/* Arkiphere — implementer learning path (shareable) */
@import url('https://fonts.googleapis.com/css2?family=DM+Sans:ital,opsz,wght@0,9..40,400;0,9..40,500;0,9..40,600;0,9..40,700&display=swap');

:root {
    --ark-navy: #1f4f7a;
    --ark-navy-dark: #163a5c;
    --ark-accent: #2563eb;
    --ark-green: #16a34a;
    --ark-grey: #64748b;
    --ark-grey-light: #94a3b8;
    --ark-bg: #f8fafc;
    --ark-border: #e2e8f0;
    --toc-w: 280px;
}

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

html { scroll-behavior: smooth; }

body {
    background: var(--ark-bg);
    color: #1e293b;
    font-family: 'DM Sans', system-ui, sans-serif;
    -webkit-font-smoothing: antialiased;
    line-height: 1.5;
}

.layout {
    display: grid;
    grid-template-columns: var(--toc-w) minmax(0, 1fr);
    min-height: 100vh;
}

.toc {
    background: #fff;
    border-right: 1px solid var(--ark-border);
    padding: 1.5rem 1rem 2rem;
    position: sticky;
    top: 0;
    height: 100vh;
    overflow-y: auto;
}

.toc__brand {
    color: var(--ark-navy);
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    margin-bottom: 0.35rem;
    text-transform: uppercase;
}

.toc__title {
    color: var(--ark-navy-dark);
    font-size: 1.05rem;
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: 1rem;
}

.toc__track {
    color: var(--ark-accent);
    font-size: 0.68rem;
    font-weight: 700;
    letter-spacing: 0.07em;
    margin: 1.1rem 0 0.4rem;
    text-transform: uppercase;
}

.toc__meta {
    color: var(--ark-grey);
    font-size: 0.78rem;
    margin-bottom: 1.25rem;
}

.toc nav ol {
    counter-reset: toc;
    list-style: none;
}

.toc nav li { margin-bottom: 0.15rem; }

.toc nav li ol {
    margin: 0.25rem 0 0.5rem 0.75rem;
    padding-left: 0;
}

.toc nav a {
    border-radius: 0.5rem;
    color: var(--ark-grey);
    display: block;
    font-size: 0.82rem;
    padding: 0.4rem 0.55rem;
    text-decoration: none;
    transition: background 0.15s, color 0.15s;
}

.toc nav a:hover,
.toc nav a.is-active {
    background: #eef4ff;
    color: var(--ark-accent);
    font-weight: 600;
}

.toc nav > ol > li > a {
    font-weight: 600;
    color: #334155;
}

.toc__share {
    border-top: 1px solid var(--ark-border);
    margin-top: 1.25rem;
    padding-top: 1rem;
}

.toc__share label {
    color: var(--ark-grey);
    display: block;
    font-size: 0.72rem;
    font-weight: 600;
    margin-bottom: 0.35rem;
    text-transform: uppercase;
}

.toc__share-row {
    display: flex;
    gap: 0.35rem;
}

.toc__share input {
    border: 1px solid var(--ark-border);
    border-radius: 0.45rem;
    flex: 1;
    font-size: 0.72rem;
    padding: 0.4rem 0.5rem;
    min-width: 0;
}

.toc__share button {
    background: var(--ark-navy);
    border: none;
    border-radius: 0.45rem;
    color: #fff;
    cursor: pointer;
    font-size: 0.72rem;
    font-weight: 600;
    padding: 0.4rem 0.65rem;
    white-space: nowrap;
}

.toc__share button:hover { background: var(--ark-navy-dark); }

.main { min-width: 0; }

.hero {
    background: linear-gradient(135deg, #eef4ff 0%, #fff 50%, #f0fdf4 100%);
    border-bottom: 1px solid var(--ark-border);
    padding: 2.5rem 2rem 2rem;
}

.hero__badge {
    background: rgba(37, 99, 235, 0.12);
    border-radius: 999px;
    color: var(--ark-accent);
    display: inline-block;
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.04em;
    margin-bottom: 0.75rem;
    padding: 0.3rem 0.75rem;
    text-transform: uppercase;
}

.hero h1 {
    color: var(--ark-navy-dark);
    font-size: clamp(1.5rem, 3vw, 2.1rem);
    font-weight: 700;
    line-height: 1.25;
    margin-bottom: 0.65rem;
    max-width: 42rem;
}

.hero__lead {
    color: var(--ark-grey);
    font-size: clamp(0.95rem, 1.4vw, 1.05rem);
    max-width: 40rem;
}

