/* app-practice.css — parte 4 del split de styles-professional.css (2026-07-18).
   Módulo Practice: selector de nivel, flashcard, caras multi-carácter, controles.
   ORDEN DE CARGA OBLIGATORIO: app-base → header-nav → home → practice →
   browse → strokes → quiz → stats → enhancements → dashboard-extras.
   La cascada depende de este orden; no reordenar los <link>. */

/* ============================================================================
   8. PRACTICE MODULE
   ============================================================================ */
.practice-container {
    max-width: 860px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 16px;
    padding: 4px 12px 24px;
    position: relative;
}

/* ----------------------------------------------------------------------------
   Practice Header Hub (Progress, Streak & Toolbar)
   ---------------------------------------------------------------------------- */
.practice-hub-header {
    display: flex;
    flex-direction: column;
    gap: 10px;
    width: 100%;
}

/* Study Progress & Streak */
.study-progress {
    background: var(--bg-panel);
    border-radius: var(--radius-lg, 16px);
    padding: 16px 20px;
    border: 1px solid var(--color-border);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.04);
    display: flex;
    flex-direction: column;
    gap: 10px;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

.study-progress-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.study-progress-info {
    display: flex;
    align-items: center;
    gap: 8px;
}

.study-progress-badge {
    font-size: 1.15rem;
    line-height: 1;
}

.study-progress-title {
    font-weight: 700;
    font-size: 0.95rem;
    color: var(--text-main);
    letter-spacing: -0.01em;
}

.study-progress-value {
    color: var(--primary, #f43f5e);
    font-weight: 800;
    font-family: var(--font-mono, monospace);
    font-size: 0.95rem;
    background: rgba(244, 63, 94, 0.08);
    border: 1px solid rgba(244, 63, 94, 0.2);
    padding: 3px 10px;
    border-radius: 999px;
}

.progress-bar {
    height: 8px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: 999px;
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, #3b82f6, var(--primary, #f43f5e));
    border-radius: 999px;
    transition: width 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 0 10px rgba(244, 63, 94, 0.35);
}

.study-streak {
    display: flex;
    justify-content: space-between;
    gap: 6px;
    margin-top: 2px;
}

.streak-day {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--text-dim);
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.06);
    transition: transform 0.15s ease, background 0.15s ease, color 0.15s ease;
}

.streak-day.active {
    background: rgba(16, 185, 129, 0.14);
    color: var(--success, #10b981);
    border-color: rgba(16, 185, 129, 0.3);
}

.streak-day.today {
    border-color: var(--primary, #f43f5e);
    color: var(--primary, #f43f5e);
    background: rgba(244, 63, 94, 0.12);
    box-shadow: 0 0 8px rgba(244, 63, 94, 0.25);
    transform: scale(1.06);
}

/* Unified Practice Toolbar */
.practice-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
    width: 100%;
}

.practice-toolbar-controls {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
    flex: 1;
}

.practice-control-group.level-selector {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: var(--bg-panel);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md, 10px);
    padding: 6px 10px;
    min-height: 40px;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.practice-control-group.level-selector:hover {
    border-color: rgba(244, 63, 94, 0.4);
}

.practice-control-label {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--text-muted);
    cursor: pointer;
    white-space: nowrap;
    user-select: none;
}

.practice-control-label svg {
    color: var(--primary, #f43f5e);
    flex-shrink: 0;
}

.practice-control-group .select-input {
    background: transparent;
    border: none;
    color: var(--text-main);
    font-size: 0.82rem;
    font-weight: 600;
    padding: 2px 4px;
    cursor: pointer;
    outline: none;
    border-radius: 4px;
    max-width: 170px;
}

.practice-control-group .select-input:focus {
    color: var(--primary, #f43f5e);
}

/* Action Tools */
.deck-quick-bar {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.practice-action-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.82rem;
    font-weight: 600;
    padding: 6px 12px;
    border-radius: var(--radius-md, 10px);
    min-height: 40px;
    border: 1px solid var(--color-border);
    transition: transform 0.15s ease, background 0.15s ease, border-color 0.15s ease;
    cursor: pointer;
    white-space: nowrap;
}

