:root {
    --primary-color: #6b8fb3;
    --badge-width: 34px;
    --badge-gap: 10px;
    --sticky-btn-height: 52px;
}

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

body {
    font-family: "Heebo", "Segoe UI", Arial, sans-serif;
    font-size: 16px;
    line-height: 1.7;
    color: #333333;
    background-color: #ffffff;
    direction: rtl;
    text-align: right;
}

#app {
    max-width: 700px;
    margin: 0 auto;
    padding: 40px 24px;
}

/* Opening Screen */

.opening-screen {
    padding-top: 80px;
    text-align: center;
}

.opening-screen * {
    text-align: center;
}

.series-title {
    font-size: 3.6rem;
    font-weight: 800;
    color: #1a1a1a;
    letter-spacing: 0.015em;
    line-height: 1.4;
    margin-bottom: 16px;
}

.quiz-line {
    font-size: 1.6rem;
    font-weight: 400;
    color: #6b6560;
    letter-spacing: 0.04em;
    margin-bottom: 44px;
}

.start-button {
    max-width: 360px;
    margin: 0 auto;
    display: block;
    padding: 16px 60px;
    border-radius: 10px;
}

.opening-footer {
    margin-top: 40px;
    font-size: 0.75rem;
    color: #a8a29e;
    text-align: center;
}

/* Buttons */

button {
    font-family: inherit;
    font-size: 1rem;
    padding: 12px 36px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    display: inline-block;
}

.start-button,
.next-button {
    background-color: var(--primary-color);
    color: #ffffff;
    font-size: 1.08rem;
    font-weight: 500;
}

.start-button:hover,
.next-button:hover {
    background-color: var(--primary-color);
    filter: brightness(0.9);
}

.confirm-button {
    background-color: #e0e0e0;
    color: #999999;
    cursor: default;
    margin-top: 24px;
}

.confirm-button:not(:disabled) {
    background-color: var(--primary-color);
    color: #ffffff;
    cursor: pointer;
    font-size: 1.08rem;
    font-weight: 500;
}

.confirm-button:not(:disabled):hover {
    background-color: var(--primary-color);
    filter: brightness(0.9);
}

.confirm-button,
.next-button {
    display: block;
    margin-left: auto;
    margin-right: auto;
}

.confirm-button {
    margin-top: 36px;
}

.next-button {
    margin-top: 32px;
}

/* Progress Indicator */

.progress-container {
    margin-bottom: 24px;
}

.progress-text {
    font-size: 1rem;
    color: #666666;
    display: block;
    margin-bottom: 6px;
}

.progress-bar {
    width: 100%;
    height: 2px;
    background-color: #eeeeee;
    border-radius: 2px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background-color: var(--primary-color);
    border-radius: 1px;
    transition: width 0.3s;
}

/* Image Frame / Flip Card */

.flip-container {
    perspective: 1000px;
    width: 100%;
    margin-bottom: 24px;
}

.flip-card {
    position: relative;
    width: 100%;
    height: 300px;
    transition: transform 0.6s;
    transform-style: preserve-3d;
}

.flip-card.flipped {
    transform: rotateY(180deg);
}

.flip-front,
.flip-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border: 1px solid #dddddd;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #fafafa;
    overflow: hidden;
}

.flip-front img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.flip-back {
    transform: rotateY(180deg);
}

/* Result on Card Back */

.result-content {
    font-size: clamp(1.2rem, 3vw, 1.6rem);
    text-align: center;
    direction: rtl;
}

.result-symbol {
    font-size: clamp(1.8rem, 5vw, 2.8rem);
    vertical-align: middle;
}

.result-feedback {
    vertical-align: middle;
}

.result-correct {
    color: #2e7d32;
}

.result-incorrect {
    color: #c62828;
}

/* Question Header */

.question-header {
    display: flex;
    align-items: baseline;
    gap: var(--badge-gap);
    margin-bottom: 24px;
    padding-right: 0;
}

.question-badge {
    font-size: 1.3rem;
    font-weight: normal;
    color: #333333;
    border: 2px solid var(--primary-color);
    border-radius: 4px;
    padding: 3px 7px;
    line-height: 1.1;
    display: inline-flex;
    align-items: baseline;
    justify-content: center;
    flex-shrink: 0;
    width: var(--badge-width);
    text-align: center;
}

.question-text {
    font-size: 1.2rem;
    font-weight: normal;
}

/* Answer Options */

.answers-container {
    margin-bottom: 8px;
    padding-right: calc(var(--badge-width) + var(--badge-gap));
}

