:root {
    --bg: #08111d;
    --bg-elevated: #0f1c2e;
    --panel: rgba(10, 23, 38, 0.88);
    --panel-border: rgba(126, 219, 255, 0.18);
    --surface: #f3f7fb;
    --surface-muted: #d6e0ea;
    --text: #dfe9f3;
    --text-muted: #97aac0;
    --ink: #06111d;
    --cyan: #73e8ff;
    --cyan-strong: #1fbfd6;
    --violet: #7b85ff;
    --success: #67d39d;
    --danger: #ff7b7b;
    --shadow: 0 24px 70px rgba(0, 0, 0, 0.28);
    --radius-lg: 28px;
    --radius-md: 18px;
    --radius-sm: 12px;
    --container: 1120px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    min-height: 100vh;
    background:
        radial-gradient(circle at top left, rgba(115, 232, 255, 0.16), transparent 35%),
        radial-gradient(circle at top right, rgba(123, 133, 255, 0.12), transparent 32%),
        linear-gradient(180deg, #07111d 0%, #0b1626 45%, #0e1928 100%);
    color: var(--text);
    font-family: "IBM Plex Sans", sans-serif;
    line-height: 1.7;
}

img {
    display: block;
    max-width: 100%;
}

a {
    color: var(--cyan);
    text-decoration: none;
}

a:hover {
    color: #aef2ff;
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
    outline: 3px solid rgba(115, 232, 255, 0.85);
    outline-offset: 3px;
}

h1,
h2,
h3,
h4,
h5,
h6 {
    color: #f7fbff;
    font-family: "Space Grotesk", sans-serif;
    line-height: 1.15;
    margin: 0 0 1rem;
}

p {
    margin: 0 0 1rem;
}

.container {
    width: min(calc(100% - 2rem), var(--container));
    margin: 0 auto;
}

.reading-width {
    width: min(calc(100% - 2rem), 880px);
}

.site-main {
    padding: 2rem 0 5rem;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    backdrop-filter: blur(18px);
    background: rgba(5, 12, 21, 0.82);
    border-bottom: 1px solid rgba(115, 232, 255, 0.12);
}

.nav-shell {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    min-height: 82px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    font-family: "Space Grotesk", sans-serif;
    letter-spacing: 0.08em;
}

.brand-mark {
    color: var(--cyan);
}

.brand-name {
    color: #f8fbff;
}

.site-nav {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-link {
    padding: 0.85rem 1rem;
    color: var(--surface);
    border-radius: 999px;
    position: relative;
}

.nav-link.is-active::after {
    content: "";
    position: absolute;
    left: 1rem;
    right: 1rem;
    bottom: 0.35rem;
    height: 2px;
    border-radius: 999px;
    background: linear-gradient(90deg, var(--cyan), var(--violet));
}

.nav-toggle {
    display: none;
    border: 1px solid rgba(115, 232, 255, 0.24);
    background: rgba(115, 232, 255, 0.08);
    color: var(--surface);
    padding: 0.8rem 1rem;
    border-radius: 999px;
    font: inherit;
}

.site-footer {
    border-top: 1px solid rgba(115, 232, 255, 0.1);
    padding: 2rem 0 3rem;
}

.footer-shell {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.footer-copy,
.footer-links a {
    color: var(--text-muted);
}

.footer-links {
    display: flex;
    gap: 1rem;
}

.message-stack {
    display: grid;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.flash {
    padding: 1rem 1.1rem;
    border-radius: var(--radius-sm);
    border: 1px solid rgba(115, 232, 255, 0.12);
    background: rgba(6, 20, 32, 0.92);
}

.flash-success {
    border-color: rgba(103, 211, 157, 0.24);
    color: #dff9eb;
}

.flash-error,
.flash-danger {
    border-color: rgba(255, 123, 123, 0.28);
    color: #ffe0e0;
}

.hero,
.page-section {
    padding: 2rem 0;
}

.hero-grid,
.contact-layout,
.courses-layout,
.article-header,
.field-row,
.cart-card {
    display: grid;
    gap: 2rem;
}

.hero-grid {
    grid-template-columns: 1fr 1.1fr;
    align-items: center;
    min-height: calc(100vh - 180px);
}

