:root {
    --color-primary: #2563EB;
    --color-primary-hover: #1D4ED8;
    --color-heading: #172033;
    --color-text: #172033;
    --color-text-muted: #64748B;
    --color-background: #F7F9FC;
    --color-surface: #FFFFFF;
    --color-border: #E5EAF1;
    --color-input-border: #D6DCE5;
    --color-info-bg: #EAF2FF;
    --color-success: #16A34A;
    --color-warning: #F59E0B;
    --color-danger: #B91C1C;
    --color-danger-bg: #FEF2F2;
    --color-danger-border: #FECACA;
    --shadow-soft: 0 4px 16px rgba(15, 23, 42, 0.04);
    --focus-ring: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

* {
    box-sizing: border-box;
}

html {
    scrollbar-gutter: stable;
}

body {
    font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
    margin: 0;
    line-height: 1.5;
    background: var(--color-background);
    color: var(--color-text);
}

h1, h2, h3 {
    color: var(--color-heading);
    letter-spacing: 0.01em;
}

p {
    color: var(--color-text);
}

a {
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease, background-color 0.2s ease;
}

a:hover {
    color: var(--color-primary-hover);
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
    outline: 2px solid transparent;
    box-shadow: var(--focus-ring);
}

.site-header {
    display: flex;
    gap: 1rem;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    padding: 0.9rem 1.25rem;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    box-shadow: 0 1px 0 rgba(23, 32, 51, 0.02);
}

.site-header__brand-row {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    min-width: 0;
}

.brand {
    display: inline-flex;
    flex: 0 0 auto;
    padding: 0.5rem;
    border-radius: 9px;
    background: var(--color-surface);
}

.brand:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Preserve the approved artwork; crop only its transparent canvas margins.
   Shared display window with the PDF: x=100, y=180, width=1800, height=450. */
.brand__logo {
    position: relative;
    display: block;
    width: clamp(9rem, 16vw, 12.25rem);
    aspect-ratio: 4 / 1;
    overflow: hidden;
}

.brand__logo img {
    position: absolute;
    display: block;
    width: 110.166667%;
    max-width: none;
    height: auto;
    left: -5.555556%;
    top: -40%;
}

.site-header__menu {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.site-header > a,
.site-header__menu > a,
.site-header__menu--public > a,
.site-header form.inline button {
    border-radius: 9px;
    padding: 0.45rem 0.65rem;
}

.site-header form.inline {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.site-header [data-auto-submit-button][hidden] {
    display: none;
}

.site-header form.inline select {
    min-width: 0;
}

.site-header__toggle {
    display: none;
    align-items: center;
    gap: 0.5rem;
    padding: 0.55rem 0.75rem;
}

.site-header__toggle-icon {
    position: relative;
    width: 1.1rem;
    height: 0.9rem;
    display: inline-block;
    color: inherit;
}

.site-header__toggle-icon::before,
.site-header__toggle-icon::after {
    content: "";
    position: absolute;
    left: 0;
    width: 100%;
    height: 0.12rem;
    border-radius: 999px;
    background: currentColor;
}

.site-header__toggle-icon::before {
    top: 0.08rem;
    box-shadow: 0 0.34rem 0 currentColor, 0 0.68rem 0 currentColor;
}

.site-header__toggle-icon::after {
    display: none;
}

.site-header > a:hover {
    background: var(--color-info-bg);
}

.site-header__menu > a,
.site-header__menu--public > a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 2.4rem;
    padding: 0.45rem 0.8rem;
    border: 1px solid transparent;
}

.site-header > a.is-active,
.site-header > a[aria-current="page"],
.site-header__menu > a.is-active,
.site-header__menu > a[aria-current="page"],
.site-header__menu--public > a.is-active,
.site-header__menu--public > a[aria-current="page"] {
    background: var(--color-info-bg);
    color: var(--color-primary-hover);
    font-weight: 700;
    border-color: rgba(37, 99, 235, 0.14);
    box-shadow: none;
}

