:root {
    --ink: #173247;
    --muted: #5d7180;
    --surface: #ffffff;
    --surface-soft: #f4f8fa;
    --line: #dce6ed;
    --blue: #1265a8;
    --blue-dark: #0c4778;
    --teal: #0c8b86;
    --orange: #e86e2f;
    --shadow: 0 18px 50px rgba(30, 62, 84, .12);
    font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    color: var(--ink);
    background: var(--surface-soft);
    line-height: 1.65;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--surface-soft); }
a { color: inherit; }
button, input, textarea, select { font: inherit; }
.shell { width: min(1180px, calc(100% - 40px)); margin-inline: auto; }
.skip-link { position: fixed; left: 1rem; top: -5rem; z-index: 100; padding: .7rem 1rem; background: white; border-radius: .5rem; }
.skip-link:focus { top: 1rem; }
.visually-hidden { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

.site-header { position: sticky; top: 0; z-index: 20; border-bottom: 1px solid rgba(220,230,237,.9); background: rgba(255,255,255,.94); backdrop-filter: blur(16px); }
.nav-row { min-height: 78px; display: flex; align-items: center; justify-content: space-between; gap: 2rem; }
.brand { display: flex; align-items: center; gap: .85rem; text-decoration: none; }
.brand-mark { display: grid; place-items: center; width: 43px; height: 43px; border-radius: 13px; color: white; background: linear-gradient(145deg, var(--blue), var(--teal)); font-weight: 800; box-shadow: 0 8px 22px rgba(18,101,168,.22); }
.brand strong, .brand small { display: block; }
.brand strong { font-size: 1.02rem; letter-spacing: -.02em; }
.brand small { color: var(--muted); font-size: .78rem; }
nav { display: flex; align-items: center; gap: 1.15rem; }
nav a { text-decoration: none; font-weight: 650; font-size: .9rem; }
nav a:hover { color: var(--blue); }

.hero, .detail-hero { overflow: hidden; color: white; background: radial-gradient(circle at 82% 18%, rgba(43,190,183,.33), transparent 30%), linear-gradient(135deg, #0b365d 0%, #1265a8 56%, #0b7975 100%); }
.hero-grid { min-height: 570px; display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(300px, .75fr); gap: clamp(2rem, 6vw, 6rem); align-items: center; padding-block: 76px; }
.eyebrow { margin: 0 0 .8rem; color: var(--teal); font-size: .78rem; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; }
.hero .eyebrow, .detail-hero .eyebrow, .cta-card .eyebrow { color: #49e0d7; }
.hero h1 { max-width: 820px; margin: 0; font-size: clamp(2.7rem, 6vw, 5.2rem); line-height: 1.02; letter-spacing: -.055em; }
.hero-copy { max-width: 780px; margin: 1.45rem 0 0; color: rgba(255,255,255,.84); font-size: clamp(1.05rem, 2vw, 1.24rem); }
.hero-actions { display: flex; flex-wrap: wrap; gap: .85rem; margin-top: 2rem; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 48px; padding: .75rem 1.2rem; border: 1px solid transparent; border-radius: 12px; text-decoration: none; font-weight: 750; cursor: pointer; transition: transform .18s ease, box-shadow .18s ease, background .18s ease; }
.button:hover { transform: translateY(-2px); }
.button.primary { color: var(--blue-dark); background: white; box-shadow: 0 13px 30px rgba(0,0,0,.18); }
.button.secondary { color: white; border-color: rgba(255,255,255,.45); background: rgba(255,255,255,.08); }
.button.light { color: var(--blue-dark); background: white; white-space: nowrap; }
.button.dark { color: white; background: var(--blue-dark); }
.hero-card { position: relative; padding: 2rem; border: 1px solid rgba(255,255,255,.22); border-radius: 26px; background: rgba(7,38,65,.34); box-shadow: 0 24px 70px rgba(0,0,0,.22); backdrop-filter: blur(13px); }
.hero-card h2 { margin: .8rem 0 1rem; font-size: 1.7rem; line-height: 1.18; }
.hero-card ul { margin: 0; padding-left: 1.2rem; color: rgba(255,255,255,.86); }
.hero-card li + li { margin-top: .65rem; }
.hero-code { display: inline-flex; padding: .34rem .62rem; border-radius: 8px; color: #052e35; background: #63e3da; font: 800 .78rem ui-monospace, SFMono-Regular, Menlo, monospace; }

.trust-strip { border-bottom: 1px solid var(--line); background: white; }
.trust-grid { display: grid; grid-template-columns: repeat(4, 1fr); }
.trust-grid article { padding: 1.55rem 1.3rem; border-right: 1px solid var(--line); }
.trust-grid article:first-child { padding-left: 0; }
.trust-grid article:last-child { border-right: 0; }
.trust-grid strong, .trust-grid span { display: block; }
.trust-grid strong { font-size: 1.22rem; }
.trust-grid span { color: var(--muted); font-size: .82rem; }

