:root {
    --sv-blue: #006AA7;
    --sv-yellow: #FECC00;
    --bg-color: #f0f4f8;
    --text-color: #333;
    --card-bg: #ffffff;
    --success: #2ecc71;
    --error: #e74c3c;
    --filter-bg: #ffffff;
    --badge-bg: #eee;
    --input-border: #eee;
    --icon-hover: #f0f0f0;
    --stat-label: #666;
}

* {
    box-sizing: border-box;
}

body.dark {
    --bg-color: #1a1a1a !important;
    --text-color: #e0e0e0 !important;
    --card-bg: #2d2d2d !important;
    --filter-bg: #2d2d2d !important;
    --badge-bg: #444 !important;
    --input-border: #444 !important;
    --icon-hover: #444 !important;
    --stat-label: #aaa !important;
    --sv-blue: #3498db !important; /* Slightly lighter blue for dark mode */
}

body {
    font-family: 'Nunito', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    min-height: 100vh;
    /* transition removed to prevent flickering */
}

.main-container {
    width: 100%;
    max-width: 500px;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

header {
    text-align: center;
    margin-bottom: 10px;
    position: relative;
}

.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 5px;
}

.streak-badge {
    font-size: 1.2rem;
    font-weight: bold;
    display: flex;
    align-items: center;
    gap: 5px;
}

/* Filter Bar */
.filters {
    background: var(--card-bg);
    padding: 15px;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    display: flex;
    justify-content: center;
}

.filter-group {
    display: flex;
    gap: 15px;
    align-items: center;
    flex-wrap: wrap;
    justify-content: center;
}

.filter-label {
    font-weight: bold;
    color: var(--stat-label);
    font-size: 0.9rem;
}

.filter-option {
    display: flex;
    align-items: center;
    gap: 5px;
    cursor: pointer;
    font-size: 0.95rem;
}

header h1 {
    color: var(--sv-blue);
    margin: 0;
    font-size: 2rem;
}

.flag-icon {
    font-size: 3rem;
}

/* Session Stats */
.session-stats {
    display: flex;
    justify-content: space-around;
    background: var(--card-bg);
    padding: 15px;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

.stat-item {
    text-align: center;
}

.stat-item .value {
    display: block;
    font-size: 1.5rem;
    font-weight: bold;
}

.stat-item.correct .value { color: var(--success); }
.stat-item.wrong .value { color: var(--error); }

/* Flashcard */
.card-container {
    perspective: 1000px;
}

.card {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 8px 20px rgba(0,0,0,0.1);
    text-align: center;
    transition: transform 0.3s ease, background-color 0.3s;
}

.card-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 20px;
    color: var(--stat-label);
    font-size: 0.9rem;
}

.badges {
    display: flex;
    gap: 10px;
}

.badge {
    background: var(--badge-bg);
    padding: 4px 8px;
    border-radius: 4px;
    font-weight: bold;
    color: var(--text-color);
}

.level-badge {
    background-color: var(--sv-blue);
    color: white;
}

.question-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    margin-bottom: 30px;
}

#question-text {
    font-size: 2rem;
    margin: 0;
    color: var(--sv-blue);
}

.icon-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 5px;
    border-radius: 50%;
    transition: background 0.2s, transform 0.1s;
    line-height: 1;
    color: var(--text-color);
}

.icon-btn:hover {
    background: var(--icon-hover);
    transform: scale(1.1);
}

.icon-btn:active {
    transform: scale(0.95);
}

.hint-text {
    font-size: 0.9rem;
    color: #e67e22; /* Orange for warning/hint */
    margin-bottom: 10px;
    font-weight: bold;
}

/* Input Area */
.input-wrapper {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 1rem;
}

.input-flag {
    font-size: 1.5rem;
    width: 30px; /* Fixed width to prevent jumping */
    text-align: center;
}

input[type="text"] {
    width: 100%;
    padding: 12px;
    border: 2px solid var(--input-border);
    border-radius: 8px;
    font-size: 1.1rem;
    outline: none;
    transition: border-color 0.2s, background-color 0.3s, color 0.3s;
    background-color: var(--card-bg);
    color: var(--text-color);
}

input[type="text"]:focus {
    border-color: var(--sv-blue);
}

.char-buttons {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin-top: 10px;
}

.char-btn {
    background: var(--badge-bg);
    border: 1px solid var(--input-border);
    border-radius: 4px;
    padding: 5px 10px;
    font-size: 1.1rem;
    cursor: pointer;
    color: var(--sv-blue);
    transition: background 0.2s;
}

.char-btn:hover {
    background: var(--icon-hover);
}

.btn {
    display: block;
    width: 100%;
    padding: 15px;
    margin-top: 20px;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: bold;
    cursor: pointer;
    transition: background 0.2s;
}