.site-header > a.is-active:hover,
.site-header > a[aria-current="page"]:hover,
.site-header__menu > a.is-active:hover,
.site-header__menu > a[aria-current="page"]:hover,
.site-header__menu--public > a.is-active:hover,
.site-header__menu--public > a[aria-current="page"]:hover {
    background: var(--color-info-bg);
    color: var(--color-primary-hover);
}

.muted-copy {
    color: var(--color-text-muted);
    font-size: 0.96rem;
}

.progress-table-scroll {
    max-width: 100%;
    overflow-x: auto;
    border: 1px solid var(--color-border);
    border-radius: 9px;
}

.progress-table-scroll:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

.progress-table {
    width: 100%;
    min-width: 42rem;
    border-collapse: collapse;
    text-align: left;
}

.progress-table caption {
    padding: 1rem;
    text-align: left;
    font-weight: 600;
}

.progress-table th,
.progress-table td {
    padding: 0.85rem 1rem;
    border-top: 1px solid var(--color-border);
    vertical-align: top;
    overflow-wrap: normal;
    word-break: normal;
}

.progress-table thead th,
.progress-table td:nth-child(2),
.progress-table td:nth-child(3),
.progress-table td:nth-child(4) {
    white-space: nowrap;
}

.progress-table thead {
    background: var(--color-info-bg);
}

.user-role {
    display: inline-flex;
    align-items: center;
    padding: 0.38rem 0.65rem;
    border-radius: 999px;
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0.01em;
}

.user-role--student {
    background: var(--color-info-bg);
    color: var(--color-primary-hover);
}

.user-role--teacher {
    background: rgba(22, 163, 74, 0.1);
    color: var(--color-success);
}

.user-role--organizer {
    background: rgba(245, 158, 11, 0.12);
    color: #9A6700;
}

.user-role--admin {
    background: rgba(23, 32, 51, 0.08);
    color: var(--color-heading);
}

.brand {
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--color-heading);
}

.container {
    max-width: 900px;
    margin: 2rem auto;
    padding: 0 1rem;
}

@media (min-width: 1200px) {
    .container {
        width: 80%;
        max-width: 1440px;
    }
}

.card {
    background: var(--color-surface);
    padding: 1.4rem;
    border-radius: 12px;
    margin-bottom: 1rem;
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-soft);
    overflow-wrap: anywhere;
}

.payment-layout {
    display: grid;
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
    gap: 1rem;
    align-items: start;
}

.payment-summary h1 {
    margin-bottom: 0.4rem;
}

.payment-summary h2 {
    margin-top: 0;
}

.payment-summary__details {
    display: grid;
    gap: 0.75rem;
    margin: 1.25rem 0;
}

.payment-summary__details div {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    padding-bottom: 0.6rem;
    border-bottom: 1px solid var(--color-border);
}

.payment-summary__details dt {
    color: var(--color-text-muted);
}

.payment-summary__details dd {
    margin: 0;
    font-weight: 700;
    text-align: right;
}

.payment-demo-notice {
    display: grid;
    gap: 0.25rem;
    margin-top: 1.25rem;
    padding: 1rem;
    border: 2px solid var(--color-success);
    border-radius: 12px;
    background: rgba(22, 163, 74, 0.1);
    color: #166534;
    text-align: center;
}

.payment-demo-notice strong {
    font-size: 1.2rem;
}

.payment-form {
    display: grid;
    gap: 1rem;
}

.payment-form fieldset {
    padding: 0.9rem;
    border: 1px solid var(--color-border);
    border-radius: 10px;
}

.payment-form legend {
    padding: 0 0.35rem;
    color: var(--color-heading);
    font-weight: 700;
}

.payment-form ul {
    display: grid;
    gap: 0.5rem;
    margin: 0;
    padding: 0;
    list-style: none;
}