.course-section, .books-section { padding-block: 82px 94px; }
.section-heading { display: flex; justify-content: space-between; align-items: end; gap: 2rem; margin-bottom: 2rem; }
.section-heading h2, .learning-section h2 { margin: 0; font-size: clamp(2rem, 4vw, 3.25rem); line-height: 1.1; letter-spacing: -.04em; }
.narrow-heading { align-items: start; }
.heading-copy { max-width: 520px; margin: 0; color: var(--muted); }
.course-count { margin: 0; color: var(--muted); white-space: nowrap; }
.course-count strong { color: var(--ink); font-size: 1.45rem; }
.filters { display: grid; gap: 1rem; margin-bottom: 2rem; }
.search-field { position: relative; display: block; max-width: 610px; }
.search-field svg { position: absolute; left: 1rem; top: 50%; width: 20px; transform: translateY(-50%); fill: none; stroke: var(--muted); stroke-width: 1.8; stroke-linecap: round; }
.search-field input { width: 100%; min-height: 52px; padding: .8rem 1rem .8rem 3rem; border: 1px solid var(--line); border-radius: 14px; color: var(--ink); background: white; box-shadow: 0 8px 25px rgba(30,62,84,.05); outline: none; }
.search-field input:focus, input:focus, textarea:focus, select:focus { border-color: var(--blue); box-shadow: 0 0 0 4px rgba(18,101,168,.12); outline: none; }
.filter-buttons { display: flex; flex-wrap: wrap; gap: .55rem; }
.filter-button { padding: .55rem .85rem; border: 1px solid var(--line); border-radius: 999px; color: var(--muted); background: white; cursor: pointer; }
.filter-button:hover, .filter-button.is-active { color: white; border-color: var(--blue); background: var(--blue); }
.course-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1.25rem; }
.course-card { display: flex; flex-direction: column; min-height: 100%; padding: 1.45rem; border: 1px solid var(--line); border-radius: 20px; background: var(--surface); box-shadow: 0 8px 28px rgba(30,62,84,.07); transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease; }
.course-card:hover { transform: translateY(-5px); border-color: #b7cfdf; box-shadow: var(--shadow); }
.course-card[hidden] { display: none; }
.card-topline { min-height: 31px; display: flex; align-items: start; justify-content: space-between; gap: .7rem; }
.topic-list { display: flex; flex-wrap: wrap; gap: .35rem; }
.topic-badge { padding: .25rem .52rem; border-radius: 999px; color: var(--blue-dark); background: #e8f3fb; font-size: .7rem; font-weight: 760; }
.availability { color: var(--teal); font-size: .72rem; font-weight: 800; white-space: nowrap; }
.course-card h3 { margin: 1rem 0 .5rem; font-size: 1.35rem; line-height: 1.22; letter-spacing: -.025em; }
.subtitle { margin: -.1rem 0 .5rem; color: var(--blue); font-weight: 650; }
.summary { flex-grow: 1; margin: .4rem 0 1.2rem; color: var(--muted); font-size: .94rem; }
.date-block { padding: .9rem 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.date-block strong, .date-block span { display: block; }
.date-block strong { font-size: .95rem; }
.date-block span { color: var(--muted); font-size: .82rem; }
details { margin-top: .35rem; }
details summary { color: var(--blue); font-size: .82rem; font-weight: 680; cursor: pointer; }
details ul { margin: .45rem 0 0; padding-left: 1.15rem; color: var(--muted); font-size: .82rem; }
.card-link, .text-link, .side-card a { display: flex; justify-content: space-between; gap: .7rem; margin-top: 1rem; color: var(--blue); text-decoration: none; font-weight: 760; }
.card-link:hover, .text-link:hover, .side-card a:hover { color: var(--orange); }
.notice { margin-bottom: 1.5rem; padding: 1rem 1.15rem; border-radius: 14px; }
.notice.warning { color: #684b00; border: 1px solid #eed78f; background: #fff8dc; }
.notice.error { color: #7a2020; border: 1px solid #efbaba; background: #fff0f0; }
.notice.success { color: #125c42; border: 1px solid #a6d9c5; background: #eefaf5; }
.notice h3 { margin: 0 0 .25rem; }
.notice p { margin: .25rem 0; }
.empty-result { padding: 2rem; text-align: center; color: var(--muted); }

.profile-section { padding-block: 90px; background: white; }
.trainer-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.4rem; }
.trainer-card { display: grid; grid-template-columns: auto 1fr; gap: 1.3rem; padding: 2rem; border: 1px solid var(--line); border-radius: 24px; background: var(--surface-soft); }
.trainer-initials { display: grid; place-items: center; width: 64px; height: 64px; border-radius: 19px; color: white; background: linear-gradient(145deg, var(--blue), var(--teal)); font-weight: 850; font-size: 1.15rem; }
.trainer-card h3 { margin: 0; font-size: 1.65rem; }
.trainer-card p { color: var(--muted); }
.trainer-role { margin: .1rem 0 1rem; color: var(--blue) !important; font-weight: 700; }
.client-panel { margin-top: 1.4rem; padding: 1.5rem 1.7rem; border-radius: 20px; color: white; background: #123a55; }
.client-panel strong { display: block; margin-bottom: .8rem; }
.client-list { display: flex; flex-wrap: wrap; gap: .55rem; }
.client-list span { padding: .35rem .65rem; border: 1px solid rgba(255,255,255,.2); border-radius: 999px; color: rgba(255,255,255,.88); font-size: .82rem; }