.practice-action-btn:hover {
    transform: translateY(-1px);
    border-color: var(--primary, #f43f5e);
}

/* ----------------------------------------------------------------------------
   Flashcard Display Stage
   ---------------------------------------------------------------------------- */
.flashcard-area {
    perspective: 1200px;
    margin: 4px 0 10px;
    width: 100%;
    display: flex;
    justify-content: center;
}

.flashcard {
    background: transparent;
    border-radius: var(--radius-xl, 20px);
    width: 100%;
    max-width: 580px;
    height: 450px;
    position: relative;
    cursor: pointer;
    user-select: none;
    outline: none;
    touch-action: manipulation;
}

.flashcard:focus-visible {
    outline: 2px solid var(--primary, #f43f5e);
    outline-offset: 4px;
}

.flashcard-inner {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: center;
    transition: transform 0.6s cubic-bezier(0.18, 0.9, 0.22, 1.15);
    transform-style: preserve-3d;
}

.flashcard.flipped .flashcard-inner {
    transform: rotateY(180deg);
}

.card-face {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    border-radius: var(--radius-xl, 20px);
    background: var(--bg-panel);
    border: 1.5px solid var(--color-border);
    box-shadow: 0 14px 36px rgba(0, 0, 0, 0.16);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 22px 26px;
    transition: box-shadow 0.25s cubic-bezier(0.16, 1, 0.3, 1), border-color 0.25s ease, transform 0.25s ease;
}

.flashcard:hover .card-face {
    border-color: rgba(244, 63, 94, 0.35);
    box-shadow: 0 18px 44px rgba(0, 0, 0, 0.22), 0 0 0 1px rgba(244, 63, 94, 0.12);
}

.card-front {
    z-index: 2;
    background: linear-gradient(175deg, var(--bg-panel) 0%, rgba(244, 63, 94, 0.02) 100%);
}

.card-back {
    transform: rotateY(180deg);
    z-index: 1;
    background: var(--bg-panel);
    padding: 20px 24px;
    justify-content: flex-start;
    overflow-y: auto;
    text-align: left;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: thin;
    scrollbar-color: var(--color-border) transparent;
}

.card-back::-webkit-scrollbar {
    width: 6px;
}
.card-back::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 4px;
}

/* Card Top Bar (Seal, Audio & Favorite) */
.card-top-bar {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 6px;
    flex-shrink: 0;
}

.card-top-actions {
    display: flex;
    align-items: center;
    gap: 8px;
}

.card-action-icon-btn {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.12);
    color: var(--text-muted);
    cursor: pointer;
    transition: transform 0.15s ease, color 0.15s ease, background 0.15s ease;
}

.card-action-icon-btn:hover {
    transform: scale(1.12);
    color: var(--primary, #f43f5e);
    background: rgba(255, 255, 255, 0.12);
}

.flashcard-fav-btn.is-fav {
    color: #f59e0b !important;
    border-color: rgba(245, 158, 11, 0.4);
    background: rgba(245, 158, 11, 0.12);
    filter: drop-shadow(0 2px 8px rgba(245, 158, 11, 0.4));
}
.flashcard-fav-btn.is-fav svg {
    fill: #f59e0b;
}

/* Academic Seals: Authentic Chinese vermillion seal stamp (印章) */
.hsk-academic-seal {
    width: 32px;
    height: 32px;
    border-radius: 6px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-chinese-serif, "Noto Serif SC", serif);
    font-size: 1.15rem;
    font-weight: 800;
    color: #ffffff;
    background: linear-gradient(135deg, #dc2626 0%, #b91c1c 100%);
    border: 1.5px solid #ef4444;
    box-shadow: 0 2px 8px rgba(220, 38, 38, 0.35), inset 0 1px 1px rgba(255, 255, 255, 0.3);
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.35);
    user-select: none;
    letter-spacing: -0.05em;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.hsk-academic-seal:hover {
    transform: scale(1.08) rotate(-2deg);
    box-shadow: 0 4px 12px rgba(220, 38, 38, 0.45);
}

