear-gradient(to right, rgba(0,0,0,0.7), rgba(0,0,0,0.2)), url('https://images.unsplash.com/photo-1552664730-d307ca884978?auto=format&fit=crop&w=1200&q=80') center/cover no-repeat;
    border-radius: 12px;
    position: relative;
    padding: 3rem;
    color: #fff;
    display: flex;
    flex-direction: column;
    justify-content: center;
    overflow: hidden;
}

.banner-badge {
    background: #1e3a8a;
    display: inline-block;
    padding: 0.3rem 0.8rem;
    font-size: 0.8rem;
    font-weight: 700;
    clip-path: polygon(0 0, 100% 0, 90% 100%, 0% 100%);
    margin-bottom: 1rem;
    width: max-content;
}

.main-banner-left h2 {
    color: #fff;
    font-size: 2.2rem;
    line-height: 1.3;
    margin-bottom: 1rem;
}

.main-banner-left p {
    font-size: 0.95rem;
    opacity: 0.9;
    margin-bottom: 2rem;
    line-height: 1.6;
}

.btn-detail {
    background: var(--accent-color);
    color: #fff;
    border: none;
    padding: 0.8rem 1.5rem;
    border-radius: 6px;
    font-weight: 700;
    width: max-content;
    cursor: pointer;
}

.banner-pagination {
    position: absolute;
    bottom: 0;
    left: 0;
    background: #fff;
    color: #333;
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
    font-weight: 600;
    border-top-right-radius: 8px;
}

.main-banner-right {
    flex: 3;
    background: #fff url('https://images.unsplash.com/photo-1506869640319-fe1a24fd76dc?auto=format&fit=crop&w=400&q=80') right bottom/50% no-repeat;
    border-radius: 12px;
    padding: 2.5rem;
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
}

.sub-banners {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.sub-banner {
    height: 160px;
    border-radius: 12px;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    position: relative;
    overflow: hidden;
    color: #fff;
}

.sub-banner::after {
    content: '';
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background: linear-gradient(to right, rgba(0,0,0,0.8) 0%, rgba(0,0,0,0.2) 100%);
    z-index: 1;
}

.sub-banner-text {
    position: relative;
    z-index: 2;
}

.sub-banner p {
    font-size: 0.8rem;
    margin-bottom: 0.5rem;
    opacity: 0.9;
}

.sub-banner h4 {
    color: #fff;
    font-size: 1.2rem;
    margin-bottom: 1rem;
    line-height: 1.3;
}

.btn-sub-detail {
    background: rgba(255,255,255,0.2);
    border: 1px solid rgba(255,255,255,0.4);
    color: #fff;
    padding: 0.4rem 1rem;
    border-radius: 20px;
    font-size: 0.8rem;
    cursor: pointer;
    width: max-content;
    position: relative;
    z-index: 2;
}

.bg-dark { background: url('https://images.unsplash.com/photo-1556761175-5973dc0f32d7?auto=format&fit=crop&w=400&q=80') center/cover; }
.bg-blue-dark { background: url('https://images.unsplash.com/photo-1573164713988-8665fc963095?auto=format&fit=crop&w=400&q=80') center/cover; }
.bg-blue-light { background: url('https://images.unsplash.com/photo-1507525428034-b723cf961d3e?auto=format&fit=crop&w=400&q=80') center/cover; }

.bg-white { background: #fff !important; }
.text-blue { color: var(--accent-color) !important; font-weight: 700; border: none; }

/* ------------------------------------
   Main Seminars Section
------------------------------------ */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem;
}

.section-header {
    margin-bottom: 3rem;
    text-align: center;
}

.section-header h2 {
    font-size: 2.25rem;
    margin-bottom: 0.5rem;
}

.section-header p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

/* Grid Layout for Cards */
.seminar-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 2rem;
}

/* Cards */
.seminar-card {
    background: var(--surface-color);
    border-radius: var(--radius-lg);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
    border: 1px solid var(--border-color);
}

.seminar-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 24px -5px rgba(0, 0, 0, 0.1);
}

.card-header {
    display: flex;
    justify-content: flex-end;
    margin-bottom: 1rem;
}

.badge {
    padding: 0.4rem 0.8rem;
    border-radius: 9999px;
    font-size: 0.8rem;
    font-weight: 700;
}

.badge-seats {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success-color);
    border: 1px solid rgba(16, 185, 129, 0.2);
}

.card-body {
    flex-grow: 1;
}

.seminar-title {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
}

.seminar-date {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 1rem;
    font-weight: 600;
}

.seminar-desc {
    color: var(--text-muted);
    font-size: 0.95rem;
    line-height: 1.5;
    margin-bottom: 1.5rem;
}

