/* Flashcard (跑臺機) Mode Styling */

.flashcard-container,
.flashcard-container * {
    box-sizing: border-box;
}

.flashcard-container {
    width: 100%;
    height: 100%;
    display: none;
    flex-direction: column;
    background-color: var(--bg-primary);
    padding: 16px;
    position: relative;
    margin: 0 auto;
    opacity: 0;
    animation: fadeIn 0.6s 0.2s ease-out forwards;
    transition: background-color 0.4s ease;
}

.progress {
    display: flex;
    justify-content: space-between;
    margin-bottom: 10px;
    gap: 16px;
    padding: 0;
    background-color: transparent;
    width: 100%;
}

.progress-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
    padding: 4px 12px;
    background-color: var(--md-sys-color-surface-container);
    border-radius: 8px;
    border: 1px solid var(--border-primary);
    font-family: 'Outfit', sans-serif;
    font-weight: 600;
    transition: all 0.3s cubic-bezier(0.2, 0, 0, 1);
    min-width: 60px;
}

.progress-item:hover {
    background-color: var(--bg-secondary);
}

.progress-item span:first-child,
#wrong,
#correct,
#mcWrong,
#mcCorrect {
    font-size: 1rem;
    line-height: 1;
}

#wrong,
#mcWrong {
    color: var(--accent-red);
}

#correct,
#mcCorrect {
    color: var(--accent-green);
}

.progress-item span:last-child {
    font-size: 0.6rem;
    opacity: 0.6;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--text-secondary);
    line-height: 1;
}

.card-content {
    position: relative;
    flex-grow: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    margin-bottom: 10px;
    border-radius: 24px;
    background-color: #FFFFFF;
    box-shadow: 0 2px 8px var(--shadow-color);
    border: 1px solid var(--border-primary);
    transition: all 0.3s cubic-bezier(0.2, 0, 0, 1);
}

.loading-screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(255, 255, 255, 0.9);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 2;
    border-radius: 10px;
    transition: background-color 0.4s ease, opacity 0.3s ease-out;
}

body.dark-mode .loading-screen {
    background-color: rgba(42, 42, 42, 0.9);
}

.spinner {
    border: 4px solid var(--border-primary);
    border-top: 4px solid var(--accent-blue);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1.2s cubic-bezier(0.5, 0, 0.5, 1) infinite;
    transition: border-color 0.4s ease;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.card-content img {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: contain;
    transition: opacity 0.5s ease-in-out;
    opacity: 0;
    border-radius: 10px;
}

.card-content img.loaded {
    opacity: 1;
}

.star-toggle {
    position: absolute;
    top: 8px;
    right: 8px;
    z-index: 2;
    width: 36px;
    height: 36px;
    border: none;
    border-radius: 999px;
    background: transparent;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.2s ease, color 0.2s ease;
}

.star-toggle:hover {
    transform: scale(1.1);
    color: #FBBF24;
}

.star-toggle.starred {
    color: #FBBF24;
}

.card-answer {
    display: none;
    flex-direction: column;
    padding: 16px;
    border-radius: 16px;
    background-color: var(--card-answer-bg);
    border: 1px solid var(--border-primary);
    margin-bottom: 12px;
    width: 100%;
    box-shadow: 0 4px 12px var(--shadow-color);
}

.answer-input-container {
    width: 100%;
    margin-bottom: 12px;
}

.answer-input {
    width: 100%;
    padding: 14px 20px;
    border-radius: 14px;
    border: 1px solid var(--border-primary);
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 1rem;
    transition: all 0.3s cubic-bezier(0.2, 0, 0, 1);
}

.answer-input:focus {
    outline: none;
    border-color: var(--accent-blue);
    box-shadow: 0 0 0 3px var(--focus-ring);
}

.bottom-buttons {
    display: flex;
    justify-content: space-between;
    width: 100%;
    gap: 12px;
}

.dont-know-button,
.answer-button {
    padding: 12px 24px;
    border-radius: 12px;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: all 0.2s ease;
}

.dont-know-button {
    background-color: var(--md-sys-color-surface-container);
    color: var(--text-primary);
    border: 1px solid var(--border-primary);
}

.dont-know-button:hover {
    background-color: var(--bg-secondary);
}

.answer-button {
    background-color: var(--accent-blue);
    color: #FFFFFF;
}

.answer-button:hover {
    filter: brightness(1.08);
}