:root {
    --primary-dark: #03045E;
    --primary-blue: #023E8A;
    --primary-medium: #0077B6;
    --primary-light: #0096C7;
    --primary-lightest: #90E0EF;
    --white: #FFFFFF;
    --light-gray: #F8F9FA;
    --medium-gray: #E9ECEF;
    --dark-gray: #495057;
    --success: #28A745;
    --danger: #DC3545;
    --warning: #FFC107;
    --shadow: rgba(3, 4, 94, 0.1);
    --shadow-strong: rgba(3, 4, 94, 0.2);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, var(--primary-lightest) 0%, var(--white) 100%);
    color: var(--dark-gray);
    min-height: 100vh;
    padding-bottom: 80px;
}

.app-header {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary-blue) 100%);
    color: var(--white);
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 10px var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.app-header h1 {
    font-size: 1.5rem;
    font-weight: 600;
}

.menu-toggle {
    background: transparent;
    border: none;
    color: var(--white);
    font-size: 1.2rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 8px;
    transition: background-color 0.3s;
}

.menu-toggle:hover {
    background: rgba(255, 255, 255, 0.1);
}

.app-main {
    padding: 1rem;
    max-width: 1200px;
    margin: 0 auto;
}

.content-section {
    display: none;
    animation: fadeIn 0.3s ease-in-out;
}

.content-section.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Home Section */
.welcome-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 20px var(--shadow);
    text-align: center;
    margin-bottom: 2rem;
}

.welcome-card h2 {
    color: var(--primary-dark);
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.quick-actions {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.action-btn {
    background: var(--white);
    border: 2px solid var(--primary-light);
    padding: 1.5rem 1rem;
    border-radius: 12px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    transition: all 0.3s;
    color: var(--primary-dark);
    font-weight: 500;
}

.action-btn:hover {
    background: var(--primary-light);
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px var(--shadow-strong);
}

.action-btn i {
    font-size: 1.5rem;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
}

.stat-card {
    background: var(--white);
    padding: 1.5rem;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 2px 10px var(--shadow);
}

.stat-card h3 {
    font-size: 2rem;
    color: var(--primary-dark);
    margin-bottom: 0.5rem;
}

/* Section Headers */
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.section-header h2 {
    color: var(--primary-dark);
    font-size: 1.5rem;
}

.filters {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.filters select {
    padding: 0.5rem 1rem;
    border: 2px solid var(--medium-gray);
    border-radius: 8px;
    background: var(--white);
    color: var(--dark-gray);
    font-size: 0.9rem;
}

.filters select:focus {
    outline: none;
    border-color: var(--primary-light);
}

/* Forms */
.phrase-form-container {
    background: var(--white);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 20px var(--shadow);
    margin-bottom: 2rem;
}

.phrase-form {
    display: grid;
    gap: 1.5rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-weight: 500;
    color: var(--primary-dark);
}

.form-group input,
.form-group select {
    padding: 0.75rem;
    border: 2px solid var(--medium-gray);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-light);
}

.form-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.form-actions button {
    flex: 1;
    min-width: 120px;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
}

.form-actions button[type="submit"] {
    background: var(--primary-light);
    color: var(--white);
}

.form-actions button[type="submit"]:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.form-actions button[type="button"] {
    background: var(--medium-gray);
    color: var(--dark-gray);
}

.form-actions button[type="button"]:hover {
    background: var(--dark-gray);
    color: var(--white);
}

/* Phrases List */
.phrases-list {
    display: grid;
    gap: 1rem;
}

.phrase-card {
    background: var(--white);
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: 0 2px 10px var(--shadow);
    border-left: 4px solid var(--primary-light);
}

.phrase-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
    gap: 1rem;
}

.phrase-text {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary-dark);
    margin-bottom: 0.5rem;
}

.phrase-translation {
    color: var(--dark-gray);
    margin-bottom: 0.5rem;
}

.phrase-meta {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 1rem;
}

.phrase-language,
.phrase-category {
    background: var(--primary-lightest);
    color: var(--primary-dark);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

.phrase-pronunciation {
    font-style: italic;
    color: var(--primary-medium);
    margin-bottom: 1rem;
}

.phrase-actions {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.phrase-btn {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.phrase-btn.play-btn {
    background: var(--success);
    color: var(--white);
}

.phrase-btn.practice-btn {
    background: var(--primary-light);
    color: var(--white);
}

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

.phrase-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

/* Practice Section */
.practice-container {
    max-width: 600px;
    margin: 0 auto;
}

.practice-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 20px var(--shadow);
    text-align: center;
}

.practice-phrase h3 {
    color: var(--primary-dark);
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.practice-translation {
    color: var(--dark-gray);
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

.practice-pronunciation {
    color: var(--primary-medium);
    font-style: italic;
    margin-bottom: 2rem;
}

.practice-controls {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}

.practice-btn {
    padding: 1rem 1.5rem;
    border: none;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    min-width: 120px;
    justify-content: center;
}

.practice-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.practice-btn i {
    font-size: 1.2rem;
}

.practice-btn:not(:disabled):hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow-strong);
}

