/* ============================================
   PREVODILAC - STYLES FOR KIDS
   Responzivni dizajn za decu
   ============================================ */

/* ========== GLOBAL STYLES ========== */
:root {
    /* Vesele boje za decu */
    --primary-color: #4A90E2;
    --primary-light: #6BA3E8;
    --primary-dark: #357ABD;
    --secondary-color: #F5A623;
    --success-color: #7ED321;
    --warning-color: #F5A623;
    --danger-color: #D0021B;
    --info-color: #50E3C2;
    
    /* Pastelne boje */
    --pastel-blue: #B8E6FF;
    --pastel-pink: #FFB8D9;
    --pastel-yellow: #FFF4B8;
    --pastel-green: #B8FFD9;
    --pastel-purple: #E6B8FF;
    
    /* Gradijenti */
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-success: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-warm: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
    
    /* Fontovi */
    --font-family: 'Nunito', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --font-family-heading: 'Fredoka', 'Nunito', sans-serif;
    --font-size-base: 18px;
    --font-size-large: 24px;
    --font-size-xlarge: 32px;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    
    /* Border radius */
    --border-radius: 15px;
    --border-radius-lg: 20px;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 8px rgba(0,0,0,0.15);
    --shadow-lg: 0 8px 16px rgba(0,0,0,0.2);
    --shadow-xl: 0 12px 24px rgba(0,0,0,0.25);
}

* {
    box-sizing: border-box;
}

html, body {
    height: 100%;
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    display: flex;
    flex-direction: column;
    position: relative;
}

/* ========== TYPOGRAPHY ========== */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-family-heading);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-sm);
    color: #2c3e50;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: var(--spacing-sm);
    font-size: var(--font-size-base);
}

/* ========== NAVBAR ========== */
.navbar {
    background: var(--gradient-primary) !important;
    box-shadow: var(--shadow-md);
    padding: 0.5rem 0 !important;
    border-radius: 0 0 var(--border-radius) var(--border-radius);
    min-height: auto !important;
    height: auto !important;
}

.navbar-brand {
    font-size: var(--font-size-large) !important;
    font-weight: 700;
    color: white !important;
    padding: 0.5rem 0 !important;
    line-height: 1.2 !important;
}

.nav-link {
    font-size: var(--font-size-base) !important;
    padding: var(--spacing-xs) var(--spacing-sm) !important;
    min-height: 44px; /* Touch-friendly */
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s ease;
}

.nav-link-text {
    /* Na desktop ekranima, prikaži tekst */
    display: inline;
}

.nav-link:hover {
    background-color: rgba(255, 255, 255, 0.2);
    border-radius: var(--border-radius);
    transform: translateY(-2px);
}

/* ========== CARDS FOR FLASH LEARNING ========== */
.card:has(.card-inner) {
    width: 100% !important;
    height: 200px !important;
    perspective: 1000px;
    cursor: pointer;
    margin-bottom: var(--spacing-md);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    min-height: 200px !important;
    max-height: none !important;
    background: transparent !important;
    border: none !important;
    padding: 0 !important;
    overflow: hidden !important;
    border-radius: var(--border-radius-lg) !important;
}

.card:has(.card-inner):hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.card:has(.card-inner):active {
    transform: translateY(-2px) scale(0.98);
}

.card-inner {
    width: 100%;
    height: 100%;
    transform-style: preserve-3d;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    border-radius: var(--border-radius-lg);
}

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

.card-front,
.card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-large);
    font-weight: 600;
    border: none;
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    box-sizing: border-box;
    top: 0;
    left: 0;
}

.card-front {
    background: var(--gradient-primary);
    color: white;
}

.card-front:hover {
    box-shadow: var(--shadow-xl);
}

.card-back {
    background: linear-gradient(135deg, #fff 0%, #f5f7fa 100%);
    color: #2c3e50;
    transform: rotateY(180deg);
    flex-direction: column;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) !important;
    overflow: visible !important;
    display: flex !important;
    justify-content: center;
    align-items: center;
}

.card-back .btn {
    margin: 0.25rem;
    white-space: nowrap;
    flex-shrink: 0;
}

/* Na mobilnim ekranima, dugmad u vertikalnom rasporedu */
@media (max-width: 575.98px) {
    .card-back {
        justify-content: space-between;
        padding: 6px 4px !important;
    }
    
    .card-back > div:first-child {
        flex-shrink: 0;
    }
    
    .card-back > div:last-child {
        flex-shrink: 0;
        margin-top: auto;
    }
}

/* ========== BUTTONS ========== */
.btn {
    min-height: 44px; /* Touch-friendly */
    min-width: 44px;
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: var(--font-size-base);
    font-weight: 600;
    border-radius: var(--border-radius);
    border: none;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-sm);
    cursor: pointer;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn:active {
    transform: translateY(0);
    box-shadow: var(--shadow-sm);
}

