:root {
    color-scheme: light;
    --l3-bg: #edf1f4;
    --l3-surface: rgba(255, 255, 255, 0.88);
    --l3-surface-strong: #ffffff;
    --l3-surface-muted: #f7f9fb;
    --l3-border: #d7dee6;
    --l3-border-strong: #b9c5d0;
    --l3-text: #17212b;
    --l3-muted: #5f6c79;
    --l3-accent: #38556d;
    --l3-accent-soft: #e6edf2;
    --l3-neon: #1f7a3d;
    --l3-neon-soft: rgba(31, 122, 61, 0.16);
    --l3-shadow: 0 18px 40px rgba(23, 33, 43, 0.08);
    --l3-radius-lg: 24px;
    --l3-radius-md: 18px;
    --l3-radius-sm: 12px;
    --l3-sidebar-width: 280px;
    --l3-shell-gutter: 1rem;
    --l3-content-max-width: 1280px;
    --l3-topbar-height: 72px;
    --l3-transition: 220ms ease;
    --l3-font-sans: "Avenir Next", "Segoe UI", "Helvetica Neue", Arial, sans-serif;
    --l3-page-highlight: rgba(255, 255, 255, 0.8);
    --l3-page-top: #f6f8fb;
    --l3-page-overlay-one: rgba(56, 85, 109, 0.04);
    --l3-page-overlay-two: rgba(130, 145, 156, 0.08);
    --l3-glass-border: rgba(255, 255, 255, 0.65);
    --l3-nav-hover-bg: rgba(255, 255, 255, 0.62);
    --l3-nav-hover-border: rgba(185, 197, 208, 0.45);
    --l3-nav-active-bg-start: rgba(56, 85, 109, 0.16);
    --l3-nav-active-bg-end: rgba(255, 255, 255, 0.9);
    --l3-nav-active-border: rgba(56, 85, 109, 0.25);
    --l3-nav-active-shadow: inset 0 0 0 1px rgba(56, 85, 109, 0.08);
    --l3-hero-border: rgba(255, 255, 255, 0.7);
    --l3-hero-bg-start: rgba(255, 255, 255, 0.88);
    --l3-hero-bg-end: rgba(246, 248, 251, 0.76);
    --l3-hero-bg-accent: rgba(56, 85, 109, 0.08);
    --l3-status-bg: rgba(255, 255, 255, 0.92);
    --l3-error-border: rgba(146, 55, 55, 0.2);
    --l3-error-bg: rgba(255, 248, 248, 0.94);
    --l3-error-text: #7e3a3a;
    --l3-card-border: rgba(255, 255, 255, 0.72);
    --l3-card-bg-start: rgba(255, 255, 255, 0.92);
    --l3-card-bg-end: rgba(248, 250, 252, 0.84);
    --l3-card-border-active: rgba(56, 85, 109, 0.2);
    --l3-trigger-hover-start: rgba(56, 85, 109, 0.06);
    --l3-trigger-hover-end: rgba(255, 255, 255, 0.4);
    --l3-date-pill-bg: rgba(95, 108, 121, 0.09);
    --l3-template-bg-start: #fbfcfd;
    --l3-template-bg-end: #f6f8fb;
    --l3-topbar-bg: rgba(246, 248, 251, 0.86);
    --l3-topbar-border: rgba(215, 222, 230, 0.72);
    --l3-mobile-button-bg: rgba(255, 255, 255, 0.86);
    --l3-mobile-button-shadow: 0 8px 18px rgba(23, 33, 43, 0.06);
    --l3-backdrop-bg: rgba(19, 27, 34, 0.4);
    --l3-toggle-track-bg: #d7e2eb;
    --l3-toggle-track-active: #587992;
    --l3-toggle-thumb-bg: #ffffff;
    --l3-toggle-thumb-shadow: 0 2px 6px rgba(23, 33, 43, 0.18);
    --l3-section-gap: 0.9rem;
    --l3-block-padding: 1.1rem;
    --l3-block-header-spacing: 0.85rem;
}

:root[data-theme="dark"] {
    color-scheme: dark;
    --l3-bg: #0f1720;
    --l3-surface: rgba(17, 26, 35, 0.9);
    --l3-surface-strong: #111b24;
    --l3-surface-muted: #17222d;
    --l3-border: #2b3945;
    --l3-border-strong: #425566;
    --l3-text: #e6edf3;
    --l3-muted: #9fb0c1;
    --l3-accent: #9ec5e6;
    --l3-accent-soft: #223243;
    --l3-neon: #63ff96;
    --l3-neon-soft: rgba(99, 255, 150, 0.2);
    --l3-shadow: 0 18px 40px rgba(2, 6, 12, 0.34);
    --l3-page-highlight: rgba(255, 255, 255, 0.06);
    --l3-page-top: #121b24;
    --l3-page-overlay-one: rgba(120, 170, 205, 0.08);
    --l3-page-overlay-two: rgba(56, 85, 109, 0.18);
    --l3-glass-border: rgba(126, 154, 177, 0.18);
    --l3-nav-hover-bg: rgba(28, 40, 52, 0.86);
    --l3-nav-hover-border: rgba(126, 154, 177, 0.22);
    --l3-nav-active-bg-start: rgba(126, 154, 177, 0.22);
    --l3-nav-active-bg-end: rgba(20, 31, 41, 0.92);
    --l3-nav-active-border: rgba(158, 197, 230, 0.22);
    --l3-nav-active-shadow: inset 0 0 0 1px rgba(158, 197, 230, 0.08);
    --l3-hero-border: rgba(126, 154, 177, 0.18);
    --l3-hero-bg-start: rgba(17, 27, 36, 0.92);
    --l3-hero-bg-end: rgba(14, 22, 30, 0.78);
    --l3-hero-bg-accent: rgba(158, 197, 230, 0.12);
    --l3-status-bg: rgba(17, 27, 36, 0.92);
    --l3-error-border: rgba(220, 120, 120, 0.2);
    --l3-error-bg: rgba(55, 28, 28, 0.86);
    --l3-error-text: #f0b3b3;
    --l3-card-border: rgba(126, 154, 177, 0.16);
    --l3-card-bg-start: rgba(17, 27, 36, 0.96);
    --l3-card-bg-end: rgba(20, 31, 41, 0.88);
    --l3-card-border-active: rgba(158, 197, 230, 0.24);
    --l3-trigger-hover-start: rgba(158, 197, 230, 0.08);
    --l3-trigger-hover-end: rgba(17, 27, 36, 0.36);
    --l3-date-pill-bg: rgba(159, 176, 193, 0.12);
    --l3-template-bg-start: #15212b;
    --l3-template-bg-end: #101923;
    --l3-topbar-bg: rgba(15, 23, 32, 0.88);
    --l3-topbar-border: rgba(66, 85, 102, 0.6);
    --l3-mobile-button-bg: rgba(17, 27, 36, 0.92);
    --l3-mobile-button-shadow: 0 8px 18px rgba(0, 0, 0, 0.24);
    --l3-backdrop-bg: rgba(3, 8, 14, 0.62);
    --l3-toggle-track-bg: #2e4050;
    --l3-toggle-track-active: #9ec5e6;
    --l3-toggle-thumb-bg: #f4f8fb;
    --l3-toggle-thumb-shadow: 0 2px 8px rgba(0, 0, 0, 0.28);
}

