:root {
    --bg-base: #09090f;
    --bg-panel: rgba(18, 18, 30, 0.8);
    --border-light: rgba(180, 130, 30, 0.18);
    --text-main: #e2e8f0;
    --text-secondary: rgba(226, 232, 240, 0.68);
    --accent-1: #b8860b;
    --accent-2: #4f46e5;
    --accent-gradient: linear-gradient(135deg, #b8860b, #4f46e5);
    --font-sans: 'Inter', system-ui, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    --radius: 14px;
    --transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
    font-family: var(--font-sans);
    background: var(--bg-base);
    color: var(--text-main);
    line-height: 1.75;
    overflow-x: hidden;
    word-break: break-word;
    overflow-wrap: break-word;
}

#field-bg {
    position: fixed;
    inset: 0;
    z-index: 0;
    pointer-events: none;
    opacity: 0.45;
}

.glass-nav {
    position: fixed;
    top: 0; left: 0; width: 100%;
    z-index: 1000;
    padding: 1.2rem 2.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(9, 9, 15, 0.65);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--border-light);
    transition: var(--transition);
}

.glass-nav.scrolled {
    padding: 0.8rem 2.5rem;
    background: rgba(9, 9, 15, 0.92);
}

.logo {
    font-weight: 800;
    font-size: 1rem;
    letter-spacing: 1px;
    text-transform: uppercase;
    text-decoration: none;
    color: var(--text-main);
}

.logo span { color: var(--accent-1); font-weight: 300; }

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.82rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 1px;
    transition: color 0.2s;
}

.nav-links a:hover { color: var(--accent-1); }

.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 0 2rem;
    position: relative;
    z-index: 1;
}

.badge {
    display: inline-block;
    padding: 0.4rem 1.2rem;
    border-radius: 50px;
    background: rgba(184, 134, 11, 0.07);
    border: 1px solid rgba(184, 134, 11, 0.3);
    color: var(--accent-1);
    font-family: var(--font-mono);
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 1.5rem;
}

.hero h1 {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 300;
    line-height: 1.1;
    letter-spacing: -1px;
    margin-bottom: 1.5rem;
}

.gradient-text {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 600;
}

.subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto 3rem;
    font-style: italic;
}

.scroll-indicator {
    position: absolute;
    bottom: 2.5rem;
    left: 50%;
    transform: translateX(-50%);
    opacity: 0.5;
}

.mouse {
    width: 24px;
    height: 36px;
    border: 1.5px solid var(--accent-1);
    border-radius: 12px;
    position: relative;
}

.mouse::before {
    content: '';
    position: absolute;
    top: 6px;
    left: 50%;
    transform: translateX(-50%);
    width: 3px;
    height: 5px;
    background: var(--accent-1);
    border-radius: 2px;
    animation: scroll-dot 2s infinite;
}

@keyframes scroll-dot {
    0% { opacity: 1; transform: translateX(-50%) translateY(0); }
    100% { opacity: 0; transform: translateX(-50%) translateY(14px); }
}

.section { padding: 6rem 0; position: relative; z-index: 1; }
.alt-bg { background: rgba(20, 18, 8, 0.4); }

.container { max-width: 860px; margin: 0 auto; padding: 0 2rem; }
.container.wide { max-width: 1100px; }

.section-header {
    text-align: center;
    margin-bottom: 3.5rem;
}

.section-header h2 {
    font-size: clamp(1.8rem, 4vw, 2.6rem);
    font-weight: 300;
    margin-bottom: 0.8rem;
    line-height: 1.2;
}

.section-header h2 span { color: var(--accent-1); font-weight: 600; }

.section-header p {
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
    font-size: 1rem;
}

.glass-panel {
    background: var(--bg-panel);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--border-light);
    border-radius: var(--radius);
    padding: 2.5rem;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

.glass-panel p { margin-bottom: 1.2rem; color: var(--text-main); }
.glass-panel p:last-child { margin-bottom: 0; }

blockquote {
    border-left: 2px solid var(--accent-1);
    padding: 1rem 1.5rem;
    margin: 2rem 0 0;
    font-style: italic;
    color: var(--text-secondary);
    font-size: 1.05rem;
}

