/* --- VARIABLES & RESET --- */
:root {
    --bg-color: #050505;
    --text-color: #ffffff;
    --accent-color: #3b82f6; /* Bleu style Nexus */
    --card-bg: #111111;
    --glass: rgba(255, 255, 255, 0.05);
    --font-main: 'Inter', sans-serif;
    --transition-speed: 0.5s;
}

/* Mode Clair (activé via JS) */
body.light-mode {
    --bg-color: #f0f0f0;
    --text-color: #1a1a1a;
    --card-bg: #ffffff;
    --glass: rgba(0, 0, 0, 0.05);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: var(--font-main);
    transition: background-color var(--transition-speed), color var(--transition-speed);
    overflow-x: hidden;
}

/* --- THEME TOGGLE --- */
.theme-btn {
    position: fixed;
    top: 20px;
    right: 20px;
    padding: 10px 20px;
    background: var(--glass);
    border: 1px solid var(--text-color);
    color: var(--text-color);
    cursor: pointer;
    border-radius: 30px;
    backdrop-filter: blur(10px);
    z-index: 1000;
    transition: 0.3s;
    font-weight: 600;
}

.theme-btn:hover {
    background: var(--text-color);
    color: var(--bg-color);
}

/* --- HERO SECTION --- */
.hero-section {
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 20px;
}

.hero-section h1 {
    font-size: 3rem;
    font-weight: 300;
    letter-spacing: 2px;
    background: linear-gradient(45deg, var(--text-color), #888);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* --- WELCOME MESSAGE --- */
.welcome-message {
    padding: 100px 20px;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
    font-size: 1.5rem;
    line-height: 1.6;
    color: #888;
}

body.light-mode .welcome-message {
    color: #555;
}

/* --- CATEGORIES & GALLERIES --- */
.category-section {
    padding: 60px 20px;
    max-width: 1200px;
    margin: 0 auto;
    opacity: 0; /* Pour l'animation au scroll */
    transform: translateY(50px);
    transition: all 0.8s ease-out;
}

.category-section.visible {
    opacity: 1;
    transform: translateY(0);
}

.category-title {
    font-size: 2rem;
    margin-bottom: 30px;
    border-left: 4px solid var(--accent-color);
    padding-left: 15px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}

.img-card {
    background: var(--card-bg);
    border-radius: 12px;
    overflow: hidden;
    position: relative;
    aspect-ratio: 16/9;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
    cursor: pointer;
}

.img-card:hover {
    transform: scale(1.02);
}

.img-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0; /* Lazy load effect */
    transition: opacity 0.5s ease;
}

.img-card img.loaded {
    opacity: 1;
}

/* --- FOOTER --- */
footer {
    text-align: center;
    padding: 50px;
    margin-top: 50px;
    border-top: 1px solid #333;
    font-size: 0.9rem;
    opacity: 0.7;
}

/* --- ANIMATIONS CLASSES --- */
.fade-in-up {
    animation: fadeInUp 1s ease-out forwards;
}

.hidden-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s ease;
}

.hidden-scroll.visible {
    opacity: 1;
    transform: translateY(0);
}

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

/* --- LIGHTBOX --- */
.lightbox {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.9);
    backdrop-filter: blur(5px);
    justify-content: center;
    align-items: center;
}

.lightbox-content {
    max-width: 90%;
    max-height: 90%;
    border-radius: 5px;
    box-shadow: 0 0 20px rgba(255,255,255,0.2);
    animation: zoomIn 0.3s;
}

.close-lightbox {
    position: absolute;
    top: 20px;
    right: 35px;
    color: #f1f1f1;
    font-size: 40px;
    font-weight: bold;
    cursor: pointer;
}

@keyframes zoomIn {
    from {transform:scale(0)} 
    to {transform:scale(1)}
}