body.l3-group-page {
    font-family: var(--l3-font-sans);
    color: var(--l3-text);
    padding-top: var(--l3-topbar-height);
    background:
        radial-gradient(circle at top left, var(--l3-page-highlight), transparent 38%),
        linear-gradient(180deg, var(--l3-page-top) 0%, var(--l3-bg) 100%);
}

body.nav-open {
    overflow: hidden;
}

body.l3-group-page::before {
    content: "";
    position: fixed;
    inset: 0;
    pointer-events: none;
    background:
        linear-gradient(135deg, var(--l3-page-overlay-one), transparent 35%),
        linear-gradient(320deg, var(--l3-page-overlay-two), transparent 40%);
}

.page-shell {
    position: relative;
    min-height: 100vh;
}

.mobile-topbar {
    position: fixed;
    inset: 0 0 auto 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    height: var(--l3-topbar-height);
    padding: 1rem 1rem 0.9rem;
    background: var(--l3-topbar-bg);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid var(--l3-topbar-border);
    z-index: 45;
}

.mobile-nav-toggle {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    min-height: 2.5rem;
    padding: 0.5rem 0.78rem;
    border: 1px solid var(--l3-border);
    border-radius: 999px;
    background: var(--l3-mobile-button-bg);
    color: var(--l3-text);
    font: inherit;
    cursor: pointer;
    box-shadow: var(--l3-mobile-button-shadow);
}

.mobile-nav-label {
    font-size: 0.95rem;
    font-weight: 500;
    line-height: 1;
}

.hamburger-lines {
    display: inline-flex;
    flex-direction: column;
    gap: 0.2rem;
}

.hamburger-lines span {
    width: 1rem;
    height: 2px;
    border-radius: 999px;
    background: currentColor;
}

.session-sidebar {
    position: fixed;
    inset: var(--l3-topbar-height) auto 0 0;
    height: calc(100vh - var(--l3-topbar-height));
    width: min(86vw, 360px);
    padding: 0.8rem;
    z-index: 30;
    transform: translateX(calc(-100% - 1rem));
    transition: transform 260ms ease;
}

body.nav-open .session-sidebar {
    transform: translateX(0);
}

.sidebar-inner {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    height: 100%;
    padding: 1rem;
    background: var(--l3-surface);
    backdrop-filter: blur(20px);
    border: 1px solid var(--l3-glass-border);
    border-radius: calc(var(--l3-radius-lg) + 4px);
    box-shadow: var(--l3-shadow);
    overflow: hidden;
}

.sidebar-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
}

.sidebar-actions,
.mobile-topbar-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.mobile-home-link {
    position: relative;
    z-index: 1;
}

.mobile-topbar-actions {
    position: relative;
    z-index: 1;
}

.sidebar-home-link,
.mobile-home-link {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    width: fit-content;
    color: var(--l3-accent);
    font-size: 0.95rem;
    font-weight: 600;
    text-decoration: none;
}

.sidebar-home-link::before,
.mobile-home-link::before {
    content: "\2190";
    font-size: 0.9em;
}

.sidebar-close {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.5rem;
    height: 2.5rem;
    border: 1px solid var(--l3-border);
    border-radius: 999px;
    background: var(--l3-surface-strong);
    color: var(--l3-text);
    cursor: pointer;
    transition: transform var(--l3-transition), border-color var(--l3-transition), background var(--l3-transition);
}

.sidebar-close:hover {
    transform: translateY(-1px);
    border-color: var(--l3-border-strong);
    background: var(--l3-surface-muted);
}

.theme-toggle {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    min-height: 2.5rem;
    padding: 0.5rem 0.8rem;
    border: 1px solid var(--l3-border);
    border-radius: 999px;
    background: var(--l3-surface-strong);
    color: var(--l3-text);
    font: inherit;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition:
        transform var(--l3-transition),
        border-color var(--l3-transition),
        background var(--l3-transition),
        color var(--l3-transition);
}

.theme-toggle:hover {
    transform: translateY(-1px);
    border-color: var(--l3-border-strong);
    background: var(--l3-surface-muted);
}

.theme-toggle-track {
    position: relative;
    display: inline-flex;
    align-items: center;
    width: 2.4rem;
    height: 1.4rem;
    padding: 0.15rem;
    background: var(--l3-toggle-track-bg);
    border-radius: 999px;
    transition: background var(--l3-transition);
}

.theme-toggle-thumb {
    display: block;
    width: 1.1rem;
    height: 1.1rem;
    border-radius: 50%;
    background: var(--l3-toggle-thumb-bg);
    box-shadow: var(--l3-toggle-thumb-shadow);
    transform: translateX(0);
    transition: transform var(--l3-transition), background var(--l3-transition), box-shadow var(--l3-transition);
}

