/* TB-Kurse, Kurse & Beratung Seite */

.tb-ku {
    --tb-ku-fg: #0E0E2A;
    --tb-ku-mut: #5b5b78;
    --tb-ku-line: #e5e7ee;
    --tb-ku-bg-alt: #f5f3ff;
    --tb-ku-accent: #7C3AED;
    --tb-ku-accent-bg: rgba(124, 58, 237, 0.10);
    --tb-ku-radius: 14px;
    color: var(--tb-ku-fg);
    line-height: 1.55;
}

.tb-ku__hero {
    padding: clamp(40px, 7vw, 96px) 0 clamp(32px, 6vw, 72px);
    background:
        /* Sanfte Punktraster, Klassenzimmer-/Whiteboard-Anklang */
        radial-gradient(circle, rgba(124, 58, 237, 0.08) 1.5px, transparent 1.5px),
        linear-gradient(180deg, #fff 0%, var(--tb-ku-bg-alt) 100%);
    background-size: 24px 24px, 100% 100%;
    position: relative;
    overflow: hidden;
}
.tb-ku__hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 95% 5%, rgba(124, 58, 237, 0.10) 0%, transparent 40%),
        radial-gradient(circle at 5% 95%, rgba(124, 58, 237, 0.06) 0%, transparent 35%);
    pointer-events: none;
    z-index: 0;
}
.tb-ku__hero-inner { position: relative; z-index: 1; }
.tb-ku__hero-inner {
    max-width: 880px;
    margin: 0 auto;
    padding: 0 clamp(16px, 4vw, 32px);
}
.tb-ku__eyebrow {
    display: inline-block;
    font-size: 12px;
    letter-spacing: 1.2px;
    text-transform: uppercase;
    color: var(--tb-ku-accent);
    background: var(--tb-ku-accent-bg);
    padding: 5px 12px;
    border-radius: 999px;
    font-weight: 700;
    margin-bottom: 18px;
}
.tb-ku__title {
    font-size: clamp(36px, 6vw, 64px);
    line-height: 1.05;
    margin: 0 0 18px;
    font-weight: 800;
    letter-spacing: -0.02em;
}
.tb-ku__title-accent { color: var(--tb-ku-accent); }
.tb-ku__lead {
    font-size: clamp(17px, 1.6vw, 20px);
    color: var(--tb-ku-mut);
    max-width: 720px;
    margin: 0 0 24px;
}
.tb-ku__hero-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}
.tb-ku__pill {
    display: inline-block;
    padding: 6px 13px;
    background: #fff;
    border: 1px solid var(--tb-ku-line);
    border-radius: 999px;
    font-size: 13px;
    font-weight: 600;
    color: var(--tb-ku-fg);
}

.tb-ku__section {
    padding: clamp(40px, 6vw, 80px) clamp(16px, 4vw, 32px);
    max-width: 1100px;
    margin: 0 auto;
}
.tb-ku__section--alt {
    max-width: none;
    background: var(--tb-ku-bg-alt);
    padding-left: 0;
    padding-right: 0;
}
.tb-ku__section--alt > * {
    max-width: 1100px;
    margin-left: auto;
    margin-right: auto;
    padding-left: clamp(16px, 4vw, 32px);
    padding-right: clamp(16px, 4vw, 32px);
}
.tb-ku__h2 {
    font-size: clamp(26px, 3.5vw, 40px);
    margin: 0 0 12px;
    font-weight: 800;
    letter-spacing: -0.01em;
}
.tb-ku__h2--centered { text-align: center; }
.tb-ku__sub {
    color: var(--tb-ku-mut);
    max-width: 760px;
    margin: 0 0 36px;
    font-size: clamp(15px, 1.4vw, 17px);
}