.learning-section { padding-block: 92px; color: white; background: #10283a; }
.learning-grid { display: grid; grid-template-columns: 1.1fr .9fr; gap: clamp(2rem, 6vw, 6rem); align-items: center; }
.learning-section p { color: rgba(255,255,255,.76); }
.check-list { padding: 0; list-style: none; }
.check-list li { position: relative; padding-left: 1.8rem; margin-top: .7rem; color: rgba(255,255,255,.86); }
.check-list li::before { content: "✓"; position: absolute; left: 0; color: #49e0d7; font-weight: 900; }
.learning-card { padding: 1.6rem; border: 1px solid rgba(255,255,255,.14); border-radius: 22px; background: #081c2b; box-shadow: 0 30px 70px rgba(0,0,0,.25); }
.terminal-dot-row { display: flex; gap: .35rem; margin-bottom: 1.2rem; }
.terminal-dot-row i { width: 10px; height: 10px; border-radius: 50%; background: #ef7567; }
.terminal-dot-row i:nth-child(2) { background: #e7be55; }
.terminal-dot-row i:nth-child(3) { background: #61c884; }
.learning-card pre { margin: 0; color: #9ff3dc; font-size: 1rem; overflow: auto; }
.learning-card p { margin: 1.3rem 0 0; }

.book-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; }
.book-grid-three { grid-template-columns: repeat(3, 1fr); }
.book-card { min-height: 250px; padding: 1.5rem; border: 1px solid var(--line); border-radius: 20px; background: white; box-shadow: 0 8px 28px rgba(30,62,84,.06); }
.book-card > span { display: inline-flex; align-items: center; justify-content: center; min-height: 32px; padding: .35rem .65rem; border-radius: 999px; color: white; background: var(--blue); font-weight: 800; font-size: .75rem; letter-spacing: .035em; text-transform: uppercase; }
.book-card h3 { margin: 1.45rem 0 .6rem; line-height: 1.2; }
.book-card p { margin: 0; color: var(--blue); font-weight: 700; }
.book-card small { display: block; margin-top: 1rem; color: var(--muted); }
.included-book-note { display: flex; justify-content: space-between; gap: 1.5rem; margin: 0 0 1.35rem; padding: 1.15rem 1.35rem; border: 1px solid #b7d8ce; border-radius: 16px; background: #edf9f5; }
.included-book-note strong { color: #0c624d; }
.included-book-note span { color: #41665c; }
.book-meta { margin: 1.15rem 0 0; padding-top: 1rem; border-top: 1px solid var(--line); }
.book-meta div { display: grid; grid-template-columns: 78px 1fr; gap: .7rem; padding: .22rem 0; }
.book-meta dt { color: var(--muted); font-size: .78rem; font-weight: 700; }
.book-meta dd { margin: 0; color: var(--ink); font-size: .84rem; font-weight: 650; }
.elearning-note { margin: 1.25rem 0 0; padding: 1rem 1.2rem; border-left: 4px solid var(--blue); background: #edf5fb; color: var(--muted); }

.cta-section { padding: 0 0 90px; }
.cta-card { display: flex; align-items: center; justify-content: space-between; gap: 2rem; padding: clamp(2rem, 5vw, 4rem); border-radius: 28px; color: white; background: linear-gradient(120deg, #0c4778, #0c8b86); box-shadow: var(--shadow); }
.cta-card h2 { margin: 0; font-size: clamp(1.7rem, 4vw, 2.7rem); line-height: 1.1; }
.cta-card p:not(.eyebrow) { max-width: 720px; margin: .8rem 0 0; color: rgba(255,255,255,.82); }

.detail-hero-grid { display: grid; grid-template-columns: minmax(0, 1.35fr) minmax(290px, .65fr); gap: clamp(2rem, 6vw, 5rem); align-items: center; padding-block: 70px; }
.breadcrumb { margin: 0 0 1.3rem; color: rgba(255,255,255,.72); }
.breadcrumb a { color: white; }
.breadcrumb span { padding: 0 .5rem; }
.light-badge { color: #073f55; background: #7ce7df; }
.detail-hero h1 { margin: 1rem 0 .8rem; font-size: clamp(2.45rem, 5vw, 4.5rem); line-height: 1.04; letter-spacing: -.045em; }
.detail-subtitle { margin: 0; color: #8df0e8; font-weight: 750; font-size: 1.15rem; }
.detail-lead { max-width: 780px; color: rgba(255,255,255,.85); font-size: 1.1rem; }
.date-panel { padding: 1.6rem; border: 1px solid rgba(255,255,255,.2); border-radius: 22px; background: rgba(5,34,54,.36); }
.date-panel h2 { margin-top: 0; }
.date-panel ul { padding: 0; list-style: none; }
.date-panel li { padding: .75rem 0; border-bottom: 1px solid rgba(255,255,255,.14); }
.date-panel li strong, .date-panel li span { display: block; }
.date-panel li span { color: rgba(255,255,255,.7); font-size: .85rem; }
.date-panel .text-link { color: white; }
.detail-content { display: grid; grid-template-columns: minmax(0, 1fr) 320px; gap: 3rem; padding-block: 78px 95px; }
.content-block + .content-block { margin-top: 4rem; }
.content-block h2 { margin: 0 0 1.2rem; font-size: clamp(1.9rem, 3vw, 2.7rem); line-height: 1.15; }
.rich-text { color: #334d60; }
.rich-text ul, .rich-text ol { padding-left: 1.4rem; }
.rich-text li + li { margin-top: .4rem; }
.rich-text h2, .rich-text h3, .rich-text h4 { margin-top: 2rem; color: var(--ink); }
.rich-text hr { border: 0; border-top: 1px solid var(--line); }
.detail-side { display: grid; align-content: start; gap: 1rem; }
.side-card { padding: 1.35rem; border: 1px solid var(--line); border-radius: 18px; background: white; }
.side-card h3 { margin-top: 0; }
.side-card p { color: var(--muted); }
.compact-rich { font-size: .9rem; }

