html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    overflow: hidden;
}
main { 
    background-color: #FCFAF8;
    display: flex;
    flex-direction: column;
}
@supports (height:100dvh){
    main { height:70dvh; }
}

.header-container {
    white-space: nowrap;
}
.header-link {

    flex-shrink: 0;
}
.exam-title {
    font-family: 'Times New Roman', Times, serif;
    text-align: center;
    font-size: 1.3em;
    font-weight: bold;
    flex-grow: 1;
    flex-shrink: 0; 
    margin: 0 20px; 
}
.exam-description {
    font-size: 0.75em;   
    color: #666;        
    margin-top: 2px;    
}

.header-right-container {
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

.student-info {
    display: table;
    line-height: 1em; 
}

.student-info-row {
    display: table-row;
}

.student-info-label, .student-info-value {
    display: table-cell;
    padding: 4px 5px; 
}

.student-info-label {
    font-family: 'Times New Roman', Times, serif;
    text-align: right; 
}

.student-info-value {
    font-family: 'Cursive', 'Comic Sans MS', 'Brush Script MT', sans-serif; 
    position: relative;
}

.student-info-value::after {
    content: '';
    display: block;
    position: absolute;
    left: 0;
    right: 0;
    bottom: 4px; 
    height: 1px; 
    width: 100%; 
    background-color: black; 
    transform: translateX(-2%);
}



.timer {
    font-size: 0.8em;
    font-weight: bold;
}


.test-header { 
    margin-top: 16px;
    padding: 0 2%;
    flex-shrink: 0;
}

.floating-box {
    position: absolute;
    top: 110%; 
    right: 0px;
    background: white;
    border: 1px solid #ccc;
    padding: 0.8vw;
    z-index: 999;
    display: none;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    max-width: min(95vw,1200px);
  }
  
#details-div .details-div-header {
    display: flex;
    align-items:flex-end;
    justify-content: space-between;
    margin-bottom: 0;
}

#details-div .details-div-tag {
    font-weight: bold;
    font-size: 0.9rem;
    padding: 4px 10px;
    background-color: var(--light-blue, #e0f0fa);
    color: #333;
    margin: 0;
}
#details-div .details-div-formula-button {
    margin-left: 12px;
    margin-bottom: 5px;
}
#details-div .details-div-quit-button {
    margin-left: 4px;
    margin-bottom: 5px;
}

#details-div .details-div-question-list {
    display: flex;
    gap: 10px;
    flex-wrap: nowrap;
    overflow-x: auto;
    background-color: var(--light-blue, #e0f0fa);
    padding: 4px 0; /* 貼住上方，但有少少空間分隔 checkbox */
}

#details-div .details-div-question-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    font-size: 0.9rem;
}

#details-div .details-div-question-label {
    margin-bottom: 4px;
    font-weight: 500;
}

#details-div .details-div-checkbox {
    width: 16px;
    height: 16px;
    border: 2px solid #999;
    border-radius: 3px;
    background-color: white;
}
#details-div .details-div-checkbox.checked {
    background-color: var(--primary-color, #00BCD4);
    border-color: var(--primary-color, #00BCD4);
    position: relative;
}

#details-div .details-div-checkbox.checked::after {
    content: '';
    position: absolute;
    top: 1px;
    left: 4px;
    width: 4px;
    height: 8px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}
#details-div .details-div-checkbox.half-checked {
    background-color: var(--primary-color, #00BCD4);
    border-color: var(--primary-color, #00BCD4);
    position: relative;opacity: .4;        
}
#details-div .details-div-checkbox.half-checked::after {
    content: '';
    position: absolute;
    top: 1px;
    left: 4px;
    width: 4px;
    height: 8px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
  }

  
.test-progress {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height:5.5vh;
    margin-bottom: 2px;
}
.test-question-counter{
    align-self: flex-end;
}
.test-progress > div {
    display: inline-block;
    align-self: flex-start;
    position: relative;
}
.progress-bar {
    width: 100%;
    height: 6px;
    background-color: #e0e0e0;
    border-radius: 3px;
    overflow: hidden;
}
  
.progress-fill {
    width: 2%; 
    height: 100%;
    background-color: #3b82f6; 
}







