/* Layout */
.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
}


:root {
    --bg-dark: #1A1D21;
    --bg-dark-2: #202328;
    --bg-panel: #1F232A;
    --accent-blue: #3A7AFE;
    --accent-blue-soft: #5A8CFF;
    --text-primary: #E6EAF0;
    --text-secondary: #AEB4BE;
    --text-muted: #7A808A;
    --divider: #2A2E34;


/* Navigation */
nav {
    background: #1A1D21;
    border-bottom: 1px solid #e5e7eb;
    padding: 12px 0;
    text-align: center;
    position: sticky;
    top: 0;
    z-index: 10;

<div class="circuit-header">
    <div class="header-logo">
        <!-- Inline JR circuit icon -->
        <svg viewBox="0 0 320 220" class="jr-icon">
            <defs>
                <filter id="redGlowHeader" x="-50%" y="-50%" width="200%" height="200%">
                    <feGaussianBlur stdDeviation="3" result="blur"/>
                    <feColorMatrix in="blur" type="matrix"
                        values="1 0 0 0 0
                                0 0 0 0 0
                                0 0 0 0 0
                                0 0 0 0.8 0" result="glow"/>
                    <feMerge>
                        <feMergeNode in="glow"/>
                        <feMergeNode in="SourceGraphic"/>
                    </feMerge>
                </filter>
            </defs>

            <!-- JR circuit (static for header) -->
            <path class="trace-static" d="
                M 60 40
                H 120
                V 60
                H 80
                V 140
                C 80 160 70 170 60 170
                H 40

                M 140 40
                H 180
                C 210 40 230 60 230 85
                C 230 110 210 130 180 130
                H 160
                V 170

                M 160 130
                L 210 170" />

            <!-- LED Nodes -->
            <circle class="node" cx="60" cy="40" r="5"/>
            <circle class="node" cx="40" cy="170" r="5"/>
            <circle class="node" cx="230" cy="85" r="5"/>
            <circle class="node" cx="210" cy="170" r="5"/>
        </svg>
    </div>

    <div class="header-line"></div>
</div>


}

nav a {
    margin: 0 15px;
    color: #1e40af;
    font-weight: 600;
    text-decoration: none;
    transition: color 0.5s ease;
}

nav a:hover {
    color: #1e3a8a;
}

/* Download Button */
.download-btn {
    background: #1A1D21;
    color: white !important;
    padding: 6px 12px;
    border-radius: 6px;
    font-weight: 600;
    margin-left: 10px;
    transition: background 0.5s ease;
}

.download-btn:hover {
    background: #1e3a8a;
}

/* Header */
header {
    background: #1A1D21;
    color: white;
    padding: 60px 0 40px;
    text-align: center;
}



}

/* Gunmetal background with cinematic sheen */
body {
    margin: 0;
    padding: 0;
    font-family: 'Inter', sans-serif;
    background: linear-gradient(to bottom, var(--bg-dark), var(--bg-dark-2));
    color: var(--text-primary);
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
}

/* Subtle metallic noise texture (CSS-only) */
body::before {
    content: "";
    position: fixed;
    inset: 0;
    pointer-events: none;
    background: repeating-linear-gradient(
        90deg,
        rgba(255,255,255,0.015) 0px,
        rgba(255,255,255,0.015) 1px,
        transparent 1px,
        transparent 2px
    );
    opacity: 0.25;
    z-index: 0;
}

/* Cinematic radial highlight behind header */
header {
    position: relative;
    padding: 60px 20px 40px;
    text-align: center;
    z-index: 1;
}

header::before {
    content: "";
    position: absolute;
    top: -200px;
    left: 50%;
    transform: translateX(-50%);
    width: 900px;
    height: 900px;
    background: radial-gradient(
        circle,
        rgba(255,255,255,0.08) 0%,
        rgba(255,255,255,0) 70%
    );
    z-index: -1;
}

/* Headings */
h1, h2, h3 {
    font-weight: 700;
    letter-spacing: 0.5px;
    margin-bottom: 10px;
}

h1 {
    font-size: 2.8rem;
    color: var(--text-primary);
}

h2 {
    font-size: 1.8rem;
    color: var(--accent-blue);
}

/* Section styling */
section {
    background: var(--bg-panel);
    margin: 40px auto;
    padding: 30px;
    border-radius: 12px;
    max-width: 900px;
    box-shadow: 0 8px 20px rgba(0,0,0,0.35);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
}

section:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 28px rgba(0,0,0,0.45);
}

/* Links */
a {
    color: var(--accent-blue);
    text-decoration: none;
    transition: color 0.2s ease, text-shadow 0.2s ease;
}

a:hover {
    color: var(--accent-blue-soft);
    text-shadow: 0 0 8px var(--accent-blue-soft);
}

/* Buttons */
button, .btn {
    background: var(--accent-blue);
    color: white;
    padding: 12px 20px;
    border-radius: 8px;
    border: none;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s ease, box-shadow 0.2s ease;
}

button:hover, .btn:hover {
    background: var(--accent-blue-soft);
    box-shadow: 0 0 12px var(--accent-blue-soft);
}

/* Lists */
ul {
    padding-left: 20px;
}

li {
    margin-bottom: 8px;
    color: var(--text-secondary);
}

/* Footer */
footer {
    text-align: center;
    padding: 40px 0;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.circuit-header {
    width: 100%;
    height: 60px;
    background: #0f0f11;
    border-bottom: 1px solid #1a1a1d;
    display: flex;
    align-items: center;
    padding-left: 20px;
    position: relative;
}

.header-logo {
    display: flex;
    align-items: center;
}

.jr-icon {
    width: 48px;
    height: auto;
}

.trace-static {
    stroke: #ff2b3b;
    stroke-width: 3;
    fill: none;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.node {
    fill: #ff2b3b;
    filter: url(#redGlowHeader);
}

.header-line {
    position: absolute;
    bottom: 0;
    left: 0;
    height: 2px;
    width: 100%;
    background: linear-gradient(
        90deg,
        rgba(255, 43, 59, 0.0) 0%,
        rgba(255, 43, 59, 0.6) 40%,
        rgba(255, 43, 59, 0.0) 100%
    );
    box-shadow: 0 0 8px rgba(255, 43, 59, 0.4);
}

/* Optional: subtle glow pulse */
@keyframes bracketPulse {
    0%, 100% { box-shadow: 0 0 6px rgba(255, 43, 59, 0.4); }
    50% { box-shadow: 0 0 10px rgba(255, 43, 59, 0.7); }
}

.circuit-bracket {
    animation: bracketPulse 4s ease-in-out infinite;
}