.payment-form li label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin: 0;
    font-weight: 500;
}

.payment-form li input {
    width: auto;
}

.payment-form__grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1rem;
}

.card h2,
.card .course-title {
    margin-top: 0.1rem;
}

.button--ghost {
    background: var(--color-surface);
    color: var(--color-primary);
    border: 1px solid var(--color-border);
}

.button--ghost:hover {
    background: var(--color-info-bg);
    color: var(--color-primary-hover);
}

/* A lesson quiz becomes a link only after video playback starts. */
.button[aria-disabled="true"] {
    opacity: 0.5;
    cursor: not-allowed;
}

button:disabled,
button[disabled] {
    opacity: 0.6;
    cursor: not-allowed;
}

.button--danger {
    background: var(--color-danger);
}

.button--danger:hover {
    background: #991b1b;
}

.course-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    align-items: center;
}

.lesson-list {
    display: grid;
    gap: 1rem;
}

.lesson-content .lesson-code {
    overflow-x: auto;
    white-space: pre;
    font-family: monospace;
}

.lesson-content .lesson-code code {
    font-family: inherit;
}

.lesson-content {
    margin-bottom: 1rem;
}

.home-hero {
    padding: 1.5rem;
    background:
        linear-gradient(180deg, rgba(234, 242, 255, 0.7), rgba(255, 255, 255, 0.96)),
        var(--color-surface);
    border: 1px solid rgba(37, 99, 235, 0.08);
}

.home-hero--video {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 16.25rem;
    align-items: center;
    gap: 2rem;
}

.home-hero__intro,
.home-hero__video {
    min-width: 0;
}

.home-video-trigger,
.home-video-player {
    display: block;
    width: 100%;
    aspect-ratio: 9 / 16;
    border: 0;
    border-radius: 14px;
    background: #091321;
    overflow: hidden;
}

.home-video-trigger {
    position: relative;
}

.home-video-trigger img {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.home-video-trigger__play {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    display: grid;
    place-items: center;
    width: 4rem;
    height: 4rem;
    border-radius: 50%;
    color: white;
    background: var(--color-primary);
    box-shadow: 0 6px 28px rgba(0, 0, 0, 0.5);
}

.home-video-trigger:hover .home-video-trigger__play,
.home-video-trigger:focus-visible .home-video-trigger__play {
    background: var(--color-primary-hover);
}

.home-video-trigger__play svg {
    width: 1.75rem;
    height: 1.75rem;
    margin-left: 0.2rem;
    fill: currentColor;
}

@media (max-width: 640px) {
    .home-hero--video {
        grid-template-columns: minmax(0, 1fr);
        gap: 1.5rem;
    }

    .home-hero__video {
        width: min(100%, 17.5rem);
        margin-inline: auto;
    }
}

.eyebrow {
    margin: 0 0 0.35rem;
    color: var(--color-primary);
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.home-hero h1 {
    margin-top: 0;
    margin-bottom: 0.4rem;
    font-size: clamp(2.5rem, 4vw, 4.2rem);
    line-height: 0.96;
    letter-spacing: -0.05em;
}

.home-hero p {
    color: var(--color-text-muted);
    font-size: clamp(1.05rem, 1.5vw, 1.35rem);
    line-height: 1.45;
}

.home-hero__callout {
    position: relative;
    margin-top: 1rem;
    padding: 1rem 1.1rem 1rem 1.2rem;
    border-left: 4px solid var(--color-primary);
    border-radius: 14px;
    background: rgba(234, 242, 255, 0.7);
    border: 1px solid rgba(37, 99, 235, 0.08);
    box-shadow: 0 10px 24px rgba(37, 99, 235, 0.04);
    overflow-wrap: anywhere;
}

.home-hero__callout p {
    margin: 0.7rem 0 0;
    color: var(--color-heading);
    font-size: clamp(1.1rem, 1.8vw, 1.45rem);
    line-height: 1.45;
    font-weight: 500;
}