.hero-visual {
    position: relative;
    padding: 1.25rem;
}

.hero-logo-shell {
    position: relative;
    z-index: 1;
    width: min(100%, 470px);
    margin: 2rem auto;
    padding: 1.1rem;
    border-radius: 30px;
    background: linear-gradient(180deg, rgba(6, 18, 32, 0.92), rgba(8, 24, 40, 0.82));
    border: 1px solid rgba(115, 232, 255, 0.16);
    box-shadow: 0 20px 50px rgba(3, 10, 20, 0.45);
}

.hero-pattern {
    position: absolute;
    inset: 0;
    border-radius: var(--radius-lg);
    background:
        linear-gradient(rgba(115, 232, 255, 0.08) 1px, transparent 1px),
        linear-gradient(90deg, rgba(115, 232, 255, 0.08) 1px, transparent 1px),
        radial-gradient(circle at 15% 20%, rgba(123, 133, 255, 0.18), transparent 18%),
        radial-gradient(circle at 68% 34%, rgba(115, 232, 255, 0.12), transparent 24%);
    background-size: 28px 28px, 28px 28px, auto, auto;
    border: 1px solid rgba(115, 232, 255, 0.15);
    box-shadow: var(--shadow);
}

.hero-pattern::before,
.hero-pattern::after {
    content: "";
    position: absolute;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(115, 232, 255, 0.7), transparent);
}

.hero-pattern::before {
    top: 30%;
    left: 10%;
    width: 52%;
    transform: rotate(-14deg);
}

.hero-pattern::after {
    bottom: 28%;
    right: 11%;
    width: 38%;
    transform: rotate(18deg);
}

.hero-photo {
    width: min(100%, 420px);
    border-radius: 24px;
    margin: 0 auto;
}

.hero-logo {
    width: 100%;
    max-width: 430px;
    aspect-ratio: 1 / 1;
    object-fit: contain;
    border-radius: 22px;
}

.eyebrow {
    margin-bottom: 0.85rem;
    color: var(--cyan);
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 0.18em;
    text-transform: uppercase;
}

.hero-copy h1,
.page-intro h1,
.article-header h1 {
    font-size: clamp(2.4rem, 5vw, 4.6rem);
}

.hero-text,
.page-intro p,
.card-copy,
.rich-copy,
.field-help {
    color: var(--surface-muted);
}

.hero-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-top: 2rem;
}

.button-primary,
.button-secondary,
.button-danger,
.button-disabled,
input[type="submit"],
button {
    display: inline-flex;
    justify-content: center;
    align-items: center;
    min-height: 50px;
    padding: 0.85rem 1.35rem;
    border-radius: 999px;
    border: 1px solid transparent;
    font: inherit;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.button-primary,
input[type="submit"]:not(.button-secondary):not(.button-danger),
button[type="submit"]:not(.button-secondary):not(.button-danger) {
    background: linear-gradient(135deg, var(--cyan-strong), var(--violet));
    color: #06111d;
}

.button-secondary {
    background: rgba(115, 232, 255, 0.08);
    border-color: rgba(115, 232, 255, 0.24);
    color: var(--surface);
}

.button-danger {
    background: rgba(255, 123, 123, 0.12);
    border-color: rgba(255, 123, 123, 0.22);
    color: #ffe1e1;
}

.button-disabled {
    background: rgba(151, 170, 192, 0.12);
    color: var(--text-muted);
    cursor: not-allowed;
}

.button-primary:hover,
.button-secondary:hover,
.button-danger:hover,
input[type="submit"]:hover,
button[type="submit"]:hover {
    transform: translateY(-1px);
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
}

.card-grid-three {
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.signal-card,
.article-card,
.console-panel,
.sidebar-panel,
.summary-panel {
    background: var(--panel);
    border: 1px solid var(--panel-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
}

.signal-card,
.summary-panel {
    padding: 1.5rem;
}

.signal-card {
    transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}

.signal-card:hover,
.signal-card:focus-within {
    transform: translateY(-4px);
    border-color: rgba(115, 232, 255, 0.32);
    box-shadow: 0 32px 80px rgba(0, 0, 0, 0.35);
}

.signal-card h2,
.article-card h1 {
    margin-bottom: 0.75rem;
}

.signal-card-header,
.console-header,
.breadcrumbs,
.category-list,
.cart-actions,
.inline-form {
    display: flex;
    gap: 0.85rem;
    flex-wrap: wrap;
    align-items: center;
}