.hsk-academic-seal.seal-back {
    background: linear-gradient(135deg, #b91c1c 0%, #991b1b 100%);
    border-color: #dc2626;
    margin-bottom: 8px;
    align-self: flex-start;
}

/* Character Calligraphy Grid (Front Face) */
.card-character-container {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 10px;
    width: 100%;
    margin: 4px auto 12px;
    min-height: 150px;
}

.card-character {
    font-size: clamp(4.4rem, 12vw, 6rem);
    font-family: var(--font-chinese-serif, "Noto Serif SC", serif);
    font-weight: 600;
    color: #1c1917;
    position: relative;
    width: clamp(124px, 28vw, 155px);
    height: clamp(124px, 28vw, 155px);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-md, 12px);
    margin: 0;
    
    /* Traditional MiZiGe Calligraphy Grid (米字格) */
    background-color: rgba(254, 252, 251, 0.88);
    border: 2px solid rgba(220, 38, 38, 0.42);
    background-image: 
        linear-gradient(45deg, transparent 49.5%, rgba(220, 38, 38, 0.24) 49.5%, rgba(220, 38, 38, 0.24) 50.5%, transparent 50.5%),
        linear-gradient(-45deg, transparent 49.5%, rgba(220, 38, 38, 0.24) 49.5%, rgba(220, 38, 38, 0.24) 50.5%, transparent 50.5%),
        linear-gradient(to bottom, transparent 49.5%, rgba(220, 38, 38, 0.24) 49.5%, rgba(220, 38, 38, 0.24) 50.5%, transparent 50.5%),
        linear-gradient(to right, transparent 49.5%, rgba(220, 38, 38, 0.24) 49.5%, rgba(220, 38, 38, 0.24) 50.5%, transparent 50.5%);
    background-size: 100% 100%;
    box-shadow: 
        inset 0 0 12px rgba(220, 38, 38, 0.08),
        0 6px 18px rgba(0, 0, 0, 0.08);
}

/* Multi-character scaling */
.card-character-container.multi-char {
    gap: 8px;
}
.card-character-container.multi-char .card-character {
    width: clamp(96px, 22vw, 116px);
    height: clamp(96px, 22vw, 116px);
    font-size: clamp(3.4rem, 9vw, 4.4rem);
}
.card-character-container.triple-char {
    gap: 6px;
}
.card-character-container.triple-char .card-character {
    width: clamp(80px, 18vw, 94px);
    height: clamp(80px, 18vw, 94px);
    font-size: clamp(2.6rem, 7.5vw, 3.4rem);
}

.plain-text-character {
    font-size: 2.4rem;
    font-weight: 700;
    color: var(--text-main);
    text-align: center;
    line-height: 1.2;
    padding: 10px 20px;
}

.punctuation-box {
    font-size: 2.8rem;
    font-family: var(--font-chinese);
    color: var(--text-dim);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 4px;
}

/* Metadata & Hints on Front */
.card-front-meta {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text-muted);
    margin: 2px 0 6px;
    padding: 4px 12px;
    border-radius: 999px;
    border: 1px solid rgba(255, 255, 255, 0.12);
    background: rgba(255, 255, 255, 0.04);
}

.card-hint {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--text-muted);
    margin: 4px 0 8px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.09);
    padding: 6px 16px;
    border-radius: 999px;
    cursor: pointer;
    transition: opacity 0.25s ease, background 0.15s ease;
}

.card-hint.hint-hidden {
    opacity: 0.25;
    filter: blur(3px);
}

.card-hint.hint-revealed {
    opacity: 1;
    filter: none;
}

.card-flip-prompt {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text-dim);
    margin-top: auto;
    padding-top: 8px;
    opacity: 0.8;
}

.card-flip-prompt svg {
    color: var(--primary, #f43f5e);
}

.desktop-kbd-hint kbd {
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.14);
    border-radius: 4px;
    padding: 1px 6px;
    font-size: 0.68rem;
    font-family: var(--font-mono, monospace);
    color: var(--text-main);
}