.btn.primary {
    background-color: var(--sv-blue);
    color: white;
}

.btn.primary:hover {
    filter: brightness(1.1);
}

.btn.secondary {
    background-color: var(--sv-yellow);
    color: #004b75;
}

.btn.danger {
    background-color: var(--error);
    color: white;
}

.btn.small {
    padding: 8px;
    font-size: 0.9rem;
    margin-top: 5px;
}

.hidden {
    display: none !important;
}

/* Feedback */
#feedback-area {
    margin-top: 20px;
    padding: 15px;
    border-radius: 8px;
}

.feedback-correct {
    background-color: rgba(46, 204, 113, 0.2);
    color: var(--success);
}

.feedback-wrong {
    background-color: rgba(231, 76, 60, 0.2);
    color: var(--error);
}

.feedback-hint {
    background-color: rgba(243, 156, 18, 0.2);
    color: #d35400; /* Darker orange */
}

.feedback-speakers {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin: 10px 0;
}

.solution {
    margin-top: 5px;
    color: var(--text-color);
    font-style: italic;
    opacity: 0.8;
}

/* Example Sentence */
.example-box {
    margin-top: 20px;
    padding: 12px;
    background-color: var(--bg-color);
    border: 1px solid var(--input-border);
    border-radius: 8px;
    text-align: left;
}

.example-label {
    font-size: 0.8rem;
    font-weight: bold;
    color: var(--stat-label);
    text-transform: uppercase;
    display: block;
    margin-bottom: 5px;
}

.example-content {
    display: flex;
    align-items: center;
    gap: 8px;
    justify-content: center;
    flex-wrap: wrap;
}

#example-text {
    font-style: italic;
    color: var(--sv-blue);
    margin: 0;
    font-size: 1.1rem;
}

.footer-links {
    text-align: center;
    margin-top: 10px;
}

.footer-links a {
    color: var(--stat-label);
    font-size: 0.8rem;
    text-decoration: none;
    opacity: 0.7;
}

.footer-links a:hover {
    opacity: 1;
    text-decoration: underline;
}

.small-btn {
    font-size: 1.2rem;
    padding: 2px;
}

/* DB Stats */
.db-stats-container {
    background: var(--card-bg);
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

.db-stats-container h3 {
    margin-top: 0;
    font-size: 1rem;
    color: var(--stat-label);
}

.box-row {
    display: flex;
    align-items: center;
    margin-bottom: 8px;
    font-size: 0.9rem;
}

.box-label {
    width: 60px;
    font-weight: bold;
}

.progress-track {
    flex-grow: 1;
    background: var(--badge-bg);
    height: 10px;
    border-radius: 5px;
    overflow: hidden;
    margin: 0 10px;
}

.progress-fill {
    height: 100%;
    background: var(--sv-blue);
}

.box-count {
    width: 40px;
    text-align: right;
    color: var(--stat-label);
}

.data-management {
    background: var(--card-bg);
    padding: 20px;
    border-radius: 12px;
    margin-bottom: 20px;
}

.data-management h3 {
    margin-top: 0;
    font-size: 1rem;
    color: var(--stat-label);
}

.data-buttons {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

/* Ko-Fi Button */
.support-section {
    margin-top: 10px;
    text-align: center;
}

.kofi-btn {
    background-color: #FF5E5B; /* Ko-Fi Red */
    color: white;
    text-decoration: none;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    transition: transform 0.2s, background-color 0.2s;
}

.kofi-btn:hover {
    background-color: #ff403d;
    transform: translateY(-2px);
}

/* Dark Mode & Help Toggle Styling */
.header-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.header-actions .icon-btn {
    font-size: 1.4rem;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--badge-bg);
    border-radius: 50%;
    cursor: pointer;
    border: 1px solid var(--input-border);
    transition: background 0.2s, transform 0.1s;
    color: var(--text-color);
    padding: 0;
    margin: 0;
}

.header-actions .icon-btn:hover {
    background-color: var(--icon-hover);
    transform: scale(1.05);
}

/* Modal Styles */
.modal {
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.6);
    display: flex;
    justify-content: center;
    align-items: center;
    backdrop-filter: blur(3px);
}

.modal-content {
    background-color: var(--card-bg);
    padding: 30px;
    border-radius: 16px;
    width: 90%;
    max-width: 450px;
    position: relative;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
    color: var(--text-color);
}

.close-modal {
    position: absolute;
    right: 20px;
    top: 15px;
    font-size: 2rem;
    cursor: pointer;
    color: var(--stat-label);
}

.modal-content h2 {
    color: var(--sv-blue);
    margin-top: 0;
}

.modal-content h3 {
    margin-bottom: 5px;
    color: var(--sv-blue);
    font-size: 1.1rem;
}

.modal-content ul {
    padding-left: 20px;
    margin-bottom: 15px;
}

.modal-content li {
    margin-bottom: 5px;
}

.modal-content p {
    line-height: 1.5;
    margin-bottom: 15px;
}