/* ===== 1. CSS Custom Properties ===== */
:root,
[data-bs-theme="light"] {
    --btw-primary: #4f46e5;
    --btw-primary-hover: #4338ca;
    --btw-gradient-start: #667eea;
    --btw-gradient-end: #764ba2;
    --btw-hero-bg: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --btw-card-shadow: 0 1px 3px rgba(0, 0, 0, 0.06), 0 6px 16px rgba(0, 0, 0, 0.06);
    --btw-card-shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.1), 0 12px 28px rgba(0, 0, 0, 0.08);
    --btw-nav-bg: rgba(255, 255, 255, 0.95);
    --btw-nav-border: rgba(0, 0, 0, 0.06);
    --btw-footer-bg: #f8f9fa;
    --btw-skeleton-bg: #e9ecef;
    --btw-skeleton-shine: #f8f9fa;
    --btw-score-bg: #f0f4ff;
    --btw-valid-color: #059669;
    --btw-invalid-color: #dc2626;
    --btw-warning-color: #d97706;
    --btw-border-radius: 12px;
    --btw-transition: all 0.2s ease;
    --btw-nav-hover-bg: rgba(79, 70, 229, 0.08);
    --btw-feature-icon-bg: rgba(79, 70, 229, 0.1);
    --btw-focus-ring: rgba(79, 70, 229, 0.15);
    --btw-focus-ring-subtle: rgba(79, 70, 229, 0.1);
    --btw-selection-bg: rgba(79, 70, 229, 0.2);
    --btw-palette-hover-bg: rgba(79, 70, 229, 0.08);
}

[data-bs-theme="dark"] {
    --btw-gradient-start: #4a5cd8;
    --btw-gradient-end: #5e3d8a;
    --btw-hero-bg: linear-gradient(135deg, #2d3561 0%, #3d2652 100%);
    --btw-card-shadow: 0 1px 3px rgba(0, 0, 0, 0.2), 0 6px 16px rgba(0, 0, 0, 0.15);
    --btw-card-shadow-hover: 0 4px 12px rgba(0, 0, 0, 0.25), 0 12px 28px rgba(0, 0, 0, 0.2);
    --btw-nav-bg: rgba(33, 37, 41, 0.95);
    --btw-nav-border: rgba(255, 255, 255, 0.08);
    --btw-footer-bg: #1a1d23;
    --btw-skeleton-bg: #2d3238;
    --btw-skeleton-shine: #3d4450;
    --btw-score-bg: #1e2235;
    --btw-valid-color: #34d399;
    --btw-invalid-color: #f87171;
    --btw-warning-color: #fbbf24;
    --btw-nav-hover-bg: rgba(79, 70, 229, 0.12);
    --btw-feature-icon-bg: rgba(79, 70, 229, 0.15);
    --btw-focus-ring: rgba(79, 70, 229, 0.2);
    --btw-focus-ring-subtle: rgba(79, 70, 229, 0.15);
    --btw-selection-bg: rgba(79, 70, 229, 0.3);
    --btw-palette-hover-bg: rgba(79, 70, 229, 0.12);
}

/* ===== 2. Typography ===== */
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-feature-settings: 'cv02', 'cv03', 'cv04', 'cv11';
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    letter-spacing: -0.02em;
}

.display-1, .display-2, .display-3, .display-4 {
    font-weight: 800;
    letter-spacing: -0.03em;
}

/* ===== 3. Navigation ===== */
.btw-navbar {
    background: var(--btw-nav-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--btw-nav-border);
    padding: 0.6rem 0;
    transition: var(--btw-transition);
}

.btw-navbar .navbar-brand {
    font-size: 1.25rem;
    letter-spacing: -0.02em;
}

.btw-navbar .nav-link {
    font-weight: 500;
    font-size: 0.9rem;
    padding: 0.5rem 0.85rem;
    border-radius: 8px;
    transition: var(--btw-transition);
}

.btw-navbar .nav-link:hover,
.btw-navbar .nav-link.active {
    background: var(--btw-nav-hover-bg);
    color: var(--btw-primary);
}

kbd {
    font-family: 'Inter', sans-serif;
    font-size: 0.7rem;
    padding: 2px 6px;
    border-radius: 4px;
    font-weight: 500;
}

/* ===== 4. Hero Section ===== */
.btw-hero {
    background: var(--btw-hero-bg);
    padding: 5rem 0 4rem;
    position: relative;
    overflow: hidden;
    color: #fff;
}

.btw-hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 600px;
    height: 600px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.05);
}

.btw-hero::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 400px;
    height: 400px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.03);
}

.btw-hero h1 {
    font-size: 2.75rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    line-height: 1.1;
}

.btw-hero .lead {
    font-size: 1.15rem;
    opacity: 0.9;
    font-weight: 400;
}

@media (max-width: 768px) {
    .btw-hero {
        padding: 3rem 0 2.5rem;
    }
    .btw-hero h1 {
        font-size: 1.85rem;
    }
}