/* ----------------------------------------------------------------------------
   Back Card Content (Detailed View)
   ---------------------------------------------------------------------------- */
.card-back .card-answer {
    display: none;
}

.card-details {
    width: 100%;
    color: var(--text-muted);
}

.card-back-header {
    display: flex;
    align-items: center;
    gap: 14px;
    width: 100%;
    margin-bottom: 8px;
}

.card-back-character-container {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    align-items: center;
}

.card-back-character {
    font-size: 2.8rem;
    font-family: var(--font-chinese-serif, "Noto Serif SC", serif);
    font-weight: 600;
    color: #1c1917;
    width: 68px;
    height: 68px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    flex-shrink: 0;
    background-color: rgba(254, 252, 251, 0.88);
    border: 1.5px solid rgba(220, 38, 38, 0.35);
    background-image: 
        linear-gradient(45deg, transparent 49.5%, rgba(220, 38, 38, 0.2) 49.5%, rgba(220, 38, 38, 0.2) 50.5%, transparent 50.5%),
        linear-gradient(-45deg, transparent 49.5%, rgba(220, 38, 38, 0.2) 49.5%, rgba(220, 38, 38, 0.2) 50.5%, transparent 50.5%),
        linear-gradient(to bottom, transparent 49.5%, rgba(220, 38, 38, 0.2) 49.5%, rgba(220, 38, 38, 0.2) 50.5%, transparent 50.5%),
        linear-gradient(to right, transparent 49.5%, rgba(220, 38, 38, 0.2) 49.5%, rgba(220, 38, 38, 0.2) 50.5%, transparent 50.5%);
    background-size: 100% 100%;
}

.card-back-character-container.multi-char .card-back-character {
    width: 54px;
    height: 54px;
    font-size: 2.1rem;
}

.card-back-character-container.triple-char .card-back-character {
    width: 46px;
    height: 46px;
    font-size: 1.8rem;
}

.card-back-header-text {
    display: flex;
    flex-direction: column;
    gap: 6px;
    align-items: flex-start;
}

.card-back-pinyin {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-main);
    display: flex;
    flex-wrap: wrap;
    gap: 4px;
}

.pinyin-syllable-badge {
    padding: 2px 8px;
    border-radius: 6px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.card-back-pronunciation {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    min-height: 32px;
    padding: 4px 10px;
    border-radius: 999px;
    border: 1px solid rgba(255, 255, 255, 0.14);
    background: rgba(255, 255, 255, 0.06);
    color: var(--text-main);
    font-size: 0.78rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.15s ease;
}

.card-back-pronunciation:hover {
    background: rgba(255, 255, 255, 0.12);
    border-color: var(--primary, #f43f5e);
    color: var(--primary, #f43f5e);
}

.card-back-meta {
    font-size: 0.75rem;
    color: var(--text-muted);
    background: rgba(255, 255, 255, 0.05);
    border-radius: 999px;
    padding: 2px 10px;
    display: inline-flex;
    align-self: flex-start;
    margin-bottom: 10px;
    font-weight: 600;
}

/* Translations Section */
.translations-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    width: 100%;
    margin-bottom: 10px;
}

.translation-item {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-md, 10px);
    padding: 10px 12px;
}

.translation-header {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-bottom: 4px;
    font-size: 0.72rem;
    font-weight: 700;
    color: var(--text-muted);
}

.lang-flag {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 24px;
    padding: 1px 5px;
    border-radius: 4px;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.15);
    font-size: 0.68rem;
    font-weight: 800;
    letter-spacing: 0.02em;
}

.translation-content {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-main);
    line-height: 1.35;
}

/* Tone Breakdown Card */
.details-grid {
    width: 100%;
    margin-bottom: 10px;
}

.detail-card {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-md, 10px);
    padding: 8px 12px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.detail-icon {
    color: var(--primary, #f43f5e);
    display: inline-flex;
}

.detail-info {
    display: flex;
    align-items: center;
    gap: 10px;
}

.detail-label {
    font-size: 0.76rem;
    font-weight: 700;
    color: var(--text-muted);
}