.practice-btn:nth-child(1) {
    background: var(--success);
    color: var(--white);
}

.practice-btn:nth-child(2) {
    background: var(--danger);
    color: var(--white);
}

.practice-btn:nth-child(2).recording {
    background: var(--warning);
    animation: pulse 1s infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

.practice-btn:nth-child(3) {
    background: var(--primary-light);
    color: var(--white);
}

.recording-status {
    min-height: 2rem;
    color: var(--primary-dark);
    font-weight: 500;
}

/* Culture Section */
.culture-container {
    max-width: 800px;
    margin: 0 auto;
}

.culture-search {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
}

.culture-search input {
    flex: 1;
    padding: 0.75rem;
    border: 2px solid var(--medium-gray);
    border-radius: 8px;
    font-size: 1rem;
}

.culture-search input:focus {
    outline: none;
    border-color: var(--primary-light);
}

.culture-search button {
    padding: 0.75rem 1.5rem;
    background: var(--primary-light);
    color: var(--white);
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
}

.culture-search button:hover {
    background: var(--primary-dark);
}

.culture-content {
    background: var(--white);
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 20px var(--shadow);
}

.culture-welcome {
    text-align: center;
    color: var(--dark-gray);
}

.culture-welcome h3 {
    color: var(--primary-dark);
    margin-bottom: 1rem;
}

.culture-info {
    text-align: left;
}

.culture-info h3 {
    color: var(--primary-dark);
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.culture-info h4 {
    color: var(--primary-medium);
    margin: 1.5rem 0 0.5rem 0;
}

.culture-info ul {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
}

.culture-info li {
    margin-bottom: 0.5rem;
}

/* FAQ Section */
.faq-container {
    max-width: 800px;
    margin: 0 auto;
    display: grid;
    gap: 1rem;
}

.faq-item {
    background: var(--white);
    border-radius: 12px;
    box-shadow: 0 2px 10px var(--shadow);
    overflow: hidden;
}

.faq-question {
    width: 100%;
    padding: 1.5rem;
    background: transparent;
    border: none;
    text-align: left;
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--primary-dark);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background-color 0.3s;
}

.faq-question:hover {
    background: var(--light-gray);
}

.faq-icon {
    font-size: 1.2rem;
    transition: transform 0.3s;
}

.faq-question[aria-expanded="true"] .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    padding: 0 1.5rem 1.5rem;
    color: var(--dark-gray);
    line-height: 1.6;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out, padding 0.3s ease-out;
}

.faq-answer.show {
    max-height: 200px;
    padding: 0 1.5rem 1.5rem;
}

/* Empty States */
.empty-state {
    text-align: center;
    padding: 3rem 2rem;
    color: var(--dark-gray);
}

.empty-state i {
    font-size: 3rem;
    color: var(--primary-light);
    margin-bottom: 1rem;
}

.empty-state h3 {
    color: var(--primary-dark);
    margin-bottom: 0.5rem;
}

/* Bottom Navigation */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--white);
    display: flex;
    justify-content: space-around;
    padding: 0.5rem 0;
    box-shadow: 0 -2px 10px var(--shadow);
    z-index: 100;
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-decoration: none;
    color: var(--dark-gray);
    padding: 0.5rem;
    border-radius: 8px;
    transition: all 0.3s;
    min-width: 60px;
}

.nav-item i {
    font-size: 1.2rem;
    margin-bottom: 0.25rem;
}

.nav-item span {
    font-size: 0.7rem;
    font-weight: 500;
}

.nav-item.active,
.nav-item:hover {
    color: var(--primary-dark);
    background: var(--primary-lightest);
}

/* Footer */
footer {
    background: var(--primary-dark);
    color: var(--white);
    text-align: center;
    padding: 1rem;
    margin-top: 2rem;
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .app-main {
        padding: 0.5rem;
    }
    
    .section-header {
        flex-direction: column;
        align-items: stretch;
    }
    
    .filters {
        justify-content: stretch;
    }
    
    .filters select {
        flex: 1;
    }
    
    .phrase-header {
        flex-direction: column;
        align-items: stretch;
    }
    
    .phrase-actions {
        justify-content: center;
    }
    
    .practice-controls {
        flex-direction: column;
        align-items: stretch;
    }
    
    .culture-search {
        flex-direction: column;
    }
    
    .form-actions {
        flex-direction: column;
    }
    
    .quick-actions {
        grid-template-columns: 1fr;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .app-header h1 {
        font-size: 1.2rem;
    }
    
    .welcome-card {
        padding: 1.5rem;
    }
    
    .phrase-form-container,
    .practice-card,
    .culture-content {
        padding: 1.5rem;
    }
    
    .nav-item span {
        font-size: 0.6rem;
    }
    
    .nav-item i {
        font-size: 1rem;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus styles for keyboard navigation */
button:focus,
input:focus,
select:focus,
.nav-item:focus {
    outline: 2px solid var(--primary-light);
    outline-offset: 2px;
}

/* Print styles */
@media print {
    .bottom-nav,
    .app-header,
    footer {
        display: none;
    }
    
    .content-section {
        display: block !important;
    }
    
    body {
        padding-bottom: 0;
    }
}