:root {
    --bg: #0a0c14;
    --text: #e6eaf5;
    --muted: #94a3b8;
    --card: rgba(255, 255, 255, 0.05);
    --glass: rgba(255, 255, 255, 0.07);
    --accent1: #6366f1;
    --accent2: #06b6d4;
    --shadow: rgba(99, 102, 241, 0.35);
    --ease: cubic-bezier(0.25, 1, 0.5, 1);
}

body.light {
    --bg: #f9fafb;
    --text: #0f172a;
    --muted: #475569;
    --card: rgba(255, 255, 255, 0.9);
    --glass: rgba(255, 255, 255, 0.85);
    --accent1: #3b82f6;
    --accent2: #9333ea;
    --shadow: rgba(59, 130, 246, 0.3);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
    transition: background 0.4s var(--ease), color 0.4s var(--ease);
}

body {
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    overflow-x: hidden;
}

/* Hero */
.hero {
    position: relative;
    text-align: center;
    padding: 6rem 1rem 4rem;
    overflow: hidden;
}
.overlay {
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 50% 0%, var(--accent1) 0%, transparent 70%);
    opacity: 0.4;
    filter: blur(90px);
}
.hero-content {
    position: relative;
    z-index: 2;
}
.hero h1 {
    font-size: 2.8rem;
    font-weight: 900;
    background: linear-gradient(90deg, var(--accent1), var(--accent2));
    -webkit-background-clip: text;
    color: transparent;
}
.hero p {
    font-size: 1.1rem;
    opacity: 0.9;
    margin-top: 0.6rem;
}
.btn-toggle {
    margin-top: 1.5rem;
    padding: 8px 14px;
    border: none;
    border-radius: 12px;
    background: var(--card);
    color: var(--text);
    box-shadow: 0 8px 24px var(--shadow);
    cursor: pointer;
}
.btn-toggle:hover {
    background: linear-gradient(90deg, var(--accent1), var(--accent2));
    color: #fff;
    transform: translateY(-3px);
}

/* Layout */
.content {
    max-width: 1080px;
    margin: 3rem auto;
    padding: 0 1rem;
}

.info-block {
    background: var(--glass);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 0 12px 36px var(--shadow);
    margin-bottom: 2.5rem;
}

/* Split sections */
.split {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1.8rem;
    margin-bottom: 2.5rem;
}
.card {
    border-radius: 18px;
    padding: 2rem;
    box-shadow: 0 12px 32px var(--shadow);
    transition: transform 0.4s var(--ease), box-shadow 0.4s var(--ease);
}
.card.glass {
    background: var(--glass);
    border: 1px solid rgba(255, 255, 255, 0.15);
}
.card.gradient {
    background: linear-gradient(135deg, var(--accent1), var(--accent2));
    color: #fff;
}
.card:hover {
    transform: translateY(-6px);
    box-shadow: 0 18px 50px var(--shadow);
}

/* Code Blocks */
.code-block {
    background: rgba(0, 0, 0, 0.25);
    padding: 1rem;
    border-radius: 12px;
    overflow-x: auto;
    font-family: "JetBrains Mono", monospace;
    color: #d1fae5;
    margin-top: 1rem;
    font-size: 0.9rem;
}

/* Buttons */
.btn-back {
    display: inline-block;
    background: var(--card);
    border-radius: 14px;
    padding: 12px 22px;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text);
    text-decoration: none;
    box-shadow: 0 8px 24px var(--shadow);
}
.btn-back:hover {
    background: linear-gradient(135deg, var(--accent1), var(--accent2));
    color: #fff;
    transform: translateY(-5px);
}

/* Footer */
.footer {
    text-align: center;
    padding: 2rem;
    font-size: 0.9rem;
    color: var(--muted);
    border-top: 1px solid rgba(255, 255, 255, 0.12);
}

/* Animation */
.fade-up {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.8s var(--ease), transform 0.8s var(--ease);
}
.fade-up.visible {
    opacity: 1;
    transform: translateY(0);
}