.tone-visual-badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 2px 8px;
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 700;
    background: rgba(255, 255, 255, 0.08);
}

/* Example Sentences */
.example-section {
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    padding-top: 10px;
    margin-top: 6px;
    width: 100%;
}

.example-title {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-dim);
    margin-bottom: 6px;
}

.example-chinese {
    font-size: 1.15rem;
    font-family: var(--font-chinese, "PingFang SC", sans-serif);
    color: var(--text-main);
    line-height: 1.45;
    margin-bottom: 4px;
}

.highlight-char {
    color: var(--primary, #f43f5e);
    font-weight: 700;
    border-bottom: 2px solid var(--primary, #f43f5e);
    padding-bottom: 1px;
}

.example-pinyin {
    font-size: 0.88rem;
    color: var(--text-muted);
    margin-bottom: 6px;
}

.example-translations {
    font-size: 0.84rem;
    color: var(--text-muted);
    display: flex;
    flex-direction: column;
    gap: 3px;
}

/* ----------------------------------------------------------------------------
   Practice Study Console (Input + Feedback + Controls)
   ---------------------------------------------------------------------------- */
.practice-study-console {
    width: 100%;
    max-width: 580px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 8px;
    align-items: center;
}

.pinyin-input-container {
    width: 100%;
    display: flex;
    gap: 8px;
    align-items: center;
    position: relative;
}

.pinyin-input-wrapper {
    position: relative;
    flex: 1;
    display: flex;
    align-items: center;
}

.pinyin-input-icon {
    position: absolute;
    left: 14px;
    color: var(--text-dim);
    pointer-events: none;
    display: flex;
    align-items: center;
}

#pinyin-input {
    background: var(--bg-panel);
    border: 1.5px solid var(--color-border);
    padding: 12px 46px 12px 38px;
    border-radius: 999px;
    color: var(--text-main);
    font-size: 1.05rem;
    font-weight: 600;
    width: 100%;
    text-align: center;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.06);
}

#pinyin-input:focus {
    outline: none;
    border-color: var(--primary, #f43f5e);
    box-shadow: 0 0 0 3px rgba(244, 63, 94, 0.22);
}

#pinyin-input.correct {
    border-color: #22c55e;
    background: rgba(34, 197, 94, 0.08);
}

#pinyin-input.incorrect {
    border-color: #ef4444;
    background: rgba(239, 68, 68, 0.08);
    animation: pinyinShake 0.4s ease;
}

@keyframes pinyinShake {
    0%, 100% { transform: translateX(0); }
    20%, 60% { transform: translateX(-6px); }
    40%, 80% { transform: translateX(6px); }
}

.speech-rec-btn {
    position: absolute;
    right: 6px;
    width: 36px;
    height: 36px;
    background: transparent;
    color: var(--primary, #f43f5e);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.15s ease, background 0.15s ease;
}

.speech-rec-btn:hover {
    transform: scale(1.1);
    background: rgba(255, 255, 255, 0.08);
}

.speech-rec-btn.recording {
    background: #ef4444;
    color: #ffffff;
    animation: micPulse 1.4s cubic-bezier(0.4, 0, 0.2, 1) infinite;
}

@keyframes micPulse {
    0% {
        box-shadow: 0 0 0 0 rgba(239, 68, 68, 0.7);
        transform: scale(1);
    }
    50% {
        box-shadow: 0 0 0 12px rgba(239, 68, 68, 0);
        transform: scale(1.08);
    }
    100% {
        box-shadow: 0 0 0 0 rgba(239, 68, 68, 0);
        transform: scale(1);
    }
}

.check-submit-btn {
    border-radius: 999px;
    padding: 10px 18px;
    font-weight: 700;
    min-height: 44px;
    background: var(--primary, #f43f5e);
    color: #fff;
    border: none;
    cursor: pointer;
    transition: background 0.15s ease, transform 0.15s ease;
}

.check-submit-btn:hover {
    background: var(--primary-hover, #e11d48);
    transform: translateY(-1px);
}

