/* CSS Variables for Color Palette */
:root {
    --primary-color: #05386B;
    --secondary-color: #379683;
    --accent-color: #5CDB95;
    --light-accent: #8EE4AF;
    --background-color: #EDF5E1;
    --white: #ffffff;
    --text-dark: #2c3e50;
    --text-light: #6c757d;
    --border-color: #dee2e6;
    --shadow-light: rgba(5, 56, 107, 0.1);
    --shadow-medium: rgba(5, 56, 107, 0.2);
    --shadow-heavy: rgba(5, 56, 107, 0.3);
    --gradient-primary: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    --gradient-accent: linear-gradient(135deg, var(--accent-color), var(--light-accent));
    --border-radius: 12px;
    --border-radius-lg: 20px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--background-color);
    color: var(--text-dark);
    line-height: 1.6;
    overflow-x: hidden;
}

html {
    scroll-behavior: smooth;
    overflow-x: hidden;
  
    background-color: #05386B;
}

body.high-contrast {
    background: #000 !important;
    color: #fff !important;
}
body.high-contrast .header,
body.high-contrast .converter-card,
body.high-contrast .quick-conversions,
body.high-contrast .history-container,
body.high-contrast .footer {
    background: #111 !important;
    color: #fff !important;
    border-color: #fff !important;
}
body.high-contrast .form-label,
body.high-contrast .result-card__title,
body.high-contrast .quick-conversions__title,
body.high-contrast .history-title {
    color: #FFD600 !important;
}
body.high-contrast .btn,
body.high-contrast .btn-outline-primary,
body.high-contrast .btn-outline-light,
body.high-contrast .btn-outline-success,
body.high-contrast .btn-outline-danger,
body.high-contrast .btn-outline-secondary {
    background: #222 !important;
    color: #FFD600 !important;
    border-color: #FFD600 !important;
}
body.high-contrast .btn:hover {
    background: #FFD600 !important;
    color: #222 !important;
}
.font-size-xs { font-size: 0.95em !important; }
.font-size-sm { font-size: 1.05em !important; }
.font-size-md { font-size: 1.15em !important; }
.font-size-lg { font-size: 1.25em !important; }
.font-size-xl { font-size: 1.35em !important; }

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

p {
    margin-bottom: 1rem;
    color: var(--text-light);
}

/* Header Styles */
.header {
    background: var(--gradient-primary);
    color: var(--white);
    padding: 2rem 0;
    position: relative;
    overflow: hidden;
}

.header::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 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="25" cy="25" r="1" fill="rgba(255,255,255,0.1)"/><circle cx="75" cy="75" r="1" fill="rgba(255,255,255,0.1)"/><circle cx="50" cy="10" r="0.5" fill="rgba(255,255,255,0.05)"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    pointer-events: none;
}

.header__title {
    font-size: 3rem;
    font-weight: 900;
    margin-bottom: 0.5rem;
    color: #fff;
    text-shadow: 0 3px 12px rgba(5, 56, 107, 0.45), 0 1px 0 #222;
    letter-spacing: 1px;
    position: relative;
    z-index: 1;
}

.header__title i {
    margin-right: 1rem;
    animation: bounce 2s infinite;
    color: #FFD600;
}

.header__subtitle {
    font-size: 1.2rem;
    opacity: 0.98;
    margin-bottom: 0;
    position: relative;
    z-index: 1;
    color: #fff;
    font-weight: 600;
    letter-spacing: 0.03em;
    text-shadow: 0 2px 8px rgba(0,0,0,0.22);
}

.language-selector {
    position: relative;
    z-index: 1;
}

/* Main Content */
.main-content {
    padding: 4rem 0;
    min-height: calc(100vh - 200px);
}

/* Converter Card */
.converter-card {
    background: var(--white);
    border-radius: var(--border-radius-lg);
    box-shadow: 0 20px 40px var(--shadow-light);
    padding: 3rem;
    margin-bottom: 2rem;
    position: relative;
    overflow: hidden;
    border: 3px solid var(--accent-color);
}

.converter-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 6px;
    background: var(--gradient-accent);
}

.converter-card__header {
    text-align: center;
    margin-bottom: 3rem;
    position: relative;
}

.converter-card__title {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    position: relative;
}

.converter-card__title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: var(--gradient-accent);
    border-radius: 2px;
}

.converter-card__description {
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 0;
}