.home-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.38rem 0.7rem;
    border-radius: 999px;
    background: rgba(37, 99, 235, 0.1);
    color: var(--color-primary-hover);
    font-size: 0.96rem;
    font-weight: 800;
    letter-spacing: -0.02em;
}

.section-heading {
    display: flex;
    justify-content: space-between;
    align-items: end;
    gap: 1rem;
    margin-bottom: 1rem;
}

.section-heading h2 {
    margin: 0.1rem 0 0;
}

.home-sections {
    margin-top: 1.5rem;
}

.topic-rail {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.category-filters {
    display: flex;
    flex-wrap: wrap;
    gap: 0.65rem;
    margin: 0 0 1rem;
}

.category-filter {
    display: inline-flex;
    align-items: center;
    padding: 0.45rem 0.75rem;
    border-radius: 999px;
    border: 1px solid var(--section-border, var(--color-border));
    background: var(--section-soft, var(--color-surface));
    color: var(--section-accent, var(--color-text));
    box-shadow: var(--shadow-soft);
    transition: border-color 0.2s ease, background-color 0.2s ease, color 0.2s ease, transform 0.2s ease;
}

.category-filter:hover {
    border-color: var(--section-accent, var(--color-primary));
    background: var(--section-soft, var(--color-info-bg));
    color: var(--section-accent, var(--color-primary-hover));
    transform: translateY(-1px);
}

.category-filter.is-active {
    border-color: var(--section-accent, var(--color-primary));
    background: var(--section-soft, var(--color-info-bg));
    color: var(--section-accent, var(--color-primary-hover));
    box-shadow: 0 0 0 2px var(--section-soft, rgba(37, 99, 235, 0.12));
}

.course-card {
    position: relative;
}

.course-card--featured {
    border: 2px solid var(--color-primary);
    background: linear-gradient(135deg, var(--color-info-bg), var(--color-surface) 65%);
}

.course-card--featured .home-badge {
    display: table;
    margin: 0 0 0.75rem;
}

.course-row {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 1rem;
    align-items: center;
    padding: 1rem 0;
    border-bottom: 1px solid var(--color-border);
}

.course-row:first-child {
    border-top: 1px solid var(--color-border);
}

.course-row:last-child:not(.course-card--featured) {
    border-bottom: 0;
}

.course-row.course-card--featured {
    padding: 1rem;
    border: 1px solid rgba(37, 99, 235, 0.18);
    border-radius: 10px;
    background: var(--color-info-bg);
}

.course-row__meta {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.course-row .course-badge {
    margin: 0;
}

.course-row .home-badge {
    margin: 0;
}

.course-row h3 {
    margin: 0.35rem 0 0.2rem;
    font-size: 1.2rem;
}

.course-row__description {
    margin: 0;
    color: var(--color-text-muted);
}

.course-badge {
    display: inline-flex;
    align-items: center;
    margin-bottom: 0.75rem;
    padding: 0.28rem 0.6rem;
    border-radius: 999px;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.02em;
    background: var(--section-soft, var(--color-info-bg));
    color: var(--section-accent, var(--color-primary-hover));
}

.course-badge--polski,
.topic-pill--polski,
.category-filter--polski,
.category-filter--polski.is-active {
    --section-accent: #7C3AED;
    --section-soft: rgba(124, 58, 237, 0.1);
    --section-border: rgba(124, 58, 237, 0.2);
}

.course-badge--chemia,
.topic-pill--chemia,
.category-filter--chemia,
.category-filter--chemia.is-active {
    --section-accent: #16A34A;
    --section-soft: rgba(22, 163, 74, 0.1);
    --section-border: rgba(22, 163, 74, 0.2);
}

.course-badge--jezyki_obce,
.topic-pill--jezyki_obce,
.category-filter--jezyki_obce,
.category-filter--jezyki_obce.is-active {
    --section-accent: #DC2626;
    --section-soft: rgba(220, 38, 38, 0.1);
    --section-border: rgba(220, 38, 38, 0.2);
}

