.ai-concepts-page {
    min-height: 100dvh;
    background:
        linear-gradient(180deg, #fbfbfd 0%, #f4f6f7 45%, #eef3f2 100%);
    color: #0f172a;
    padding: 1rem 1rem 4rem;
}

.ai-concepts-frame {
    max-width: 1180px;
}

.ai-library-topbar {
    margin-bottom: 0.75rem;
    border: 1px solid rgba(15, 23, 42, 0.08);
    border-radius: 8px;
    background:
        linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(247, 249, 250, 0.94));
    padding: 0.72rem;
    box-shadow: 0 18px 46px rgba(15, 23, 42, 0.07);
}

.ai-concepts-hero {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 0.75rem;
    align-items: center;
    margin-bottom: 0.6rem;
}

.ai-concepts-kicker {
    margin: 0 0 0.4rem;
    color: #0f766e;
    font-size: 0.82rem;
    font-weight: 950;
    letter-spacing: 0;
}

.ai-concepts-hero h1,
.ai-card-list__head h2,
.ai-reader__bar h2 {
    margin: 0;
    letter-spacing: 0;
    color: #0f172a;
}

.ai-concepts-hero h1 {
    font-size: clamp(1.4rem, 1.9vw, 1.85rem);
    line-height: 1.08;
    font-weight: 950;
    text-wrap: balance;
}

.ai-concepts-hero__summary {
    max-width: 58ch;
    margin: 0.36rem 0 0;
    color: #475569;
    font-size: 0.94rem;
    font-weight: 780;
    line-height: 1.45;
    word-break: keep-all;
}

.ai-concepts-stats {
    display: inline-flex;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 0.35rem;
    width: min(12rem, 100%);
}

.ai-concepts-stats span {
    display: inline-flex;
    gap: 0.28rem;
    align-items: baseline;
    min-height: 32px;
    border: 1px solid rgba(15, 23, 42, 0.08);
    border-radius: 8px;
    background: #f1f5f4;
    padding: 0.24rem 0.54rem;
    color: #475569;
    font-size: 0.74rem;
    font-weight: 900;
    text-align: center;
}

.ai-concepts-stats strong {
    color: #0f172a;
    font-size: 0.98rem;
    line-height: 1;
}

.ai-tool-series-nav {
    display: grid;
    gap: 0.5rem;
    margin: 0 0 0.75rem;
    border: 1px solid rgba(91, 67, 230, 0.14);
    border-radius: 8px;
    background: rgba(246, 244, 255, 0.82);
    padding: 0.65rem;
}

.ai-tool-series-nav__label {
    margin: 0;
    color: #5146a7;
    font-size: 0.76rem;
    font-weight: 950;
}

.ai-tool-series-nav__items {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0.4rem;
}

.ai-tool-series-filter {
    display: flex;
    min-width: 0;
    min-height: 44px;
    align-items: center;
    justify-content: space-between;
    gap: 0.5rem;
    border: 1px solid rgba(91, 67, 230, 0.16);
    border-radius: 7px;
    background: #ffffff;
    padding: 0.48rem 0.65rem;
    color: #334155;
    cursor: pointer;
    text-align: left;
    transition: border-color 0.16s ease, background 0.16s ease, color 0.16s ease, transform 0.16s ease;
}

.ai-tool-series-filter strong {
    min-width: 0;
    overflow: hidden;
    font-size: 0.82rem;
    font-weight: 950;
    line-height: 1.15;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.ai-tool-series-filter small {
    flex: 0 0 auto;
    border-radius: 999px;
    background: #eef2ff;
    padding: 0.16rem 0.38rem;
    color: #5b43e6;
    font-size: 0.7rem;
    font-weight: 950;
}

.ai-tool-series-filter:hover,
.ai-tool-series-filter:focus-visible {
    border-color: rgba(91, 67, 230, 0.46);
    transform: translateY(-1px);
}

.ai-tool-series-filter:focus-visible {
    outline: 3px solid rgba(91, 67, 230, 0.2);
    outline-offset: 2px;
}

.ai-tool-series-filter.is-active {
    border-color: #4c3bc2;
    background: #4c3bc2;
    color: #ffffff;
}

.ai-tool-series-filter.is-active small {
    background: rgba(255, 255, 255, 0.18);
    color: #ffffff;
}

.ai-library-controls {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: 0.75rem;
    align-items: center;
    border-top: 1px solid rgba(148, 163, 184, 0.18);
    padding: 0.75rem;
}

.ai-library-discovery {
    overflow: hidden;
    border: 1px solid rgba(148, 163, 184, 0.24);
    border-radius: 8px;
    background: rgba(248, 250, 252, 0.88);
}

.ai-library-discovery summary {
    display: grid;
    grid-template-columns: auto minmax(0, 1fr) auto;
    gap: 0.6rem;
    align-items: center;
    min-height: 44px;
    padding: 0.6rem 0.75rem;
    color: #0f172a;
    cursor: pointer;
    list-style: none;
}

.ai-library-discovery summary::-webkit-details-marker {
    display: none;
}

.ai-library-discovery summary:focus-visible {
    outline: 3px solid rgba(20, 184, 166, 0.48);
    outline-offset: -3px;
}

.ai-library-discovery__label {
    display: inline-flex;
    gap: 0.45rem;
    align-items: center;
    font-size: 0.92rem;
    font-weight: 950;
}

.ai-library-discovery summary small {
    min-width: 0;
    overflow: hidden;
    color: #64748b;
    font-size: 0.82rem;
    font-weight: 850;
    text-align: right;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.ai-library-discovery__chevron {
    color: #64748b;
    transition: transform 0.18s ease;
}

.ai-library-discovery[open] {
    background: #ffffff;
}

.ai-library-discovery[open] .ai-library-discovery__chevron {
    transform: rotate(180deg);
}

.ai-library-discovery[open] .ai-library-controls {
    animation: ai-discovery-enter 0.2s ease-out;
}

@keyframes ai-discovery-enter {
    from {
        opacity: 0;
        transform: translateY(-8px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.ai-book-switcher {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0.32rem;
    width: 100%;
    margin: 0;
    overflow: visible;
    border: 1px solid rgba(15, 23, 42, 0.08);
    border-radius: 8px;
    background: #eef4f4;
    padding: 0.28rem;
}

.ai-book-switcher__item {
    display: inline-flex;
    justify-content: center;
    gap: 0.34rem;
    align-items: center;
    min-width: 0;
    min-height: 42px;
    border: 1px solid rgba(148, 163, 184, 0.28);
    border-radius: 6px;
    background: rgba(255, 255, 255, 0.72);
    padding: 0.42rem 0.72rem;
    color: #475569;
    text-decoration: none;
    text-align: center;
    transition: background 0.16s ease, border-color 0.16s ease, color 0.16s ease, box-shadow 0.16s ease, transform 0.16s ease;
}

.ai-book-switcher__item .ai-book-switcher__part,
.ai-book-switcher__item small {
    color: inherit;
    font-size: 0.82rem;
    font-weight: 950;
    line-height: 1;
}

