* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #020259 0%, #0d0d7a 50%, #1a1a9e 100%);
    min-height: 100vh;
    color: #ffffff;
    line-height: 1.6;
    position: relative;
    overflow-x: hidden;
    opacity: 1;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 40px 20px;
    position: relative;
    z-index: 1;
}

/* ========== 배경 애니메이션 ========== */
.background-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    overflow: hidden;
    pointer-events: none;
}

.floating-circle {
    position: absolute;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
    animation: float-random 20s infinite ease-in-out;
}

.floating-circle:nth-child(1) {
    width: 300px;
    height: 300px;
    top: 10%;
    left: 10%;
    animation-delay: 0s;
    animation-duration: 25s;
}

.floating-circle:nth-child(2) {
    width: 200px;
    height: 200px;
    top: 60%;
    right: 15%;
    animation-delay: 5s;
    animation-duration: 30s;
}

.floating-circle:nth-child(3) {
    width: 250px;
    height: 250px;
    bottom: 15%;
    left: 20%;
    animation-delay: 10s;
    animation-duration: 35s;
}

.floating-circle:nth-child(4) {
    width: 180px;
    height: 180px;
    top: 40%;
    right: 25%;
    animation-delay: 15s;
    animation-duration: 28s;
}

@keyframes float-random {
    0%, 100% {
        transform: translate(0, 0) scale(1);
        opacity: 0.3;
    }
    25% {
        transform: translate(30px, -50px) scale(1.1);
        opacity: 0.5;
    }
    50% {
        transform: translate(-20px, -80px) scale(0.9);
        opacity: 0.4;
    }
    75% {
        transform: translate(50px, -30px) scale(1.05);
        opacity: 0.45;
    }
}

/* ========== 헤더 ========== */
header {
    text-align: center;
    margin-bottom: 60px;
    animation: fadeInDown 1s ease;
    opacity: 1;
    position: relative;  /* 이 줄 추가 */
}

header p,
.subtitle {
    font-size: clamp(0.9rem, 2.5vw, 1.2rem);
    color: #b8c5d6;
    opacity: 0.9;
    word-break: keep-all; /* 단어 단위로 줄바꿈 */
    overflow-wrap: break-word; /* 너무 긴 단어는 강제로 줄바꿈 */
    line-height: 1.5;
}

.header-links {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 30px;
    position: relative;
    z-index: 10;
}

/* 상단 링크 버튼들 */
.top-links-left {
    display: flex;
    gap: 12px;
}

.top-links-right {
    display: flex;
    gap: 12px;
}

.top-link-button {
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
    padding: 12px 20px;
    border-radius: 50px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    white-space: nowrap;
}

.top-link-button:hover {
    background: rgba(255, 255, 255, 0.25);
    border-color: rgba(255, 255, 255, 0.5);
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(0, 0, 0, 0.4);
}

.top-link-button:active {
    transform: translateY(0);
}

.link-icon {
    font-size: 18px;
    display: inline-flex;  /* 이 줄 추가 */
    align-items: center;   /* 이 줄 추가 */
    justify-content: center; /* 이 줄 추가 */
}

.feedback-button .link-icon {
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.1);
    }
}

.logo-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
    margin-bottom: 16px;
}

.logo-icon {
    font-size: 3rem;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

.header-content h1 {
    font-size: 3.5rem;
    font-weight: 800;
    color: #ffffff;
    letter-spacing: -2px;
    text-shadow: 0 4px 30px rgba(0, 0, 0, 0.4);
}

.subtitle {
    font-size: 1.1rem;
    color: #b8b8ff;
    font-weight: 400;
    margin-top: 12px;
}

/* ========== 퀴즈 섹션 ========== */
.quiz-section {
    animation: fadeInUp 1s ease 0.3s both;
}

.section-header {
    text-align: center;
    margin-bottom: 40px;
}

.section-header h2 {
    font-size: 1.8rem;
    margin-bottom: 10px;
    font-weight: 600;
    color: #ffffff;
}

.section-header p {
    font-size: 0.95rem;
    color: #b8b8ff;
}

/* ========== 책갈피 스타일 컨테이너 ========== */
.bookmark-container {
    display: flex;
    flex-direction: column;
    gap: 12px;
    max-width: 800px;
    margin: 0 auto;
}

/* 책갈피 탭 */
.bookmark-tab {
    position: relative;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.bookmark-content {
    background: rgba(255, 255, 255, 0.08);
    backdrop-filter: blur(20px);
    border-radius: 12px;
    padding: 16px 24px;
    display: flex;
    align-items: center;
    gap: 20px;
    border: 2px solid transparent;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.bookmark-content::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    width: 6px;
    height: 100%;
    transition: all 0.4s ease;
}