.simple-page { min-height: 60vh; padding-block: 80px 100px; }
.simple-page > h1, .contact-intro h1 { margin: 0 0 1.2rem; font-size: clamp(2.4rem, 5vw, 4.4rem); line-height: 1.04; letter-spacing: -.045em; }
.legal-page { max-width: 850px; }
.legal-page h2 { margin-top: 2.5rem; }
.legal-note { margin-top: 2.5rem; padding: 1rem; border-left: 4px solid var(--orange); background: #fff4ec; }
.contact-page { display: grid; grid-template-columns: .8fr 1.2fr; gap: clamp(2rem, 6vw, 5rem); align-items: start; }
.contact-intro > p { color: var(--muted); }
.contact-facts { margin-top: 2rem; }
.contact-facts p { padding: 1rem 0; border-bottom: 1px solid var(--line); }
.contact-facts strong, .contact-facts span { display: block; }
.contact-facts span { color: var(--muted); font-size: .9rem; }
.form-card { padding: 2rem; border: 1px solid var(--line); border-radius: 24px; background: white; box-shadow: var(--shadow); }
.form-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem; }
.form-grid label { color: var(--ink); font-size: .88rem; font-weight: 700; }
.form-grid input, .form-grid textarea, .form-grid select { width: 100%; margin-top: .35rem; padding: .78rem .85rem; border: 1px solid var(--line); border-radius: 10px; color: var(--ink); background: white; font-weight: 400; }
.full-field { grid-column: 1 / -1; }
.spam-protection { padding: 1rem 1.1rem; border: 1px solid #d8cfa9; border-radius: 14px; background: #fffaf0; }
.spam-protection > strong { display: block; color: #74530b; font-size: .98rem; }
.spam-protection > p { margin: .25rem 0 .75rem; color: #6b6250; font-size: .84rem; font-weight: 400; }
.spam-protection label { display: block; max-width: 360px; }
.privacy-check { display: flex; gap: .65rem; align-items: start; margin: 1.1rem 0 1.4rem; color: var(--muted); font-size: .88rem; }
.privacy-check input { margin-top: .25rem; }
.trap { position: absolute !important; left: -10000px !important; }

.site-footer { color: #d7e6ef; background: #10283a; }
.footer-grid { min-height: 120px; display: flex; justify-content: space-between; align-items: center; gap: 2rem; }
.footer-grid p { margin: .25rem 0 0; color: #9fb4c3; }
.footer-grid nav a { color: white; }
.copyright { padding: 1rem 0 1.5rem; border-top: 1px solid rgba(255,255,255,.1); color: #8fa5b4; font-size: .82rem; }

@media (max-width: 1000px) {
    nav { gap: .8rem; }
    nav a { font-size: .82rem; }
    .course-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .hero-grid, .detail-hero-grid, .learning-grid, .detail-content, .contact-page { grid-template-columns: 1fr; }
    .hero-card { max-width: 650px; }
    .date-panel { max-width: 650px; }
    .detail-side { grid-template-columns: repeat(2, 1fr); }
    .book-grid, .book-grid-three { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 760px) {
    .shell { width: min(100% - 24px, 1180px); }
    .nav-row { min-height: 68px; }
    .brand small { display: none; }
    .site-header nav > a:not(:last-child) { display: none; }
    .hero-grid { padding-block: 55px; }
    .hero h1 { font-size: clamp(2.45rem, 13vw, 4rem); }
    .trust-grid { grid-template-columns: repeat(2, 1fr); }
    .trust-grid article { border-bottom: 1px solid var(--line); }
    .trust-grid article:nth-child(2) { border-right: 0; }
    .course-section, .books-section { padding-block: 60px 72px; }
    .section-heading, .cta-card, .footer-grid { align-items: flex-start; flex-direction: column; }
    .trainer-grid, .course-grid, .detail-side, .form-grid { grid-template-columns: 1fr; }
    .trainer-card { grid-template-columns: 1fr; }
    .full-field { grid-column: auto; }
    .book-grid, .book-grid-three { grid-template-columns: 1fr; }
    .included-book-note { flex-direction: column; gap: .35rem; }
    .cta-card { border-radius: 22px; }
    .footer-grid { justify-content: center; padding-block: 2rem; gap: 1rem; }
    .footer-grid nav { flex-wrap: wrap; }
}

