/* ============================================
   LINGIVA - Modern Language Learning Platform
   Design System & Theme
   Mobile-First Approach
   ============================================ */

/* ============================================
   1. CSS VARIABLES (Design Tokens)
   ============================================ */
:root {
    /* Primary Colors - Indigo (Trust & Technology) */
    --lingiva-primary: #6366f1;
    --lingiva-primary-dark: #4f46e5;
    --lingiva-primary-light: #818cf8;
    --lingiva-primary-lighter: #c7d2fe;
    
    /* Accent Colors - Amber (Energy & Motivation) */
    --lingiva-accent: #f59e0b;
    --lingiva-accent-dark: #d97706;
    --lingiva-accent-light: #fbbf24;
    
    /* Success - Emerald (Progress & Learning) */
    --lingiva-success: #10b981;
    --lingiva-success-dark: #059669;
    
    /* Neutral Colors */
    --lingiva-dark: #1e293b;
    --lingiva-gray: #64748b;
    --lingiva-gray-light: #cbd5e1;
    --lingiva-gray-lighter: #f1f5f9;
    --lingiva-white: #ffffff;
    
    /* Gradients */
    --lingiva-gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #06b6d4 100%);
    --lingiva-gradient-warm: linear-gradient(135deg, #f59e0b 0%, #ef4444 100%);
    --lingiva-gradient-cool: linear-gradient(135deg, #06b6d4 0%, #3b82f6 100%);
    
    /* Shadows */
    --lingiva-shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --lingiva-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --lingiva-shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --lingiva-shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --lingiva-shadow-xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    
    /* Spacing */
    --lingiva-spacing-xs: 0.5rem;
    --lingiva-spacing-sm: 1rem;
    --lingiva-spacing-md: 1.5rem;
    --lingiva-spacing-lg: 2rem;
    --lingiva-spacing-xl: 3rem;
    
    /* Border Radius */
    --lingiva-radius-sm: 0.5rem;
    --lingiva-radius-md: 0.75rem;
    --lingiva-radius-lg: 1rem;
    --lingiva-radius-xl: 1.5rem;
    --lingiva-radius-full: 9999px;
    
    /* Transitions */
    --lingiva-transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ============================================
   2. GLOBAL STYLES
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    color: var(--lingiva-dark);
    background-color: var(--lingiva-gray-lighter);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   3. NAVBAR (Mobile-First)
   ============================================ */
.lingiva-navbar {
    background: var(--lingiva-gradient-primary);
    box-shadow: var(--lingiva-shadow-md);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
}

.lingiva-navbar .navbar-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--lingiva-white) !important;
    transition: var(--lingiva-transition);
}

.lingiva-navbar .navbar-brand:hover {
    transform: scale(1.05);
}

.lingiva-navbar .nav-link {
    color: rgba(255, 255, 255, 0.9) !important;
    font-weight: 500;
    padding: 0.5rem 1rem !important;
    border-radius: var(--lingiva-radius-md);
    transition: var(--lingiva-transition);
    margin: 0.25rem 0;
}

.lingiva-navbar .nav-link:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-2px);
}

.lingiva-navbar .btn-register {
    background: var(--lingiva-white) !important;
    color: var(--lingiva-primary) !important;
    font-weight: 600;
    padding: 0.5rem 1.5rem !important;
    border-radius: var(--lingiva-radius-full);
    box-shadow: var(--lingiva-shadow);
}

.lingiva-navbar .btn-register:hover {
    transform: translateY(-2px);
    box-shadow: var(--lingiva-shadow-lg);
}

/* ============================================
   4. HERO SECTION (Mobile-First)
   ============================================ */
.lingiva-hero {
    background: var(--lingiva-gradient-primary);
    color: var(--lingiva-white);
    padding: 3rem 1rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.lingiva-hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="rgba(255,255,255,0.05)" d="M0,96L48,112C96,128,192,160,288,160C384,160,480,128,576,122.7C672,117,768,139,864,138.7C960,139,1056,117,1152,101.3C1248,85,1344,75,1392,69.3L1440,64L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>') bottom center no-repeat;
    background-size: cover;
    opacity: 0.5;
}