.tb-ku__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 22px;
}
.tb-ku__card {
    background: #fff;
    border: 1px solid var(--tb-ku-line);
    border-radius: var(--tb-ku-radius);
    padding: 24px 26px;
    border-top: 4px solid var(--tb-ku-accent);
    display: flex;
    flex-direction: column;
}
.tb-ku__card-titel {
    font-size: 19px;
    font-weight: 800;
    margin: 0 0 6px;
    letter-spacing: -0.005em;
}
.tb-ku__card-zg {
    color: var(--tb-ku-mut);
    font-style: italic;
    margin: 0 0 14px;
    font-size: 14px;
}
.tb-ku__card-meta {
    list-style: none;
    margin: 0 0 14px;
    padding: 12px 0;
    border-top: 1px solid var(--tb-ku-line);
    border-bottom: 1px solid var(--tb-ku-line);
    font-size: 13.5px;
}
.tb-ku__card-meta li { margin-bottom: 4px; }
.tb-ku__card-meta strong { color: var(--tb-ku-mut); font-weight: 600; min-width: 64px; display: inline-block; }
.tb-ku__card-inhalt {
    margin: 0;
    font-size: 14.5px;
    line-height: 1.6;
    flex: 1;
}

.tb-ku__cols {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 22px;
}
.tb-ku__col {
    background: #fff;
    border: 1px solid var(--tb-ku-line);
    border-radius: var(--tb-ku-radius);
    padding: 24px 26px;
}
.tb-ku__col h3 {
    font-size: 18px;
    font-weight: 800;
    margin: 0 0 12px;
    letter-spacing: -0.005em;
}
.tb-ku__col p {
    margin: 0;
    color: var(--tb-ku-fg);
    font-size: 14.5px;
    line-height: 1.6;
}

.tb-ku__cta {
    text-align: center;
    padding: clamp(48px, 8vw, 100px) clamp(16px, 4vw, 32px);
    max-width: 780px;
    margin: 0 auto;
}
.tb-ku__cta-lead {
    color: var(--tb-ku-mut);
    margin: 0 0 28px;
    font-size: 16px;
}
.tb-ku__cta-row {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 28px;
}
.tb-ku__btn {
    display: inline-block;
    padding: 12px 22px;
    border-radius: 999px;
    font-weight: 700;
    text-decoration: none;
    border: 1px solid var(--tb-ku-line);
    color: var(--tb-ku-fg);
    background: #fff;
    transition: transform 120ms ease, box-shadow 120ms ease;
}
.tb-ku__btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 18px rgba(14,14,42,0.08);
}
.tb-ku__btn--primary {
    background: var(--tb-ku-accent);
    color: #fff;
    border-color: var(--tb-ku-accent);
}
.tb-ku__cta-foot {
    color: var(--tb-ku-mut);
    font-style: italic;
    font-size: 13px;
    margin: 0;
}

@media (prefers-reduced-motion: reduce) {
    .tb-ku__btn { transition: none; }
}

/* ── Live-MNIST-Demo Section ─────────────────────────────────────── */
.tb-ku__section--demo {
    background: linear-gradient(180deg, #fbfbff, #f5f5fc);
    border-top: 1px solid var(--tb-ku-line);
    border-bottom: 1px solid var(--tb-ku-line);
}
.tb-ku__eyebrow--inline {
    display: inline-block;
    margin-bottom: 0.5rem;
    color: var(--tb-ku-accent);
    font-weight: 700;
    letter-spacing: 0.16em;
    font-size: 0.78rem;
    text-transform: uppercase;
}
.tb-ku__demo-explain {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin-top: 1.6rem;
}
@media (max-width: 720px) {
    .tb-ku__demo-explain { grid-template-columns: 1fr; }
}
.tb-ku__demo-card {
    background: #fff;
    border: 1px solid var(--tb-ku-line);
    border-radius: 12px;
    padding: 1.1rem 1.2rem;
}
.tb-ku__demo-card h3 {
    margin: 0 0 0.4rem;
    font-size: 1rem;
    font-weight: 700;
    color: var(--tb-ku-fg);
}
.tb-ku__demo-card p {
    margin: 0;
    font-size: 0.92rem;
    line-height: 1.55;
    color: var(--tb-ku-mut);
}
.tb-ku__demo-foot {
    margin-top: 1.4rem;
    font-size: 0.88rem;
    line-height: 1.6;
    color: var(--tb-ku-mut);
    text-align: center;
    max-width: 720px;
    margin-left: auto;
    margin-right: auto;
}
.tb-ku__demo-foot a {
    color: var(--tb-ku-accent);
    text-decoration: underline;
    text-underline-offset: 2px;
}