.hero__lead-en {
    color: var(--ark-grey-light);
    font-size: 0.88rem;
    margin-top: 0.5rem;
    max-width: 40rem;
}

.hero__cta {
    display: flex;
    flex-wrap: wrap;
    gap: 0.65rem;
    margin-top: 1.25rem;
}

.btn {
    border-radius: 0.65rem;
    display: inline-flex;
    font-size: 0.88rem;
    font-weight: 600;
    padding: 0.65rem 1.1rem;
    text-decoration: none;
    transition: transform 0.15s, box-shadow 0.15s;
}

.btn:hover { transform: translateY(-1px); }

.btn--primary {
    background: var(--ark-green);
    box-shadow: 0 4px 14px rgba(22, 163, 74, 0.25);
    color: #fff;
}

.btn--ghost {
    background: #fff;
    border: 1px solid var(--ark-border);
    color: var(--ark-navy);
}

.section {
    border-bottom: 1px solid var(--ark-border);
    padding: 2rem;
    scroll-margin-top: 1rem;
}

.section:nth-child(even) { background: #fff; }

.section__header {
    align-items: flex-start;
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem 1.25rem;
    justify-content: space-between;
    margin-bottom: 1.25rem;
}

.section__num {
    background: var(--ark-navy);
    border-radius: 0.45rem;
    color: #fff;
    font-size: 0.72rem;
    font-weight: 700;
    padding: 0.25rem 0.5rem;
}

.section h2 {
    color: var(--ark-navy-dark);
    flex: 1;
    font-size: clamp(1.15rem, 2vw, 1.45rem);
    font-weight: 700;
    min-width: 12rem;
}

.section__subtitle {
    color: var(--ark-grey-light);
    font-size: 0.85rem;
    font-weight: 500;
    width: 100%;
}

.video-wrap {
    aspect-ratio: 16 / 9;
    background: #0f172a;
    border-radius: 1rem;
    box-shadow: 0 16px 40px rgba(15, 23, 42, 0.12);
    margin-bottom: 1.25rem;
    max-width: 960px;
    overflow: hidden;
    width: 100%;
}

.video-wrap video {
    display: block;
    height: 100%;
    object-fit: contain;
    width: 100%;
}

.section__body {
    display: grid;
    gap: 1.25rem;
    grid-template-columns: minmax(0, 1fr) minmax(0, 280px);
    max-width: 960px;
}

.section__text p {
    color: var(--ark-grey);
    font-size: 0.92rem;
    margin-bottom: 0.65rem;
}

.section__text p strong { color: #334155; }

.section__points {
    background: #f8fafc;
    border: 1px solid var(--ark-border);
    border-radius: 0.85rem;
    padding: 1rem 1.1rem;
}

.section__points h3 {
    color: var(--ark-navy);
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.04em;
    margin-bottom: 0.55rem;
    text-transform: uppercase;
}

.section__points ul {
    color: var(--ark-grey);
    font-size: 0.82rem;
    list-style: none;
    padding: 0;
}

.section__points li {
    padding: 0.25rem 0 0.25rem 1rem;
    position: relative;
}

.section__points li::before {
    color: var(--ark-green);
    content: "✓";
    font-size: 0.72rem;
    font-weight: 700;
    left: 0;
    position: absolute;
}

.footer {
    color: var(--ark-grey-light);
    font-size: 0.78rem;
    padding: 2rem;
    text-align: center;
}

.footer a { color: var(--ark-accent); }

.toc-toggle {
    display: none;
}

@media (max-width: 900px) {
    .layout { grid-template-columns: 1fr; }

    .toc {
        border-right: none;
        border-bottom: 1px solid var(--ark-border);
        height: auto;
        position: relative;
    }

    .toc-toggle {
        background: var(--ark-navy);
        border: none;
        border-radius: 0.5rem;
        color: #fff;
        cursor: pointer;
        display: block;
        font-size: 0.82rem;
        font-weight: 600;
        margin-bottom: 0.75rem;
        padding: 0.5rem 0.85rem;
        width: 100%;
    }

    .toc nav { display: none; }
    .toc nav.is-open { display: block; }

    .section__body { grid-template-columns: 1fr; }
    .hero, .section { padding: 1.5rem 1.25rem; }
}

@media print {
    .toc { display: none; }
    .layout { grid-template-columns: 1fr; }
    .video-wrap { break-inside: avoid; }
}