.ai-book-switcher__item .ai-book-switcher__part {
    color: inherit;
    min-width: 0;
    line-height: 1.15;
    text-wrap: balance;
    white-space: normal;
    word-break: keep-all;
}

.ai-book-switcher__item small {
    flex: 0 0 auto;
    border-radius: 999px;
    background: #e2e8f0;
    padding: 0.16rem 0.36rem;
    color: #64748b;
    font-size: 0.7rem;
    text-align: center;
}

.ai-book-switcher__item:hover {
    border-color: rgba(15, 118, 110, 0.28);
    background: #ffffff;
    color: #0f172a;
    transform: translateY(-1px);
}

.ai-book-switcher__item.is-active {
    background: #111827;
    border-color: #111827;
    color: #ffffff;
    box-shadow: 0 8px 16px rgba(15, 23, 42, 0.16);
}

.ai-book-switcher__item.is-active .ai-book-switcher__part {
    color: #ffffff;
}

.ai-book-switcher__item.is-active small {
    background: rgba(255, 255, 255, 0.18);
    color: #ffffff;
}

.ai-concepts-page.is-design-reference-book {
    background:
        linear-gradient(180deg, #fbfbfd 0%, #f7faf9 44%, #eef6f4 100%);
}

.ai-concepts-page.is-design-reference-book .ai-concepts-frame {
    max-width: 1320px;
}

.ai-concepts-page.is-design-reference-book .ai-library-topbar {
    margin-bottom: 1rem;
    border-color: rgba(109, 91, 208, 0.12);
    background:
        linear-gradient(135deg, rgba(255, 255, 255, 0.96), rgba(244, 247, 246, 0.9)),
        radial-gradient(circle at 8% 0%, rgba(109, 91, 208, 0.1), transparent 30%),
        radial-gradient(circle at 92% 18%, rgba(15, 118, 110, 0.08), transparent 28%);
    padding: clamp(0.9rem, 1.5vw, 1.2rem);
    box-shadow: 0 16px 38px rgba(15, 23, 42, 0.06);
}

.ai-concepts-page.is-design-reference-book .ai-concepts-hero {
    margin-bottom: 0.85rem;
}

.ai-concepts-page.is-design-reference-book .ai-concepts-kicker {
    color: #6d5bd0;
}

.ai-concepts-page.is-design-reference-book .ai-concepts-hero h1 {
    font-size: clamp(1.7rem, 2.8vw, 2.6rem);
}

.ai-concepts-page.is-design-reference-book .ai-concepts-hero__summary {
    max-width: 64ch;
}

.ai-concepts-page.is-design-reference-book .ai-concepts-stats {
    width: auto;
    min-width: min(12rem, 100%);
}

.ai-concepts-page.is-design-reference-book .ai-concepts-stats span {
    background: #ffffff;
}

.ai-concepts-page.is-design-reference-book .ai-book-switcher {
    background: rgba(255, 255, 255, 0.68);
}

.ai-concepts-page.is-design-reference-book .ai-book-switcher__item.is-active {
    border-color: #5f55c8;
    background: #5f55c8;
    box-shadow: 0 10px 20px rgba(95, 85, 200, 0.2);
}

.ai-concepts-toolbar {
    display: flex;
    gap: 0.5rem;
    align-items: center;
    justify-content: flex-end;
    margin: 0;
}

.ai-concepts-search {
    display: flex;
    align-items: center;
    gap: 0.52rem;
    width: min(15.5rem, 100%);
    min-height: 40px;
    border: 1px solid rgba(15, 23, 42, 0.1);
    border-radius: 8px;
    background: #ffffff;
    padding: 0 0.72rem;
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.9);
    color: #64748b;
}

.ai-concepts-search input {
    width: 100%;
    min-width: 0;
    border: 0;
    outline: 0;
    background: transparent;
    color: #0f172a;
    font-size: 0.88rem;
    font-weight: 800;
}

.ai-concepts-search input::placeholder {
    color: #94a3b8;
}

.ai-concepts-segments {
    display: inline-flex;
    flex-wrap: nowrap;
    flex-shrink: 0;
    gap: 0.16rem;
    padding: 0.2rem;
    border: 1px solid rgba(15, 23, 42, 0.08);
    border-radius: 8px;
    background: #edf2f3;
}

.ai-concepts-segments button {
    min-width: 52px;
    min-height: 34px;
    border: 0;
    border-radius: 6px;
    background: transparent;
    color: #475569;
    padding: 0 0.62rem;
    font-size: 0.82rem;
    font-weight: 950;
    white-space: nowrap;
    cursor: pointer;
    transition: background 0.16s ease, color 0.16s ease, box-shadow 0.16s ease;
}

.ai-concepts-segments button[aria-pressed="true"] {
    background: #0f766e;
    color: #ffffff;
    box-shadow: 0 8px 16px rgba(15, 118, 110, 0.18);
}

.ai-reading-panel {
    display: flex;
    flex-wrap: wrap;
    gap: 0.65rem;
    align-items: center;
    justify-content: space-between;
    margin-top: 0.75rem;
    border: 1px solid rgba(15, 118, 110, 0.14);
    border-radius: 8px;
    background: rgba(247, 251, 250, 0.9);
    padding: 0.68rem 0.78rem;
}

.ai-reading-panel__copy {
    min-width: min(18rem, 100%);
}

.ai-reading-panel__copy p {
    margin: 0;
    color: #334155;
    font-size: 0.86rem;
    font-weight: 900;
}

.ai-reading-panel__actions {
    display: inline-flex;
    flex-wrap: wrap;
    gap: 0.4rem;
    align-items: center;
}

.ai-reading-button {
    display: inline-flex;
    gap: 0.38rem;
    align-items: center;
    justify-content: center;
    min-height: 36px;
    border: 1px solid rgba(15, 23, 42, 0.1);
    border-radius: 8px;
    background: #ffffff;
    color: #0f172a;
    padding: 0 0.72rem;
    font-size: 0.82rem;
    font-weight: 950;
    line-height: 1;
    text-decoration: none;
    white-space: nowrap;
    cursor: pointer;
    transition: transform 0.15s ease, background 0.15s ease, color 0.15s ease, opacity 0.15s ease;
}

.ai-reading-button:hover:not(:disabled) {
    transform: translateY(-1px);
    background: #111827;
    color: #ffffff;
}

.ai-reading-button--admin {
    border-color: rgba(91, 67, 230, 0.22);
    background: #f5f3ff;
    color: #5146a7;
}

.ai-reading-button--admin:hover:not(:disabled) {
    background: #5146a7;
}

.ai-reading-button:disabled {
    cursor: not-allowed;
    opacity: 0.42;
}

.ai-concepts-segments button:disabled {
    cursor: not-allowed;
    opacity: 0.42;
}

.ai-reader,
.ai-material-board,
.ai-card-list {
    border: 1px solid rgba(148, 163, 184, 0.22);
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.94);
    box-shadow: 0 18px 42px rgba(15, 23, 42, 0.08);
}

.ai-material-board {
    margin-bottom: 1rem;
    padding: 1rem;
    scroll-margin-top: calc(var(--main-nav-height, 64px) + 1rem);
}