.lingiva-hero-content {
    position: relative;
    z-index: 1;
    max-width: 900px;
    margin: 0 auto;
}

.lingiva-hero h1 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.lingiva-hero p {
    font-size: 1.125rem;
    opacity: 0.95;
    margin-bottom: 2rem;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

@media (min-width: 768px) {
    .lingiva-hero {
        padding: 5rem 2rem;
    }
    
    .lingiva-hero h1 {
        font-size: 3.5rem;
    }
    
    .lingiva-hero p {
        font-size: 1.25rem;
    }
}

/* ============================================
   5. CTA CARDS (Mobile-First)
   ============================================ */
.lingiva-cta-section {
    padding: 3rem 1rem;
}

.lingiva-cta-card {
    background: var(--lingiva-white);
    border-radius: var(--lingiva-radius-xl);
    overflow: hidden;
    box-shadow: var(--lingiva-shadow-md);
    transition: var(--lingiva-transition);
    margin-bottom: 2rem;
    height: 100%;
}

.lingiva-cta-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--lingiva-shadow-xl);
}

.lingiva-cta-image {
    height: 250px;
    width: 100%;
    object-fit: cover;
    object-position: center;
}

.lingiva-cta-content {
    padding: 2rem;
}

.lingiva-cta-title {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--lingiva-dark);
    margin-bottom: 1rem;
}

.lingiva-cta-desc {
    color: var(--lingiva-gray);
    font-size: 1rem;
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.lingiva-btn-primary {
    background: var(--lingiva-gradient-primary);
    color: var(--lingiva-white);
    border: none;
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--lingiva-radius-full);
    box-shadow: var(--lingiva-shadow);
    transition: var(--lingiva-transition);
    display: inline-block;
    text-decoration: none;
}

.lingiva-btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--lingiva-shadow-lg);
    color: var(--lingiva-white);
}

.lingiva-btn-accent {
    background: var(--lingiva-gradient-warm);
    color: var(--lingiva-white);
    border: none;
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--lingiva-radius-full);
    box-shadow: var(--lingiva-shadow);
    transition: var(--lingiva-transition);
    display: inline-block;
    text-decoration: none;
}

.lingiva-btn-accent:hover {
    transform: translateY(-2px);
    box-shadow: var(--lingiva-shadow-lg);
    color: var(--lingiva-white);
}

@media (min-width: 768px) {
    .lingiva-cta-image {
        height: 300px;
    }
    
    .lingiva-cta-content {
        padding: 2.5rem;
    }
}

/* ============================================
   5b. TITU UNIVERSITY PARTNERSHIP BANNER
   ============================================ */
.lingiva-titu-banner {
    background: var(--lingiva-white);
    border-radius: var(--lingiva-radius-xl);
    padding: 1.5rem;
    margin-top: -1.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--lingiva-shadow);
    border-left: 4px solid var(--lingiva-primary);
    transition: var(--lingiva-transition);
}

.lingiva-titu-banner:hover {
    box-shadow: var(--lingiva-shadow-md);
}

.lingiva-titu-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.lingiva-titu-logo {
    max-height: 60px;
    width: auto;
    object-fit: contain;
}

.lingiva-titu-text {
    text-align: center;
}

.lingiva-titu-desc {
    color: var(--lingiva-dark);
    font-size: 1.05rem;
    line-height: 1.7;
    margin: 0;
    font-weight: 600;
}

@media (min-width: 768px) {
    .lingiva-titu-content {
        flex-direction: row;
        justify-content: center;
        gap: 1.5rem;
    }

    .lingiva-titu-logo {
        max-height: 70px;
    }

    .lingiva-titu-text {
        text-align: left;
    }

    .lingiva-titu-desc {
        font-size: 1.2rem;
        font-weight: 600;
    }
}

/* ============================================
   6. CATEGORY FILTERS (Mobile-First)
   ============================================ */
.lingiva-filter-section {
    background: var(--lingiva-white);
    border-radius: var(--lingiva-radius-xl);
    padding: 1.5rem;
    box-shadow: var(--lingiva-shadow);
    margin-bottom: 2rem;
}