/* V6 systems focus additions */
.proof-section { padding-block: 82px; }
.proof-section .specialist-points { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: .9rem; }
.specialist-points article { padding: 1.25rem 1.35rem; border: 1px solid var(--line); border-radius: 8px 22px 8px 22px; background: white; box-shadow: 0 8px 28px rgba(30,62,84,.05); }
.specialist-points span { color: var(--blue); font: 850 .75rem ui-monospace, SFMono-Regular, Menlo, monospace; }
.specialist-points h3 { margin: .45rem 0 .25rem; font-size: 1.05rem; }
.specialist-points p { margin: 0; color: var(--muted); font-size: .9rem; }
.detail-focus li { color: var(--ink); }
.detail-focus li::before { color: var(--teal); }
.source-note { padding: 1rem 1.15rem; border-left: 4px solid var(--teal); background: var(--surface-soft); }
.compact-list { margin-top: 1rem !important; }
@media (max-width: 1000px) { .proof-section .specialist-points { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 650px) { .proof-section .specialist-points { grid-template-columns: 1fr; } }

/* ============================================================
   Technical course presentation layer
   ============================================================ */
:root {
    --linux: #1d9364;
    --shell: #8aa51e;
    --admin-track: #236c93;
    --dev-track: #e78a28;
    --strategy-track: #6f5a8f;
    --tech: #5d7180;
    --navy-950: #06131f;
    --navy-900: #0a1d2d;
    --navy-800: #102d43;
}

.site-header::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    bottom: -1px;
    height: 2px;
    background: linear-gradient(90deg, var(--linux) 0 24%, var(--admin-track) 24% 45%, var(--shell) 45% 66%, var(--dev-track) 66% 84%, var(--strategy-track) 84% 100%);
    opacity: .78;
}
.brand-mark {
    border-radius: 10px 18px 10px 18px;
    background: linear-gradient(145deg, var(--navy-800), var(--blue));
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

.systems-hero {
    position: relative;
    background:
        radial-gradient(circle at 12% 15%, rgba(22,130,196,.28), transparent 26%),
        radial-gradient(circle at 86% 18%, rgba(141,187,51,.20), transparent 24%),
        radial-gradient(circle at 78% 84%, rgba(29,147,100,.18), transparent 28%),
        linear-gradient(135deg, #06131f 0%, #0a2235 48%, #0c3850 100%);
}
.hero-grid-pattern {
    position: absolute;
    inset: 0;
    pointer-events: none;
    opacity: .22;
    background-image:
        linear-gradient(rgba(255,255,255,.07) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,.07) 1px, transparent 1px);
    background-size: 34px 34px;
    mask-image: linear-gradient(to bottom, rgba(0,0,0,.9), transparent 90%);
}
.systems-hero .hero-grid { position: relative; min-height: 620px; }
.systems-hero .hero-main { position: relative; z-index: 1; }
.systems-hero .eyebrow { color: #9ed8ff; }
.systems-hero h1 { max-width: 860px; font-size: clamp(2.65rem, 5.6vw, 5.05rem); }
.hero-emphasis {
    display: inline;
    color: #fff;
    background: linear-gradient(90deg, #9ed8ff, #f1a279, #94d8b9);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}
.hero-proof span { background: rgba(255,255,255,.045); }

.system-stack {
    position: relative;
    z-index: 1;
    padding: 1rem;
    border: 1px solid rgba(255,255,255,.16);
    border-radius: 14px 34px 14px 34px;
    background: rgba(3,15,24,.72);
    box-shadow: 0 36px 90px rgba(0,0,0,.35);
    backdrop-filter: blur(16px);
}
.stack-toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: .25rem .25rem .9rem;
    border-bottom: 1px solid rgba(255,255,255,.1);
}
.stack-toolbar .terminal-dot-row { margin: 0; }
.stack-toolbar code { color: rgba(255,255,255,.52); font-size: .7rem; }
.stack-layer {
    --track: var(--tech);
    display: grid;
    grid-template-columns: 28px 1fr auto;
    gap: .8rem;
    align-items: center;
    margin-top: .7rem;
    padding: .9rem 1rem;
    border: 1px solid rgba(255,255,255,.11);
    border-left: 4px solid var(--track);
    border-radius: 9px 18px 9px 18px;
    background: linear-gradient(90deg, color-mix(in srgb, var(--track) 14%, transparent), rgba(255,255,255,.035));
}
.stack-layer > span { color: rgba(255,255,255,.4); font: 800 .7rem ui-monospace, SFMono-Regular, Menlo, monospace; }
.stack-layer strong, .stack-layer small { display: block; }
.stack-layer strong { color: white; font-size: 1rem; }
.stack-layer small { margin-top: .08rem; color: rgba(255,255,255,.55); font-size: .72rem; }
.stack-layer > code { color: var(--track); font: 900 1.05rem ui-monospace, SFMono-Regular, Menlo, monospace; }
.stack-linux { --track: var(--linux); }
.stack-shell { --track: var(--shell); }
.stack-caption { margin: 1rem .35rem .2rem; color: rgba(255,255,255,.58); font-size: .82rem; }