.theme-toggle[aria-pressed="true"] .theme-toggle-track {
    background: var(--l3-toggle-track-active);
}

.theme-toggle[aria-pressed="true"] .theme-toggle-thumb {
    transform: translateX(0.95rem);
}

.theme-toggle-icons {
    gap: 0.45rem;
    min-width: auto;
    padding: 0.5rem 0.65rem;
    justify-content: center;
}

.theme-toggle-compact {
    gap: 0.45rem;
    min-width: auto;
    padding: 0.5rem 0.65rem;
    justify-content: center;
}

.theme-toggle-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 0.95rem;
    color: var(--l3-muted);
    font-size: 0.88rem;
    line-height: 1;
    transition: color var(--l3-transition), opacity var(--l3-transition), filter var(--l3-transition);
}

.theme-toggle-compact[aria-pressed="false"] .theme-toggle-icon-sun,
.theme-toggle-compact[aria-pressed="true"] .theme-toggle-icon-moon,
.theme-toggle-icons[aria-pressed="false"] .theme-toggle-icon-sun,
.theme-toggle-icons[aria-pressed="true"] .theme-toggle-icon-moon {
    color: var(--l3-accent);
}

.theme-toggle-icons .theme-toggle-text,
.theme-toggle-compact .theme-toggle-text {
    display: none;
}

:root[data-theme="dark"] .theme-toggle[aria-pressed="true"] .theme-toggle-icon-sun {
    opacity: 0.48;
    filter: grayscale(1) saturate(0.2);
}

.page-eyebrow {
    margin: 0;
    font-size: clamp(1.18rem, 2.5vw, 1.95rem);
    font-weight: 700;
    line-height: 1.1;
    letter-spacing: 0.02em;
    color: var(--l3-muted);
    overflow-wrap: anywhere;
    word-break: break-word;
    text-align: center;
}

.page-eyebrow-accent {
    color: var(--l3-neon);
}

.topbar-title {
    margin: 0;
    position: absolute;
    left: 50%;
    top: 50%;
    max-width: min(34rem, calc(100vw - 18rem));
    transform: translate(-50%, -50%);
    display: grid;
    justify-items: center;
    gap: 0.08rem;
    color: var(--l3-muted);
    font-size: clamp(0.82rem, 1.25vw, 1rem);
    font-weight: 400;
    line-height: 1.04;
    letter-spacing: 0.02em;
    text-align: center;
    pointer-events: none;
}

.topbar-title-line {
    display: block;
    max-width: 100%;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.topbar-title-line-primary {
    font-size: 1.1em;
    font-weight: 500;
}

.topbar-title-line-secondary {
    font-size: 0.84em;
    letter-spacing: 0.035em;
}

.hero-intro {
    margin: 0;
    max-width: 44rem;
    color: var(--l3-muted);
    font-size: clamp(1rem, 1.35vw, 1.16rem);
    line-height: 1.7;
    overflow-wrap: anywhere;
    word-break: break-word;
    text-align: center;
}

.session-nav {
    flex: 1;
    min-height: 0;
    overflow-y: auto;
    margin-right: -0.55rem;
    padding-right: 0.55rem;
}

.session-nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 0.65rem;
}

.session-nav-link {
    display: grid;
    gap: 0.2rem;
    width: 100%;
    padding: 0.95rem 1rem;
    border: 1px solid transparent;
    border-radius: var(--l3-radius-sm);
    background: transparent;
    color: var(--l3-text);
    text-decoration: none;
    transition:
        transform var(--l3-transition),
        background var(--l3-transition),
        border-color var(--l3-transition),
        box-shadow var(--l3-transition);
}

.session-nav-link:hover {
    transform: translateX(2px);
    background: var(--l3-nav-hover-bg);
    border-color: var(--l3-nav-hover-border);
}

.session-nav-link.is-active {
    background: linear-gradient(135deg, var(--l3-nav-active-bg-start), var(--l3-nav-active-bg-end));
    border-color: var(--l3-nav-active-border);
    box-shadow: var(--l3-nav-active-shadow);
}

.session-nav-title {
    font-size: 0.98rem;
    font-weight: 600;
    line-height: 1.3;
}

.session-nav-meta {
    font-size: 0.84rem;
    color: var(--l3-muted);
}

.sidebar-backdrop {
    position: fixed;
    inset: var(--l3-topbar-height) 0 0 0;
    display: block;
    background: var(--l3-backdrop-bg);
    opacity: 0;
    pointer-events: none;
    transition: opacity 260ms ease;
    z-index: 20;
}

body.nav-open .sidebar-backdrop {
    opacity: 1;
    pointer-events: auto;
}

.session-main {
    margin-left: 0;
    padding: 1rem var(--l3-shell-gutter) 3rem;
}

.page-hero {
    position: relative;
    display: grid;
    justify-items: center;
    gap: 0.9rem;
    width: 100%;
    max-width: none;
    margin: 0 0 1.2rem;
    padding: 1.7rem 1.75rem;
    border: 1px solid var(--l3-hero-border);
    border-radius: var(--l3-radius-lg);
    background:
        linear-gradient(135deg, var(--l3-hero-bg-start), var(--l3-hero-bg-end)),
        linear-gradient(120deg, var(--l3-hero-bg-accent), transparent);
    box-shadow: var(--l3-shadow);
}

.sessions-list {
    display: flex;
    flex-direction: column;
    gap: var(--l3-section-gap);
    width: 100%;
    max-width: none;
    margin: 0;
}

.session-status {
    width: 100%;
    max-width: none;
    margin: 0;
    padding: 1.15rem 1.25rem;
    border: 1px solid var(--l3-border);
    border-radius: var(--l3-radius-md);
    background: var(--l3-status-bg);
    color: var(--l3-muted);
    box-shadow: var(--l3-shadow);
}

.session-status.is-error {
    border-color: var(--l3-error-border);
    background: var(--l3-error-bg);
    color: var(--l3-error-text);
}