.lingiva-filter-btn {
    background: var(--lingiva-gray-lighter);
    color: var(--lingiva-dark);
    border: 2px solid transparent;
    padding: 0.625rem 1.25rem;
    font-size: 0.875rem;
    font-weight: 600;
    border-radius: var(--lingiva-radius-full);
    transition: var(--lingiva-transition);
    margin: 0.25rem;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
}

.lingiva-filter-btn .filter-icon {
    font-size: 1.1em;
    display: inline-block;
    transition: transform 0.2s ease;
}

.lingiva-filter-btn:hover {
    background: var(--lingiva-primary-lighter);
    color: var(--lingiva-primary-dark);
    transform: translateY(-2px);
}

.lingiva-filter-btn:hover .filter-icon {
    transform: scale(1.15) rotate(5deg);
}

.lingiva-filter-btn.active {
    background: var(--lingiva-gradient-primary);
    color: var(--lingiva-white);
    border-color: var(--lingiva-primary);
    box-shadow: var(--lingiva-shadow);
}

.lingiva-filter-btn.active .filter-icon {
    transform: scale(1.1);
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.2));
}

@media (min-width: 768px) {
    .lingiva-filter-btn {
        font-size: 1rem;
        padding: 0.75rem 1.5rem;
        gap: 0.625rem;
    }
    
    .lingiva-filter-btn .filter-icon {
        font-size: 1.2em;
    }
}

/* ============================================
   7. TEACHER CARDS (Mobile-First)
   ============================================ */
.lingiva-teacher-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    padding: 1rem 0;
}

@media (min-width: 640px) {
    .lingiva-teacher-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .lingiva-teacher-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

.lingiva-teacher-card {
    background: var(--lingiva-white);
    border-radius: var(--lingiva-radius-xl);
    overflow: hidden;
    box-shadow: var(--lingiva-shadow);
    transition: var(--lingiva-transition);
    display: flex;
    flex-direction: column;
    height: 100%;
}

.lingiva-teacher-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--lingiva-shadow-xl);
}

.lingiva-teacher-photo {
    width: 100%;
    height: 250px;
    object-fit: cover;
    object-position: center top;
}

.lingiva-teacher-content {
    padding: 1.5rem;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.lingiva-teacher-name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--lingiva-dark);
    margin-bottom: 0.5rem;
}

.lingiva-teacher-rating {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.75rem;
}

.lingiva-star {
    color: var(--lingiva-accent);
    font-size: 1.25rem;
}

.lingiva-teacher-stats {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
    font-size: 0.875rem;
    color: var(--lingiva-gray);
}

.lingiva-teacher-languages {
    margin-bottom: 1rem;
}

.lingiva-lang-badge {
    display: inline-block;
    background: var(--lingiva-primary-lighter);
    color: var(--lingiva-primary-dark);
    padding: 0.25rem 0.75rem;
    border-radius: var(--lingiva-radius-full);
    font-size: 0.75rem;
    font-weight: 600;
    margin: 0.25rem;
}

.lingiva-teacher-bio {
    color: var(--lingiva-gray);
    font-size: 0.875rem;
    line-height: 1.6;
    margin-bottom: 1rem;
    flex: 1;
}

.lingiva-teacher-price {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--lingiva-success);
    margin-bottom: 1rem;
}

.lingiva-teacher-actions {
    display: flex;
    gap: 0.75rem;
}

.lingiva-btn-view {
    flex: 1;
    background: var(--lingiva-gradient-cool);
    color: var(--lingiva-white);
    border: none;
    padding: 0.75rem 1.5rem;
    font-size: 0.875rem;
    font-weight: 600;
    border-radius: var(--lingiva-radius-md);
    transition: var(--lingiva-transition);
    text-align: center;
    text-decoration: none;
}

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

.lingiva-btn-book {
    flex: 1;
    background: var(--lingiva-gradient-warm);
    color: var(--lingiva-white);
    border: none;
    padding: 0.75rem 1.5rem;
    font-size: 0.875rem;
    font-weight: 600;
    border-radius: var(--lingiva-radius-md);
    transition: var(--lingiva-transition);
    text-align: center;
    text-decoration: none;
}