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

.btn-success {
    background: linear-gradient(135deg, #7ED321 0%, #5BA817 100%);
    color: white;
}

.btn-warning {
    background: linear-gradient(135deg, #F5A623 0%, #D68910 100%);
    color: white;
}

.btn-secondary {
    background: linear-gradient(135deg, #95a5a6 0%, #7f8c8d 100%);
    color: white;
}

/* ========== FORMS ========== */
.form-control,
.form-select {
    min-height: 48px; /* Touch-friendly */
    font-size: var(--font-size-base);
    border-radius: var(--border-radius);
    border: 2px solid #ddd;
    padding: var(--spacing-xs) var(--spacing-sm);
    transition: all 0.3s ease;
}

.form-control:focus,
.form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 0.2rem rgba(74, 144, 226, 0.25);
    outline: none;
}

.form-label {
    font-size: var(--font-size-base);
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
    color: #2c3e50;
}

textarea.form-control {
    min-height: 120px;
    resize: vertical;
}

/* ========== ALERTS ========== */
.alert {
    border-radius: var(--border-radius);
    border: none;
    box-shadow: var(--shadow-sm);
    font-size: var(--font-size-base);
    padding: var(--spacing-md);
}

.alert-success {
    background: linear-gradient(135deg, #d4edda 0%, #c3e6cb 100%);
    color: #155724;
    border-left: 4px solid var(--success-color);
}

.alert-danger {
    background: linear-gradient(135deg, #f8d7da 0%, #f5c6cb 100%);
    color: #721c24;
    border-left: 4px solid var(--danger-color);
}

.alert-info {
    background: linear-gradient(135deg, #d1ecf1 0%, #bee5eb 100%);
    color: #0c5460;
    border-left: 4px solid var(--info-color);
}

/* ========== ANIMATIONS ========== */
@keyframes bounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeOut {
    from {
        opacity: 1;
        transform: translateY(0);
    }
    to {
        opacity: 0;
        transform: translateY(-20px);
    }
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

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

.animate-bounce {
    animation: bounce 0.6s ease-in-out;
}

.animate-fadeIn {
    animation: fadeIn 0.5s ease-out;
}

.animate-slideIn {
    animation: slideIn 0.5s ease-out;
}

.animate-pulse {
    animation: pulse 2s ease-in-out infinite;
}

/* ========== CATEGORY CARDS ========== */
.category-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md);
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    text-decoration: none;
    color: #333;
    transition: all 0.3s ease;
    min-height: 120px;
    border: 2px solid transparent;
}

.category-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
    text-decoration: none;
    color: #333;
}

.category-card.active {
    background: var(--gradient-primary);
    color: white;
    border-color: var(--primary-dark);
    box-shadow: var(--shadow-lg);
}

.category-card.active:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.category-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-xs);
    line-height: 1;
}

.category-name {
    font-size: 0.9rem;
    font-weight: 600;
    text-align: center;
    line-height: 1.2;
}

.category-card.active .category-name {
    color: white;
    font-weight: 700;
}

/* Responsive category cards */
@media (max-width: 575.98px) {
    .category-card {
        min-height: 100px;
        padding: var(--spacing-sm);
    }
    
    .category-icon {
        font-size: 2rem;
    }
    
    .category-name {
        font-size: 0.8rem;
    }
}

@media (min-width: 576px) and (max-width: 767.98px) {
    .category-card {
        min-height: 110px;
    }
    
    .category-icon {
        font-size: 2.2rem;
    }
}

/* ========== CONTAINER & CARDS ========== */
.container {
    padding: var(--spacing-md);
    padding-bottom: 2rem; /* Extra bottom padding */
}

main {
    flex: 1 0 auto;
    display: flex;
    flex-direction: column;
    min-height: 0;
    width: 100%;
}

/* General card styles - for forms and other cards */
.card:not(:has(.card-inner)) {
    border-radius: var(--border-radius-lg);
    border: none;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    overflow: visible !important;
    margin-bottom: var(--spacing-lg);
    height: auto !important;
    min-height: auto !important;
}

/* Hover for form cards */
.card:not(:has(.card-inner)):hover {
    box-shadow: var(--shadow-lg);
}

.card-header {
    background: var(--gradient-primary);
    color: white;
    font-weight: 700;
    font-size: var(--font-size-large);
    padding: var(--spacing-md);
    border: none;
}

.card-body {
    padding: var(--spacing-lg) !important;
    padding-bottom: var(--spacing-lg) !important;
    min-height: auto;
    overflow: visible !important;
    position: relative;
    max-height: none !important;
    height: auto !important;
    display: flex;
    flex-direction: column;
}