.session-card {
    scroll-margin-top: calc(var(--l3-topbar-height) + 0.9rem);
    border: 1px solid var(--l3-card-border);
    border-radius: var(--l3-radius-lg);
    background: linear-gradient(180deg, var(--l3-card-bg-start), var(--l3-card-bg-end));
    box-shadow: var(--l3-shadow);
    overflow: clip;
}

.session-card.is-expanded {
    border-color: var(--l3-card-border-active);
}

.session-trigger {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 1rem;
    width: 100%;
    padding: 1.45rem 1.5rem;
    border: 0;
    background: transparent;
    color: inherit;
    text-align: left;
    cursor: pointer;
    transition: background var(--l3-transition), transform var(--l3-transition);
}

.session-trigger:hover {
    background: linear-gradient(135deg, var(--l3-trigger-hover-start), var(--l3-trigger-hover-end));
}

.session-trigger:active {
    transform: translateY(1px);
}

.session-trigger-main {
    display: grid;
    gap: 0.28rem;
    min-width: 0;
}

.session-title {
    margin: 0;
    font-size: clamp(1.22rem, 1.55vw, 1.5rem);
    font-weight: 600;
    line-height: 1.25;
    overflow-wrap: anywhere;
    word-break: break-word;
}

.session-summary {
    margin: 0;
    color: var(--l3-muted);
    font-size: 0.98rem;
    line-height: 1.45;
}

.session-header-details {
    display: grid;
    gap: 0.14rem;
    margin-top: 0;
}

.session-header-detail {
    margin: 0;
    color: var(--l3-muted);
    font-size: 0.95rem;
    line-height: 1.45;
    overflow-wrap: anywhere;
    word-break: break-word;
}

.session-chevron {
    align-self: center;
    width: 0.95rem;
    height: 0.95rem;
    margin-top: 0.2rem;
    border-right: 2px solid currentColor;
    border-bottom: 2px solid currentColor;
    color: var(--l3-muted);
    transform: rotate(45deg);
    transition: transform var(--l3-transition), color var(--l3-transition);
}

.session-card.is-expanded .session-chevron {
    color: var(--l3-neon);
    transform: rotate(225deg);
}

.session-panel {
    display: grid;
    grid-template-rows: 0fr;
    visibility: hidden;
    opacity: 0;
    transition:
        grid-template-rows 320ms ease,
        opacity 220ms ease,
        visibility 220ms ease;
}

.session-card.is-expanded .session-panel {
    grid-template-rows: 1fr;
    visibility: visible;
    opacity: 1;
}

.session-panel-inner {
    min-height: 0;
    overflow: hidden;
}

.session-card.is-expanded .session-panel-inner {
    overflow: visible;
}

.session-content {
    display: flex;
    flex-direction: column;
    gap: var(--l3-section-gap);
    padding: 0 1.5rem 1.15rem;
}

.session-subsection {
    border: 1px solid var(--l3-border);
    border-radius: var(--l3-radius-md);
    background: var(--l3-surface-strong);
    overflow: hidden;
}

.session-subsection[open] {
    border-color: var(--l3-neon);
    box-shadow: 0 0 0 1px var(--l3-neon-soft);
}

.session-subsection-summary {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 0.95rem 1.1rem;
    cursor: pointer;
    list-style: none;
    user-select: none;
    transition: background var(--l3-transition);
}

.session-subsection-summary::-webkit-details-marker {
    display: none;
}

.session-subsection-summary:hover {
    background: var(--l3-trigger-hover-end);
}

.session-subsection-heading {
    display: grid;
    gap: 0.16rem;
    min-width: 0;
}

.session-subsection-title {
    font-size: 1rem;
    font-weight: 600;
    overflow-wrap: anywhere;
    word-break: break-word;
}

.session-subsection-caption {
    font-size: 0.88rem;
    color: var(--l3-muted);
    overflow-wrap: anywhere;
    word-break: break-word;
}

.session-subsection-chevron {
    flex: 0 0 auto;
    width: 0.82rem;
    height: 0.82rem;
    border-right: 2px solid currentColor;
    border-bottom: 2px solid currentColor;
    color: var(--l3-muted);
    transform: rotate(45deg);
    transition: transform var(--l3-transition), color var(--l3-transition);
}

.session-subsection[open] .session-subsection-chevron {
    color: var(--l3-neon);
    transform: rotate(225deg);
}

.session-subsection-body {
    padding: 0 1.1rem 1.1rem;
    border-top: 1px solid var(--l3-border);
    min-width: 0;
}

.snapshot-grid {
    display: grid;
    grid-template-columns: 1.4fr 1fr;
    gap: var(--l3-section-gap);
    padding-top: 0.95rem;
}

.snapshot-column {
    display: grid;
    align-content: start;
    gap: 0.75rem;
    min-width: 0;
}

.snapshot-column h4 {
    margin: 0;
    font-size: 1rem;
    font-weight: 600;
    color: var(--l3-text);
}

.snapshot-list {
    margin: 0;
    padding-left: 1.25rem;
}

.snapshot-list li + li {
    margin-top: 0.55rem;
}

.snapshot-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.65rem;
}

.tutorial-rich-content,
.useful-info-content,
.slide-view-content {
    display: grid;
    gap: var(--l3-section-gap);
    padding-top: 0.95rem;
    min-width: 0;
}

.slide-view-actions {
    display: flex;
    justify-content: flex-start;
}

.pdf-mobile-fallback {
    display: none;
    gap: 0.75rem;
    padding: 1rem 1.05rem;
    border: 1px solid var(--l3-border);
    border-radius: var(--l3-radius-md);
    background: linear-gradient(180deg, var(--l3-template-bg-start), var(--l3-template-bg-end));
}

.pdf-mobile-title,
.pdf-mobile-copy {
    margin: 0;
}

.pdf-mobile-title {
    font-size: 0.98rem;
    font-weight: 600;
    color: var(--l3-text);
    overflow-wrap: anywhere;
    word-break: break-word;
}

.pdf-mobile-copy {
    color: var(--l3-muted);
    line-height: 1.55;
    overflow-wrap: anywhere;
    word-break: break-word;
}

