/* 연구 자료 — 목록(research_list.html), 상세(research.html / research_report.html)
 * 색상·폰트·간격·모션 토큰은 base.css / animations.css를 그대로 계승한다.
 */

/* ---------- 헤더 로그인 상태 영역 ---------- */

.header_user {
    display: flex;
    align-items: center;
    gap: var(--space_2);
}

/*
 * 이메일은 길어서 헤더를 밀어낸다.
 * 1023px 이하에서는 감추고 로그아웃 버튼만 두며, 1024px부터 노출한다.
 */
.header_user_email {
    display: none;
    max-width: 220px;
    overflow: hidden;
    color: rgba(255, 255, 255, 0.72);
    font-size: 13px;
    font-weight: 500;
    letter-spacing: -0.02em;
    white-space: nowrap;
    text-overflow: ellipsis;
}

/* ---------- 페이지 ---------- */

.research_page {
    padding: calc(var(--header_height) + var(--space_10)) var(--page_padding) 96px;
}

.research_inner {
    width: 100%;
    max-width: 760px;
    margin-inline: auto;
}

.research_back {
    display: inline-flex;
    align-items: center;
    gap: var(--space_2);
    color: var(--color_brand);
    font-size: 14px;
    font-weight: 600;
    letter-spacing: -0.02em;
    transition: gap 0.22s var(--ease_out_soft);
}

.research_back svg {
    width: 16px;
    height: 16px;
    fill: none;
    stroke: currentColor;
    stroke-width: 2;
}

/* ---------- 자료 헤더 ---------- */

.research_header {
    margin-top: var(--space_6);
    padding-bottom: var(--space_6);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.research_tag {
    display: inline-flex;
    padding: 5px 12px;
    border-radius: var(--radius_pill);
    background-color: rgba(43, 161, 255, 0.12);
    color: var(--color_brand);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.research_title {
    margin-top: var(--space_4);
    font-size: 26px;
    font-weight: 700;
    line-height: 1.35;
    letter-spacing: -0.02em;
    word-break: keep-all;
}

.research_meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space_2) var(--space_4);
    margin-top: var(--space_5);
    color: var(--color_text_sub);
    font-size: 13px;
    font-weight: 500;
    letter-spacing: -0.02em;
}

.research_meta dt {
    display: inline;
    font-weight: 600;
}

.research_meta dd {
    display: inline;
    margin: 0 0 0 var(--space_1);
}

.research_meta > div {
    display: flex;
    align-items: center;
    gap: var(--space_1);
}

/* ---------- 대표 이미지 ---------- */

.research_cover {
    margin-top: var(--space_8);
    border-radius: var(--radius_card);
    overflow: hidden;
    aspect-ratio: 16 / 9;
}

.research_cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* ---------- 본문 ---------- */

.research_summary {
    margin-top: var(--space_8);
    padding: 22px 20px;
    border-left: 3px solid var(--color_brand);
    border-radius: 0 10px 10px 0;
    background-color: rgba(43, 161, 255, 0.06);
    font-size: 15px;
    font-weight: 500;
    line-height: 1.75;
    letter-spacing: -0.02em;
    word-break: keep-all;
}

.research_section {
    margin-top: var(--space_10);
}

.research_section_title {
    font-size: 19px;
    font-weight: 700;
    line-height: 1.4;
    letter-spacing: -0.02em;
}

.research_section p {
    margin-top: var(--space_3);
    color: var(--color_text_muted);
    font-size: 15px;
    font-weight: 500;
    line-height: 1.8;
    letter-spacing: -0.02em;
    word-break: keep-all;
}

.research_points {
    display: grid;
    gap: var(--space_3);
    margin-top: var(--space_4);
}

.research_points li {
    position: relative;
    padding-left: var(--space_5);
    color: var(--color_text_muted);
    font-size: 15px;
    font-weight: 500;
    line-height: 1.7;
    letter-spacing: -0.02em;
    word-break: keep-all;
}

.research_points li::before {
    content: "";
    position: absolute;
    top: 10px;
    left: 0;
    width: 7px;
    height: 7px;
    transform: rotate(-45deg);
    background: linear-gradient(135deg, var(--color_brand) 0%, var(--color_brand_light) 100%);
}

/* ---------- 첨부 자료 ---------- */

.research_files {
    display: grid;
    gap: var(--space_3);
    margin-top: var(--space_5);
}

.research_file {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space_4);
    padding: 16px 18px;
    border: 1px solid rgba(0, 0, 0, 0.1);
    border-radius: 12px;
    transition:
        border-color 0.22s ease,
        box-shadow 0.22s ease,
        transform 0.22s var(--ease_out_soft);
}