.ai-reader {
    overflow: hidden;
    scroll-margin-top: calc(var(--main-nav-height, 64px) + 1rem);
}

.ai-reader__bar {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    align-items: center;
    border-bottom: 1px solid rgba(148, 163, 184, 0.18);
    padding: 0.85rem 1rem;
}

.ai-reader__heading {
    min-width: 0;
}

.ai-reader__eyebrow {
    margin: 0 0 0.22rem;
    color: #b45309;
    font-size: 0.8rem;
    font-weight: 950;
}

.ai-reader__bar h2 {
    font-size: 1.18rem;
    font-weight: 950;
    line-height: 1.25;
}

.ai-reader__actions {
    display: inline-flex;
    flex-shrink: 0;
    gap: 0.45rem;
    align-items: center;
}

.ai-share-status {
    max-width: 7.5rem;
    color: #0f766e;
    font-size: 0.75rem;
    font-weight: 900;
    line-height: 1.2;
}

.ai-icon-link,
.ai-icon-button {
    display: inline-grid;
    place-items: center;
    width: 42px;
    height: 42px;
    border: 1px solid rgba(148, 163, 184, 0.28);
    border-radius: 8px;
    background: #f8fafc;
    color: #0f172a;
    cursor: pointer;
    transition: transform 0.15s ease, background 0.15s ease, color 0.15s ease;
}

.ai-reader__nav-label {
    display: inline;
    font-size: 0.84rem;
    font-weight: 950;
    white-space: nowrap;
}

.ai-icon-link:hover,
.ai-icon-button:hover:not(:disabled) {
    transform: translateY(-1px);
    background: #0f172a;
    color: #ffffff;
}

.ai-reader-tool-button {
    display: inline-flex;
    min-height: 44px;
    align-items: center;
    justify-content: center;
    gap: 0.45rem;
    border: 1px solid rgba(15, 118, 110, 0.22);
    border-radius: 8px;
    background: #ecfdf5;
    padding: 0.55rem 0.8rem;
    color: #0f766e;
    font-size: 0.82rem;
    font-weight: 950;
    white-space: nowrap;
    transition: transform 0.16s ease, background-color 0.16s ease, color 0.16s ease;
}

.ai-reader-tool-button:hover,
.ai-reader-tool-button:focus-visible {
    transform: translateY(-1px);
    background: #0f766e;
    color: #ffffff;
}

.ai-icon-button.is-active {
    border-color: rgba(15, 118, 110, 0.32);
    background: #0f766e;
    color: #ffffff;
}

.ai-icon-button:disabled,
.ai-reader__nav:disabled {
    cursor: not-allowed;
    opacity: 0.34;
}

.ai-reader__stage {
    position: relative;
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    align-items: center;
    background:
        radial-gradient(circle at 18% 16%, rgba(245, 158, 11, 0.12), transparent 28%),
        linear-gradient(135deg, #0f172a 0%, #1f2937 45%, #0f766e 100%);
    padding: clamp(0.85rem, 1.6vw, 1.1rem);
}

.ai-reader__controls {
    display: grid;
    grid-template-columns: minmax(8.5rem, auto) minmax(12rem, 1fr) minmax(8.5rem, auto);
    gap: 0.75rem;
    align-items: center;
    border-top: 1px solid rgba(148, 163, 184, 0.18);
    background: #ffffff;
    padding: 0.72rem 1rem 0.85rem;
}

.ai-reader__nav {
    display: inline-flex;
    min-width: 8.5rem;
    min-height: 46px;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    border: 1px solid rgba(148, 163, 184, 0.3);
    border-radius: 8px;
    background: #f8fafc;
    color: #0f172a;
    padding: 0 0.9rem;
    cursor: pointer;
    box-shadow: 0 8px 18px rgba(15, 23, 42, 0.06);
    transition: transform 0.15s ease, border-color 0.15s ease, background 0.15s ease, color 0.15s ease, box-shadow 0.15s ease;
}

.ai-reader__nav:hover:not(:disabled) {
    transform: translateY(-1px);
    border-color: #0f766e;
    background: #0f766e;
    color: #ffffff;
    box-shadow: 0 10px 22px rgba(15, 118, 110, 0.18);
}

.ai-reader__nav:focus-visible {
    outline: 3px solid rgba(20, 184, 166, 0.38);
    outline-offset: 2px;
}

.ai-reader__nav:disabled {
    border-color: rgba(148, 163, 184, 0.18);
    background: #f8fafc;
    color: #94a3b8;
    opacity: 1;
    box-shadow: none;
}

.ai-reader__spread {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.9rem;
    min-height: min(72vh, 760px);
    align-items: center;
    padding: 0;
}

.ai-reader__spread[data-mode="single"] {
    grid-template-columns: minmax(0, min(620px, 100%));
    justify-content: center;
}

.ai-loading-spinner {
    display: block;
    width: 1.55rem;
    height: 1.55rem;
    border: 3px solid rgba(15, 118, 110, 0.18);
    border-top-color: #0f766e;
    border-radius: 999px;
    animation: ai-loading-spin 0.78s linear infinite;
}

@keyframes ai-loading-spin {
    to {
        transform: rotate(360deg);
    }
}

.ai-reader-card {
    position: relative;
    margin: 0;
    align-self: center;
}

.ai-reader-card__open {
    position: relative;
    display: grid;
    place-items: center;
    width: min(100%, calc(min(72vh, 760px) * var(--ai-card-width-ratio, 0.708)));
    aspect-ratio: var(--ai-card-aspect, 906 / 1280);
    overflow: hidden;
    border: 0;
    border-radius: 8px;
    background:
        linear-gradient(135deg, rgba(248, 250, 252, 0.98), rgba(226, 232, 240, 0.94));
    box-shadow: 0 18px 34px rgba(0, 0, 0, 0.34);
    margin: 0 auto;
    padding: 0;
    cursor: zoom-in;
}

.ai-reader-card__open.is-reader-page {
    cursor: default;
}

.ai-reader-card__open::before {
    content: "";
    position: absolute;
    inset: 0;
    z-index: 0;
    background:
        linear-gradient(135deg, rgba(255, 255, 255, 0.96), rgba(241, 245, 249, 0.9)),
        repeating-linear-gradient(45deg, rgba(15, 23, 42, 0.045) 0 1px, transparent 1px 12px);
    opacity: 0;
    transition: opacity 0.16s ease;
}

.ai-reader-card__open.is-loading::before,
.ai-reader-card__open.is-error::before {
    opacity: 1;
}

.ai-reader-card__open.is-error::after {
    content: "이미지 불러오기 실패";
    position: absolute;
    z-index: 2;
    max-width: 80%;
    border-radius: 8px;
    background: rgba(15, 23, 42, 0.86);
    color: #ffffff;
    padding: 0.55rem 0.72rem;
    font-size: 0.86rem;
    font-weight: 900;
    text-align: center;
}