.feedback-message {
    min-height: 22px;
    font-size: 0.9rem;
    font-weight: 700;
    text-align: center;
    transition: opacity 0.2s ease;
}

.feedback-message.correct-text {
    color: #22c55e;
}

.feedback-message.incorrect-text {
    color: #ef4444;
}

/* ----------------------------------------------------------------------------
   Controls Row (Card Navigation & SRS Rating Bar)
   ---------------------------------------------------------------------------- */
.practice-controls-row {
    width: 100%;
    display: flex;
    flex-direction: column;
    gap: 8px;
    align-items: center;
}

.card-nav-group {
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
}

.card-nav-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    font-weight: 700;
    border-radius: var(--radius-md, 10px);
    min-height: 42px;
    padding: 8px 16px;
    cursor: pointer;
    border: 1px solid var(--color-border);
    background: var(--bg-panel);
    color: var(--text-main);
    transition: all 0.15s ease;
    touch-action: manipulation;
}

.card-nav-btn:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-1px);
}

.card-flip-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font-weight: 700;
    border-radius: var(--radius-md, 10px);
    min-height: 42px;
    padding: 8px 22px;
    cursor: pointer;
    background: var(--primary, #f43f5e);
    color: #ffffff;
    border: none;
    box-shadow: 0 4px 14px rgba(244, 63, 94, 0.25);
    transition: all 0.15s ease;
    touch-action: manipulation;
}

.card-flip-btn:hover {
    background: var(--primary-hover, #e11d48);
    transform: translateY(-1px);
    box-shadow: 0 6px 18px rgba(244, 63, 94, 0.35);
}

/* SRS Rating Bar */
.srs-rating-bar {
    width: 100%;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 8px;
    margin-top: 2px;
    opacity: 0.35;
    pointer-events: none;
    transition: opacity 0.25s ease, transform 0.25s ease;
}

.practice-container.card-is-flipped .srs-rating-bar,
.flashcard.flipped ~ .practice-study-console .srs-rating-bar {
    opacity: 1;
    pointer-events: auto;
}

.srs-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2px;
    padding: 8px 6px;
    border-radius: var(--radius-md, 12px);
    border: 1.5px solid transparent;
    cursor: pointer;
    min-height: 54px;
    transition: transform 0.15s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.2s ease, background 0.2s ease, border-color 0.2s ease;
    user-select: none;
    touch-action: manipulation;
    position: relative;
    overflow: hidden;
}

.srs-btn:hover {
    transform: translateY(-2px);
}

.srs-btn:active,
.srs-btn.active-rating {
    transform: translateY(1px) scale(0.97);
}

.srs-key {
    font-size: 0.65rem;
    font-weight: 800;
    font-family: var(--font-mono, monospace);
    background: rgba(255, 255, 255, 0.14);
    border-radius: 4px;
    padding: 1px 6px;
    line-height: 1.2;
}

.srs-label {
    font-size: 0.86rem;
    font-weight: 700;
    letter-spacing: -0.01em;
}

.srs-sub {
    font-size: 0.68rem;
    font-weight: 600;
    opacity: 0.85;
    font-family: var(--font-mono, monospace);
}

.srs-again {
    background: rgba(244, 63, 94, 0.12);
    color: #f43f5e;
    border-color: rgba(244, 63, 94, 0.3);
}
.srs-again:hover {
    background: rgba(244, 63, 94, 0.22);
    border-color: #f43f5e;
    box-shadow: 0 4px 16px rgba(244, 63, 94, 0.35);
}

.srs-hard {
    background: rgba(245, 158, 11, 0.12);
    color: #f59e0b;
    border-color: rgba(245, 158, 11, 0.3);
}
.srs-hard:hover {
    background: rgba(245, 158, 11, 0.22);
    border-color: #f59e0b;
    box-shadow: 0 4px 16px rgba(245, 158, 11, 0.35);
}

.srs-good {
    background: rgba(59, 130, 246, 0.12);
    color: #3b82f6;
    border-color: rgba(59, 130, 246, 0.3);
}
.srs-good:hover {
    background: rgba(59, 130, 246, 0.22);
    border-color: #3b82f6;
    box-shadow: 0 4px 16px rgba(59, 130, 246, 0.35);
}