.bookmark-content::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    transition: left 0.6s;
}

.bookmark-tab:hover .bookmark-content::after {
    left: 100%;
}

/* 각 SET별 색상 */
.bookmark-tab[data-set="A"] .bookmark-content::before {
    background: linear-gradient(180deg, #86b5d9, #5a8fb8);
}

.bookmark-tab[data-set="B"] .bookmark-content::before {
    background: linear-gradient(180deg, #9db8cf, #7499b8);
}

.bookmark-tab[data-set="C"] .bookmark-content::before {
    background: linear-gradient(180deg, #b8a5c9, #9580a8);
}

.bookmark-tab[data-set="D"] .bookmark-content::before {
    background: linear-gradient(180deg, #c9b58a, #a89468);
}

.bookmark-tab[data-set="E"] .bookmark-content::before {
    background: linear-gradient(180deg, #b59bb8, #947998);
}

/* 호버 효과 */
.bookmark-tab:hover .bookmark-content {
    background: rgba(255, 255, 255, 0.12);
    transform: translateX(20px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3);
}

.bookmark-tab[data-set="A"]:hover .bookmark-content {
    border-color: rgba(134, 181, 217, 0.4);
}

.bookmark-tab[data-set="B"]:hover .bookmark-content {
    border-color: rgba(157, 184, 207, 0.4);
}

.bookmark-tab[data-set="C"]:hover .bookmark-content {
    border-color: rgba(184, 165, 201, 0.4);
}

.bookmark-tab[data-set="D"]:hover .bookmark-content {
    border-color: rgba(201, 181, 138, 0.4);
}

.bookmark-tab[data-set="E"]:hover .bookmark-content {
    border-color: rgba(181, 155, 184, 0.4);
}

.bookmark-tab:active .bookmark-content {
    transform: translateX(15px) scale(0.98);
}

/* 아이콘 */
.bookmark-icon {
    font-size: 2rem;
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.08);
    border-radius: 50%;
    flex-shrink: 0;
    transition: all 0.4s ease;
}

.bookmark-tab:hover .bookmark-icon {
    transform: rotate(10deg) scale(1.1);
    background: rgba(255, 255, 255, 0.15);
}

/* 정보 영역 */
.bookmark-info {
    flex: 1;
    min-width: 0;
}

.bookmark-title {
    font-size: 1.2rem;
    font-weight: 700;
    color: #ffffff;
    margin-bottom: 4px;
    letter-spacing: -0.5px;
}

.bookmark-subtitle {
    font-size: 0.9rem;
    color: #b8b8ff;
    font-weight: 500;
}

/* 뱃지 */
.bookmark-badge {
    display: flex;
    flex-direction: column;
    gap: 6px;
    align-items: flex-end;
}

.badge-level,
.badge-count {
    padding: 5px 14px;
    border-radius: 10px;
    font-size: 0.8rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.badge-level {
    background: rgba(255, 255, 255, 0.15);
    color: #ffffff;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.badge-count {
    padding: 3px 10px;
    border-radius: 4px;
    font-size: 0.7rem;
    font-weight: 500;
    background: rgba(134, 239, 172, 0.08);
    color: rgba(134, 239, 172, 0.7);
    border: 1px solid rgba(134, 239, 172, 0.15);
    letter-spacing: 0.3px;
    transition: none;
}

/* badge-count들을 가로로 나열하기 위한 래퍼 */
.badge-count-wrapper {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
    justify-content: flex-end;
}

.bookmark-tab:hover .badge-level {
    transform: scale(1.05);
}

/* ========== 반응형 ========== */
@media (max-width: 768px) {
    .bookmark-badge {
        gap: 5px;
    }

    .badge-level {
        font-size: 0.7rem;
        padding: 4px 10px;
    }

    .badge-count {
        font-size: 0.6rem;
        padding: 2px 7px;
        border-radius: 3px;
    }

    .badge-count-wrapper {
        gap: 5px;
    }
}

@media (max-width: 480px) {
    .bookmark-content {
        flex-direction: column;
        align-items: flex-start;
        padding: 14px 16px;
        gap: 12px;
    }

    .bookmark-badge {
        align-self: stretch;
        flex-direction: column;
        align-items: flex-start;
        gap: 5px;
    }

    .badge-level {
        font-size: 0.65rem;
        padding: 3px 8px;
        align-self: flex-start;
    }

    .badge-count {
        font-size: 0.55rem;
        padding: 2px 5px;
        border-radius: 2px;
        letter-spacing: 0.2px;
    }