/* Form specific styles */
.card-body form {
    margin-bottom: 0;
    position: relative;
    z-index: 1;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.card-body .btn {
    margin-top: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
    width: 100%;
    position: relative;
    z-index: 2;
    display: block !important;
    visibility: visible !important;
    opacity: 1 !important;
    color: white !important;
    text-align: center !important;
    flex-shrink: 0;
}

/* Ensure buttons are visible */
.btn-lg {
    min-height: 52px;
    font-size: var(--font-size-base);
    font-weight: 600;
    padding: var(--spacing-sm) var(--spacing-md);
    display: inline-block !important;
    visibility: visible !important;
    opacity: 1 !important;
}

/* ========== RESPONSIVE DESIGN ========== */

/* Mobile First - Small devices (phones, 320px and up) */
@media (max-width: 575.98px) {
    :root {
        --font-size-base: 16px;
        --font-size-large: 20px;
        --font-size-xlarge: 24px;
    }
    
    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.5rem; }
    
    .card:has(.card-inner) {
        height: 220px !important;
        min-height: 220px !important;
        margin-bottom: var(--spacing-sm);
    }
    
    .card-front {
        font-size: 18px;
        padding: var(--spacing-xs);
    }
    
    .card-back {
        font-size: 14px;
        padding: 8px 4px !important;
        gap: 4px !important;
    }
    
    .card-back > div:first-child {
        font-size: 16px;
        margin-bottom: 4px;
    }
    
    .card-back .btn {
        font-size: 11px;
        padding: 6px 8px;
        margin: 2px 1px;
        white-space: normal;
        line-height: 1.2;
        min-height: 36px;
        width: 100%;
        max-width: 100%;
    }
    
    .card-back .btn i {
        font-size: 12px;
    }
    
    .card-back > div:last-child {
        width: 100%;
        display: flex;
        flex-direction: column;
        gap: 4px;
        margin-top: 4px;
    }
    
    .navbar-brand {
        font-size: 1.25rem !important;
    }
    
    .nav-link {
        font-size: 16px !important;
        padding: var(--spacing-xs) !important;
    }
    
    .container {
        padding: var(--spacing-sm);
        padding-bottom: var(--spacing-xl);
    }
    
    .btn {
        width: 100%;
        margin-bottom: var(--spacing-xs);
    }
    
    .card-body {
        padding: var(--spacing-md);
    }
    
    .card-body.p-4 {
        padding: var(--spacing-md) !important;
    }
}

/* Tablets (576px and up) */
@media (min-width: 576px) and (max-width: 991.98px) {
    .card:has(.card-inner) {
        height: 180px !important;
        min-height: 180px !important;
    }
    
    .card-front,
    .card-back {
        font-size: 20px;
    }
}

/* Desktop (992px and up) */
@media (min-width: 992px) {
    .card:has(.card-inner) {
        height: 220px !important;
        min-height: 220px !important;
    }
    
    .card-front,
    .card-back {
        font-size: 26px;
    }
    
    .container {
        max-width: 1200px;
    }
}

/* Large Desktop (1200px and up) */
@media (min-width: 1200px) {
    .card:has(.card-inner) {
        height: 240px !important;
        min-height: 240px !important;
    }
    
    .card-front,
    .card-back {
        font-size: 28px;
    }
}

/* ========== TOUCH OPTIMIZATION ========== */
@media (hover: none) and (pointer: coarse) {
    /* Touch devices */
    .card:has(.card-inner) {
        -webkit-tap-highlight-color: transparent;
    }
    
    .btn,
    .nav-link {
        min-height: 48px;
        min-width: 48px;
    }
    
    .form-control,
    .form-select {
        min-height: 52px;
        font-size: 18px; /* Prevents zoom on iOS */
    }
}

/* ========== UTILITY CLASSES ========== */
.text-gradient {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.shadow-custom {
    box-shadow: var(--shadow-lg);
}

.rounded-custom {
    border-radius: var(--border-radius-lg);
}

/* ========== LOADING STATES ========== */
.loading {
    opacity: 0.6;
    pointer-events: none;
}

.spinner-border-sm {
    width: 1rem;
    height: 1rem;
    border-width: 0.15em;
}

/* ========== FOOTER ========== */
.footer {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    margin-top: auto;
    padding: 1rem 0 !important;
    border-radius: 0;
    position: relative;
    z-index: 0;
    min-height: auto !important;
    height: auto !important;
    width: 100%;
    flex-shrink: 0;
}


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

/* Focus styles for keyboard navigation */
*:focus {
    outline: 3px solid var(--primary-color);
    outline-offset: 2px;
}

/* ========== PRINT STYLES ========== */
@media print {
    .navbar,
    .footer,
    .btn {
        display: none;
    }
    
    .card {
        break-inside: avoid;
        page-break-inside: avoid;
    }
}