.ai-reader-card__loading {
    position: absolute;
    inset: 0;
    z-index: 2;
    display: none;
    place-content: center;
    justify-items: center;
    gap: 0.72rem;
    padding: 1rem;
    color: #0f172a;
    font-size: 0.92rem;
    font-weight: 950;
    text-align: center;
}

.ai-card-state-badges {
    position: absolute;
    top: 0.52rem;
    left: 0.52rem;
    z-index: 3;
    display: flex;
    flex-wrap: wrap;
    gap: 0.28rem;
    max-width: calc(100% - 1.04rem);
    pointer-events: none;
}

.ai-card-state-badge {
    display: inline-flex;
    align-items: center;
    min-height: 24px;
    border: 1px solid rgba(255, 255, 255, 0.44);
    border-radius: 999px;
    background: rgba(15, 23, 42, 0.78);
    color: #ffffff;
    padding: 0 0.48rem;
    font-size: 0.68rem;
    font-weight: 950;
    line-height: 1;
    white-space: nowrap;
    box-shadow: 0 8px 18px rgba(15, 23, 42, 0.18);
    backdrop-filter: blur(8px);
}

.ai-card-state-badge--read {
    background: rgba(51, 65, 85, 0.82);
}

.ai-card-state-badge--saved {
    background: rgba(15, 118, 110, 0.88);
}

.ai-card-state-badge--confused {
    background: rgba(180, 83, 9, 0.9);
}

.ai-reader-card__open.is-loading .ai-reader-card__loading {
    display: grid;
}

.ai-reader-card__open:focus-visible {
    outline: 3px solid rgba(20, 184, 166, 0.9);
    outline-offset: 4px;
}

.ai-reader-card img {
    position: relative;
    z-index: 1;
    display: block;
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: 8px;
    background: #ffffff;
    user-select: none;
    -webkit-user-drag: none;
}

.ai-reader-card__open.is-loading img,
.ai-reader-card__open.is-error img {
    opacity: 0;
}

.ai-reader-card figcaption {
    margin-top: 0.55rem;
    color: rgba(255, 255, 255, 0.86);
    font-size: 0.84rem;
    font-weight: 850;
    text-align: center;
}

.ai-reader--design-board {
    overflow: visible;
}

.ai-reader--design-board .ai-reader__bar {
    background:
        linear-gradient(135deg, rgba(255, 255, 255, 0.98), rgba(240, 253, 250, 0.9)),
        radial-gradient(circle at 96% 10%, rgba(124, 58, 237, 0.12), transparent 30%);
}

.ai-reader--design-board .ai-reader__eyebrow {
    color: #6d5bd0;
}

.ai-reader--design-board .ai-reader__stage {
    align-items: start;
    overflow: visible;
    background:
        radial-gradient(circle at 9% 8%, rgba(124, 58, 237, 0.1), transparent 28%),
        linear-gradient(180deg, #f8fafc 0%, #edf4f3 100%);
    padding: clamp(0.55rem, 1.8vw, 1.1rem);
}

.ai-reader--design-board .ai-reader__spread {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: clamp(0.9rem, 2vw, 1.25rem);
    min-height: 0;
    padding: 0;
}

.ai-reader--design-board .ai-reader__spread[data-mode="board"] {
    grid-template-columns: minmax(0, 1fr);
}

.ai-design-board {
    display: grid;
    gap: 0.55rem;
    margin: 0;
    min-width: 0;
}

.ai-design-board__shell {
    position: relative;
    overflow-x: auto;
    overflow-y: hidden;
    overscroll-behavior-x: contain;
    border: 1px solid rgba(15, 23, 42, 0.1);
    border-radius: 8px;
    background: #ffffff;
    padding: clamp(0.4rem, 1.2vw, 0.7rem);
    box-shadow: 0 18px 34px rgba(15, 23, 42, 0.1);
    scrollbar-color: #94a3b8 #e2e8f0;
    scrollbar-width: thin;
}

.ai-design-board__shell:focus-visible {
    outline: 3px solid rgba(109, 91, 208, 0.36);
    outline-offset: 3px;
}

.ai-design-board__shell::-webkit-scrollbar {
    height: 0.75rem;
}

.ai-design-board__shell::-webkit-scrollbar-track {
    border-radius: 999px;
    background: #e2e8f0;
}

.ai-design-board__shell::-webkit-scrollbar-thumb {
    border: 3px solid #e2e8f0;
    border-radius: 999px;
    background: #94a3b8;
}

.ai-design-board__shell img {
    display: block;
    width: max(100%, var(--ai-board-width, 1402px));
    max-width: none;
    height: auto;
    border-radius: 6px;
    background: #ffffff;
    user-select: none;
    -webkit-user-drag: none;
}

.ai-design-board__shell.is-loading img,
.ai-design-board__shell.is-error img {
    opacity: 0;
}

.ai-design-board__loading {
    position: absolute;
    inset: 0;
    z-index: 2;
    display: none;
    place-content: center;
    justify-items: center;
    gap: 0.72rem;
    background:
        linear-gradient(135deg, rgba(255, 255, 255, 0.92), rgba(241, 245, 249, 0.9)),
        repeating-linear-gradient(45deg, rgba(15, 23, 42, 0.045) 0 1px, transparent 1px 12px);
    color: #0f172a;
    font-size: 0.92rem;
    font-weight: 950;
    text-align: center;
}

.ai-design-board__shell.is-loading .ai-design-board__loading {
    display: grid;
}

.ai-design-board__shell.is-error::after {
    content: "보드 불러오기 실패";
    position: absolute;
    inset: 50% auto auto 50%;
    z-index: 3;
    transform: translate(-50%, -50%);
    border-radius: 8px;
    background: rgba(15, 23, 42, 0.86);
    color: #ffffff;
    padding: 0.55rem 0.72rem;
    font-size: 0.86rem;
    font-weight: 900;
    text-align: center;
}

.ai-design-board figcaption {
    color: #475569;
    font-size: 0.84rem;
    font-weight: 850;
    text-align: center;
}

.ai-reader__progress {
    display: grid;
    gap: 0.12rem;
    min-width: 0;
    align-items: center;
}

.ai-reader__position {
    color: #475569;
    font-size: 0.78rem;
    font-weight: 950;
    line-height: 1;
    text-align: center;
}

.ai-reader__progress input {
    display: block;
    width: 100%;
    min-height: 1.75rem;
    margin: 0;
    accent-color: #0f766e;
    cursor: pointer;
}

.ai-reader__progress input:focus-visible {
    outline: 3px solid rgba(20, 184, 166, 0.34);
    outline-offset: 2px;
}

.ai-reader:fullscreen,
.ai-reader.is-fullscreen {
    position: fixed;
    inset: 0;
    z-index: 2147482000;
    display: grid;
    grid-template-rows: auto minmax(0, 1fr) auto;
    width: 100vw;
    height: 100vh;
    height: 100dvh;
    overflow: hidden;
    border: 0;
    border-radius: 0;
    background: #070b12;
    box-shadow: none;
}