    .badge-count-wrapper {
        gap: 4px;
        justify-content: flex-start;
    }
}

@media (max-width: 360px) {
    .badge-level {
        font-size: 0.6rem;
        padding: 3px 7px;
    }

    .badge-count {
        font-size: 0.5rem;
        padding: 2px 4px;
        border-radius: 2px;
        letter-spacing: 0.1px;
    }

    .badge-count-wrapper {
        gap: 3px;
    }
}
/* ========== 푸터 ========== */
footer {
    text-align: center;
    padding: 50px 20px 30px;
    margin-top: 80px;
    color: #8888cc;
    font-size: 0.9rem;
}

/* ========== 애니메이션 ========== */
@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ========== 반응형 ========== */
@media (max-width: 1024px) {
    .top-links-left,
    .top-links-right {
        gap: 8px;
    }

    .top-link-button {
        padding: 10px 16px;
        font-size: 13px;
    }

    .bookmark-container {
        max-width: 700px;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 30px 16px;
    }

    .header-content h1 {
        font-size: 2.8rem;
    }

    .logo-icon {
        font-size: 2.5rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .section-header h2 {
        font-size: 1.6rem;
    }

    .bookmark-content {
        padding: 14px 18px;
        gap: 16px;
    }

    .bookmark-icon {
        width: 50px;
        height: 50px;
        font-size: 1.8rem;
    }

    .bookmark-title {
        font-size: 1.1rem;
    }

    .bookmark-subtitle {
        font-size: 0.85rem;
    }

    .bookmark-badge {
        gap: 5px;
    }

    .badge-level,
    .badge-count {
        font-size: 0.75rem;
        padding: 4px 12px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 24px 14px;
    }

    .header-content h1 {
        font-size: 2.2rem;
    }

    .logo-wrapper {
        gap: 12px;
    }

    .logo-icon {
        font-size: 2rem;
    }

    .subtitle {
        font-size: 0.9rem;
    }

    .section-header h2 {
        font-size: 1.4rem;
    }

    .bookmark-content {
        flex-direction: column;
        align-items: flex-start;
        padding: 14px 16px;
        gap: 12px;
    }

    .bookmark-icon {
        width: 46px;
        height: 46px;
        font-size: 1.6rem;
    }

    .bookmark-title {
        font-size: 1rem;
    }

    .bookmark-subtitle {
        font-size: 0.8rem;
    }

    .bookmark-badge {
        align-self: stretch;
        flex-direction: row;
        justify-content: space-between;
    }

    .badge-level,
    .badge-count {
        font-size: 0.7rem;
        padding: 4px 10px;
    }
}

/* 만든 사람들 섹션 */
.creators-section {
    margin-top: 80px;
    padding: 40px;
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.creators-container {
    display: flex;
    justify-content: center;
    gap: 40px;
    flex-wrap: wrap;
    margin-bottom: 50px;
}

.creator-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
    padding: 30px;
    background: rgba(255, 255, 255, 0.08);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    border: 2px solid rgba(255, 255, 255, 0.15);
    transition: all 0.3s ease;
    min-width: 250px;
}

.creator-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    border-color: rgba(255, 255, 255, 0.3);
}

.creator-image {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    border: 4px solid rgba(255, 255, 255, 0.2);
    transition: all 0.3s ease;
}

.creator-card:hover .creator-image {
    transform: scale(1.05);
    border-color: rgba(255, 255, 255, 0.4);
}

.creator-info {
    text-align: center;
}

.creator-name {
    font-size: 1.4rem;
    font-weight: 700;
    color: #ffffff;
    margin-bottom: 5px;
}

.creator-real-name {
    font-size: 1rem;
    color: #b8b8ff;
    margin-bottom: 15px;
}

.github-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 20px;
    color: #ffffff;
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.github-link:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: rgba(255, 255, 255, 0.4);
    transform: scale(1.05);
}

.github-icon {
    font-size: 1rem;
}

/* 도움주신 분들 */
.contributors-section {
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.contributors-title {
    text-align: center;
    font-size: 1.2rem;
    color: #b8b8ff;
    margin-bottom: 20px;
    font-weight: 600;
}

.contributors-list {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 12px;
}

.contributor-item {
    padding: 6px 14px;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 20px;
    color: #ffffff;
    font-size: 0.85rem;
    font-weight: 500;
    transition: all 0.3s ease;
    text-decoration: none;
}

.contributor-item:hover {
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

a.contributor-item {
    cursor: pointer;
}

/* 반응형 */
@media (max-width: 768px) {
    .header-links {
        margin-bottom: 20px;
    }