.session-block {
    padding: var(--l3-block-padding);
    border: 1px solid var(--l3-border);
    border-radius: var(--l3-radius-md);
    background: var(--l3-surface-strong);
}

.session-block-header {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
    margin-bottom: var(--l3-block-header-spacing);
}

.session-block-header h3,
.session-template-card h4 {
    margin: 0;
}

.session-block-header h3 {
    font-size: 1.15rem;
}

.session-block-header p {
    flex-basis: 100%;
    margin: 0;
    color: var(--l3-muted);
}

.session-pdf-link,
.resource-link {
    color: var(--l3-accent);
    font-weight: 500;
}

.session-pdf-link {
    text-decoration: none;
}

.session-pdf-link-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: fit-content;
    padding: 0.72rem 0.98rem;
    border: 1px solid var(--l3-border-strong);
    border-radius: 999px;
    background: var(--l3-surface-strong);
    font-weight: 600;
}

.session-pdf-link:hover,
.resource-link:hover {
    text-decoration: underline;
}

.session-pdf-link-button:hover {
    border-color: var(--l3-neon);
    background: var(--l3-accent-soft);
    text-decoration: none;
}

.pdf-frame-wrap {
    overflow: hidden;
    border: 1px solid var(--l3-border);
    border-radius: var(--l3-radius-sm);
    background: var(--l3-surface-muted);
}

.pdf-frame {
    display: block;
    width: 100%;
    height: clamp(575px, 77.5vh, 1025px);
    border: 0;
}

.recap-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--l3-section-gap);
}

.tutorial-rich-body {
    display: block;
}

.tutorial-rich-body {
    min-width: 0;
    max-width: 100%;
    padding: 0.3rem 1.15rem 0;
    border: 1px solid var(--l3-border);
    border-radius: var(--l3-radius-md);
    background: var(--l3-surface-strong);
    box-sizing: border-box;
    overflow-x: hidden;
}

.tutorial-meta {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--l3-section-gap);
    padding: var(--l3-block-padding);
    border: 1px solid var(--l3-border);
    border-radius: var(--l3-radius-md);
    background: linear-gradient(180deg, var(--l3-template-bg-start), var(--l3-template-bg-end));
}

.tutorial-meta-item {
    display: grid;
    gap: 0.3rem;
    min-width: 0;
}

.tutorial-meta-label {
    font-size: 0.74rem;
    font-weight: 700;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--l3-muted);
}

.tutorial-meta-value {
    font-weight: 600;
    line-height: 1.5;
}

.tutorial-section {
    padding: 1.15rem 0 1.25rem;
    border: 0;
    border-top: 1px solid var(--l3-border);
    border-radius: 0;
    background: transparent;
    min-width: 0;
    max-width: 100%;
    box-sizing: border-box;
}

.tutorial-section > * {
    min-width: 0;
    max-width: 100%;
    box-sizing: border-box;
}

.tutorial-rich-body .tutorial-section:first-child {
    padding-top: 0.95rem;
    border-top: 0;
}

.tutorial-rich-body .tutorial-section:last-child {
    padding-bottom: 1rem;
}

.tutorial-section h4 {
    margin: 0 0 0.35rem;
    font-size: 1.22rem;
    font-weight: 600;
    line-height: 1.3;
    color: var(--l3-text);
}

.tutorial-section h5 {
    margin: 1.1rem 0 0.55rem;
    font-size: 0.94rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    line-height: 1.45;
    color: var(--l3-neon);
}

.tutorial-section p {
    margin: 0 0 0.9rem;
    line-height: 1.7;
}

.tutorial-section p:last-child {
    margin-bottom: 0;
}

.tutorial-section-intro {
    color: var(--l3-muted);
}

.tutorial-section ul,
.tutorial-section ol {
    margin: 0;
    padding-left: 2.25rem;
}

.tutorial-section li + li {
    margin-top: 0.65rem;
}

.tutorial-section li::marker {
    color: var(--l3-neon);
    font-weight: 700;
}

.tutorial-section strong {
    color: var(--l3-text);
    font-weight: 700;
}

.tutorial-section h4,
.tutorial-section h5,
.tutorial-section p,
.tutorial-section li,
.tutorial-section th,
.tutorial-section td,
.tutorial-link-list a,
.tutorial-callout,
.session-header-detail,
.session-summary {
    overflow-wrap: anywhere;
    word-break: break-word;
}

.tutorial-callout {
    margin-top: 1rem;
    max-width: 100%;
    padding: 0.95rem 1rem;
    border-left: 4px solid var(--l3-neon);
    border-radius: 0 var(--l3-radius-sm) var(--l3-radius-sm) 0;
    background: var(--l3-accent-soft);
    box-sizing: border-box;
}

.tutorial-callout p {
    margin: 0;
    padding-left: 0;
}

.tutorial-table-wrap {
    overflow-x: auto;
    margin-top: 0.35rem;
    border: 1px solid var(--l3-border);
    border-radius: var(--l3-radius-sm);
    background: var(--l3-surface-strong);
}

.tutorial-table {
    width: 100%;
    min-width: 560px;
    border-collapse: collapse;
}

.tutorial-table th,
.tutorial-table td {
    padding: 0.8rem 0.9rem;
    border-bottom: 1px solid var(--l3-border);
    text-align: left;
    vertical-align: top;
}

.tutorial-table th {
    background: var(--l3-surface-muted);
    font-size: 0.88rem;
    letter-spacing: 0.04em;
}

.tutorial-table tr:last-child td {
    border-bottom: 0;
}

.tutorial-link-list {
    list-style: none;
    padding: 0;
    min-width: 0;
}

.tutorial-link-list li {
    margin: 0;
    min-width: 0;
}

.tutorial-link-list li + li {
    margin-top: 0.75rem;
}

.tutorial-link-list a {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 0.85rem;
    min-width: 0;
    max-width: 100%;
    padding: 0.9rem 1rem;
    border: 1px solid var(--l3-border);
    border-radius: var(--l3-radius-sm);
    background: linear-gradient(180deg, var(--l3-template-bg-start), var(--l3-template-bg-end));
    color: var(--l3-accent);
    font-weight: 600;
    text-decoration: none;
    transition: border-color var(--l3-transition), background var(--l3-transition), transform var(--l3-transition);
    box-sizing: border-box;
}