.divider {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin: 2rem 0;
}

.divider-line { flex: 1; height: 1px; background: var(--border-light); }
.divider-glyph { color: var(--accent-1); opacity: 0.6; }

/* EQUATION CARDS */
.eq-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.eq-card {
    display: flex;
    flex-direction: column;
}

.eq-label {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--accent-1);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 1rem;
}

.eq-body {
    font-size: 1.1rem;
    text-align: center;
    padding: 1.5rem;
    background: rgba(184, 134, 11, 0.04);
    border-radius: 8px;
    margin-bottom: 1rem;
    flex: 1;
    overflow-x: auto;
}

.eq-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 0 !important;
}

.highlight-card {
    border-color: rgba(184, 134, 11, 0.4);
    box-shadow: 0 0 30px rgba(184, 134, 11, 0.08);
    grid-column: span 2;
}

.highlight-card .eq-body {
    background: rgba(184, 134, 11, 0.08);
    font-size: 1.3rem;
}

/* RESULT BLOCK */
.result-block {
    background: rgba(0, 0, 0, 0.25);
    border: 1px solid var(--border-light);
    border-radius: 8px;
    margin: 1.5rem 0;
    overflow: hidden;
}

.result-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.9rem 1.5rem;
    border-bottom: 1px solid rgba(255,255,255,0.04);
}

.result-row:last-child { border-bottom: none; }

.result-label { font-size: 0.9rem; color: var(--text-secondary); }
.result-value {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    color: var(--text-main);
}

.highlight-row { background: rgba(184, 134, 11, 0.08); }
.highlight-row .result-label,
.highlight-row .result-value { color: var(--accent-1); font-weight: 600; }

/* OPTIONS GRID */
.options-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin: 1.5rem 0;
}

.option-card {
    background: rgba(255,255,255,0.03);
    border: 1px solid var(--border-light);
    border-radius: 10px;
    padding: 1.5rem;
}

.option-num {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: rgba(184, 134, 11, 0.15);
    border: 1px solid var(--accent-1);
    color: var(--accent-1);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1rem;
    font-weight: 600;
}

.option-card p { font-size: 0.88rem; color: var(--text-secondary); margin: 0; }
.option-card strong { color: var(--text-main); }

/* LABO IA */
.ia-details {
    cursor: pointer;
    outline: none;
}

.ia-summary {
    list-style: none;
    font-family: var(--font-mono);
    color: var(--accent-1);
    font-size: 0.88rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    display: flex;
    align-items: center;
}

.ia-summary::-webkit-details-marker { display: none; }

.ia-content {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px dashed var(--border-light);
    font-size: 0.95rem;
    color: var(--text-secondary);
}

.ia-content h4 {
    color: var(--accent-1);
    font-weight: 500;
    margin: 1.5rem 0 0.6rem;
    font-size: 1rem;
}

.ia-content h4:first-child { margin-top: 0; }
.ia-content p { margin-bottom: 0.8rem; }

/* ANIMATIONS */
.fade-in {
    opacity: 0;
    animation: fadeIn 1s ease-out forwards;
    animation-delay: 0.3s;
}

@keyframes fadeIn { to { opacity: 1; } }

.reveal-up {
    opacity: 0;
    transform: translateY(28px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.reveal-up.active {
    opacity: 1;
    transform: translateY(0);
}

.text-center { text-align: center; }

/* RESPONSIVE */
@media (max-width: 768px) {
    .glass-nav { padding: 1rem; }
    .nav-links { display: none; }
    .eq-grid { grid-template-columns: 1fr; }
    .highlight-card { grid-column: span 1; }
    .options-grid { grid-template-columns: 1fr; }
    .glass-panel { padding: 1.5rem; }
    .result-row { flex-direction: column; align-items: flex-start; gap: 0.3rem; }
    .container { padding: 0 1rem; }
    .section { padding: 4rem 0; }
}