.question-answer-container {
    flex: 1 1 auto;
    opacity: 1;
    margin: 20px 2%;
    min-height: 0; 
    overflow-y: auto;
}
.question-answer-container.slide-out-left {
    transform: translateX(-100%);
    transition: transform 0.18s cubic-bezier(0.8, 0.2, 0.8, 0.2), opacity 0.18s cubic-bezier(0.8, 0.2, 0.8, 0.2);
    opacity: 0;
}
.question-answer-container.slide-move-left {
    transform: translateX(100%);
    transition: transform 0.01s ease-in-out, opacity 0.01s ease-in-out;
    opacity: 0;
}
.question-answer-container.slide-in-left {
    transform: translateX(0%);
    transition: transform 0.18s cubic-bezier(0.2, 0.8, 0.2, 0.8), opacity 0.18s cubic-bezier(0.2, 0.8, 0.2, 0.8);
    opacity: 1;
}
.question-answer-container.slide-out-right {
    transform: translateX(100%);
    transition: transform 0.18s cubic-bezier(0.8, 0.2, 0.8, 0.2), opacity 0.18s cubic-bezier(0.8, 0.2, 0.8, 0.2);
    opacity: 0;
}
.question-answer-container.slide-move-right {
    transform: translateX(-100%);
    transition: transform 0.01s ease-in-out, opacity 0.01s ease-in-out;
    opacity: 0;
}
.question-answer-container.slide-in-right {
    transform: translateX(0%);
    transition: transform 0.18s cubic-bezier(0.2, 0.8, 0.2, 0.8), opacity 0.18s cubic-bezier(0.2, 0.8, 0.2, 0.8);
    opacity: 1;
}
.question-answer-container.bounce-left {
    animation: bounce-left 0.3s ease;
}
@keyframes bounce-left {
    0% {
        transform: translateX(0);
    }
    50% {
        transform: translateX(-10px);
    }
    100% {
        transform: translateX(0); 
    }
}
.question-answer-container.bounce-right {
    animation: bounce-right 0.3s ease;
}
@keyframes bounce-right {
    0% {
        transform: translateX(0);
    }
    50% {
        transform: translateX(10px);
    }
    100% {
        transform: translateX(0); 
    }
}
.question-answer-container.slide-out-up {
    transform: translateY(-100%);
    transition: transform 0.18s cubic-bezier(0.8, 0.2, 0.8, 0.2), opacity 0.18s cubic-bezier(0.8, 0.2, 0.8, 0.2);
    opacity: 0;
}
.question-answer-container.slide-move-up {
    transform: translateY(100%);
    transition: transform 0.01s ease-in-out, opacity 0.01s ease-in-out;
    opacity: 0;
}
.question-answer-container.slide-in-up {
    transform: translateY(0%);
    transition: transform 0.18s cubic-bezier(0.2, 0.8, 0.2, 0.8), opacity 0.18s cubic-bezier(0.2, 0.8, 0.2, 0.8);
    opacity: 1;
}
.question-answer-container.slide-out-down {
    transform: translateY(100%);
    transition: transform 0.18s cubic-bezier(0.8, 0.2, 0.8, 0.2), opacity 0.18s cubic-bezier(0.8, 0.2, 0.8, 0.2);
    opacity: 0;
}
.question-answer-container.slide-move-down {
    transform: translateY(-100%);
    transition: transform 0.01s ease-in-out, opacity 0.01s ease-in-out;
    opacity: 0;
}
.question-answer-container.slide-in-down {
    transform: translateY(0%);
    transition: transform 0.18s cubic-bezier(0.2, 0.8, 0.2, 0.8), opacity 0.18s cubic-bezier(0.2, 0.8, 0.2, 0.8);
    opacity: 1;
}
.question-answer-container.bounce-up {
    animation: bounce-up 0.3s ease;
}
@keyframes bounce-up {
    0% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
    100% {
        transform: translateY(0); 
    }
}
.question-answer-container.bounce-down {
    animation: bounce-down 0.3s ease;
}
@keyframes bounce-down {
    0% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(10px);
    }
    100% {
        transform: translateY(0); 
    }
}