.meta-chip {
    display: inline-flex;
    align-items: center;
    min-height: 32px;
    padding: 0.35rem 0.8rem;
    border-radius: 999px;
    background: rgba(115, 232, 255, 0.12);
    color: var(--cyan);
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0.04em;
}

.meta-rail,
.article-subhead,
.breadcrumbs,
.breadcrumbs a {
    color: var(--text-muted);
}

.page-intro {
    margin-bottom: 2rem;
}

.text-link {
    font-weight: 700;
}

.stack-lg,
.stack-md,
.form-stack {
    display: grid;
    gap: 1.5rem;
}

.article-shell {
    display: grid;
    gap: 1.5rem;
    width: min(calc(100% - 2rem), 960px);
}

.article-shell-wide {
    width: min(calc(100% - 2rem), var(--container));
}

.article-back-link {
    justify-self: start;
    width: fit-content;
    min-height: 38px;
    padding: 0.55rem 0.95rem;
    font-size: 0.9rem;
}

.article-card {
    padding: 2rem;
}

.article-header {
    grid-template-columns: minmax(0, 1fr) 240px;
    align-items: start;
    margin-bottom: 2rem;
}

.article-header-course {
    grid-template-columns: minmax(0, 1fr) 220px;
}

.meta-panel {
    display: grid;
    gap: 0.9rem;
    padding: 1.2rem;
    border-radius: var(--radius-md);
    background: rgba(115, 232, 255, 0.06);
    border: 1px solid rgba(115, 232, 255, 0.12);
}

.meta-panel p,
.price-tag {
    margin: 0;
}

.meta-panel span {
    display: block;
    color: var(--text-muted);
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.rich-copy {
    max-width: 72ch;
}

.rich-copy h2,
.rich-copy h3,
.rich-copy h4 {
    margin-top: 2rem;
}

.rich-copy pre,
.rich-copy code {
    font-family: "IBM Plex Mono", "SFMono-Regular", monospace;
}

.rich-copy pre {
    overflow-x: auto;
    padding: 1rem;
    border-radius: var(--radius-sm);
    background: #06101a;
    border: 1px solid rgba(115, 232, 255, 0.15);
}

.rich-copy table {
    width: 100%;
    border-collapse: collapse;
    margin: 1.5rem 0;
}

.rich-copy th,
.rich-copy td {
    padding: 0.8rem;
    border-bottom: 1px solid rgba(115, 232, 255, 0.12);
    text-align: left;
}

.comment-section {
    display: grid;
    gap: 1.5rem;
    width: min(100%, calc(var(--container) / 2));
    justify-self: center;
}

.comment-card p:last-child {
    margin-bottom: 0;
}

.contact-layout {
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
    align-items: start;
}

.console-panel {
    padding: 1.5rem;
}

.console-header {
    padding-bottom: 1rem;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid rgba(115, 232, 255, 0.12);
}

.console-header p {
    margin: 0;
    color: var(--surface);
    font-weight: 600;
}

.console-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--success);
    box-shadow: 0 0 0 6px rgba(103, 211, 157, 0.16);
}

.field-row {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.field-group {
    display: grid;
    gap: 0.55rem;
}

.field-group.has-error input,
.field-group.has-error textarea,
.field-group.has-error select {
    border-color: rgba(255, 123, 123, 0.75);
    background-color: rgba(90, 17, 17, 0.24);
    box-shadow: 0 0 0 1px rgba(255, 123, 123, 0.18);
}

.field-group label {
    font-weight: 600;
    color: var(--surface);
}

input[type="text"],
input[type="email"],
input[type="search"],
textarea,
select {
    width: 100%;
    border: 1px solid rgba(115, 232, 255, 0.16);
    border-radius: 16px;
    background: rgba(3, 12, 22, 0.74);
    color: var(--surface);
    padding: 0.9rem 1rem;
    font: inherit;
}

select {
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    padding-right: 3.2rem;
    background-image:
        linear-gradient(45deg, transparent 50%, var(--cyan) 50%),
        linear-gradient(135deg, var(--cyan) 50%, transparent 50%);
    background-position:
        calc(100% - 1.4rem) calc(50% - 0.2rem),
        calc(100% - 0.95rem) calc(50% - 0.2rem);
    background-size: 0.5rem 0.5rem, 0.5rem 0.5rem;
    background-repeat: no-repeat;
    cursor: pointer;
}

select option {
    background: #0b1626;
    color: var(--surface);
}

textarea {
    min-height: 220px;
    resize: vertical;
}

.comment-section textarea,
textarea.comment-textarea {
    height: 110px;
    min-height: 110px;
}