.tutorial-link-list a:hover {
    transform: translateY(-1px);
    border-color: var(--l3-neon);
    background: var(--l3-accent-soft);
    text-decoration: none;
}

.tutorial-rich-body pre[class*="language-"],
.tutorial-rich-body pre {
    margin: 0.9rem 0 0;
    max-width: 100%;
    padding: 1rem 1.1rem;
    overflow: auto;
    border: 1px solid #243241;
    border-radius: var(--l3-radius-sm);
    background: #101820;
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.03);
    box-sizing: border-box;
}

.tutorial-rich-body code[class*="language-"],
.tutorial-rich-body pre[class*="language-"] {
    font-size: 0.92rem;
    line-height: 1.6;
}

.tutorial-rich-body :not(pre) > code {
    padding: 0.12rem 0.38rem;
    border: 1px solid var(--l3-border);
    border-radius: 999px;
    background: var(--l3-surface-muted);
    font-size: 0.92em;
}

.tutorial-section a {
    color: var(--l3-accent);
}

.session-template-card {
    display: flex;
    flex-direction: column;
    gap: 0.85rem;
    min-width: 0;
    padding: 1.1rem;
    border: 1px solid var(--l3-border);
    border-radius: var(--l3-radius-sm);
    background: linear-gradient(180deg, var(--l3-template-bg-start), var(--l3-template-bg-end));
}

.session-template-card p {
    margin: 0;
    color: var(--l3-muted);
}

.session-template-card ul,
.session-template-card ol {
    margin: 0;
    padding-left: 1.2rem;
}

.session-template-card li + li {
    margin-top: 0.55rem;
}

.session-template-card ol li::marker {
    font-weight: 700;
    color: var(--l3-accent);
}

.resource-list {
    list-style: none;
    padding: 0;
}

.resource-list li {
    margin: 0;
}

.resource-list li + li {
    margin-top: 0.7rem;
}

.resource-link {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
}

.resource-link::after {
    content: "\2197";
    font-size: 0.88em;
}

@media (max-width: 1180px) {
    .snapshot-grid,
    .tutorial-meta {
        grid-template-columns: 1fr;
    }

    .recap-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 960px) {
    body.l3-group-page {
        padding-top: var(--l3-topbar-height);
    }

    body.nav-open {
        overflow: hidden;
    }

    .mobile-topbar {
        position: fixed;
        inset: 0 0 auto 0;
        display: grid;
        grid-template-columns: auto minmax(0, 1fr) auto;
        align-items: center;
        gap: 1rem;
        height: var(--l3-topbar-height);
        padding: 1rem 1rem 0.9rem;
        background: var(--l3-topbar-bg);
        backdrop-filter: blur(18px);
        border-bottom: 1px solid var(--l3-topbar-border);
        z-index: 45;
    }

    .mobile-nav-toggle {
        display: inline-flex;
        align-items: center;
        gap: 0.75rem;
        min-height: 2.5rem;
        padding: 0.5rem 0.78rem;
        border: 1px solid var(--l3-border);
        border-radius: 999px;
        background: var(--l3-mobile-button-bg);
        color: var(--l3-text);
        font: inherit;
        cursor: pointer;
        box-shadow: var(--l3-mobile-button-shadow);
    }

    .mobile-nav-label {
        font-size: 0.95rem;
        font-weight: 500;
    }

    .hamburger-lines {
        display: inline-flex;
        flex-direction: column;
        gap: 0.2rem;
    }

    .hamburger-lines span {
        width: 1rem;
        height: 2px;
        border-radius: 999px;
        background: currentColor;
    }

    .session-sidebar {
        inset: var(--l3-topbar-height) auto 0 0;
        height: calc(100vh - var(--l3-topbar-height));
        width: min(86vw, 360px);
        padding: 0.8rem;
        transform: translateX(calc(-100% - 1rem));
        transition: transform 260ms ease;
    }

    body.nav-open .session-sidebar {
        transform: translateX(0);
    }

    .sidebar-inner {
        gap: 1rem;
    }

    .sidebar-close {
        display: inline-flex;
    }

    .sidebar-backdrop {
        position: fixed;
        inset: var(--l3-topbar-height) 0 0 0;
        display: block;
        background: var(--l3-backdrop-bg);
        opacity: 0;
        pointer-events: none;
        transition: opacity 260ms ease;
        z-index: 20;
    }

    body.nav-open .sidebar-backdrop {
        opacity: 1;
        pointer-events: auto;
    }

    .session-main {
        margin-left: 0;
        padding: 1rem 1rem 2.25rem;
    }

    .page-hero {
        padding: 1.35rem;
        margin-bottom: 1rem;
    }

    .slide-view-actions,
    .pdf-frame-wrap {
        display: none;
    }

    .pdf-mobile-fallback {
        display: grid;
    }

}

@media (max-width: 720px) {
    :root {
        --l3-topbar-height: 92px;
    }

    .session-main {
        padding: 0.9rem 0.75rem 2rem;
    }

    .mobile-topbar {
        display: grid;
        grid-template-columns: minmax(0, 1fr) auto;
        grid-template-areas:
            "title title"
            "home actions";
        align-items: end;
        row-gap: 0.45rem;
        height: var(--l3-topbar-height);
        padding-top: 0.8rem;
        padding-bottom: 0.7rem;
    }

    .mobile-home-link {
        grid-area: home;
    }

    .mobile-topbar-actions {
        grid-area: actions;
    }

    .topbar-title {
        position: static;
        left: auto;
        top: auto;
        max-width: none;
        transform: none;
        grid-area: title;
        gap: 0.06rem;
        white-space: normal;
        text-overflow: clip;
        overflow: visible;
        font-size: 0.84rem;
        line-height: 1.08;
        font-weight: 400;
        pointer-events: auto;
    }