.track-section { padding-block: 78px 68px; }
.track-heading { margin-bottom: 1.45rem; }
.track-grid { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: .8rem; }
.track-card {
    --track: var(--tech);
    display: grid;
    grid-template-columns: auto 1fr auto;
    align-items: center;
    gap: .75rem;
    min-height: 92px;
    padding: 1rem;
    border: 1px solid var(--line);
    border-top: 3px solid var(--track);
    border-radius: 10px 22px 10px 22px;
    background: white;
    box-shadow: 0 8px 28px rgba(30,62,84,.055);
    text-decoration: none;
    transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
}
.track-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: color-mix(in srgb, var(--track) 45%, var(--line)); }
.track-symbol {
    display: grid;
    place-items: center;
    width: 42px;
    height: 42px;
    border-radius: 9px 14px 9px 14px;
    color: white;
    background: var(--track);
    font: 850 .82rem ui-monospace, SFMono-Regular, Menlo, monospace;
}
.track-card strong, .track-card small { display: block; }
.track-card strong { font-size: .98rem; }
.track-card small { margin-top: .1rem; color: var(--muted); font-size: .73rem; }
.track-arrow { color: var(--track); font-size: 1.15rem; }
.category-linux { --track: var(--linux); }
.category-shell { --track: var(--shell); }
.category-tech { --track: var(--tech); }

.course-section { padding-top: 74px; background: #fff; }
.filters {
    grid-template-columns: minmax(280px, 1fr) auto;
    align-items: center;
    gap: 1rem 1.4rem;
    padding: 1rem;
    border: 1px solid var(--line);
    border-radius: 14px 26px 14px 26px;
    background: #f8fbfc;
}
.search-field { max-width: none; }
.filter-buttons { justify-content: flex-end; }
.filter-button { --track: var(--blue); position: relative; font-weight: 720; }
.filter-button.category-linux { --track: var(--linux); }
.filter-button.category-shell { --track: var(--shell); }
.filter-button:hover, .filter-button.is-active { border-color: var(--track); background: var(--track); }

.course-grid { gap: 1.05rem; }
.course-card {
    --track: var(--tech);
    position: relative;
    overflow: hidden;
    padding: 1.35rem 1.35rem 1.15rem;
    border-radius: 10px 24px 10px 24px;
    border-color: #dce6ed;
    background: linear-gradient(180deg, #fff 0%, #fff 70%, color-mix(in srgb, var(--track) 2.7%, #fff) 100%);
}
.course-card:hover { border-color: color-mix(in srgb, var(--track) 38%, #dce6ed); }
.card-accent { position: absolute; inset: 0 0 auto; height: 5px; background: var(--track); }
.category-badge {
    display: inline-flex;
    align-items: center;
    min-height: 26px;
    padding: .2rem .58rem;
    border-radius: 6px 11px 6px 11px;
    color: var(--track);
    background: color-mix(in srgb, var(--track) 10%, #fff);
    border: 1px solid color-mix(in srgb, var(--track) 20%, #fff);
    font: 800 .72rem ui-monospace, SFMono-Regular, Menlo, monospace;
}
.availability { display: inline-flex; align-items: center; gap: .38rem; color: #287251; }
.availability i { width: 7px; height: 7px; border-radius: 50%; background: #2aa66f; box-shadow: 0 0 0 4px rgba(42,166,111,.11); }
.course-card h3 { margin-top: 1.15rem; }
.card-meta {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    align-items: end;
    margin-top: auto;
    padding-top: 1rem;
    border-top: 1px solid var(--line);
}
.card-meta .date-block { padding: 0; border: 0; }
.card-meta .date-block > span { font-size: .7rem; text-transform: uppercase; letter-spacing: .07em; }
.card-meta .date-block strong { margin-top: .1rem; }
.card-meta .date-block small { display: block; margin-top: .1rem; color: var(--muted); font-size: .72rem; }
.course-code { color: color-mix(in srgb, var(--track) 75%, var(--muted)); font: 800 .72rem ui-monospace, SFMono-Regular, Menlo, monospace; white-space: nowrap; }
.course-card .card-link { color: var(--track); padding-top: .1rem; }

.profile-section { position: relative; overflow: hidden; background: #f5f8fa; }
.profile-section::before {
    content: "";
    position: absolute;
    width: 420px;
    height: 420px;
    right: -180px;
    top: -190px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(91,91,214,.10), transparent 68%);
}
.trainer-feature-grid { position: relative; display: grid; grid-template-columns: minmax(0, 1.65fr) minmax(260px, .75fr); gap: 1.2rem; }
.trainer-feature {
    display: grid;
    grid-template-columns: 210px 1fr;
    gap: 1.8rem;
    padding: 1.2rem;
    border: 1px solid var(--line);
    border-radius: 12px 34px 12px 34px;
    background: white;
    box-shadow: 0 18px 50px rgba(30,62,84,.09);
}
.trainer-photo-wrap { position: relative; min-height: 270px; }
.trainer-photo-wrap img { width: 100%; height: 100%; min-height: 270px; object-fit: cover; border-radius: 9px 26px 9px 26px; }
.trainer-badge {
    position: absolute;
    left: 12px;
    bottom: 12px;
    padding: .4rem .7rem;
    border-radius: 6px 12px 6px 12px;
    color: white;
    background: var(--navy-900);
    box-shadow: 0 8px 20px rgba(0,0,0,.18);
    font-size: .72rem;
    font-weight: 800;
    letter-spacing: .04em;
    text-transform: uppercase;
}
.trainer-feature-copy { align-self: center; padding: .6rem .6rem .6rem 0; }
.trainer-kicker { margin: 0 0 .35rem; color: var(--admin-track); font-size: .76rem; font-weight: 800; letter-spacing: .05em; text-transform: uppercase; }
.trainer-feature h3 { margin: 0 0 .75rem; font-size: clamp(2rem, 3.2vw, 3rem); letter-spacing: -.04em; }
.trainer-feature-copy > p:not(.trainer-kicker) { color: var(--muted); }
.trainer-tags { display: flex; flex-wrap: wrap; gap: .45rem; margin-top: 1.15rem; }
.trainer-tags span { padding: .34rem .62rem; border: 1px solid #d7d7f2; border-radius: 999px; color: #4444ad; background: #f4f4ff; font-size: .75rem; font-weight: 740; }
.trainer-support {
    display: grid;
    grid-template-columns: 74px 1fr;
    align-content: start;
    gap: 1rem;
    padding: 1.25rem;
    border: 1px solid var(--line);
    border-radius: 12px 28px 12px 28px;
    background: #10283a;
    color: white;
}
.trainer-support img { width: 74px; height: 74px; object-fit: cover; border-radius: 50%; border: 3px solid rgba(255,255,255,.15); }
.trainer-support h3 { margin: .1rem 0 .4rem; }
.trainer-support p { margin: 0; color: rgba(255,255,255,.67); font-size: .88rem; }
.support-label { color: #94d8b9; font-size: .7rem; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; }