.answer-option {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 0;
    cursor: pointer;
    border-radius: 6px;
    transition: background-color 0.15s;
}

.answer-option:hover {
    background-color: #f5f5f5;
}

.answer-option.selected {
    background-color: #f0f4f8;
}

.circle {
    width: 16px;
    height: 16px;
    min-width: 16px;
    border: 1.25px solid #999999;
    border-radius: 50%;
    flex-shrink: 0;
    position: relative;
}

.answer-option.selected .circle {
    border-color: var(--primary-color);
}

.answer-option.selected .circle::after {
    content: "";
    position: absolute;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background-color: var(--primary-color);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

/* Multiple-choice: square checkbox */

.question-screen.multiple .circle {
    border-radius: 4px;
}

.question-screen.multiple .answer-option.selected .circle::after {
    border-radius: 2px;
}

.answer-text {
    font-size: 1rem;
}

/* Feedback Section */

.feedback-section {
    margin-top: 24px;
    padding-right: calc(var(--badge-width) + var(--badge-gap));
}

.feedback-text {
    font-size: 1.1rem;
    font-weight: bold;
    margin-bottom: 16px;
}

.feedback-correct {
    color: #2e7d32;
}

.feedback-incorrect {
    color: #c62828;
}

/* Correct Answer Block */

.correct-block {
    margin-bottom: 4px;
}

.correct-label,
.correct-label-only {
    font-weight: normal;
    color: #333333;
    font-size: 1.05rem;
}

.correct-label-only {
    margin-bottom: 4px;
}

.correct-value {
    font-size: 1.05rem;
}

.correct-answer {
    font-size: 1.05rem;
    margin-bottom: 4px;
}

.explanation {
    margin-top: 16px;
    margin-bottom: 16px;
    font-size: 1.05rem;
    line-height: 1.8;
}

/* Explanation Markers */

.marker-correct {
    color: #2e7d32;
}

.marker-incorrect {
    color: #c62828;
}

/* Final Screen */

.final-screen {
    padding-top: 80px;
    text-align: center;
}

.final-title {
    font-size: 1.6rem;
    font-weight: bold;
    margin-bottom: 8px;
}

.final-score {
    font-size: 1.3rem;
    margin-bottom: 8px;
}

.final-percentage {
    font-size: 2.5rem;
    font-weight: bold;
    margin-bottom: 16px;
}

.final-evaluation {
    font-size: 1.1rem;
}

/* Mobile */

/* Scroll Hint (hidden on desktop) */

.scroll-hint {
    display: none;
}

/* Mobile */

@media (max-width: 768px) {
    .flip-card {
        height: 35vh;
    }

    .question-screen {
        padding-bottom: calc(var(--sticky-btn-height) + 16px);
    }

    .feedback-section {
        padding-bottom: calc(var(--sticky-btn-height) + 16px);
    }

    .confirm-button,
    .next-button {
        position: fixed;
        bottom: 12px;
        left: 50%;
        right: auto;
        transform: translateX(-50%);
        z-index: 10;
        margin: 0;
        width: auto;
        max-width: 80vw;
        display: inline-block;
        padding: 12px 48px;
        border-radius: 6px;
    }

    .scroll-hint {
        display: flex;
        flex-direction: column;
        align-items: center;
        position: fixed;
        bottom: calc(var(--sticky-btn-height) + 18px);
        left: 50%;
        transform: translateX(-50%);
        z-index: 11;
        background: none;
        border: none;
        padding: 4px 10px;
        cursor: pointer;
        width: auto;
        height: auto;
        opacity: 0.6;
        transition: opacity 0.3s ease;
    }

    /* Stem */
    .scroll-hint::before {
        content: "";
        display: block;
        width: 1.5px;
        height: 12px;
        background-color: var(--primary-color);
    }

    /* Arrowhead */
    .scroll-hint::after {
        content: "";
        display: block;
        width: 8px;
        height: 8px;
        border-right: 1.5px solid var(--primary-color);
        border-bottom: 1.5px solid var(--primary-color);
        transform: rotate(45deg);
        margin-top: -5px;
    }

    .scroll-hint:hover {
        opacity: 0.8;
    }

    .scroll-hint.scrolling {
        opacity: 0.35;
    }

    .scroll-hint.hidden {
        opacity: 0;
        pointer-events: none;
    }
}