/* Form Styles */
.converter-form {
    position: relative;
}

.form-group {
    margin-bottom: 2rem;
    position: relative;
}

.form-label {
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.8rem;
    display: flex;
    align-items: center;
    font-size: 1.1rem;
}

.form-label i {
    margin-right: 0.5rem;
    color: var(--secondary-color);
}

.form-control,
.form-select {
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1rem 1.25rem;
    font-size: 1.1rem;
    transition: var(--transition);
    background: var(--white);
}

.form-control:focus,
.form-select:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 0.25rem rgba(92, 219, 149, 0.25);
    background: var(--white);
}

.input-group-text {
    background: var(--accent-color);
    border: 2px solid var(--accent-color);
    color: var(--primary-color);
    font-weight: 600;
}

/* Button Styles */
.btn {
    border-radius: var(--border-radius);
    font-weight: 600;
    transition: var(--transition);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

.btn:hover::before {
    left: 100%;
}

.btn-primary {
    background: var(--gradient-primary);
    border: none;
    color: var(--white);
    padding: 1rem 2rem;
    font-size: 1.1rem;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(5, 56, 107, 0.3);
}

.btn-convert {
    width: 100%;
    padding: 1.25rem;
    font-size: 1.2rem;
    font-weight: 700;
}

.btn-swap {
    padding: 0.75rem 1.5rem;
    border: 2px solid var(--secondary-color);
    color: var(--secondary-color);
    background: transparent;
}

.btn-swap:hover {
    background: var(--secondary-color);
    color: var(--white);
    transform: rotate(180deg);
}

/* Result Styles */
.result-container {
    margin-top: 3rem;
    animation: slideInUp 0.5s ease-out;
}

.result-card {
    background: var(--gradient-accent);
    border-radius: var(--border-radius-lg);
    padding: 2.5rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.result-card::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
    animation: shimmer 3s infinite;
}

.result-card__title {
    color: var(--primary-color);
    font-size: 1.8rem;
    margin-bottom: 2rem;
    position: relative;
    z-index: 1;
}

.result-display {
    margin-bottom: 2rem;
    position: relative;
    z-index: 1;
}

.result-value {
    font-size: 2.5rem;
    font-weight: 900;
    color: var(--primary-color);
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}

.result-formula {
    font-size: 1.2rem;
    color: var(--text-light);
    font-style: italic;
}

.result-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    position: relative;
    z-index: 1;
}

/* Quick Conversions */
.quick-conversions {
    background: var(--white);
    border-radius: var(--border-radius-lg);
    padding: 2.5rem;
    box-shadow: 0 10px 30px var(--shadow-light);
    border: 2px solid var(--light-accent);
}

.quick-conversions__title {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 2rem;
    color: var(--primary-color);
}

.quick-conversion-btn {
    width: 100%;
    padding: 1rem;
    margin-bottom: 1rem;
    background: var(--white);
    border: 2px solid var(--accent-color);
    color: var(--primary-color);
    border-radius: var(--border-radius);
    transition: var(--transition);
    font-weight: 600;
}

.quick-conversion-btn:hover {
    background: var(--accent-color);
    color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(92, 219, 149, 0.3);
}

/* History Styles */
.history-container {
    background: var(--white);
    border-radius: var(--border-radius-lg);
    padding: 2.5rem;
    box-shadow: 0 10px 30px var(--shadow-light);
    border: 2px solid var(--secondary-color);
}

.history-title {
    color: var(--primary-color);
    font-size: 2rem;
}

.history-item {
    background: var(--background-color);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin-bottom: 1rem;
    border-left: 4px solid var(--accent-color);
    transition: var(--transition);
    position: relative;
}

.history-item:hover {
    transform: translateX(5px);
    box-shadow: 0 5px 15px var(--shadow-light);
}

.history-item__content {
    font-size: 1.1rem;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.history-item__time {
    font-size: 0.9rem;
    color: var(--text-light);
    font-style: italic;
}

.history-item__actions {
    position: absolute;
    top: 1rem;
    right: 1rem;
}