.research_file_name {
    font-size: 15px;
    font-weight: 600;
    letter-spacing: -0.02em;
    word-break: keep-all;
}

.research_file_size {
    flex-shrink: 0;
    color: var(--color_text_sub);
    font-size: 13px;
    font-weight: 500;
    letter-spacing: -0.02em;
}

/* ========================================================
 * 반응형
 * ======================================================== */

/* ========================================================
 * 연구 자료 목록 (research_list.html)
 * ======================================================== */

.research_list_head {
    margin-top: var(--space_8);
    padding-bottom: var(--space_6);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.research_list_eyebrow {
    color: var(--color_brand);
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 0.14em;
}

.research_list_title {
    margin-top: var(--space_3);
    font-size: 30px;
    font-weight: 800;
    line-height: 1.25;
    letter-spacing: -0.03em;
}

.research_list_desc {
    margin-top: var(--space_4);
    color: var(--color_text_sub);
    font-size: 14px;
    font-weight: 500;
    line-height: 1.7;
    letter-spacing: -0.02em;
    word-break: keep-all;
}

.research_list_count {
    display: block;
    margin-top: var(--space_2);
    color: var(--color_brand);
    font-weight: 600;
}

.research_list {
    display: grid;
    gap: var(--space_5);
    margin-top: var(--space_8);
}

.research_card_link {
    display: grid;
    grid-template-rows: auto 1fr;
    height: 100%;
    border: 1px solid rgba(0, 0, 0, 0.1);
    border-radius: var(--radius_card);
    background-color: var(--color_surface);
    overflow: hidden;
    transition:
        transform 0.28s var(--ease_out_soft),
        box-shadow 0.28s ease,
        border-color 0.28s ease;
}

.research_card_media {
    display: block;
    aspect-ratio: 16 / 9;
    overflow: hidden;
}

.research_card_media img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s var(--ease_out_soft);
}

.research_card_body {
    display: flex;
    flex-direction: column;
    gap: var(--space_2);
    padding: 20px 22px 24px;
}

.research_card_series {
    align-self: flex-start;
    padding: 4px 10px;
    border-radius: var(--radius_pill);
    background-color: rgba(43, 161, 255, 0.1);
    color: var(--color_brand);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: -0.01em;
}

.research_card_title {
    margin-top: var(--space_1);
    font-size: 18px;
    font-weight: 700;
    line-height: 1.45;
    letter-spacing: -0.02em;
    word-break: keep-all;
}

/* 목록에서는 초록을 세 줄까지만 보여준다. */
.research_card_summary {
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
    color: var(--color_text_sub);
    font-size: 13px;
    font-weight: 500;
    line-height: 1.7;
    letter-spacing: -0.02em;
    word-break: keep-all;
}

.research_card_meta {
    margin-top: auto;
    padding-top: var(--space_3);
    color: var(--color_text_sub);
    font-size: 12px;
    font-weight: 500;
    letter-spacing: -0.02em;
}

/* ========================================================
 * 연구보고서 상세 (research_report.html)
 * ======================================================== */

.report_page {
    padding-bottom: 96px;
}

/* 시안의 상단 이미지 + 제목 겹침 구성 */
.report_hero {
    position: relative;
    display: flex;
    align-items: flex-end;
    min-height: 260px;
    padding: calc(var(--header_height) + var(--space_10)) var(--page_padding) var(--space_8);
    overflow: hidden;
}

.report_hero_media {
    position: absolute;
    inset: 0;
    z-index: -1;
}

.report_hero_media img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.report_hero_media::after {
    content: "";
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, rgba(0, 0, 0, 0.42) 0%, rgba(0, 0, 0, 0.68) 100%);
}

.report_hero_body {
    width: 100%;
    max-width: var(--content_max);
    margin-inline: auto;
}

.report_headline {
    color: #ffffff;
    font-size: 26px;
    font-weight: 700;
    line-height: 1.4;
    letter-spacing: -0.02em;
    word-break: keep-all;
}

.report_back {
    display: inline-flex;
    align-items: center;
    gap: var(--space_2);
    margin-top: var(--space_6);
    color: var(--color_text_sub);
    font-size: 14px;
    font-weight: 600;
    letter-spacing: -0.02em;
}

.report_back svg {
    width: 18px;
    height: 18px;
    fill: none;
    stroke: currentColor;
    stroke-width: 2;
}