.course-badge--programowanie,
.topic-pill--programowanie,
.category-filter--programowanie,
.category-filter--programowanie.is-active {
    --section-accent: #172033;
    --section-soft: rgba(23, 32, 51, 0.08);
    --section-border: rgba(23, 32, 51, 0.16);
}

.course-badge--it,
.topic-pill--it,
.category-filter--it,
.category-filter--it.is-active {
    --section-accent: #4F46E5;
    --section-soft: rgba(79, 70, 229, 0.1);
    --section-border: rgba(79, 70, 229, 0.2);
}

.course-badge--iot,
.topic-pill--iot,
.category-filter--iot,
.category-filter--iot.is-active {
    --section-accent: #0F766E;
    --section-soft: rgba(15, 118, 110, 0.1);
    --section-border: rgba(15, 118, 110, 0.2);
}

.course-badge--polski {
    background: rgba(124, 58, 237, 0.12);
}

.course-badge--chemia {
    background: rgba(22, 163, 74, 0.12);
}

.course-badge--jezyki_obce {
    background: rgba(220, 38, 38, 0.12);
}

.course-badge--programowanie {
    background: rgba(23, 32, 51, 0.1);
}

.course-badge--it {
    background: rgba(79, 70, 229, 0.12);
}

.course-badge--iot {
    background: rgba(15, 118, 110, 0.12);
}

.topic-pill {
    display: inline-flex;
    flex-direction: column;
    gap: 0.15rem;
    min-width: 0;
    flex: 1 1 180px;
    padding: 0.85rem 1rem;
    border-radius: 14px;
    border: 1px solid var(--section-border, var(--color-border));
    background: linear-gradient(
        180deg,
        var(--section-soft, var(--color-info-bg)),
        var(--color-surface)
    );
    color: var(--color-heading);
    box-shadow: var(--shadow-soft);
}

.topic-pill span {
    font-weight: 700;
    color: var(--section-accent, var(--color-heading));
}

.topic-pill small {
    color: var(--color-text-muted);
}

.topic-pill:hover {
    color: var(--color-heading);
    transform: translateY(-1px);
}

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

.form label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--color-heading);
    font-weight: 700;
    font-size: 1.04rem;
}

.form input,
.form textarea,
.form select {
    width: 100%;
    padding: 0.8rem 0.9rem;
    border: 1px solid var(--color-input-border);
    border-radius: 10px;
    background: var(--color-surface);
    color: var(--color-text);
    font-size: 1rem;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.form input:focus,
.form textarea:focus,
.form select:focus {
    border-color: var(--color-primary);
    outline: none;
    box-shadow: var(--focus-ring);
}

.form .helptext {
    color: var(--color-text-muted);
    font-size: 0.92rem;
}

button,
.button {
    display: inline-block;
    padding: 0.72rem 1.1rem;
    border: 0;
    border-radius: 10px;
    background: var(--color-primary);
    color: var(--color-surface);
    text-decoration: none;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 700;
    transition: background-color 0.2s ease, transform 0.05s ease;
}

button:hover,
.button:hover {
    background: var(--color-primary-hover);
    color: var(--color-surface);
}

button:active,
.button:active {
    transform: translateY(1px);
}

/* Official pre-approved Google artwork; keep overrides local to this button. */
.google-sign-in-form {
    margin-top: 1rem;
}

.google-sign-in-button {
    display: inline-flex;
    max-width: 100%;
    padding: 0;
    border-radius: 4px;
    background: transparent;
    vertical-align: middle;
    transition: box-shadow 0.2s ease;
}

.google-sign-in-button img {
    display: block;
    width: 180px;
    max-width: 100%;
    height: auto;
}

.google-sign-in-button:hover {
    background: transparent;
    box-shadow: 0 1px 3px rgba(60, 64, 67, 0.25);
}