/* Footer */
.footer {
    background: var(--gradient-primary);
    color: var(--white);
    padding: 2rem 0 1rem 0;
    text-align: center;
}
.footer__text, .footer__credit {
    text-align: center;
    margin-bottom: 0.5rem;
    width: 100%;
    display: block;
    color: #fff;
    font-size: 1.05rem;
    font-weight: 600;
    letter-spacing: 0.02em;
    text-shadow: 0 2px 8px rgba(0,0,0,0.25);
    line-height: 1.7;
}
.footer__credit a {
    color: #FFD600;
    text-decoration: underline;
    font-weight: 700;
    text-shadow: 0 1px 4px rgba(0,0,0,0.18);
}
.footer__credit a:hover {
    color: #fff700;
    text-decoration: underline;
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.loading-spinner {
    text-align: center;
    color: var(--white);
}

.loading-spinner i {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: var(--accent-color);
}

/* Toast Styles */
.toast {
    border-radius: var(--border-radius);
    border: none;
    box-shadow: 0 10px 30px var(--shadow-medium);
}

.toast-success {
    background: var(--accent-color);
    color: var(--primary-color);
}

.toast-error {
    background: #dc3545;
    color: var(--white);
}

/* Alert Styles */
.alert {
    border-radius: var(--border-radius);
    border: none;
    padding: 1.5rem;
    margin-top: 2rem;
}

.alert-danger {
    background: linear-gradient(135deg, #dc3545, #c82333);
    color: var(--white);
}

.alert-success {
    background: #e8f5e9;
    color: #2e7d32;
    border: 2px solid #2e7d32;
}

/* Animations */
@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-10px);
    }
    60% {
        transform: translateY(-5px);
    }
}

@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes shimmer {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .header__title {
        font-size: 2.5rem;
    }
    
    .header__subtitle {
        font-size: 1rem;
    }
    
    .converter-card {
        padding: 2rem 1.5rem;
        margin: 1rem;
    }
    
    .converter-card__title {
        font-size: 2rem;
    }
    
    .result-value {
        font-size: 2rem;
    }
    
    .quick-conversions,
    .history-container {
        padding: 2rem 1.5rem;
        margin: 1rem;
    }
    
    .result-actions {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .btn-swap {
        padding: 0.5rem 1rem;
        font-size: 0.9rem;
    }
}

@media (max-width: 767.98px) {
    .header {
        padding: 1.2rem 0;
    }
    .header__title {
        font-size: 2rem;
    }
    .main-content {
        padding: 1.5rem 0;
    }
    .converter-card, .quick-conversions, .history-container {
        padding: 1.2rem;
    }
    .converter-card__title, .quick-conversions__title, .history-title {
        font-size: 1.3rem;
    }
    .result-value {
        font-size: 1.5rem;
    }
    .result-card__title {
        font-size: 1.2rem;
    }
    .form-label {
        font-size: 1rem;
    }
    .quick-conversion-btn {
        padding: 0.7rem;
        font-size: 1em;
    }
    .footer__text, .footer__credit {
        text-align: center;
        justify-content: center;
    }
    .footer .row {
        flex-direction: column;
        align-items: center;
    }
}

@media (max-width: 576px) {
    .header {
        padding: 1.5rem 0;
    }
    
    .header__title {
        font-size: 2rem;
    }
    
    .main-content {
        padding: 2rem 0;
    }
    
    .converter-card {
        padding: 1.5rem 1rem;
    }
    
    .converter-card__title {
        font-size: 1.8rem;
    }
    
    .form-control,
    .form-select {
        padding: 0.75rem 1rem;
        font-size: 1rem;
    }
    
    .btn-convert {
        padding: 1rem;
        font-size: 1.1rem;
    }
    
    .result-value {
        font-size: 1.8rem;
    }
    
    .quick-conversions__title,
    .history-title {
        font-size: 1.5rem;
    }
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
    :root {
        --shadow-light: rgba(0, 0, 0, 0.5);
        --shadow-medium: rgba(0, 0, 0, 0.7);
        --shadow-heavy: rgba(0, 0, 0, 0.9);
    }
    
    .form-control,
    .form-select {
        border-width: 3px;
    }
    
    .btn {
        border-width: 2px;
    }
}

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

/* Print Styles */
@media print {
    .header,
    .footer,
    .btn,
    .loading-overlay {
        display: none !important;
    }
    
    .converter-card,
    .result-card {
        box-shadow: none;
        border: 2px solid var(--text-dark);
    }
    
    body {
        background: var(--white);
    }
}

/* Focus Styles for Accessibility */
.form-control:focus,
.form-select:focus,
.btn:focus {
    outline: 3px solid var(--accent-color);
    outline-offset: 2px;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--background-color);
}

::-webkit-scrollbar-thumb {
    background: var(--secondary-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-color);
}