.learning-section { background: linear-gradient(135deg, #071622, #10283a 62%, #13394a); }
.learning-card { border-radius: 10px 30px 10px 30px; }
.terminal-title { margin: -.55rem 0 1rem; padding-bottom: .7rem; border-bottom: 1px solid rgba(255,255,255,.10); color: rgba(255,255,255,.38); font: .72rem ui-monospace, SFMono-Regular, Menlo, monospace; }
.cta-card { border-radius: 12px 36px 12px 36px; background: linear-gradient(115deg, #0b3150, #145b72 48%, #176d59); }

/* Category-aware course detail pages */
.detail-hero { --track: var(--blue); position: relative; background:
    radial-gradient(circle at 83% 18%, color-mix(in srgb, var(--track) 34%, transparent), transparent 28%),
    linear-gradient(135deg, #06131f, #0a263a 60%, #0c3b4c); }
.detail-hero.category-linux { --track: var(--linux); }
.detail-hero.category-shell { --track: var(--shell); }
.detail-hero .light-badge { color: white; background: color-mix(in srgb, var(--track) 72%, #111); border: 1px solid rgba(255,255,255,.15); }
.detail-hero .detail-subtitle { color: color-mix(in srgb, var(--track) 55%, white); }
.detail-hero .date-panel { border-top: 4px solid var(--track); }
.detail-category-label { display: inline-flex; padding: .28rem .58rem; border-radius: 6px 11px 6px 11px; color: white; background: var(--track); font: 800 .72rem ui-monospace, SFMono-Regular, Menlo, monospace; }
.side-trainer { display: grid; grid-template-columns: 52px 1fr; gap: .8rem; align-items: center; }
.side-trainer img { width: 52px; height: 52px; border-radius: 50%; object-fit: cover; }
.side-trainer h3 { margin: 0; }
.side-trainer p { margin: .15rem 0 0; }

@media (max-width: 1100px) {
    .track-grid { grid-template-columns: repeat(3, minmax(0,1fr)); }
    .filters { grid-template-columns: 1fr; }
    .filter-buttons { justify-content: flex-start; }
}
@media (max-width: 1000px) {
    .trainer-feature-grid { grid-template-columns: 1fr; }
    .trainer-support { max-width: 620px; }
}
@media (max-width: 760px) {
    .systems-hero .hero-grid { min-height: auto; }
    .system-stack { max-width: 620px; }
    .track-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
    .trainer-feature { grid-template-columns: 1fr; }
    .trainer-photo-wrap { min-height: 0; }
    .trainer-photo-wrap img { height: min(430px, 90vw); min-height: 0; }
    .trainer-feature-copy { padding: .25rem .5rem .7rem; }
}
@media (max-width: 520px) {
    .track-grid { grid-template-columns: 1fr; }
    .stack-layer { grid-template-columns: 24px 1fr auto; padding: .8rem; }
    .card-meta { align-items: start; flex-direction: column; }
}