/* ===== 5. Search Box ===== */
.btw-search-box {
    background: rgba(255, 255, 255, 0.12);
    backdrop-filter: blur(10px);
    border-radius: var(--btw-border-radius);
    padding: 1.5rem;
    border: 1px solid rgba(255, 255, 255, 0.15);
}

.btw-search-box .form-control,
.btw-search-box .form-select {
    border-radius: 10px;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    border: 2px solid transparent;
    transition: var(--btw-transition);
}

.btw-search-box .form-control:focus,
.btw-search-box .form-select:focus {
    border-color: var(--btw-primary);
    box-shadow: 0 0 0 3px var(--btw-focus-ring);
}

.btw-search-box .btn-check-vat {
    padding: 0.75rem 2rem;
    font-weight: 600;
    border-radius: 10px;
    font-size: 1rem;
    background: #fff;
    color: var(--btw-primary);
    border: none;
    transition: var(--btw-transition);
}

.btw-search-box .btn-check-vat:hover {
    background: #f0f0ff;
    transform: translateY(-1px);
}

/* ===== 6. Cards ===== */
.btw-card {
    background: var(--bs-body-bg);
    border: 1px solid var(--bs-border-color);
    border-radius: var(--btw-border-radius);
    box-shadow: var(--btw-card-shadow);
    transition: var(--btw-transition);
    overflow: hidden;
}

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

.btw-card .card-body {
    padding: 1.5rem;
}

.btw-feature-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    background: var(--btw-feature-icon-bg);
    color: var(--btw-primary);
    margin-bottom: 1rem;
}

/* ===== 7. Steps Section ===== */
.btw-step-number {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1rem;
    background: var(--btw-primary);
    color: #fff;
    margin-bottom: 1rem;
}

/* ===== 8. Trust Badges ===== */
.btw-trust-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.4rem 0.85rem;
    border-radius: 50px;
    font-size: 0.8rem;
    font-weight: 500;
    background: rgba(255, 255, 255, 0.15);
    color: #fff;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

/* ===== 9. Result Card ===== */
.btw-result-card {
    border-radius: var(--btw-border-radius);
    box-shadow: var(--btw-card-shadow);
    overflow: hidden;
    border: 1px solid var(--bs-border-color);
}

.btw-result-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--bs-border-color);
}

.btw-status-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.5rem 1rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.9rem;
}

.btw-status-badge.valid {
    background: rgba(5, 150, 105, 0.1);
    color: var(--btw-valid-color);
    border: 1px solid rgba(5, 150, 105, 0.2);
}

.btw-status-badge.invalid {
    background: rgba(220, 38, 38, 0.1);
    color: var(--btw-invalid-color);
    border: 1px solid rgba(220, 38, 38, 0.2);
}

.btw-status-badge.unavailable {
    background: rgba(217, 119, 6, 0.1);
    color: var(--btw-warning-color);
    border: 1px solid rgba(217, 119, 6, 0.2);
}

/* ===== 10. Trust Score ===== */
.btw-trust-score {
    background: var(--btw-score-bg);
    border-radius: var(--btw-border-radius);
    padding: 1.5rem;
}

.btw-score-circle {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    font-weight: 800;
    margin: 0 auto;
    position: relative;
    background: var(--bs-body-bg);
    box-shadow: var(--btw-card-shadow);
}

.btw-score-bar {
    height: 8px;
    border-radius: 4px;
    background: var(--bs-border-color);
    overflow: hidden;
}

.btw-score-bar-fill {
    height: 100%;
    border-radius: 4px;
    transition: width 1.5s ease-out;
    background: linear-gradient(90deg, var(--btw-gradient-start), var(--btw-gradient-end));
}

/* ===== 11. Skeleton Loaders ===== */
.skeleton {
    background: var(--btw-skeleton-bg);
    border-radius: 6px;
    position: relative;
    overflow: hidden;
}

.skeleton::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(
        90deg,
        transparent,
        var(--btw-skeleton-shine),
        transparent
    );
    animation: shimmer 1.5s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.skeleton-text {
    height: 16px;
    margin-bottom: 8px;
}

.skeleton-title {
    height: 24px;
    width: 60%;
    margin-bottom: 12px;
}

.skeleton-badge {
    height: 32px;
    width: 100px;
    border-radius: 50px;
}

.skeleton-circle {
    width: 100px;
    height: 100px;
    border-radius: 50%;
}

/* ===== 12. Toast Notifications ===== */
.btw-toast {
    border-radius: 10px;
    box-shadow: var(--btw-card-shadow-hover);
    border: none;
    animation: slideInRight 0.3s ease;
}

@keyframes slideInRight {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

/* ===== 13. Command Palette ===== */
.btw-command-palette {
    border-radius: var(--btw-border-radius);
    box-shadow: var(--btw-card-shadow-hover);
    border: 1px solid var(--bs-border-color);
    overflow: hidden;
}

.btw-command-palette .list-group-item {
    border: none;
    padding: 0.75rem 1.25rem;
    transition: var(--btw-transition);
    cursor: pointer;
}