    .top-links-left,
    .top-links-right {
        gap: 6px;
    }

    .top-link-button {
        padding: 10px;
        font-size: 12px;
        width: 44px;
        height: 44px;
        justify-content: center;
        align-items: center;  /* 이 줄 추가 */

    }

    .link-text {
        display: none !important;
    }

    .link-icon {
        font-size: 20px;
        display: inline-flex !important;
    }

    .creators-section {
        padding: 30px 20px;
        margin-top: 60px;
    }

    .creators-container {
        gap: 30px;
    }

    .creator-card {
        min-width: 200px;
        padding: 25px;
    }

    .creator-image {
        width: 100px;
        height: 100px;
    }

    .creator-name {
        font-size: 1.2rem;
    }

    .contributors-list {
        gap: 10px;
    }

    .contributor-item {
        font-size: 0.8rem;
        padding: 5px 12px;
    }
}

@media (max-width: 480px) {
    .creators-container {
        flex-direction: column;
        align-items: center;
    }

    .creator-card {
        width: 100%;
        max-width: 280px;
    }
    .top-links-left {
        flex-direction: column;
        gap: 8px;
    }

    .top-link-button {
        padding: 10px;
        width: 44px;
        height: 44px;
        justify-content: center;
    }

    .link-icon {
        font-size: 20px;
    }
}

/* 상단 링크 버튼들 */
/*.top-links-left {*/
/*    position: fixed;*/
/*    top: 20px;*/
/*    left: 20px;*/
/*    display: flex;*/
/*    gap: 12px;*/
/*    z-index: 1000;*/
/*}*/

/*.top-links-right {*/
/*    position: fixed;*/
/*    top: 20px;*/
/*    right: 20px;*/
/*    display: flex;*/
/*    gap: 12px;*/
/*    z-index: 1000;*/
/*}*/

/*.top-link-button {*/
/*    background: rgba(255, 255, 255, 0.15);*/
/*    backdrop-filter: blur(10px);*/
/*    color: white;*/
/*    border: 2px solid rgba(255, 255, 255, 0.3);*/
/*    padding: 12px 20px;*/
/*    border-radius: 50px;*/
/*    font-size: 14px;*/
/*    font-weight: 600;*/
/*    cursor: pointer;*/
/*    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);*/
/*    transition: all 0.3s ease;*/
/*    display: flex;*/
/*    align-items: center;*/
/*    gap: 8px;*/
/*    text-decoration: none;*/
/*    white-space: nowrap;*/
/*}*/

/*.top-link-button:hover {*/
/*    background: rgba(255, 255, 255, 0.25);*/
/*    border-color: rgba(255, 255, 255, 0.5);*/
/*    transform: translateY(-2px);*/
/*    box-shadow: 0 6px 25px rgba(0, 0, 0, 0.4);*/
/*}*/

/*.top-link-button:active {*/
/*    transform: translateY(0);*/
/*}*/

/*.link-icon {*/
/*    font-size: 18px;*/
/*}*/

/*.feedback-button .link-icon {*/
/*    animation: pulse 2s infinite;*/
/*}*/

/*@keyframes pulse {*/
/*    0%, 100% {*/
/*        transform: scale(1);*/
/*    }*/
/*    50% {*/
/*        transform: scale(1.1);*/
/*    }*/
/*}*/

/*!* 반응형 *!*/
/*@media (max-width: 1024px) {*/
/*    .top-links-left,*/
/*    .top-links-right {*/
/*        gap: 8px;*/
/*    }*/

/*    .top-link-button {*/
/*        padding: 10px 16px;*/
/*        font-size: 13px;*/
/*    }*/
/*}*/

/*@media (max-width: 768px) {*/
/*    .header-links {*/
/*        margin-bottom: 20px;*/
/*    }*/

/*    .top-links-left,*/
/*    .top-links-right {*/
/*        gap: 6px;*/
/*    }*/

/*    .top-link-button {*/
/*        padding: 10px;*/
/*        font-size: 12px;*/
/*        width: 44px;*/
/*        height: 44px;*/
/*        justify-content: center;*/
/*    }*/

/*    .link-text {*/
/*        display: none;*/
/*    }*/

/*    .link-icon {*/
/*        font-size: 20px;*/
/*        display: block;*/
/*    }*/
/*}*/

/*@media (max-width: 480px) {*/
/*    .top-links-left {*/
/*        flex-direction: column;*/
/*        gap: 8px;*/
/*    }*/

/*    .top-link-button {*/
/*        padding: 10px;*/
/*        width: 44px;*/
/*        height: 44px;*/
/*        justify-content: center;*/
/*    }*/

/*    .link-icon {*/
/*        font-size: 20px;*/
/*    }*/
/*}*/