.subq-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0px;
  align-items: center;
  margin: 8px 0 12px;
}
.subq-tab { 
    flex: 1; 
    margin: 0; 
    font-size: 16px;
}
.subq-tab.active {
  background-color: var(--primary-color);
  box-shadow: 0 0 0 2px rgba(255,255,255,.2) inset; 
}
.subq-tab.active:hover {
  background-color: var(--primary-color);
}
.subq-tab:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px rgba(99,102,241,.35);
}


.question {
    font-size: clamp(24px, 5vw, 36px);
    margin-bottom: 20px;
    text-align: left;
}
.question p {
    margin-top: 0;
    margin-bottom:3px;
}
.question .q-row {
  display: flex;
  align-items: flex-start;
  gap: 3px;
  height:auto;
}
.question .q-number {
  flex: 0 0 0.5em;       
  text-align: right;
  padding-right: 6px;
  font-weight: 550;
}
.question .q-body {
  flex: 1 1 auto;
  align-items: flex-start; 
}
@media (max-width: 768px) {
    .question {
        font-size: clamp(22px, 5vw, 36px);
    }
    .question-container {
        margin:10px 0;
    }
    
}






.input-container {
    display: flex;
    align-items: center;
    width: 300px;
    margin: 20px auto;
    border: none;
    padding: 0;
    box-shadow: none;

}
input.answer-input,
input#input-field {
    flex:1 1 auto;
    width:unset;
    margin-bottom:0.3em;
    padding: 4px 6px;      
    background: rgba(0,0,0,0.03);   
    border: none;                  
    border-bottom: 2px dotted #6F7177; 
    border-radius: 4px;            
    outline: none;
    box-shadow: none;
        
}

/* === 可重用：偽 input 樣式 === */
.faux-input.answer-input {
    flex: 1 1 0%;
    min-height: 36px; 
    width:85%;
    padding: 8px 10px;
    background: rgba(0,0,0,.03);
    border: none; 
    outline: none; 
    font-size: clamp(20px, 4vw, 30px);
    box-shadow: none;
    border-bottom: 2px dotted #6F7177;
    display: inline-flex; 
    align-items: center;
    cursor: text;
}
.faux-input.answer-input.is-placeholder { 
    color: #9ca3af;
}
@media (max-width: 768px) {
    .faux-input.answer-input {
        font-size: clamp(18px, 4vw, 30px);
    }
    
    
}


/* 令 prefix/suffix 與字基線對齊 */
.answer-row, .answer-row.inline { 
    display:flex; 
    align-items: baseline; 
    gap: 6px; 
}
.answer-row.inline .answer-input { 
    flex: 1 1 auto; 
    min-width: 0; 
}





input.answer-input:focus,
input#input-field:focus {
  background: rgba(0,0,0,0.05);  
  border-bottom-color: var(--primary-color);
}


.answer-fields { display: flex; flex-direction: column; gap: 8px; }
.answer-row { 
    display: flex; 
    align-items: center; 
    gap: 6px; 
    flex-wrap: wrap; 
    margin-bottom: 10px;
}
.answer-prefix,
.answer-suffix{
  flex:0 0 auto;
  white-space:pre;          
}
.answer-row.inline { 
    flex-wrap: nowrap; 
}
.answer-row.inline .answer-input  {
    width:100%;
}


.input-container #sqrt-button {
    margin-left: 10px;
    padding: 5px 10px;
    font-size: 18px;
    cursor: pointer;
    background-color: var(--secondary-color);
    color: var(--white);
    border: none;
    border-radius: 3px;
}


.input-container #sqrt-button:hover {
    background-color: var(--button-hover-color);
}


.answer-options-container {
    font-size: clamp(36px, 5vw, 48px);
}


.answer-box-container {
    display: flex;
    justify-content: space-between;
    padding:0 10%;
    margin: 20px 0;
}

.answer-box {
    text-align: center;
}

.answer-box-label {
    display: block;
    font-size: 24px;
    margin-bottom: 5px;
}