.google-sign-in-button:active {
    background: transparent;
    transform: none;
}

.google-sign-in-button:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 3px;
    box-shadow: none;
}

.inline {
    display: inline;
}

.message {
    padding: 1rem 1.15rem;
    margin-bottom: 1rem;
    border-radius: 12px;
    border: 1px solid rgba(37, 99, 235, 0.18);
    background: rgba(234, 242, 255, 0.9);
    color: var(--color-heading);
    font-weight: 600;
    box-shadow: 0 8px 22px rgba(15, 23, 42, 0.04);
}

.message.success {
    border-color: rgba(22, 163, 74, 0.28);
    background: rgba(22, 163, 74, 0.08);
    color: #166534;
}

.message.warning {
    border-color: rgba(245, 158, 11, 0.35);
    background: rgba(245, 158, 11, 0.12);
    color: #92400E;
}

.message.error {
    border: 1px solid var(--color-danger-border);
    background: var(--color-danger-bg);
    color: var(--color-danger);
    box-shadow: 0 8px 22px rgba(185, 28, 28, 0.06);
}

.errorlist {
    margin: 0.35rem 0 0.7rem;
    padding: 0.55rem 0.75rem;
    list-style: none;
    border: 1px solid var(--color-danger-border);
    border-radius: 9px;
    background: var(--color-danger-bg);
    color: var(--color-danger);
}

.pagination {
    display: flex;
    justify-content: space-between;
    gap: 0.65rem;
    margin: 1.5rem 0;
    align-items: center;
    color: var(--color-text-muted);
}

.pagination a {
    padding: 0.45rem 0.7rem;
    border-radius: 9px;
    border: 1px solid transparent;
    background: var(--color-surface);
    box-shadow: var(--shadow-soft);
}

.pagination a:hover {
    border-color: var(--color-border);
    background: var(--color-info-bg);
}

.pagination span {
    font-size: 0.95rem;
}

.lesson-video {
    width: 100%;
    max-width: 100%;
    aspect-ratio: 16 / 9;
    border: 0;
    border-radius: 12px;
    background: #000;
}

.summary-heading {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.55rem;
}

.summary-heading h2 {
    margin: 0;
}

.summary-source-badge {
    padding: 0.18rem 0.5rem;
    border: 1px solid var(--color-border);
    border-radius: 999px;
    background: var(--color-background);
    color: var(--color-text-muted);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.02em;
}

.summary-dialog {
    width: min(1120px, calc(100% - 2rem));
    height: min(760px, calc(100dvh - 2rem));
    max-height: calc(100dvh - 2rem);
    padding: 0;
    border: 0;
    border-radius: 18px;
    background: var(--color-surface);
    color: var(--color-text);
    box-shadow: 0 24px 70px rgba(15, 23, 42, 0.28);
}

.summary-dialog::backdrop {
    background: rgba(15, 23, 42, 0.66);
    backdrop-filter: blur(3px);
}

.summary-dialog__surface {
    display: flex;
    flex-direction: column;
    height: 100%;
    max-height: calc(100dvh - 2rem);
}

.summary-dialog__header,
.summary-dialog__actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem 1.25rem;
    background: var(--color-surface);
}

.summary-dialog__header {
    justify-content: space-between;
    border-bottom: 1px solid var(--color-border);
}

.summary-dialog__header h2,
.summary-dialog__header p {
    margin: 0;
}

.summary-dialog__close {
    width: 2.75rem;
    height: 2.75rem;
    flex: 0 0 2.75rem;
    padding: 0;
    border-radius: 50%;
    font-size: 1.8rem;
    line-height: 1;
}

.summary-comparison {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    flex: 1;
    gap: 1rem;
    min-height: 0;
    padding: 1rem 1.25rem;
    overflow: hidden;
    overscroll-behavior: contain;
    background: var(--color-background);
}