.btw-command-palette .list-group-item:hover,
.btw-command-palette .list-group-item.active {
    background: var(--btw-palette-hover-bg);
}

.btw-command-palette .list-group-item .bi {
    width: 24px;
    text-align: center;
    margin-right: 0.75rem;
    opacity: 0.5;
}

/* ===== 14. Footer ===== */
.btw-footer {
    background: var(--btw-footer-bg);
    border-top: 1px solid var(--bs-border-color);
}

.btw-footer a:hover {
    color: var(--btw-primary) !important;
}

/* ===== 15. Section Styling ===== */
.btw-section {
    padding: 4rem 0;
}

.btw-section-alt {
    background: var(--btw-footer-bg);
}

.btw-section-title {
    font-size: 2rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    margin-bottom: 0.75rem;
}

.btw-section-subtitle {
    font-size: 1.1rem;
    color: var(--bs-secondary-color);
    max-width: 600px;
    margin: 0 auto;
}

/* ===== 16. Form Styling ===== */
.btw-form .form-control,
.btw-form .form-select {
    border-radius: 10px;
    padding: 0.7rem 1rem;
    transition: var(--btw-transition);
    border: 2px solid var(--bs-border-color);
}

.btw-form .form-control:focus,
.btw-form .form-select:focus {
    border-color: var(--btw-primary);
    box-shadow: 0 0 0 3px var(--btw-focus-ring-subtle);
}

.btw-form .form-label {
    font-weight: 500;
    font-size: 0.9rem;
    margin-bottom: 0.4rem;
}

/* ===== 17. Tool Cards ===== */
.btw-tool-card {
    text-decoration: none;
    color: inherit;
    display: block;
}

.btw-tool-card:hover {
    color: inherit;
}

.btw-tool-card:hover .btw-card {
    border-color: var(--btw-primary);
}

/* ===== 18. Table Styling ===== */
.btw-table {
    border-radius: var(--btw-border-radius);
    overflow: hidden;
    box-shadow: var(--btw-card-shadow);
}

.btw-table th {
    font-weight: 600;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 0.85rem 1rem;
}

.btw-table td {
    padding: 0.75rem 1rem;
    vertical-align: middle;
}

/* ===== 19. Breadcrumbs ===== */
.btw-breadcrumb {
    padding: 0.75rem 0;
    font-size: 0.85rem;
}

.btw-breadcrumb .breadcrumb-item a {
    text-decoration: none;
    color: var(--bs-secondary-color);
}

.btw-breadcrumb .breadcrumb-item a:hover {
    color: var(--btw-primary);
}

/* ===== 20. Animations ===== */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.btw-pulse {
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { opacity: 1; }
    50% { opacity: 0.5; }
    100% { opacity: 1; }
}

/* ===== 21. CTA Section ===== */
.btw-cta {
    background: var(--btw-hero-bg);
    color: #fff;
    border-radius: var(--btw-border-radius);
    padding: 3rem;
    position: relative;
    overflow: hidden;
}

.btw-cta::before {
    content: '';
    position: absolute;
    top: -30%;
    right: -10%;
    width: 300px;
    height: 300px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.06);
}

/* ===== 22. Admin Dashboard ===== */
.btw-stat-card {
    border-radius: var(--btw-border-radius);
    padding: 1.25rem;
    border: 1px solid var(--bs-border-color);
    background: var(--bs-body-bg);
}

.btw-stat-card .stat-value {
    font-size: 2rem;
    font-weight: 800;
    letter-spacing: -0.02em;
}

.btw-stat-card .stat-label {
    font-size: 0.8rem;
    color: var(--bs-secondary-color);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 600;
}

/* ===== 23. Responsive ===== */
@media (max-width: 576px) {
    .btw-section {
        padding: 2.5rem 0;
    }

    .btw-section-title {
        font-size: 1.5rem;
    }

    .btw-card .card-body {
        padding: 1.25rem;
    }

    .btw-cta {
        padding: 2rem 1.5rem;
    }

    .btw-search-box {
        padding: 1rem;
    }
}

/* ===== 24. Print ===== */
@media print {
    .btw-navbar,
    .btw-footer,
    .toast-container,
    #commandPalette {
        display: none !important;
    }
}

/* ===== 25. Misc ===== */
.cursor-pointer {
    cursor: pointer;
}

.btw-divider {
    height: 3px;
    width: 50px;
    background: var(--btw-primary);
    border-radius: 2px;
    margin: 1rem 0;
}

.btw-gradient-text {
    background: linear-gradient(135deg, var(--btw-gradient-start), var(--btw-gradient-end));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Country flag emoji size */
.country-flag {
    font-size: 1.25em;
    line-height: 1;
}

/* Smooth scroll */
html {
    scroll-behavior: smooth;
}

/* Focus visible for accessibility */
:focus-visible {
    outline: 2px solid var(--btw-primary);
    outline-offset: 2px;
}

/* Selection color */
::selection {
    background: var(--btw-selection-bg);
}