.srs-easy {
    background: rgba(16, 185, 129, 0.12);
    color: #10b981;
    border-color: rgba(16, 185, 129, 0.3);
}
.srs-easy:hover {
    background: rgba(16, 185, 129, 0.22);
    border-color: #10b981;
    box-shadow: 0 4px 16px rgba(16, 185, 129, 0.35);
}

/* Keyboard Hints Bar */
.practice-keyboard-hints {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font-size: 0.74rem;
    color: var(--text-dim);
    margin-top: 4px;
}

.hint-item {
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.hint-item kbd {
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.14);
    border-radius: 4px;
    padding: 1px 5px;
    font-family: var(--font-mono, monospace);
    font-size: 0.68rem;
    color: var(--text-main);
}

.hint-dot {
    color: rgba(255, 255, 255, 0.15);
}

/* ----------------------------------------------------------------------------
   Touch Swipe Badges (Visual Feedback on Mobile Swiping)
   ---------------------------------------------------------------------------- */
.flashcard::before,
.flashcard::after {
    position: absolute;
    top: 24px;
    z-index: 10;
    font-weight: 800;
    font-size: 1rem;
    letter-spacing: 0.05em;
    padding: 6px 14px;
    border-radius: var(--radius-md, 10px);
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.15s ease, transform 0.15s ease;
}

.flashcard::before {
    content: "✓ BIEN";
    left: 20px;
    background: rgba(34, 197, 94, 0.92);
    color: #ffffff;
    border: 2px solid #22c55e;
    transform: rotate(-12deg) scale(0.85);
}

.flashcard::after {
    content: "↺ REPASAR";
    right: 20px;
    background: rgba(239, 68, 68, 0.92);
    color: #ffffff;
    border: 2px solid #ef4444;
    transform: rotate(12deg) scale(0.85);
}

.flashcard.swiping-right::before {
    opacity: 1;
    transform: rotate(-12deg) scale(1);
}

.flashcard.swiping-left::after {
    opacity: 1;
    transform: rotate(12deg) scale(1);
}

.flashcard.swiping-up {
    border-color: #3b82f6;
    box-shadow: 0 -10px 28px rgba(59, 130, 246, 0.45);
}

.flashcard.swiping-up::before {
    content: "★ FÁCIL";
    left: 50%;
    top: 20px;
    bottom: auto;
    right: auto;
    background: rgba(59, 130, 246, 0.94);
    color: #ffffff;
    border: 2px solid #60a5fa;
    opacity: 1;
    transform: translateX(-50%) scale(1.05);
}

html[lang="en"] .flashcard::before {
    content: "✓ GOOD";
}

html[lang="en"] .flashcard::after {
    content: "↺ AGAIN";
}

html[lang="en"] .flashcard.swiping-up::before {
    content: "★ EASY";
}

/* ----------------------------------------------------------------------------
   Hands-Free Floating Player Bar
   ---------------------------------------------------------------------------- */
.hands-free-player {
    position: fixed;
    bottom: calc(var(--bottom-nav-height, 60px) + var(--safe-area-bottom, 0px) + 12px);
    left: 50%;
    transform: translateX(-50%);
    width: calc(100% - 24px);
    max-width: 580px;
    z-index: 1040;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 10px 16px;
    background: var(--bg-panel);
    border: 1px solid var(--color-primary);
    border-radius: var(--radius-xl, 20px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    animation: hfSlideUp 0.25s ease-out;
}

@keyframes hfSlideUp {
    from { opacity: 0; transform: translate(-50%, 20px); }
    to { opacity: 1; transform: translate(-50%, 0); }
}

@media (min-width: 769px) {
    .hands-free-player {
        bottom: 24px;
    }
}

.hf-track-info {
    display: flex;
    align-items: baseline;
    gap: 8px;
    min-width: 0;
    flex: 1;
    overflow: hidden;
}

.hf-char {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-primary);
    flex-shrink: 0;
}