.ai-reader:fullscreen .ai-reader__bar,
.ai-reader.is-fullscreen .ai-reader__bar {
    border-bottom-color: rgba(226, 232, 240, 0.16);
    background: rgba(7, 11, 18, 0.94);
    padding: 0.72rem clamp(0.8rem, 2vw, 1.3rem);
}

.ai-reader:fullscreen .ai-reader__bar h2,
.ai-reader.is-fullscreen .ai-reader__bar h2 {
    max-width: min(64vw, 36rem);
    overflow: hidden;
    color: #f8fafc;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.ai-reader:fullscreen .ai-reader__eyebrow,
.ai-reader.is-fullscreen .ai-reader__eyebrow {
    color: #fbbf24;
}

.ai-reader:fullscreen .ai-icon-link,
.ai-reader:fullscreen .ai-icon-button,
.ai-reader.is-fullscreen .ai-icon-link,
.ai-reader.is-fullscreen .ai-icon-button {
    border-color: rgba(226, 232, 240, 0.24);
    background: rgba(15, 23, 42, 0.72);
    color: #f8fafc;
}

.ai-reader:fullscreen .ai-reader__stage,
.ai-reader.is-fullscreen .ai-reader__stage {
    min-height: 0;
    overflow: hidden;
    background:
        radial-gradient(circle at 16% 14%, rgba(20, 184, 166, 0.18), transparent 28%),
        linear-gradient(135deg, #070b12 0%, #101826 48%, #052e2b 100%);
    padding: clamp(0.7rem, 2vw, 1.1rem);
}

.ai-reader:fullscreen .ai-reader__spread,
.ai-reader.is-fullscreen .ai-reader__spread {
    grid-template-columns: repeat(2, minmax(0, min(44vw, 100%)));
    align-content: center;
    align-items: stretch;
    justify-content: center;
    min-height: 0;
    height: 100%;
    padding: 0;
}

.ai-reader:fullscreen .ai-reader__spread[data-mode="single"],
.ai-reader.is-fullscreen .ai-reader__spread[data-mode="single"] {
    grid-template-columns: minmax(0, min(100%, 72vw));
}

.ai-reader:fullscreen .ai-reader-card,
.ai-reader.is-fullscreen .ai-reader-card {
    display: grid;
    width: 100%;
    height: 100%;
    min-height: 0;
    place-items: center;
}

.ai-reader:fullscreen .ai-reader-card__open,
.ai-reader.is-fullscreen .ai-reader-card__open {
    width: min(100%, calc(var(--ai-reader-fit-height, 720px) * var(--ai-card-width-ratio, 0.708)));
    height: auto;
    max-width: 100%;
    max-height: 100%;
    box-shadow: 0 22px 58px rgba(0, 0, 0, 0.5);
}

.ai-reader:fullscreen .ai-reader-card figcaption,
.ai-reader.is-fullscreen .ai-reader-card figcaption {
    display: none;
}

.ai-reader:fullscreen .ai-reader__controls,
.ai-reader.is-fullscreen .ai-reader__controls {
    border-top: 1px solid rgba(226, 232, 240, 0.16);
    background: rgba(7, 11, 18, 0.94);
    padding: 0.6rem clamp(0.9rem, 3vw, 1.5rem) 0.75rem;
}

.ai-reader:fullscreen .ai-reader__nav,
.ai-reader.is-fullscreen .ai-reader__nav {
    border-color: rgba(226, 232, 240, 0.2);
    background: rgba(15, 23, 42, 0.78);
    color: #f8fafc;
    box-shadow: none;
}

.ai-reader:fullscreen .ai-reader__nav:hover:not(:disabled),
.ai-reader.is-fullscreen .ai-reader__nav:hover:not(:disabled) {
    border-color: #14b8a6;
    background: #0f766e;
}

.ai-reader:fullscreen .ai-reader__nav:disabled,
.ai-reader.is-fullscreen .ai-reader__nav:disabled {
    color: #64748b;
    opacity: 0.7;
}

.ai-reader:fullscreen .ai-reader__position,
.ai-reader.is-fullscreen .ai-reader__position {
    color: #cbd5e1;
}

.ai-reader:fullscreen .ai-reader__progress input,
.ai-reader.is-fullscreen .ai-reader__progress input {
    accent-color: #14b8a6;
}

body.ai-reader-fullscreen-is-open {
    overflow: hidden;
}

body.ai-reader-fullscreen-is-open #mainNav,
body.ai-reader-fullscreen-is-open .service-left-rail-aside {
    display: none !important;
}

.ai-zoom[hidden] {
    display: none;
}

.ai-zoom {
    position: fixed;
    inset: 0;
    z-index: 2147483000;
    display: grid;
    place-items: center;
    padding: 1.25rem;
}

.ai-zoom__backdrop {
    position: absolute;
    inset: 0;
    border: 0;
    background: rgba(15, 23, 42, 0.72);
    cursor: zoom-out;
}

.ai-zoom__panel {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-rows: auto minmax(0, 1fr);
    width: min(1120px, 100%);
    height: min(92vh, 920px);
    overflow: hidden;
    border: 1px solid rgba(226, 232, 240, 0.32);
    border-radius: 8px;
    background: #f8fafc;
    box-shadow: 0 28px 80px rgba(0, 0, 0, 0.42);
}

.ai-zoom__toolbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    border-bottom: 1px solid rgba(148, 163, 184, 0.28);
    background: rgba(255, 255, 255, 0.96);
    padding: 0.85rem 1rem;
}

.ai-zoom__title {
    min-width: 0;
}

.ai-zoom__title h2 {
    margin: 0;
    overflow: hidden;
    color: #0f172a;
    font-size: 1.05rem;
    font-weight: 950;
    line-height: 1.25;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.ai-zoom__actions {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    flex-shrink: 0;
}

.ai-zoom__actions [data-ai-zoom-level] {
    min-width: 3.25rem;
    color: #334155;
    font-size: 0.82rem;
    font-weight: 950;
    text-align: center;
}

.ai-zoom__canvas {
    min-height: 0;
    overflow: auto;
    background:
        radial-gradient(circle at 20% 10%, rgba(15, 118, 110, 0.14), transparent 32%),
        linear-gradient(135deg, #111827 0%, #0f172a 44%, #134e4a 100%);
    padding: 1rem;
    text-align: center;
}

.ai-zoom__canvas img {
    display: block;
    height: auto;
    max-width: none;
    margin: 0 auto;
    border-radius: 8px;
    background: #ffffff;
    box-shadow: 0 18px 46px rgba(0, 0, 0, 0.44);
    user-select: none;
    -webkit-user-drag: none;
}

body.ai-zoom-is-open {
    overflow: hidden;
}

.ai-material-board__head {
    display: flex;
    align-items: end;
    justify-content: space-between;
    gap: 1rem;
    margin-bottom: 0.85rem;
}

.ai-material-board__head h2 {
    margin: 0;
    color: #0f172a;
    font-size: 1.35rem;
    font-weight: 950;
    letter-spacing: 0;
}

.ai-material-board__head > p {
    margin: 0;
    color: #64748b;
    font-size: 0.88rem;
    font-weight: 950;
}

.ai-text-material-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.85rem;
    align-items: start;
}

