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

:root {
    /* ── Layout & Chrome ── */
    --color-bg:        #ffffff;
    --color-text:      #1a1a2e;
    --color-muted:     #6b7280;
    --color-accent:    #4f46e5;
    --color-accent-hv: #4338ca;
    --color-header-bg: #1a1a2e;
    --color-header-tx: #f8fafc;
    --color-footer-bg: #111827;
    --color-footer-tx: #9ca3af;
    --color-border:    #e5e7eb;
    --color-drop-bg:   #ffffff;
    --font-sans:       system-ui, -apple-system, 'Segoe UI', sans-serif;
    --radius:          6px;
    --shadow-drop:     0 4px 16px rgba(0,0,0,.12);
    --header-h:        64px;
    --max-w:           1200px;

    /* ── Block design tokens (rc-* blocks) ── */
    --rc-accent:       #4f46e5;   /* primary brand color          */
    --rc-accent-dark:  #1a1a2e;   /* dark hero / CTA background   */
    --rc-accent-fg:    #ffffff;   /* text on accent backgrounds   */
    --rc-bg:           #ffffff;   /* light section background     */
    --rc-bg-alt:       #f8fafc;   /* alternate section background */
    --rc-text:         #1a1a2e;   /* headings / primary text      */
    --rc-text-body:    #374151;   /* body text                    */
    --rc-text-muted:   #6b7280;   /* secondary / muted text       */
    --rc-text-faint:   #9ca3af;   /* placeholder / faint text     */
    --rc-border:       #e5e7eb;   /* border color                 */
    --rc-radius:       16px;      /* card border radius           */
    --rc-radius-sm:    8px;       /* button / small radius        */
    --rc-section-pad:  80px 20px; /* section padding              */
    --rc-max-w:        1100px;    /* content max-width            */
    --rc-success:      #16a34a;   /* checkmark / success color    */
}

html { font-size: 16px; scroll-behavior: smooth; }

body {
    font-family: var(--font-sans);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* ── Header ─────────────────────────────────── */
header {
    background: var(--color-header-bg);
    color: var(--color-header-tx);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 1px 0 rgba(255,255,255,.06);
}

header nav {
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 0 1.5rem;
    height: var(--header-h);
    display: flex;
    align-items: center;
    gap: 2rem;
}

.site-name {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--color-header-tx);
    text-decoration: none;
    white-space: nowrap;
    letter-spacing: -.01em;
    flex-shrink: 0;
}

.site-name:hover { color: #c7d2fe; }

/* ── Top-nav list ────────────────────────────── */
header nav > ul {
    list-style: none;
    display: flex;
    align-items: center;
    gap: .25rem;
    flex-wrap: wrap;
}

header nav > ul > li { position: relative; }

header nav > ul > li > a {
    display: block;
    padding: .5rem .875rem;
    border-radius: var(--radius);
    color: #cbd5e1;
    text-decoration: none;
    font-size: .9375rem;
    font-weight: 500;
    transition: background .15s, color .15s;
    white-space: nowrap;
}

header nav > ul > li > a:hover,
header nav > ul > li:focus-within > a {
    background: rgba(255,255,255,.09);
    color: #fff;
}

header nav > ul > li > a.active,
header nav > ul > li > a[aria-current="page"] {
    background: var(--color-accent);
    color: #fff;
}

/* dropdown indicator */
header nav li.has-children > a::after {
    content: '▾';
    margin-left: .35rem;
    font-size: .75em;
    opacity: .7;
}

/* ── Dropdown ────────────────────────────────── */
header nav li.has-children > ul {
    list-style: none;
    position: absolute;
    top: calc(100% + .5rem);
    left: 0;
    min-width: 200px;
    background: var(--color-drop-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    box-shadow: var(--shadow-drop);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-6px);
    transition: opacity .18s, transform .18s, visibility .18s;
}

header nav li.has-children:hover > ul,
header nav li.has-children:focus-within > ul {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

header nav li.has-children > ul li a {
    display: block;
    padding: .6rem 1rem;
    color: var(--color-text);
    text-decoration: none;
    font-size: .9rem;
    transition: background .12s;
}

header nav li.has-children > ul li a:hover { background: #f3f4f6; }
header nav li.has-children > ul li a.active { color: var(--color-accent); font-weight: 600; }
header nav li.has-children > ul li + li { border-top: 1px solid var(--color-border); }

/* ── Main ────────────────────────────────────── */
main {
    flex: 1;
    max-width: var(--max-w);
    width: 100%;
    margin: 0 auto;
    padding: 2.5rem 1.5rem;
}

/* ── Footer ──────────────────────────────────── */
footer {
    background: var(--color-footer-bg);
    color: var(--color-footer-tx);
    padding: 2rem 1.5rem;
}

footer > .footer-inner {
    max-width: var(--max-w);
    margin: 0 auto;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 1.25rem;
}

footer ul {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: .25rem;
}

footer ul li a {
    display: block;
    padding: .3rem .7rem;
    border-radius: var(--radius);
    color: #9ca3af;
    text-decoration: none;
    font-size: .875rem;
    transition: color .15s;
}

footer ul li a:hover { color: #f9fafb; }
footer ul li a.active { color: #c7d2fe; }

footer .copyright {
    margin-left: auto;
    font-size: .8125rem;
    color: #4b5563;
}

@media (max-width: 640px) {
    footer > .footer-inner { flex-direction: column; align-items: flex-start; }
    footer .copyright { margin-left: 0; }
}