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

/* ============================================
   8. FOOTER (Mobile-First)
   ============================================ */
.lingiva-footer {
    background: var(--lingiva-dark);
    color: rgba(255, 255, 255, 0.8);
    padding: 2rem 1rem;
    margin-top: 4rem;
}

.lingiva-footer-content {
    max-width: 1200px;
    margin: 0 auto;
    text-align: center;
}

/* ============================================
   9. UTILITY CLASSES
   ============================================ */
.lingiva-section {
    padding: 3rem 1rem;
}

/* Teachers section - less top space for Titu banner */
#teachers.lingiva-section {
    padding-top: 1rem;
}

@media (min-width: 768px) {
    .lingiva-section {
        padding: 4rem 2rem;
    }

    #teachers.lingiva-section {
        padding-top: 1.5rem;
    }
}

.lingiva-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1rem;
}

.lingiva-heading {
    font-size: 2rem;
    font-weight: 700;
    color: var(--lingiva-dark);
    margin-bottom: 2rem;
    text-align: center;
}

@media (min-width: 768px) {
    .lingiva-heading {
        font-size: 2.5rem;
    }
}

/* ============================================
   10. ANIMATIONS
   ============================================ */
@keyframes lingiva-fade-in {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.lingiva-fade-in {
    animation: lingiva-fade-in 0.6s ease-out;
}

/* ============================================
   11. ACCESSIBILITY
   ============================================ */
.lingiva-btn-primary:focus,
.lingiva-btn-accent:focus,
.lingiva-btn-view:focus,
.lingiva-btn-book:focus,
.lingiva-filter-btn:focus {
    outline: 3px solid var(--lingiva-accent);
    outline-offset: 2px;
}

/* ============================================
   12. LANGUAGE SWITCHER (Modern)
   ============================================ */
.lingiva-lang-switcher {
    position: relative;
}

.lingiva-lang-btn {
    background: rgba(255, 255, 255, 0.15);
    border: 2px solid rgba(255, 255, 255, 0.2);
    color: var(--lingiva-white);
    padding: 0.5rem 1rem;
    border-radius: var(--lingiva-radius-full);
    font-weight: 600;
    font-size: 0.875rem;
    transition: var(--lingiva-transition);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    backdrop-filter: blur(10px);
}

.lingiva-lang-btn:hover {
    background: rgba(255, 255, 255, 0.25);
    border-color: rgba(255, 255, 255, 0.4);
    transform: translateY(-2px);
}

.lingiva-lang-dropdown {
    position: absolute;
    top: calc(100% + 0.5rem);
    right: 0;
    background: var(--lingiva-white);
    border-radius: var(--lingiva-radius-md);
    box-shadow: var(--lingiva-shadow-xl);
    min-width: 180px;
    overflow: hidden;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--lingiva-transition);
    z-index: 1000;
}

.lingiva-lang-switcher:hover .lingiva-lang-dropdown,
.lingiva-lang-dropdown:hover {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.lingiva-lang-option {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.875rem 1.25rem;
    margin: 0.25rem 0.5rem;
    color: var(--lingiva-dark);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.875rem;
    transition: var(--lingiva-transition);
    border-radius: var(--lingiva-radius-md);
    border: 2px solid transparent;
}

.lingiva-lang-option:hover {
    background: var(--lingiva-gray-lighter);
    border-color: var(--lingiva-primary);
    color: var(--lingiva-primary);
    transform: translateX(4px);
}

.lingiva-lang-option.active {
    background: var(--lingiva-primary-lighter);
    color: var(--lingiva-primary-dark);
    border-color: var(--lingiva-primary);
    font-weight: 600;
}

.lingiva-lang-flag {
    font-size: 1.25rem;
    line-height: 1;
}

@media (max-width: 991px) {
    .lingiva-lang-switcher {
        width: 100%;
    }
    
    .lingiva-lang-btn {
        width: 100%;
        justify-content: center;
    }
    
    .lingiva-lang-dropdown {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
        margin-top: 0.5rem;
        box-shadow: none;
        border: 1px solid var(--lingiva-gray-light);
    }
}

/* ============================================
   END OF LINGIVA THEME
   Design by Nexus - 2025
   ============================================ */