.summary-comparison__panel {
    display: flex;
    min-width: 0;
    min-height: 0;
    flex-direction: column;
    overflow: hidden;
    padding: 1rem;
    border: 1px solid var(--color-border);
    border-radius: 12px;
    background: var(--color-surface);
}

.summary-comparison__panel--new {
    border-color: var(--color-primary);
}

.summary-comparison__panel h3 {
    margin-top: 0;
}

.summary-comparison__content {
    flex: 1;
    min-height: 0;
    overflow-y: auto;
}

.summary-dialog__actions {
    justify-content: flex-end;
    flex-wrap: wrap;
    border-top: 1px solid var(--color-border);
}

.htmx-request {
    opacity: 0.72;
}

.htmx-request .card {
    transition: opacity 0.2s ease;
}

@media (max-width: 768px) {
    html {
        font-size: 17px;
    }

    body {
        line-height: 1.6;
    }

    .container {
        margin-top: 1.25rem;
    }

    .payment-layout,
    .payment-form__grid {
        grid-template-columns: 1fr;
    }

    .site-header {
        align-items: stretch;
        flex-direction: column;
        padding: 0.8rem 0.9rem;
        gap: 0.6rem;
    }

    .site-header__brand-row {
        justify-content: space-between;
    }

    .site-header__toggle {
        display: inline-flex;
    }

    .site-header__menu[data-menu-panel] {
        display: none;
        width: 100%;
        padding-top: 0.35rem;
        border-top: 1px solid var(--color-border);
    }

    .site-header__menu[data-menu-panel].is-open {
        display: flex;
        flex-direction: column;
        align-items: stretch;
    }

    .site-header__menu--public {
        width: 100%;
        display: flex;
        flex-direction: column;
        align-items: stretch;
        gap: 0.5rem;
        padding-top: 0.35rem;
        border-top: 1px solid var(--color-border);
    }

    .site-header__menu > a,
    .site-header__menu form.inline,
    .site-header__menu form.inline button,
    .site-header__menu form.inline select {
        width: 100%;
        font-size: 1rem;
    }

    .site-header__menu form.inline {
        flex-direction: column;
        align-items: stretch;
    }

    .site-header__menu form.inline label {
        font-size: 0.9rem;
    }

    .section-heading,
    .theme-section__header {
        align-items: flex-start;
        flex-direction: column;
    }

    .home-hero h1 {
        font-size: clamp(2.1rem, 11vw, 2.9rem);
        line-height: 1;
    }

    .card h2,
    .card .course-title {
        font-size: 1.35rem;
        line-height: 1.2;
    }

    .card p,
    .message,
    .pagination span,
    .topic-pill,
    .category-filter,
    .user-role {
        font-size: 1rem;
    }

    .course-actions,
    .course-actions .inline {
        width: 100%;
        flex-direction: column;
        align-items: stretch;
    }

    .course-actions .button,
    .course-actions button {
        width: 100%;
        text-align: center;
    }

    .category-filters,
    .topic-rail {
        width: 100%;
    }

    .category-filter,
    .topic-pill {
        width: 100%;
    }

    .summary-dialog {
        width: calc(100% - 1rem);
        height: calc(100dvh - 1rem);
        max-height: calc(100dvh - 1rem);
        border-radius: 12px;
    }

    .summary-dialog__surface {
        max-height: calc(100dvh - 1rem);
    }

    .summary-dialog__header,
    .summary-dialog__actions,
    .summary-comparison {
        padding: 0.8rem;
    }

    .summary-comparison {
        grid-template-columns: 1fr;
        overflow-y: auto;
    }

    .summary-comparison__content {
        flex: none;
        min-height: 8rem;
        max-height: 27dvh;
    }

    .summary-dialog__actions,
    .summary-dialog__actions .inline,
    .summary-dialog__actions button {
        width: 100%;
    }
}