    .topbar-title-line {
        white-space: normal;
        text-overflow: clip;
        overflow: visible;
    }

    .topbar-title-line-primary {
        font-size: 1.08em;
    }

    .topbar-title-line-secondary {
        font-size: 0.82em;
        letter-spacing: 0.03em;
    }

    .session-trigger,
    .session-content {
        padding-left: 0.75rem;
        padding-right: 0.75rem;
    }

    .session-trigger {
        padding-top: 1.15rem;
        padding-bottom: 1.15rem;
    }

    .session-block {
        padding: 1rem;
    }

    .session-title {
        font-size: 1.15rem;
    }

    .session-summary {
        font-size: 0.96rem;
    }

    .session-header-detail {
        font-size: 0.92rem;
    }

    .page-hero {
        padding: 1.15rem 1rem;
    }

    .session-subsection-summary {
        align-items: flex-start;
        gap: 0.75rem;
        padding: 0.82rem 0.85rem;
    }

    .session-subsection-body {
        padding: 0 0.75rem 0.85rem;
    }

    .tutorial-rich-content,
    .useful-info-content,
    .slide-view-content {
        padding-top: 0.65rem;
    }

    .tutorial-rich-body {
        min-width: 0;
        padding: 0.15rem 0.75rem 0;
    }

    .tutorial-section {
        padding: 0.95rem 0 1rem;
    }

    .tutorial-section h4 {
        font-size: 1.08rem;
    }

    .tutorial-section h5 {
        font-size: 0.88rem;
    }

    .tutorial-section ul,
    .tutorial-section ol {
        padding-left: 1.55rem;
    }

    .tutorial-table {
        min-width: 430px;
    }

    .tutorial-callout {
        padding: 0.82rem 0.85rem;
    }

    .tutorial-link-list,
    .tutorial-link-list li,
    .tutorial-link-list a,
    .tutorial-table-wrap {
        min-width: 0;
    }

    .tutorial-link-list a {
        display: block;
        padding: 0.82rem 0.85rem;
        line-height: 1.5;
    }

    .tutorial-rich-body pre[class*="language-"],
    .tutorial-rich-body pre {
        margin-left: 0;
        padding: 0.85rem 0.9rem;
        white-space: pre-wrap;
        overflow-wrap: anywhere;
        word-break: break-word;
    }

    .tutorial-rich-body code[class*="language-"],
    .tutorial-rich-body pre[class*="language-"] {
        white-space: pre-wrap;
        overflow-wrap: anywhere;
        word-break: break-word;
    }

    .tutorial-rich-body :not(pre) > code {
        white-space: normal;
        overflow-wrap: anywhere;
        word-break: break-word;
    }

    .pdf-frame {
        height: min(70vh, 520px);
    }

    .pdf-mobile-fallback {
        padding: 0.9rem 0.95rem;
    }
}

@media (max-width: 850px) {
    :root {
        --l3-topbar-height: 106px;
    }

    .mobile-topbar {
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        align-items: center;
        column-gap: 0.65rem;
        row-gap: 0.42rem;
        padding-top: 0.72rem;
        padding-bottom: 0.72rem;
    }

    .mobile-topbar::after {
        content: "";
        order: 2;
        flex: 0 0 100%;
        height: 1px;
        background: var(--l3-topbar-border);
        opacity: 0.95;
    }

    .topbar-title {
        order: 1;
        flex: 0 0 100%;
        justify-self: auto;
        position: static;
        left: auto;
        top: auto;
        max-width: none;
        transform: none;
        gap: 0.06rem;
        white-space: normal;
        text-overflow: clip;
        overflow: visible;
        font-size: 0.84rem;
        line-height: 1.08;
        font-weight: 400;
        pointer-events: auto;
    }

    .mobile-home-link {
        order: 3;
        justify-self: auto;
    }

    .mobile-topbar-actions {
        order: 4;
        justify-self: auto;
    }

    .mobile-topbar-actions {
        gap: 0.65rem;
    }

    .topbar-title-line {
        white-space: normal;
        text-overflow: clip;
        overflow: visible;
    }

    .topbar-title-line-primary {
        font-size: 1.08em;
    }

    .topbar-title-line-secondary {
        font-size: 0.82em;
        letter-spacing: 0.03em;
    }
}

@media (max-width: 540px) {
    :root {
        --l3-topbar-height: 110px;
    }

    .session-main {
        padding-left: 0.65rem;
        padding-right: 0.65rem;
    }

    .mobile-topbar {
        padding-left: 0.8rem;
        padding-right: 0.8rem;
    }

    .mobile-topbar-actions {
        gap: 0.55rem;
    }

    .theme-toggle-compact {
        padding: 0.48rem 0.5rem;
        gap: 0.35rem;
    }

    .theme-toggle-icon {
        width: 0.8rem;
        font-size: 0.78rem;
    }

    .mobile-nav-toggle {
        min-height: 2.36rem;
        padding: 0.48rem 0.72rem;
    }

    .page-hero,
    .session-card,
    .sidebar-inner {
        border-radius: 18px;
    }

    .page-hero {
        padding: 1rem 0.9rem;
    }

    .session-trigger {
        grid-template-columns: minmax(0, 1fr) auto;
        gap: 0.6rem;
        padding-left: 0.65rem;
        padding-right: 0.65rem;
    }

    .session-content {
        padding-left: 0.65rem;
        padding-right: 0.65rem;
    }

    .session-title {
        font-size: 1.05rem;
    }

    .session-summary,
    .session-header-detail {
        font-size: 0.9rem;
    }

    .tutorial-table {
        min-width: 340px;
    }

    .tutorial-table th,
    .tutorial-table td {
        padding: 0.72rem 0.7rem;
    }

    .session-subsection-summary {
        padding: 0.78rem 0.8rem;
    }

    .session-subsection-body {
        padding: 0 0.7rem 0.8rem;
    }

    .tutorial-rich-body {
        padding: 0.1rem 0.7rem 0;
    }

    .tutorial-section ul,
    .tutorial-section ol {
        padding-left: 1.35rem;
    }