.ai-text-material-card {
    min-width: 0;
    align-self: start;
}

.ai-text-material-card details {
    border: 1px solid rgba(148, 163, 184, 0.24);
    border-radius: 8px;
    background:
        linear-gradient(180deg, rgba(255, 255, 255, 0.98), rgba(248, 250, 252, 0.95));
    box-shadow: 0 12px 28px rgba(15, 23, 42, 0.06);
}

.ai-text-material-card summary {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 0.36rem 0.75rem;
    align-items: start;
    min-height: 9rem;
    padding: 0.9rem;
    cursor: pointer;
    list-style: none;
}

.ai-text-material-card summary::-webkit-details-marker {
    display: none;
}

.ai-text-material-card summary:focus-visible {
    outline: 3px solid rgba(20, 184, 166, 0.55);
    outline-offset: 3px;
}

.ai-text-material-card__label {
    grid-column: 1 / -1;
    color: #0f766e;
    font-size: 0.78rem;
    font-weight: 950;
}

.ai-text-material-card summary strong {
    color: #0f172a;
    font-size: 1.06rem;
    font-weight: 950;
    line-height: 1.28;
    word-break: keep-all;
}

.ai-text-material-card summary > span:not(.ai-text-material-card__label) {
    grid-column: 1 / -1;
    color: #475569;
    font-size: 0.88rem;
    font-weight: 780;
    line-height: 1.55;
    word-break: keep-all;
}

.ai-text-material-card summary small {
    align-self: start;
    border-radius: 6px;
    background: #fff7ed;
    color: #b45309;
    padding: 0.22rem 0.42rem;
    font-size: 0.74rem;
    font-weight: 950;
    line-height: 1;
    white-space: nowrap;
}

.ai-text-material-card__body {
    display: grid;
    gap: 0.72rem;
    border-top: 1px solid rgba(148, 163, 184, 0.18);
    padding: 0 0.9rem 0.95rem;
}

.ai-text-material-card__body section,
.ai-text-material-card__checklist {
    display: grid;
    gap: 0.28rem;
    max-width: 68ch;
}

.ai-text-material-card__body h3 {
    margin: 0;
    color: #0f172a;
    font-size: 0.92rem;
    font-weight: 950;
}

.ai-text-material-card__body p {
    margin: 0;
    color: #334155;
    font-size: 0.88rem;
    font-weight: 760;
    line-height: 1.62;
    word-break: keep-all;
}

.ai-text-material-card__checklist {
    border-radius: 8px;
    background: #f0fdfa;
    padding: 0.72rem;
}

.ai-text-material-card__checklist ul {
    display: grid;
    gap: 0.3rem;
    margin: 0;
    padding-left: 1.05rem;
    color: #0f766e;
    font-size: 0.86rem;
    font-weight: 850;
    line-height: 1.45;
}

.ai-vibeclass-import[hidden] {
    display: none !important;
}

.ai-vibeclass-import {
    position: fixed;
    inset: 0;
    z-index: 2147482001;
    display: grid;
    place-items: center;
    padding: 1rem;
}

.ai-vibeclass-import__backdrop {
    position: absolute;
    inset: 0;
    border: 0;
    background: rgba(15, 23, 42, 0.68);
}

.ai-vibeclass-import__panel {
    position: relative;
    z-index: 1;
    display: grid;
    width: min(30rem, 100%);
    max-height: min(80vh, 42rem);
    overflow: hidden;
    border: 1px solid rgba(226, 232, 240, 0.9);
    border-radius: 8px;
    background: #ffffff;
    box-shadow: 0 24px 80px rgba(15, 23, 42, 0.28);
}

.ai-vibeclass-import__head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    border-bottom: 1px solid #e2e8f0;
    padding: 1rem;
}

.ai-vibeclass-import__head h2 {
    margin: 0.16rem 0 0;
    color: #0f172a;
    font-size: 1.15rem;
    font-weight: 950;
}

.ai-vibeclass-import__status {
    min-height: 1.25rem;
    padding: 0.75rem 1rem 0;
    color: #475569;
    font-size: 0.86rem;
    font-weight: 800;
}

.ai-vibeclass-import__status.is-error {
    color: #be123c;
}

.ai-vibeclass-import__status.is-success {
    color: #0f766e;
}

.ai-vibeclass-import__targets {
    display: grid;
    gap: 0.55rem;
    overflow-y: auto;
    padding: 0.85rem 1rem 1rem;
}

.ai-vibeclass-target {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 0.75rem;
    min-height: 54px;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    background: #f8fafc;
    padding: 0.75rem;
    color: #0f172a;
    text-align: left;
}

.ai-vibeclass-target:hover:not(:disabled),
.ai-vibeclass-target:focus-visible {
    border-color: rgba(15, 118, 110, 0.55);
    background: #ecfdf5;
}

.ai-vibeclass-target:disabled {
    cursor: wait;
    opacity: 0.62;
}

.ai-vibeclass-target strong {
    overflow: hidden;
    font-size: 0.92rem;
    font-weight: 950;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.ai-vibeclass-target span {
    border-radius: 999px;
    background: #0f172a;
    padding: 0.28rem 0.55rem;
    color: #ffffff;
    font-size: 0.72rem;
    font-weight: 950;
}

.ai-vibeclass-target--new {
    border-color: rgba(15, 118, 110, 0.34);
    background: #0f766e;
    color: #ffffff;
}

.ai-vibeclass-target--new span {
    background: rgba(255, 255, 255, 0.18);
}

.ai-vibeclass-result-link {
    display: inline-flex;
    min-height: 40px;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    background: #0f172a;
    padding: 0.55rem 0.85rem;
    color: #ffffff;
    font-weight: 950;
}

body.ai-vibeclass-import-is-open {
    overflow: hidden;
}

.ai-card-list {
    margin-top: 1rem;
    padding: 1rem;
}

.ai-card-list__head {
    display: flex;
    align-items: end;
    justify-content: space-between;
    gap: 1rem;
    margin-bottom: 0.85rem;
}

.ai-card-list__head h2 {
    font-size: 1.35rem;
    font-weight: 950;
}

.ai-card-list__head > p {
    margin: 0;
    color: #64748b;
    font-size: 0.88rem;
    font-weight: 950;
}

.ai-card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(164px, 1fr));
    gap: 0.85rem;
}

.ai-card-grid.ai-card-grid--grouped {
    display: block;
}

.ai-tool-card-group {
    border: 1px solid rgba(91, 67, 230, 0.14);
    border-top: 3px solid #5b43e6;
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.72);
    padding: 0.8rem;
}

.ai-tool-card-group + .ai-tool-card-group {
    margin-top: 1rem;
}

.ai-tool-card-group[data-ai-tool-group="open-minis"] {
    border-top-color: #ff6b4a;
}

.ai-tool-card-group[data-ai-tool-group="gemini-spark"] {
    border-top-color: #20a995;
}

.ai-tool-card-group__head {
    display: flex;
    align-items: end;
    justify-content: space-between;
    gap: 1rem;
    margin-bottom: 0.75rem;
}