.field-error,
.form-errors {
    color: #ffd7d7;
}

.field-error {
    display: inline-flex;
    align-items: center;
    width: fit-content;
    padding: 0.45rem 0.75rem;
    border-radius: 999px;
    border: 1px solid rgba(255, 123, 123, 0.38);
    background: rgba(110, 24, 24, 0.45);
    font-size: 0.92rem;
    font-weight: 700;
    letter-spacing: 0.01em;
}

.form-errors {
    padding: 1rem;
    border-radius: var(--radius-sm);
    border: 1px solid rgba(255, 123, 123, 0.24);
    background: rgba(90, 17, 17, 0.28);
}

.form-status {
    min-height: 1.4rem;
    color: var(--text-muted);
}

.courses-layout {
    grid-template-columns: 260px minmax(0, 1fr);
    align-items: start;
}

.sidebar-panel,
.content-panel {
    padding: 1.5rem;
}

.category-list {
    flex-direction: column;
    align-items: stretch;
}

.category-link {
    padding: 0.85rem 1rem;
    border-radius: 14px;
    color: var(--surface-muted);
    background: rgba(255, 255, 255, 0.03);
}

.category-link.is-active,
.category-link:hover {
    background: rgba(115, 232, 255, 0.12);
    color: var(--surface);
}

.course-card {
    display: grid;
    gap: 1rem;
}

.course-image-link {
    display: block;
}

.course-image {
    width: 100%;
    aspect-ratio: 16 / 9;
    object-fit: cover;
    border-radius: 20px;
}

.course-detail-image {
    width: 100%;
    max-width: 220px;
    aspect-ratio: 1 / 1;
    object-fit: cover;
    border-radius: 24px;
    justify-self: end;
}

.purchase-panel {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 1rem;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(115, 232, 255, 0.1);
}

.purchase-panel select {
    width: auto;
    min-width: 84px;
}

.cart-card {
    grid-template-columns: 120px minmax(0, 1fr) auto;
    align-items: center;
}

.cart-image {
    width: 120px;
    aspect-ratio: 1 / 1;
    object-fit: cover;
    border-radius: 18px;
}

.cart-main h2,
.cart-summary p {
    margin-bottom: 0.5rem;
}

.cart-summary {
    text-align: right;
}

.summary-panel {
    margin-top: 1.5rem;
}

.pagination {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.75rem;
    margin-top: 2rem;
}

.page-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 44px;
    min-height: 44px;
    padding: 0.75rem 1rem;
    border-radius: 999px;
    border: 1px solid rgba(115, 232, 255, 0.16);
    color: var(--surface);
    background: rgba(255, 255, 255, 0.03);
}

.page-link.is-current {
    background: linear-gradient(135deg, var(--cyan-strong), var(--violet));
    color: #06111d;
}

.page-link.is-disabled {
    color: var(--text-muted);
    opacity: 0.7;
}

@media (max-width: 920px) {
    .hero-grid,
    .contact-layout,
    .courses-layout,
    .article-header,
    .article-header-course {
        grid-template-columns: 1fr;
    }

    .meta-panel,
    .course-detail-image {
        justify-self: start;
    }
}

@media (max-width: 760px) {
    .nav-toggle {
        display: inline-flex;
    }

    .site-nav {
        position: absolute;
        top: 82px;
        right: 1rem;
        left: 1rem;
        display: none;
        flex-direction: column;
        align-items: stretch;
        padding: 1rem;
        border-radius: 24px;
        background: rgba(4, 12, 22, 0.96);
        border: 1px solid rgba(115, 232, 255, 0.12);
        box-shadow: var(--shadow);
    }

    .site-nav.is-open {
        display: flex;
    }

    .field-row,
    .cart-card {
        grid-template-columns: 1fr;
    }

    .cart-summary {
        text-align: left;
    }
}

@media (max-width: 480px) {
    .container {
        width: min(calc(100% - 1.25rem), var(--container));
    }

    .hero-copy h1,
    .page-intro h1,
    .article-header h1 {
        font-size: 2rem;
    }

    .article-card,
    .console-panel,
    .sidebar-panel,
    .content-panel,
    .signal-card {
        padding: 1.2rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        animation: none !important;
        transition: none !important;
    }
}