.card-footer {
    border-top: 1px solid var(--border-color);
    padding-top: 1.5rem;
    display: flex;
    justify-content: stretch;
}

.card-footer .btn-primary {
    width: 100%;
}

/* ------------------------------------
   Modal Styles
------------------------------------ */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(17, 24, 39, 0.5);
    backdrop-filter: blur(4px);
    z-index: 1000;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 1rem;
}

.modal-content {
    width: 100%;
    max-width: 450px;
    padding: 2rem;
    animation: slideUp 0.3s ease-out forwards;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.close-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-muted);
    transition: color var(--transition-fast);
}

.close-btn:hover {
    color: var(--danger-color);
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ------------------------------------
   Admin Layout Structure
------------------------------------ */
.admin-layout {
    display: flex;
    min-height: 100vh;
    background-color: var(--bg-color);
}

.sidebar {
    width: 260px;
    background: var(--primary-color);
    color: #fff;
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    z-index: 50;
}

.sidebar-header {
    padding: 2rem 1.5rem;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.sidebar-header .logo {
    color: #fff;
}

.sidebar-menu {
    flex-grow: 1;
    padding: 1.5rem 0;
}

.sidebar-menu li a {
    display: block;
    padding: 1rem 1.5rem;
    color: rgba(255, 255, 255, 0.7);
    font-weight: 600;
    transition: all var(--transition-fast);
}

.sidebar-menu li a:hover,
.sidebar-menu li a.active {
    background: rgba(255,255,255,0.1);
    color: #fff;
    border-left: 4px solid var(--accent-color);
}

.sidebar-footer {
    padding: 1.5rem;
    font-size: 0.8rem;
    color: rgba(255,255,255,0.5);
    border-top: 1px solid rgba(255,255,255,0.1);
}

.admin-content {
    flex-grow: 1;
    margin-left: 260px;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.admin-topbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.admin-profile {
    display: flex;
    align-items: center;
    gap: 1rem;
    font-weight: 600;
}

.avatar {
    width: 40px;
    height: 40px;
    background: var(--accent-color);
    color: #fff;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
}

.admin-dashboard-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}

/* ------------------------------------
   Admin Forms & Tables
------------------------------------ */
.section-card {
    padding: 2rem;
}

.section-card h2 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.section-desc {
    color: var(--text-muted);
    margin-bottom: 2rem;
}

.grid-form {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.full-width {
    grid-column: 1 / -1;
}

.form-actions {
    display: flex;
    justify-content: flex-end;
}

.section-header-flex {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.filter-select {
    width: auto;
    min-width: 250px;
}

/* Table Design */
.table-responsive {
    overflow-x: auto;
}

.modern-table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
}

.modern-table th, 
.modern-table td {
    padding: 1.25rem 1rem;
    border-bottom: 1px solid var(--border-color);
}

.modern-table th {
    background: rgba(243, 244, 246, 0.5);
    font-weight: 600;
    color: var(--primary-color);
    text-transform: uppercase;
    font-size: 0.85rem;
    letter-spacing: 0.05em;
}

.modern-table tbody tr {
    transition: background-color var(--transition-fast);
}

.modern-table tbody tr:hover {
    background-color: rgba(243, 244, 246, 0.6);
}

.pill-label {
    background: var(--bg-color);
    padding: 0.4rem 0.8rem;
    border-radius: 9999px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--primary-color);
    border: 1px solid var(--border-color);
}

.empty-state {
    grid-column: 1 / -1;
    text-align: center;
    padding: 3rem;
    color: var(--text-muted);
    background: var(--surface-color);
    border: 1px dashed var(--border-color);
    border-radius: var(--radius-lg);
    font-weight: 600;
}

/* ------------------------------------
   Responsive Adjustments
------------------------------------ */
@media (max-width: 992px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform var(--transition-normal);
    }
    .admin-content {
        margin-left: 0;
    }
}

@media (max-width: 768px) {
    .hero {
        padding: 8rem 1rem 4rem;
    }
    .hero-title {
        font-size: 2.25rem;
    }
    .header-container {
        padding: 1rem;
    }
    .nav-links {
        gap: 1rem;
        font-size: 0.9rem;
    }
    .gnb-container {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }
    .search-bar {
        width: 100%;
    }
    .lnb-container {
        flex-direction: column;
        gap: 1rem;
        align-items: flex-start;
        padding: 0.5rem 1rem 1rem;
    }
    .lnb-left {
        flex-wrap: wrap;
    }
    .main-banners {
        flex-direction: column;
        height: auto;
    }
    .sub-banners {
        grid-template-columns: 1fr;
    }
    .main-banner-left {
        padding: 2rem;
    }
    .section-header-flex {
        flex-direction: column;
        align-items: flex-start;
    }
}