.ai-tool-card-group__head p,
.ai-tool-card-group__head h3 {
    margin: 0;
}

.ai-tool-card-group__head div > p:first-child {
    margin-bottom: 0.18rem;
    color: #5b43e6;
    font-size: 0.7rem;
    font-weight: 950;
}

.ai-tool-card-group__head h3 {
    color: #0f172a;
    font-size: 1.06rem;
    font-weight: 950;
}

.ai-tool-card-group__head div > p:last-child {
    margin-top: 0.22rem;
    color: #64748b;
    font-size: 0.8rem;
    font-weight: 780;
    line-height: 1.4;
    word-break: keep-all;
}

.ai-tool-card-group__head > span {
    flex: 0 0 auto;
    border-radius: 999px;
    background: #ede9fe;
    padding: 0.28rem 0.55rem;
    color: #5b43e6;
    font-size: 0.76rem;
    font-weight: 950;
}

.ai-tool-card-group__grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(164px, 1fr));
    gap: 0.85rem;
}

.ai-card-list__more {
    display: flex;
    width: min(100%, 24rem);
    min-height: 44px;
    align-items: center;
    justify-content: center;
    margin: 0.85rem auto 0;
    border: 1px solid rgba(15, 118, 110, 0.24);
    border-radius: 8px;
    background: #f0fdfa;
    color: #0f766e;
    font-size: 0.92rem;
    font-weight: 950;
    cursor: pointer;
}

.ai-card-list__more:hover,
.ai-card-list__more:focus-visible {
    border-color: #0f766e;
    background: #0f766e;
    color: #ffffff;
}

.ai-card-tile {
    display: flex;
    flex-direction: column;
    gap: 0.65rem;
    min-width: 0;
    border: 1px solid rgba(148, 163, 184, 0.22);
    border-radius: 8px;
    background: #ffffff;
    padding: 0.65rem;
    color: inherit;
    cursor: pointer;
    text-align: left;
    text-decoration: none;
    box-shadow: 0 10px 22px rgba(15, 23, 42, 0.05);
    transition: transform 0.15s ease, border-color 0.15s ease, box-shadow 0.15s ease;
}

.ai-card-tile:hover,
.ai-card-tile[aria-current="true"] {
    transform: translateY(-2px);
    border-color: rgba(15, 118, 110, 0.42);
    box-shadow: 0 14px 26px rgba(15, 118, 110, 0.12);
}

.ai-card-tile__thumb {
    position: relative;
    display: block;
    width: 100%;
    overflow: hidden;
    aspect-ratio: 1055 / 1491;
    border-radius: 6px;
    background:
        linear-gradient(135deg, rgba(248, 250, 252, 0.98), rgba(226, 232, 240, 0.92));
}

.ai-card-tile__thumb img {
    position: absolute;
    inset: 0;
    display: block;
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0;
    transition: opacity 0.18s ease;
    user-select: none;
    -webkit-user-drag: none;
}

.ai-card-tile__thumb.is-loaded img {
    opacity: 1;
}

.ai-card-tile__loading {
    position: absolute;
    inset: 0;
    z-index: 1;
    display: grid;
    place-content: center;
    justify-items: center;
    gap: 0.42rem;
    padding: 0.7rem;
    color: #475569;
    font-size: 0.76rem;
    font-weight: 950;
    text-align: center;
}

.ai-card-tile__thumb.is-loaded .ai-card-tile__loading {
    display: none;
}

.ai-card-tile__thumb.is-error .ai-loading-spinner {
    display: none;
}

.ai-card-tile__thumb.is-error .ai-card-tile__loading {
    color: #991b1b;
}

.ai-card-tile__meta {
    display: grid;
    gap: 0.25rem;
    min-width: 0;
}

.ai-card-tile__meta strong {
    color: #0f172a;
    font-size: 0.9rem;
    font-weight: 950;
    line-height: 1.3;
}

.ai-card-tile__meta span {
    color: #64748b;
    font-size: 0.78rem;
    font-weight: 850;
}

.ai-empty {
    grid-column: 1 / -1;
    border: 1px dashed rgba(148, 163, 184, 0.5);
    border-radius: 8px;
    padding: 2rem;
    color: #64748b;
    font-weight: 900;
    text-align: center;
}

.ai-library-empty {
    margin-top: 1rem;
    background: rgba(255, 255, 255, 0.82);
}

[hidden] {
    display: none !important;
}

@media (prefers-reduced-motion: reduce) {
    .ai-loading-spinner {
        animation: none;
    }

    .ai-library-discovery[open] .ai-library-controls {
        animation: none;
    }

    .ai-library-discovery__chevron {
        transition-duration: 1ms;
    }

    .ai-reader-tool-button {
        transition-duration: 1ms;
    }

    .ai-reader-tool-button:hover,
    .ai-reader-tool-button:focus-visible {
        transform: none;
    }
}

@media (max-width: 920px) {
    .ai-concepts-hero,
    .ai-library-controls,
    .ai-concepts-toolbar {
        grid-template-columns: 1fr;
        flex-direction: column;
        align-items: stretch;
    }

    .ai-concepts-stats {
        width: 100%;
        justify-content: flex-start;
    }

    .ai-tool-series-nav__items {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .ai-concepts-search {
        width: 100%;
    }

    .ai-text-material-grid {
        grid-template-columns: 1fr;
    }

    .ai-concepts-segments.ai-concepts-segments--view {
        display: none;
    }

    .ai-reading-panel {
        align-items: stretch;
    }

    .ai-reading-panel__actions {
        width: 100%;
    }

    .ai-reader__spread {
        grid-template-columns: minmax(0, 1fr);
        min-height: auto;
        padding: 0;
    }

    .ai-reader:fullscreen .ai-reader__spread,
    .ai-reader.is-fullscreen .ai-reader__spread {
        grid-template-columns: minmax(0, min(100%, 92vw));
        gap: 0;
        padding: 0;
    }

    .ai-reader:fullscreen .ai-reader__spread[data-mode="single"],
    .ai-reader.is-fullscreen .ai-reader__spread[data-mode="single"] {
        grid-template-columns: minmax(0, min(100%, 92vw));
    }
}

@media (max-width: 640px) {
    .ai-tool-series-filter {
        min-height: 54px;
        align-items: flex-start;
        flex-direction: column;
        justify-content: center;
        gap: 0.14rem;
    }

    .ai-tool-series-filter strong {
        overflow: visible;
        text-overflow: clip;
        white-space: normal;
        word-break: keep-all;
    }

    .ai-tool-series-filter small {
        padding: 0;
        background: transparent;
    }

    .ai-concepts-page {
        padding-top: 0.75rem;
        padding-left: 0.75rem;
        padding-right: 0.75rem;
    }

    .ai-library-topbar {
        margin-bottom: 0.75rem;
        border: 0;
        background: transparent;
        padding: 0;
        box-shadow: none;
    }

    .ai-concepts-hero {
        grid-template-columns: minmax(0, 1fr) auto;
        gap: 0.65rem;
        align-items: start;
        margin-bottom: 0.75rem;
        padding: 0 0.1rem;
    }