.report_article {
    margin-top: var(--space_8);
}

/* 제목 / 저자 / 발행일 / 키워드 서지 항목 */
.report_fields {
    display: grid;
    gap: var(--space_6);
    padding-bottom: var(--space_8);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.report_field dt {
    font-size: 18px;
    font-weight: 700;
    line-height: 1.35;
    letter-spacing: -0.02em;
}

.report_field dd {
    margin: var(--space_2) 0 0;
    color: var(--color_text_muted);
    font-size: 16px;
    font-weight: 400;
    line-height: 1.65;
    letter-spacing: -0.02em;
    word-break: keep-all;
}

.report_keywords {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space_2);
}

.report_keyword {
    padding: 5px 11px;
    border-radius: var(--radius_pill);
    background-color: rgba(43, 161, 255, 0.09);
    color: var(--color_brand);
    font-size: 13px;
    font-weight: 600;
    letter-spacing: -0.02em;
}

.report_block {
    margin-top: var(--space_10);
}

.report_block_title {
    font-size: 20px;
    font-weight: 700;
    line-height: 1.35;
    letter-spacing: -0.02em;
}

.report_abstract {
    display: grid;
    gap: var(--space_5);
    margin-top: var(--space_5);
}

.report_abstract p {
    color: var(--color_text_muted);
    font-size: 15px;
    font-weight: 400;
    line-height: 1.85;
    letter-spacing: -0.02em;
    word-break: keep-all;
}

.report_toc {
    margin-top: var(--space_5);
}

.report_toc_part {
    margin-top: var(--space_5);
    font-size: 15px;
    font-weight: 700;
    line-height: 1.8;
    letter-spacing: -0.02em;
}

.report_toc_part:first-child {
    margin-top: 0;
}

/* 하위 항목은 한 단 들여써 대분류와 구분한다. */
.report_toc_item {
    padding-left: var(--space_4);
    color: var(--color_text_muted);
    font-size: 15px;
    font-weight: 400;
    line-height: 1.8;
    letter-spacing: -0.02em;
    word-break: keep-all;
}

.report_block_plain {
    margin-top: var(--space_10);
    padding-top: var(--space_6);
    border-top: 1px solid rgba(0, 0, 0, 0.1);
}

.report_meta {
    display: grid;
    gap: var(--space_1);
}

.report_meta li {
    color: var(--color_text_sub);
    font-size: 13px;
    font-weight: 500;
    line-height: 1.7;
    letter-spacing: -0.02em;
    word-break: keep-all;
}

@media (min-width: 768px) {
    /* 목록 카드는 태블릿부터 2열 */
    .research_list {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--space_5);
    }

    .research_list_title {
        font-size: 38px;
    }

    .research_card_title {
        font-size: 19px;
    }

    .report_hero {
        min-height: 320px;
    }

    .report_headline {
        font-size: 34px;
    }

    .report_field dt {
        font-size: 20px;
    }

    .report_field dd,
    .report_abstract p,
    .report_toc_part,
    .report_toc_item {
        font-size: 16px;
    }

    .research_page {
        padding-top: calc(var(--header_height) + 64px);
        padding-bottom: 120px;
    }

    .research_title {
        font-size: 34px;
    }

    .research_meta {
        font-size: 14px;
    }

    .research_summary {
        padding: 26px 24px;
        font-size: 16px;
    }

    .research_section_title {
        font-size: 22px;
    }

    .research_section p,
    .research_points li {
        font-size: 16px;
    }
}

@media (min-width: 1024px) {
    .header_user_email {
        display: inline;
    }

    /* 데스크톱은 3열 */
    .research_list {
        grid-template-columns: repeat(3, 1fr);
        gap: var(--space_6);
    }

    .research_list_title {
        font-size: 44px;
    }

    .report_hero {
        min-height: 380px;
    }

    .report_headline {
        font-size: 40px;
    }

    .research_page {
        padding-top: calc(var(--header_height) + 88px);
    }

    .research_title {
        font-size: 40px;
    }
}

@media (hover: hover) {
    .research_card_link:hover {
        transform: translateY(-4px);
        border-color: rgba(43, 161, 255, 0.4);
        box-shadow: 0 18px 36px rgba(43, 161, 255, 0.16);
    }

    .research_card_link:hover .research_card_media img {
        transform: scale(1.05);
    }

    .report_back:hover {
        color: var(--color_brand);
    }

    .research_back:hover {
        gap: var(--space_3);
    }

    .research_file:hover {
        border-color: var(--color_brand);
        box-shadow: 0 6px 18px rgba(43, 161, 255, 0.16);
        transform: translateY(-2px);
    }
}