.hf-pinyin {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-main);
    flex-shrink: 0;
}

.hf-meaning {
    font-size: 0.8rem;
    color: var(--text-muted);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.hf-controls {
    display: flex;
    align-items: center;
    gap: 6px;
    flex-shrink: 0;
}

.hf-btn {
    background: var(--color-bg-hover);
    border: 1px solid var(--color-border);
    color: var(--text-main);
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: transform var(--transition-fast), background var(--transition-fast);
    touch-action: manipulation;
}

.hf-btn:hover {
    background: var(--color-bg-panel);
    transform: scale(1.05);
}

.hf-btn.hf-play-pause {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: #ffffff;
    width: 40px;
    height: 40px;
}

.hf-btn.hf-play-pause:hover {
    background: var(--color-primary-hover);
}

.hf-speed-select {
    background: var(--color-bg-hover);
    color: var(--text-main);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    padding: 4px 6px;
    font-size: 0.78rem;
    font-weight: 600;
    cursor: pointer;
}

.hf-btn.hf-close {
    font-size: 0.9rem;
    border-radius: 50%;
}

/* ----------------------------------------------------------------------------
   Responsive Optimizations (Mobile & Tablet)
   ---------------------------------------------------------------------------- */
@media (max-width: 768px) {
    .practice-container {
        gap: 12px;
        padding: 2px 10px 18px;
    }

    .study-progress {
        padding: 12px 14px;
        gap: 8px;
    }

    .streak-day {
        width: 26px;
        height: 26px;
        font-size: 0.7rem;
    }

    .practice-toolbar {
        gap: 8px;
    }

    .practice-control-group.level-selector {
        padding: 4px 8px;
        min-height: 38px;
    }

    .practice-control-label {
        font-size: 0.74rem;
    }

    .practice-action-btn {
        min-height: 38px;
        font-size: 0.78rem;
        padding: 4px 10px;
    }

    .flashcard {
        height: clamp(300px, 45dvh, 380px);
        max-width: 100%;
    }

    .card-face {
        padding: 16px 14px;
    }

    .card-character {
        width: 110px;
        height: 110px;
        font-size: clamp(3.2rem, 11vw, 4.5rem);
    }

    .card-character-container {
        min-height: 110px;
    }

    .srs-rating-bar {
        gap: 5px;
    }

    .srs-btn {
        min-height: 48px;
        padding: 4px 2px;
    }

    .translations-section {
        grid-template-columns: 1fr;
        gap: 8px;
    }

    .card-nav-group {
        width: 100%;
    }

    .card-nav-btn {
        flex: 1;
        padding: 8px 10px;
        font-size: 0.82rem;
    }

    .card-flip-btn {
        flex: 1.4;
        padding: 8px 12px;
        font-size: 0.85rem;
    }

    .practice-keyboard-hints {
        display: none;
    }
}

@media (max-width: 540px) {
    .practice-toolbar-controls {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 6px;
        width: 100%;
    }

    .practice-control-group.level-selector {
        width: 100%;
    }

    .practice-control-group.level-selector:nth-child(3) {
        grid-column: span 2;
    }

    .deck-quick-bar {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 6px;
        width: 100%;
    }

    .practice-action-btn {
        justify-content: center;
        width: 100%;
        font-size: 0.76rem;
        padding: 6px 4px;
        min-width: 0;
    }

    .practice-action-btn span {
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
        min-width: 0;
    }

    .flashcard {
        height: 360px;
    }

    .card-character {
        width: 110px;
        height: 110px;
        font-size: 3.8rem;
    }

    .card-character-container {
        min-height: 110px;
    }

    .card-hint {
        font-size: 0.92rem;
        padding: 4px 12px;
    }

    #pinyin-input {
        font-size: 1rem;
        min-height: 44px;
        padding: 10px 42px 10px 34px;
    }

    .srs-btn {
        min-height: 48px;
        padding: 4px 2px;
    }

    .srs-label {
        font-size: 0.78rem;
    }

    .srs-sub {
        font-size: 0.64rem;
    }
}