    .ai-concepts-hero h1 {
        font-size: 1.35rem;
        line-height: 1.22;
        text-wrap: pretty;
    }

    .ai-concepts-kicker {
        margin-bottom: 0.28rem;
        font-size: 0.78rem;
    }

    .ai-concepts-hero__summary {
        display: -webkit-box;
        margin-top: 0.35rem;
        overflow: hidden;
        font-size: 0.9rem;
        line-height: 1.45;
        -webkit-box-orient: vertical;
        -webkit-line-clamp: 2;
    }

    .ai-concepts-stats {
        width: auto;
        justify-content: flex-end;
    }

    .ai-concepts-stats span {
        min-height: 28px;
        padding: 0.2rem 0.45rem;
    }

    .ai-concepts-stats strong {
        font-size: 0.88rem;
    }

    .ai-library-discovery summary {
        grid-template-columns: auto minmax(0, 1fr) auto;
        min-height: 48px;
        padding: 0.65rem 0.75rem;
    }

    .ai-library-discovery summary small {
        font-size: 0.78rem;
    }

    .ai-library-controls {
        gap: 0.65rem;
        padding: 0.65rem;
    }

    .ai-book-switcher {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .ai-book-switcher__item {
        min-height: 40px;
        padding: 0.44rem 0.56rem;
    }

    .ai-book-switcher__item .ai-book-switcher__part {
        font-size: 0.82rem;
    }

    .ai-concepts-segments {
        display: grid;
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .ai-concepts-segments button {
        padding: 0 0.35rem;
        font-size: 0.78rem;
    }

    .ai-reading-button {
        min-height: 40px;
        flex: 0 0 auto;
    }

    .ai-material-board,
    .ai-card-list {
        padding: 0.78rem;
    }

    .ai-material-board__head,
    .ai-card-list__head {
        align-items: start;
    }

    .ai-text-material-card summary {
        grid-template-columns: minmax(0, 1fr);
        min-height: 0;
    }

    .ai-text-material-card summary small {
        justify-self: start;
    }

    .ai-reading-panel {
        display: grid;
        grid-template-columns: minmax(0, 1fr) auto;
        align-items: center;
        padding: 0.6rem 0.7rem;
    }

    .ai-reading-panel__copy {
        min-width: 0;
    }

    .ai-reading-panel__copy p {
        line-height: 1.4;
    }

    .ai-reading-panel__actions {
        width: auto;
    }

    .ai-reader__bar {
        align-items: center;
        gap: 0.55rem;
        padding: 0.75rem;
    }

    .ai-reader__bar h2 {
        display: -webkit-box;
        overflow: hidden;
        font-size: 1.05rem;
        line-height: 1.25;
        -webkit-box-orient: vertical;
        -webkit-line-clamp: 2;
    }

    .ai-reader__eyebrow {
        margin-bottom: 0.12rem;
        font-size: 0.76rem;
    }

    .ai-reader__actions {
        gap: 0.3rem;
        flex-wrap: nowrap;
    }

    .ai-reader__actions .ai-icon-link {
        display: none;
    }

    .ai-reader:fullscreen .ai-reader__bar,
    .ai-reader.is-fullscreen .ai-reader__bar {
        align-items: center;
        gap: 0.55rem;
        padding: 0.58rem 0.68rem;
    }

    .ai-reader:fullscreen .ai-reader__bar h2,
    .ai-reader.is-fullscreen .ai-reader__bar h2 {
        max-width: calc(100vw - 8.7rem);
        font-size: 0.98rem;
    }

    .ai-reader:fullscreen .ai-reader__eyebrow,
    .ai-reader.is-fullscreen .ai-reader__eyebrow {
        margin-bottom: 0.12rem;
        font-size: 0.72rem;
    }

    .ai-reader__stage {
        grid-template-columns: minmax(0, 1fr);
        gap: 0;
        padding: 0.75rem;
    }

    .ai-reader:fullscreen .ai-reader__stage,
    .ai-reader.is-fullscreen .ai-reader__stage {
        padding: 0.55rem 0.35rem;
    }

    .ai-reader__spread {
        padding: 0;
    }

    .ai-reader-card figcaption {
        display: none;
    }

    .ai-reader:fullscreen .ai-reader__spread,
    .ai-reader.is-fullscreen .ai-reader__spread {
        grid-template-columns: minmax(0, min(100%, 94vw));
        padding: 0;
    }

    .ai-reader:fullscreen .ai-reader__spread[data-mode="single"],
    .ai-reader.is-fullscreen .ai-reader__spread[data-mode="single"] {
        grid-template-columns: minmax(0, min(100%, 94vw));
    }

    .ai-icon-link,
    .ai-icon-button {
        width: 38px;
        height: 38px;
    }

    .ai-reader__controls {
        grid-template-columns: minmax(0, 1fr) minmax(5.5rem, 0.82fr) minmax(0, 1fr);
        gap: 0.35rem;
        padding: 0.55rem 0.6rem 0.65rem;
    }

    .ai-reader__nav {
        min-width: 0;
        min-height: 46px;
        gap: 0.35rem;
        width: 100%;
        padding: 0 0.42rem;
    }

    .ai-reader__nav:hover:not(:disabled) {
        transform: translateY(-1px);
    }

    .ai-reader__nav-label {
        font-size: 0.78rem;
    }

    .ai-reader__progress {
        gap: 0;
    }

    .ai-reader__position {
        font-size: 0.72rem;
    }

    .ai-reader__progress input {
        min-height: 1.5rem;
    }

    .ai-reader:fullscreen .ai-reader__controls,
    .ai-reader.is-fullscreen .ai-reader__controls {
        padding: 0.48rem 0.72rem 0.58rem;
    }

    .ai-zoom {
        padding: 0.55rem;
    }

    .ai-zoom__panel {
        height: 94vh;
    }

    .ai-zoom__toolbar {
        align-items: start;
        flex-direction: column;
        gap: 0.7rem;
    }

    .ai-zoom__actions {
        width: 100%;
        justify-content: space-between;
    }

    .ai-card-grid {
        grid-template-columns: minmax(0, 1fr);
        gap: 0.55rem;
    }

    .ai-tool-card-group {
        padding: 0.65rem;
    }

    .ai-tool-card-group__head {
        align-items: start;
    }

    .ai-tool-card-group__grid {
        grid-template-columns: minmax(0, 1fr);
        gap: 0.55rem;
    }

    .ai-card-tile {
        display: grid;
        grid-template-columns: 84px minmax(0, 1fr);
        gap: 0.75rem;
        align-items: center;
        min-height: 132px;
        padding: 0.5rem;
    }

    .ai-card-tile__thumb {
        width: 84px;
    }

    .ai-card-tile__meta {
        gap: 0.32rem;
    }

    .ai-card-tile__meta strong {
        font-size: 1rem;
        line-height: 1.35;
        word-break: keep-all;
    }

    .ai-card-tile__meta span {
        font-size: 0.82rem;
    }

    .ai-card-tile .ai-card-state-badge--read {
        display: none;
    }
}