/* linux-kurse.eu v4 — Linux-specific presentation */
:root { --forest:#146b48; --forest-dark:#0b4c34; --lime:#8dbb33; --amber:#e78a28; --entry:#2b8a5d; --admin:#236c93; --dev:#8a5a2b; --strategy:#6f5a8f; }
.brand-mark { background:linear-gradient(145deg,var(--forest-dark),var(--forest)); box-shadow:0 8px 22px rgba(20,107,72,.22); }
.hero,.detail-hero { background:radial-gradient(circle at 82% 18%,rgba(141,187,51,.28),transparent 30%),linear-gradient(135deg,#082d24 0%,#0d5b43 58%,#335d27 100%); }
.hero-emphasis { color:#d8f2a3; }
.hero .eyebrow,.detail-hero .eyebrow,.cta-card .eyebrow { color:#c9ed84; }
.button.primary,.button.light { color:var(--forest-dark); }
.button.dark { background:var(--forest-dark); }
nav a:hover,.card-link,.text-link,.side-card a { color:var(--forest); }
.specialist-section { padding-block:82px; background:#eef5ef; }
.specialist-grid { display:grid; grid-template-columns:minmax(0,1.25fr) minmax(320px,.75fr); gap:clamp(2rem,6vw,5rem); }
.specialist-copy h2 { margin:0 0 1.2rem; font-size:clamp(1.8rem,3.2vw,2.8rem); line-height:1.08; letter-spacing:-.04em; }
.specialist-copy>p:not(.eyebrow){color:var(--muted)}
.specialist-emphasis { margin-top:1.5rem; padding:1.2rem 1.35rem; border-left:4px solid var(--lime); background:white; box-shadow:0 8px 28px rgba(30,62,84,.05); }
.specialist-points { display:grid; gap:.8rem; }
.specialist-points article { padding:1.25rem 1.35rem; border:1px solid var(--line); border-radius:8px 22px 8px 22px; background:white; }
.specialist-points span { color:var(--forest); font:850 .75rem ui-monospace,SFMono-Regular,Menlo,monospace; }
.specialist-points h3 { margin:.45rem 0 .25rem; }.specialist-points p { margin:0;color:var(--muted);font-size:.9rem; }
.stack-entry { --track:var(--entry); }.stack-admin { --track:var(--admin); }.stack-dev { --track:var(--amber); }
.category-entry { --track:var(--entry); }.category-admin { --track:var(--admin); }.category-shell { --track:var(--shell); }.category-dev { --track:var(--amber); }.category-strategy { --track:var(--strategy); }
.filter-button.category-entry { --track:var(--entry); }.filter-button.category-admin { --track:var(--admin); }.filter-button.category-shell { --track:var(--shell); }.filter-button.category-dev { --track:var(--amber); }.filter-button.category-strategy { --track:var(--strategy); }
.detail-hero.category-entry { --track:var(--entry); }.detail-hero.category-admin { --track:var(--admin); }.detail-hero.category-shell { --track:var(--shell); }.detail-hero.category-dev { --track:var(--amber); }.detail-hero.category-strategy { --track:var(--strategy); }
.trainer-photo-circle { width:84px;height:84px;object-fit:cover;border-radius:50%;box-shadow:0 8px 20px rgba(0,0,0,.12); }
.process-section { padding-block:82px; background:#f4f8f5; }.process-grid { display:grid;grid-template-columns:repeat(3,1fr);gap:1rem; }.process-grid article { padding:1.5rem;border:1px solid var(--line);border-radius:10px 24px 10px 24px;background:white; }.process-grid span { display:grid;place-items:center;width:36px;height:36px;border-radius:10px;color:white;background:var(--forest);font-weight:850; }.process-grid h3 { margin:.9rem 0 .35rem; }.process-grid p { margin:0;color:var(--muted); }
.cta-card { background:linear-gradient(115deg,#0b3829,#146b48 52%,#617b27); }.cta-actions{display:flex;flex-wrap:wrap;gap:.7rem;align-items:center}.cta-card .button.secondary{border-color:rgba(255,255,255,.5)}
@media(max-width:1000px){.specialist-grid{grid-template-columns:1fr}.process-grid{grid-template-columns:1fr}.trainer-grid{grid-template-columns:1fr}}


/* v5: trainer presentation aligned with python-schulungen.de */
.profile-layout { display:grid; grid-template-columns:minmax(0,1.45fr) minmax(300px,.65fr); gap:clamp(2rem,7vw,6rem); }
.profile-lead { max-width:760px; color:var(--muted); font-size:1.05rem; }
.trainer-lines { display:grid; gap:1rem; margin-top:2rem; }
.trainer-lines article { display:grid; grid-template-columns:auto 1fr; gap:1rem; padding-top:1.25rem; border-top:1px solid var(--line); }
.trainer-photo { width:76px; height:76px; object-fit:cover; border-radius:50%; border:3px solid white; box-shadow:0 8px 24px rgba(31,24,68,.15); }
.trainer-lines h3 { margin:0 0 .25rem; }
.trainer-lines p { margin:0; color:var(--muted); }
.experience-panel { align-self:start; padding:2rem; border-radius:8px 35px 8px 35px; color:white; background:var(--forest-dark,#0b3829); box-shadow:var(--shadow); }
.experience-panel .eyebrow { color:#b8db55; }
.experience-panel h3 { margin:.2rem 0 .8rem; font-size:1.75rem; line-height:1.18; }
.experience-panel p { color:rgba(255,255,255,.8); }
.experience-panel .text-link { color:#d4ee82; }
.experience-panel .client-list { margin:1.2rem 0 1.35rem; }
.experience-panel .client-list span { border-color:rgba(255,255,255,.22); color:rgba(255,255,255,.92); background:rgba(255,255,255,.05); }
@media(max-width:900px){ .profile-layout{grid-template-columns:1fr;} }
@media(max-width:620px){ .trainer-lines article{grid-template-columns:auto 1fr;} .trainer-photo{width:68px;height:68px;} }

/* v6: filters remain usable without JavaScript. */
.filter-button { text-decoration:none; display:inline-flex; align-items:center; justify-content:center; }
.filter-submit { min-height:46px; justify-self:start; }