.site-footer {
    margin-top: 2rem;
    padding-top: 1.25rem;
    padding-bottom: 1.5rem;
    border-top: 1px solid var(--color-border);
    font-size: 0.9rem;
    overflow-wrap: anywhere;
}

.site-footer p {
    margin: 0 0 0.5rem;
}

/* Home-page disclosures; catalog cards keep their existing layout. */
.home-course-details summary {
    position: relative;
    cursor: pointer;
    color: var(--color-primary-hover);
    font-weight: 600;
    padding: 0.65rem 1.75rem 0.65rem 0;
    min-height: 44px;
    list-style: none;
}

.home-course-details summary::-webkit-details-marker {
    display: none;
}

.home-course-details summary::after {
    position: absolute;
    top: 50%;
    right: 0.2rem;
    width: 0.55rem;
    height: 0.55rem;
    border-right: 2px solid currentColor;
    border-bottom: 2px solid currentColor;
    content: "";
    transform: translateY(-65%) rotate(45deg);
    transition: transform 0.2s ease;
}

.home-course-details[open] summary::after {
    transform: translateY(-25%) rotate(225deg);
}

.home-course-details summary:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 3px;
    border-radius: 4px;
}

.home-course-details__content {
    min-width: 10rem;
    padding-top: 0.25rem;
}

.home-course-details__content p {
    margin: 0.35rem 0;
}

@media (max-width: 600px) {
    .course-row {
        grid-template-columns: 1fr;
        gap: 0.35rem;
        align-items: start;
    }

    .course-row.course-card--featured {
        padding: 0.85rem;
    }

    .home-course-details {
        width: 100%;
    }

    .home-course-details__content {
        padding-bottom: 0.25rem;
    }

    .home-course-details__content .button {
        display: block;
        text-align: center;
    }
}

@media (prefers-reduced-motion: reduce) {
    .home-course-details a,
    .home-course-details summary::after {
        transition: none;
    }
}

/* Keep the management entry visible alongside Start, including on mobile. */
.site-header__brand-row .management-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 2.75rem;
    padding: 0.45rem 0.8rem;
    border: 1px solid rgba(37, 99, 235, 0.2);
    border-radius: 9px;
    background: var(--color-info-bg);
    color: var(--color-primary-hover);
    font-weight: 700;
    text-align: center;
    text-decoration: none;
}
.site-header__brand-row .management-link--active {
    text-decoration: underline;
    text-underline-offset: 0.3em;
    text-decoration-thickness: 2px;
}
.management-link:hover { filter: brightness(0.96); }
.management-link:focus-visible { outline: 2px solid currentColor; outline-offset: 3px; }
.management-heading {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 1.5rem;
}
.management-heading h1 { margin: 0; }
@media (max-width: 768px) {
    .site-header__brand-row { flex-wrap: wrap; }
    .site-header__brand-row .management-link { flex: 1; font-size: 0.9rem; }
}

/* Keep footer links distinct and comfortable to tap on narrow screens. */
.site-footer nav {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.25rem 0.75rem;
    margin-top: 0.5rem;
}

.site-footer nav a {
    display: inline-flex;
    align-items: center;
    min-height: 44px;
    padding: 0.25rem 0.375rem;
}

.site-footer nav a + a::before {
    content: "·";
    margin-right: 0.75rem;
    pointer-events: none;
}

/* Imported lesson content stays readable on desktop and narrow screens. */
.lesson-markdown { overflow-wrap: anywhere; overflow-x: auto; }
.lesson-markdown pre { overflow-x: auto; padding: 1rem; white-space: pre; background: #111827; color: #f9fafb; border-radius: .5rem; }
.lesson-markdown pre code { white-space: pre; }
.lesson-markdown table { border-collapse: collapse; width: 100%; }
.lesson-markdown th, .lesson-markdown td { border: 1px solid currentColor; padding: .5rem; text-align: left; }
.lesson-markdown blockquote { border-left: 3px solid currentColor; padding-left: 1rem; margin-left: 0; }