    .tutorial-callout,
    .tutorial-link-list a {
        padding: 0.78rem 0.8rem;
    }

    .pdf-mobile-fallback {
        padding: 0.82rem 0.85rem;
    }

    .session-pdf-link-button {
        width: 100%;
    }

    .tutorial-rich-body pre[class*="language-"],
    .tutorial-rich-body pre {
        padding: 0.78rem 0.8rem;
    }
}

@media (max-width: 430px) {
    :root {
        --l3-topbar-height: 114px;
    }

    .session-main {
        padding-left: 0.42rem;
        padding-right: 0.42rem;
    }

    .page-hero {
        padding: 0.82rem 0.72rem;
    }

    .session-trigger,
    .session-content {
        padding-left: 0.42rem;
        padding-right: 0.42rem;
    }

    .session-trigger {
        gap: 0.42rem;
    }

    .session-title {
        font-size: 0.9rem;
        line-height: 1.18;
    }

    .session-summary,
    .session-header-detail,
    .session-subsection-caption,
    .hero-intro,
    .pdf-mobile-copy,
    .mobile-nav-label {
        font-size: 0.8rem;
        line-height: 1.36;
    }

    .session-subsection-title,
    .pdf-mobile-title {
        font-size: 0.86rem;
        line-height: 1.24;
    }

    .session-subsection-summary {
        gap: 0.5rem;
        padding: 0.62rem 0.62rem;
    }

    .session-subsection-body {
        padding: 0 0.5rem 0.64rem;
    }

    .tutorial-rich-body {
        padding: 0 0.5rem 0;
    }

    .tutorial-section {
        padding: 0.8rem 0 0.84rem;
    }

    .tutorial-section h4 {
        font-size: 0.9rem;
        line-height: 1.24;
    }

    .tutorial-section h5 {
        font-size: 0.74rem;
        line-height: 1.3;
        letter-spacing: 0.04em;
    }

    .tutorial-section ul,
    .tutorial-section ol {
        padding-left: 1rem;
    }

    .tutorial-callout,
    .tutorial-link-list a,
    .pdf-mobile-fallback {
        padding: 0.64rem 0.66rem;
    }

    .tutorial-rich-body pre[class*="language-"],
    .tutorial-rich-body pre {
        padding: 0.64rem 0.66rem;
        font-size: 0.8rem;
    }

    .session-pdf-link-button,
    .mobile-nav-toggle,
    .theme-toggle-compact {
        font-size: 0.84rem;
    }

    .tutorial-rich-body,
    .tutorial-section,
    .tutorial-callout,
    .tutorial-table-wrap,
    .tutorial-link-list,
    .tutorial-link-list li,
    .tutorial-link-list a,
    .pdf-mobile-fallback,
    .pdf-mobile-fallback > *,
    .tutorial-rich-body pre[class*="language-"],
    .tutorial-rich-body pre {
        min-width: 0;
        max-width: 100%;
        box-sizing: border-box;
    }

    .session-title,
    .session-summary,
    .session-header-detail,
    .session-subsection-title,
    .session-subsection-caption,
    .tutorial-section h4,
    .tutorial-section h5,
    .tutorial-section p,
    .tutorial-section li,
    .tutorial-link-list a,
    .pdf-mobile-title,
    .pdf-mobile-copy {
        white-space: normal;
        overflow-wrap: anywhere;
        word-break: break-word;
        hyphens: auto;
    }
}

@media (max-width: 300px) {
    :root {
        --l3-topbar-height: 120px;
    }

    .session-main {
        padding-left: 0.34rem;
        padding-right: 0.34rem;
    }

    .page-hero {
        padding: 0.74rem 0.62rem;
    }

    .page-eyebrow {
        font-size: 0.62rem;
        letter-spacing: 0.1em;
    }

    .session-trigger,
    .session-content {
        padding-left: 0.34rem;
        padding-right: 0.34rem;
    }

    .session-trigger {
        gap: 0.34rem;
    }

    .session-title {
        font-size: 0.82rem;
        line-height: 1.14;
    }

    .session-summary,
    .session-header-detail,
    .session-subsection-caption,
    .hero-intro,
    .pdf-mobile-copy,
    .mobile-nav-label {
        font-size: 0.68rem;
        line-height: 1.22;
    }

    .session-subsection-title,
    .pdf-mobile-title {
        font-size: 0.74rem;
        line-height: 1.14;
    }

    .session-subsection-summary {
        gap: 0.42rem;
        padding: 0.54rem 0.54rem;
    }

    .session-subsection-body {
        padding: 0 0.42rem 0.56rem;
    }

    .tutorial-rich-body {
        padding: 0 0.42rem 0;
    }

    .tutorial-section {
        padding: 0.72rem 0 0.76rem;
    }

    .tutorial-section h4 {
        font-size: 0.76rem;
        line-height: 1.14;
    }

    .tutorial-section h5 {
        font-size: 0.64rem;
        line-height: 1.18;
        letter-spacing: 0.03em;
    }

    .tutorial-section p,
    .tutorial-section li,
    .tutorial-table th,
    .tutorial-table td,
    .tutorial-link-list a,
    .tutorial-callout p {
        font-size: 0.72rem;
        line-height: 1.24;
    }

    .tutorial-section ul,
    .tutorial-section ol {
        padding-left: 0.9rem;
    }

    .tutorial-callout,
    .tutorial-link-list a,
    .pdf-mobile-fallback {
        padding: 0.56rem 0.58rem;
    }

    .tutorial-rich-body pre[class*="language-"],
    .tutorial-rich-body pre {
        padding: 0.56rem 0.58rem;
        font-size: 0.74rem;
    }

    .session-pdf-link-button,
    .mobile-nav-toggle,
    .theme-toggle-compact {
        font-size: 0.72rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    .session-nav-link,
    .session-trigger,
    .session-chevron,
    .session-panel,
    .session-sidebar,
    .sidebar-backdrop,
    .sidebar-close,
    .theme-toggle,
    .theme-toggle-track,
    .theme-toggle-thumb {
        transition: none;
    }
}