:root {
    /* Primary surfaces */
    --bg: #0a0710; /* page background (very dark indigo) */
    --card: #0f0b18; /* cards, panels */
    --elevated: #120819; /* slightly different elevated surface */

    /* Typography */
    --text: #eef2ff; /* main text (soft white with blue tint) */
    --muted: #b8b3d9; /* secondary / muted text */
    --muted-2: #988fb2; /* tertiary / less-emphasized */

    /* Accent */
    --accent: #8b5cf6; /* primary interactive color (violet) */
    --accent-600: #6d28d9; /* darker accent for hover */
    --accent-rgb: 139, 92, 246;

    /* Borders & subtle strokes */
    --border-strong: rgba(255, 255, 255, 0.2);
    --border-subtle: rgba(255, 255, 255, 0.1);

    /* Code / pre */
    --code-bg: #0b0710;
    --code-border: rgba(255, 255, 255, 0.03);

    /* Form controls */
    --input-bg: #0b0710;
    --input-border: rgba(255, 255, 255, 0.06);

    /* Shadows */
    --shadow-sm: 0 8px 24px rgba(15, 7, 27, 0.6);
    --shadow-md: 0 20px 50px rgba(15, 7, 27, 0.7);

    /* Layout & misc */
    --radius: 10px;
    --gap: 1rem;
    --max-width: 900px;
    --mono:
        ui-monospace, SFMono-Regular, Menlo, Monaco, "Roboto Mono",
        "Courier New", monospace;
    --ui-font:
        Inter, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue",
        Arial;
    --transition: 180ms cubic-bezier(0.2, 0.9, 0.3, 1);
}

/* Global resets and base */
* {
    box-sizing: border-box;
}
html,
body {
    height: 100%;
}
body {
    margin: 0;
    font-family: var(--ui-font);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    background: var(--bg);
    color: var(--text);
    line-height: 1.45;
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
}

/* Layout container */
.container {
    max-width: var(--max-width);
    margin: 40px auto;
    padding: 0 1rem;
}

/* Card */
.card {
    background:
        linear-gradient(180deg, rgba(255, 255, 255, 0.01), transparent),
        var(--card);
    padding: 1.25rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-subtle);
}

/* Header */
.site-header {
    background: transparent;
    border-bottom: 1px solid var(--border-subtle);
}
.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 1rem 0;
}
.brand {
    font-weight: 700;
    font-size: 1.1rem;
    text-decoration: none;
    color: inherit;
}
.nav {
    display: flex;
    gap: 0.75rem;
    align-items: center;
}
.nav a {
    text-decoration: none;
    color: var(--muted);
    padding: 0.35rem 0.5rem;
    border-radius: 6px;
}
.nav a:hover {
    color: var(--accent);
    background: rgba(var(--accent-rgb), 0.06);
}

/* Main content */
.main-content {
    margin-top: 1rem;
}

/* Typography */
h1,
h2,
h3 {
    margin: 0 0 0.5rem 0;
    line-height: 1.15;
    color: var(--text);
}
h1 {
    font-size: 1.6rem;
}
h2 {
    font-size: 1.25rem;
    margin-top: 1rem;
}
p {
    margin: 0 0 1rem 0;
    color: var(--muted-2);
}

/* Sections */
section {
    margin-bottom: 2rem;
}
hr {
    border: none;
    border-top: 1px solid var(--border-subtle);
    margin: 2rem 0;
}
.section-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--text);
}

/* Buttons & links */
a {
    color: var(--accent);
    text-decoration: none;
}
a:hover {
    text-decoration: underline;
}

.btn {
    display: inline-block;
    padding: 0.5rem 0.85rem;
    border-radius: 8px;
    background: linear-gradient(180deg, var(--accent), var(--accent-600));
    color: #fff;
    font-weight: 600;
    text-decoration: none;
    border: none;
    cursor: pointer;
    transition:
        transform var(--transition),
        box-shadow var(--transition),
        background var(--transition);
    box-shadow: 0 8px 24px rgba(109, 40, 217, 0.12);
}
.btn:hover {
    transform: translateY(-1px);
    background: linear-gradient(180deg, var(--accent-600), #4c1d95);
    box-shadow: var(--shadow-sm);
    text-decoration: none !important;
}
.btn.secondary {
    background: transparent;
    color: var(--accent);
    border: 1px solid rgba(var(--accent-rgb), 0.12);
}

/* Form elements */
form {
    margin-top: 1rem;
    display: flex;
    gap: 0.5rem;
    align-items: center;
    flex-wrap: wrap;
}
label {
    display: inline-block;
    font-weight: 500;
    margin-right: 0.3rem;
    color: var(--muted);
}
input[type="text"],
input[type="search"],
input[type="email"],
textarea,
select {
    padding: 0.5rem 0.6rem;
    border: 1px solid var(--input-border);
    border-radius: 6px;
    background: var(--input-bg);
    color: var(--text);
    outline: none;
    min-height: 38px;
    transition:
        box-shadow var(--transition),
        border-color var(--transition),
        background var(--transition);
}
input::placeholder,
textarea::placeholder {
    color: var(--muted);
}
input:focus,
textarea:focus,
select:focus {
    box-shadow: 0 10px 30px rgba(var(--accent-rgb), 0.08);
    border-color: var(--accent);
}

/* Utility & small text */
.small {
    font-size: 0.95rem;
    color: var(--muted);
}
.note {
    color: var(--muted);
    font-size: 0.95rem;
}

/* Preformatted, code, blockquote */
pre,
code {
    font-family: var(--mono);
    font-size: 0.92rem;
    background: var(--code-bg);
    color: var(--text);
    padding: 0.15rem 0.35rem;
    border-radius: 6px;
    border: 1px solid var(--code-border);
}
pre {
    padding: 1rem;
    overflow: auto;
    border-radius: 8px;
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.02);
}
blockquote {
    margin: 0 0 1rem 0;
    padding: 0.75rem 1rem;
    border-left: 4px solid rgba(139, 92, 246, 0.12);
    color: var(--muted);
    background: linear-gradient(90deg, rgba(139, 92, 246, 0.02), transparent);
    border-radius: 6px;
}

/* Layout helpers */
.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1rem;
}
.row {
    display: flex;
    gap: 1rem;
    align-items: center;
    flex-wrap: wrap;
}

/* Footer */
.site-footer {
    margin-top: 2rem;
    padding: 1rem 0;
    color: var(--muted);
    text-align: center;
    font-size: 0.95rem;
}

/* Static asset helpers */
img {
    max-width: 100%;
    height: auto;
    border-radius: 6px;
}

/* Responsive adjustments */
@media (max-width: 720px) {
    .header-inner {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
    .container {
        margin: 20px auto;
        padding: 0 0.75rem;
    }
    h1 {
        font-size: 1.35rem;
    }
    form {
        flex-direction: column;
        align-items: stretch;
        gap: 0.5rem;
    }
    .nav {
        gap: 0.5rem;
    }
}

/* Accessibility / reduced motion */
@media (prefers-reduced-motion: reduce) {
    .btn,
    a,
    input,
    textarea {
        transition: none !important;
        animation: none !important;
    }
}

/* Extra helpers for emphasis */
.lead {
    color: var(--text);
    font-weight: 600;
}
.muted {
    color: var(--muted);
}