/* COLOR PALETTE (From Grenoble INP - ESISAR Graphic Chart) */
:root {
    --primary-blue: #2A2E46;
    --esisar-magenta: #951B81;
    
    /* Light Mode Frosted Glass */
    --bg-color: #e2e5ed; /* Slightly darker gray base so white glass pops */
    --card-bg: rgba(255, 255, 255, 0.65);
    --card-bg-hover: rgba(255, 255, 255, 0.85);
    --text-color: #1a1c24;
    --text-muted: #5c6175;
    --border-color: rgba(255, 255, 255, 0.8);
    --header-bg: rgba(42, 46, 70, 0.92);
    --header-text: #ffffff;
    
    /* Glassmorphism settings */
    --glass-blur: blur(14px);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
}

/* Dark Mode Frosted Glass */
[data-theme="dark"] {
    --bg-color: #0d0e14;
    --card-bg: rgba(26, 28, 36, 0.6);
    --card-bg-hover: rgba(35, 38, 50, 0.75);
    --text-color: #f4f5f7;
    --text-muted: #a0a6b8;
    --border-color: rgba(255, 255, 255, 0.08);
    --header-bg: rgba(28, 30, 43, 0.88);
    --header-text: #f4f5f7;
    
    /* Darker glass shadows */
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.45);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    padding: 40px 20px;
    min-height: 100vh;
}

.container {
    max-width: 900px;
    margin: 0 auto;
}

/* Top Action Bar (Theme Switcher) */
.top-bar {
    display: flex;
    justify-content: flex-end;
    margin-bottom: 15px;
}

.theme-toggle-btn {
    background-color: var(--card-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    padding: 8px 16px;
    border-radius: 20px;
    cursor: pointer;
    font-weight: 500;
    font-size: 0.85rem;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    box-shadow: var(--glass-shadow);
}

.theme-toggle-btn:hover {
    border-color: var(--esisar-magenta);
    background-color: var(--card-bg-hover);
}

/* Header / Info Section */
header {
    background-color: var(--header-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    color: var(--header-text);
    padding: 30px;
    border-radius: 16px;
    box-shadow: var(--glass-shadow);
    margin-bottom: 40px;
    border-bottom: 4px solid var(--esisar-magenta);
    border-top: 1px solid rgba(255, 255, 255, 0.15);
}

.header-main {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    border-bottom: 1px solid rgba(255, 255, 255, 0.15);
    padding-bottom: 15px;
    margin-bottom: 15px;
}

h1 {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.5px;
}

.server-status {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(255, 255, 255, 0.12);
    backdrop-filter: blur(4px);
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    color: #ffffff;
}

[data-theme="dark"] .server-status {
    background: rgba(149, 27, 129, 0.25);
    color: #f4f5f7;
}

.status-dot {
    width: 9px;
    height: 9px;
    background-color: #10b981;
    border-radius: 50%;
    box-shadow: 0 0 8px #10b981;
}

.breadcrumb {
    font-size: 0.95rem;
    opacity: 0.9;
}

.breadcrumb a {
    color: #ffffff;
    text-decoration: underline;
    text-decoration-color: var(--esisar-magenta);
    text-underline-offset: 3px;
}

.breadcrumb a:hover {
    color: var(--esisar-magenta);
    text-decoration-color: #ffffff;
}

/* Content Sections */
.section-title {
    font-size: 1.3rem;
    color: var(--text-color);
    margin-bottom: 20px;
    border-left: 4px solid var(--esisar-magenta);
    padding-left: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.grid-section {
    margin-bottom: 40px;
}

.links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 20px;
}

/* Frosted Glass Link Cards */
.card {
    background-color: var(--card-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border-radius: 12px;
    padding: 20px;
    box-shadow: var(--glass-shadow);
    border: 1px solid var(--border-color);
    text-decoration: none;
    color: inherit;
    display: flex;
    flex-direction: column;
    justify-content: center;
    cursor: pointer;
}

.card:hover {
    transform: translateY(-3px);
    background-color: var(--card-bg-hover);
    border-color: var(--esisar-magenta);
    box-shadow: 0 12px 28px rgba(0, 0, 0, 0.12);
}

.card h3 {
    color: var(--text-color);
    margin-bottom: 8px;
    font-size: 1.1rem;
    word-break: break-word;
}

.card:hover h3 {
    color: var(--esisar-magenta);
}

.card p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Image Grid Overrides */
.image-grid {
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
}

.image-card {
    padding: 0;
    position: relative;
    aspect-ratio: 1 / 1;
    overflow: hidden;
}

.image-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: opacity 0.2s;
}

.image-card:hover img {
    opacity: 0.8;
}

.image-label {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(18, 19, 26, 0.75);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    padding: 0.5rem;
    font-size: 0.85rem;
    text-align: center;
    color: #ffffff;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    border-top: 1px solid var(--esisar-magenta);
}

/* Lightbox (Full Screen Viewer) */
#lightbox {
    display: none;
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(13, 14, 20, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    z-index: 1000;
    justify-content: center;
    align-items: center;
    flex-direction: column;
}

#lightbox img {
    max-width: 90%;
    max-height: 85vh;
    border-radius: 12px;
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.6);
    border: 1px solid var(--border-color);
}

#lightbox-caption {
    margin-top: 1rem;
    font-size: 1.2rem;
    color: #ffffff;
}

.close-btn {
    position: absolute;
    top: 20px;
    right: 30px;
    font-size: 3rem;
    color: #ffffff;
    cursor: pointer;
    opacity: 0.7;
    transition: opacity 0.2s;
}

.close-btn:hover {
    opacity: 1;
    color: var(--esisar-magenta);
}

/* Footer */
footer {
    text-align: center;
    margin-top: 60px;
    color: var(--text-muted);
    font-size: 0.85rem;
    border-top: 1px solid var(--border-color);
    padding-top: 20px;
}

/* Responsive handling */
@media (max-width: 600px) {
    body { padding: 20px 10px; }
    header { padding: 20px; }
    h1 { font-size: 1.6rem; }
    .header-main { gap: 10px; }
}