.answer-box-box {
    width: 50px;
    height: 20px;
    border: 2px solid;
    transition: box-shadow 0.3s ease, background-image 0.3s ease;
}
.answer-box.active .answer-box-box {
    background-image: linear-gradient(to bottom, transparent 0%, #6F7177 50%, transparent 100%);
    
    background-repeat: no-repeat;
    background-position: center;
}
@media (max-width: 768px) {
    .answer-options-container {
        font-size: clamp(22px, 5vw, 36px);
    }
    .input-container {
        width: 90%;
        margin: 60px auto;
        padding: 5px;
    }
    input.answer-input,
    input#input-field {
        font-size: 6vw;
    }
    .input-container #sqrt-button {
        font-size: 16px;
    }
}
.marks-badge {
    font-size: 14px;
    color:#9ca3af;
    text-align: center;
}




.nav-buttons-container {
    margin-top: auto; 
    display: flex;
    justify-content: center;
    margin: 2%;
}

.nav-buttons-container button {

    background-color: var(--white);
    color: var(--text-color);
    border: none;
    z-index: 500;
    transition: opacity 0.3s ease, transform 0.3s ease;
} 
.nav-buttons-container button {
    flex: 1;
    padding: 12px 0;
    font-size: 16px;
    border: 1px solid var(--input-border-color); 
    border-radius: 0;
    background-color: var(--primary-color);
    color: white;
    cursor: pointer;
    transition: background-color 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}
.nav-buttons-container button:focus {
    outline: none;
}

.nav-buttons-container button:first-child {
    border-right: none;
    flex-grow: 1;
    border-top-left-radius: 8px;
    border-bottom-left-radius: 8px;
}

.nav-buttons-container button:last-child {
    flex-grow: 1;
    border-top-right-radius: 8px;
    border-bottom-right-radius: 8px;
}

.nav-buttons-container button:hover {
    background-color: var(--button-hover-color);
}

.arrow-left, .arrow-right {
    font-size: 18px;
    margin: 0 6px;
}





.test-footer-container { 
    margin-top: auto;
    display: fixed;
    bottom: 0;
    flex-shrink: 0;
}
.test-footer { 
    display: flex;
    flex-direction: column;
    padding: 0 2%;
}



.side-nav-btn {
    display:none;
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(255, 255, 255, 0.9);
    border: none;
    font-size: 1.5rem;
    color: #333;
    cursor: pointer;
    padding: 6px 10px;

    z-index: 1000;
    box-shadow: 0 0 5px rgba(0,0,0,0.2);
    opacity: 1;
    transition: opacity 0.5s ease;
}
.side-nav-btn.hidden {
    opacity: 0;
    pointer-events: none;
}
.side-nav-btn.left {
    left: -7px;
}

.side-nav-btn.right {
    right: -7px;
}



@media (max-width: 768px) {
    .exam-title {
        margin: 0; 
    }
    
  
    .nav-buttons-container button {
        font-size: 5vw;
        margin-bottom: 1vw;
        padding-left: 1.9vw;
  
    }
    .side-nav-btn {
        display:block;
    }
}



/* ===== Confirm Submit: Answer Summary (scoped) ===== */
#confirmSubmitModal .kas-list[data-ctx="answer-summary"] {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: .45rem;
}
#confirmSubmitModal .kas-row {
  display: flex;
  align-items: baseline;
  gap: .6rem;
}
#confirmSubmitModal .kas-qno {
  font-weight: 600;
  min-width: 4.2rem;
  color: #111827;
}

#confirmSubmitModal .kas-badge {
  display: inline-block;
  padding: .15rem .5rem;
  border-radius: .5rem;
  font-size: .85rem;
  line-height: 1;
  border: 1px solid transparent;
  user-select: none;
  white-space: nowrap;
}
#confirmSubmitModal .kas-badge.is-ok {
  background: rgba(16,185,129,.12);
  color: #065f46;
  border-color: #10b981;
}
#confirmSubmitModal .kas-badge.is-warn {
  background: rgba(239,68,68,.12);
  color: #7f1d1d;
  border-color: #ef4444;
}

#confirmSubmitModal .kas-sub {
  list-style: none;
  padding: 0;
  margin: .25rem 0 0 0;
  display: flex;
  flex-direction: column;
  gap: .25rem;
}
#confirmSubmitModal .kas-sub-row {
  display: flex;
  align-items: baseline;
  gap: .5rem;
}
#confirmSubmitModal .kas-sub-label {
  width: 1.6rem;
  text-align: right;
  font-weight: 500;
  color: #374151;
}