:root {
    --font-family: 'Segoe UI', system-ui, -apple-system, BlinkMacSystemFont, 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    --primary-color: #007bff;
    --primary-color-hover: #0056b3;
    --text-color: #212529;
    --background-color: #f8f9fa;
    --container-background: #ffffff;
    --input-background: #ffffff;
    --input-border-color: #ced4da;
    --table-border-color: #dee2e6;
    --table-header-background: #007bff;
    --table-header-color: #ffffff;
    --table-even-row-background: #f8f9fa;
    --box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.15);
    --button-text-color: #ffffff;
    --lang-btn-hover-border: #6c757d;
    --slider-background: #ced4da;
    --slider-foreground: #ffffff;
    --icon-color: #6c757d;
    --help-text-background: #e9ecef;
    --help-text-border: #ced4da;
}

body.dark-mode {
    --primary-color: #0d6efd;
    --primary-color-hover: #0a58ca;
    --text-color: #dee2e6;
    --background-color: #121212;
    --container-background: #1e1e1e;
    --input-background: #2a2a2a;
    --input-border-color: #495057;
    --table-border-color: #495057;
    --table-header-background: #0d6efd;
    --table-header-color: #ffffff;
    --table-even-row-background: #2a2a2a;
    --box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.5);
    --lang-btn-hover-background: #343a40;
    --icon-color: #adb5bd;
    --help-text-background: #343a40;
    --help-text-border: #495057;
}

/* Header */
header {
    background-color: var(--container-background);
    box-shadow: var(--box-shadow);
    padding: 1rem 2rem;
    width: 100%;
    z-index: 1000;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
}

.main-title {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--primary-color);
    margin: 0;
}

.header-controls {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

/* Theme Switch */
.theme-switch-wrapper {
    display: flex;
    align-items: center;
    flex-direction: column;
}

.theme-toggle-label {
    font-size: 0.75rem;
    margin-top: 4px;
    color: var(--text-color);
}

.theme-switch {
    display: inline-block;
    height: 34px;
    position: relative;
    width: 60px;
}

.theme-switch {
    display: inline-block;
    height: 34px;
    position: relative;
    width: 60px;
}

.theme-switch input {
    display: none;
}

.slider {
    background-color: var(--slider-background);
    bottom: 0;
    cursor: pointer;
    left: 0;
    position: absolute;
    right: 0;
    top: 0;
    transition: .4s;
    border-radius: 34px;
}

.slider:before {
    background-color: var(--slider-foreground);
    bottom: 4px;
    content: "";
    height: 26px;
    left: 4px;
    position: absolute;
    transition: .4s;
    width: 26px;
    border-radius: 50%;
    z-index: 1;
}

.sun-icon, .moon-icon {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    color: var(--icon-color);
    transition: opacity 0.4s;
}

.sun-icon {
    left: 8px;
    opacity: 0;
}

.moon-icon {
    right: 8px;
    opacity: 1;
}

input:checked + .slider {
    background-color: var(--primary-color);
}

input:checked + .slider:before {
    transform: translateX(26px);
}

input:checked + .slider .sun-icon {
    opacity: 1;
}

input:checked + .slider .moon-icon {
    opacity: 0;
}

/* Language Switcher */
.language-switcher {
    display: flex;
    align-items: center;
}

.lang-btn {
    cursor: pointer;
    border: none;
    background: none;
    padding: 0;
    margin-left: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;
    transition: background-color 0.3s, transform 0.1s;
}

.lang-btn:active {
    transform: scale(0.95);
}

.lang-btn img {
    width: 30px;
    height: 30px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid transparent;
    transition: border-color 0.3s;
}

.lang-btn:hover img {
    border-color: var(--lang-btn-hover-border);
}

.lang-btn span {
    font-size: 0.75rem;
    margin-top: 4px;
    color: var(--text-color);
}

body.dark-mode .lang-btn:hover {
    background-color: var(--lang-btn-hover-background);
    border-radius: 5px;
}

/* Main Navigation */
.main-nav {
    background-color: var(--container-background);
    border-bottom: 1px solid var(--table-border-color);
}

.main-nav ul {
    display: flex;
    justify-content: center;
    list-style: none;
    margin: 0;
    padding: 0;
}

.main-nav a {
    display: block;
    padding: 1rem 1.5rem;
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    border-bottom: 2px solid transparent;
    transition: border-color 0.3s, color 0.3s;
}

.main-nav a:hover,
.main-nav a.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

/* Main Content */
body {
    font-family: var(--font-family);
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    transition: background-color 0.3s, color 0.3s;
}

.main-content {
    padding: 2rem;
}

.container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.calculator-column, .results-column {
    background-color: var(--container-background);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--box-shadow);
}

.form-row {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
}

.form-row .form-group {
    flex: 1;
    min-width: 0;
}

.form-group {
    margin-bottom: 1rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

input, select, button {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--input-border-color);
    border-radius: 4px;
    box-sizing: border-box;
    font-size: 1rem;
    background-color: var(--input-background);
    color: var(--text-color);
}

button {
    background-color: var(--primary-color);
    color: var(--button-text-color);
    cursor: pointer;
    transition: background-color 0.3s, transform 0.1s;
    border: none;
}

button:hover {
    background-color: var(--primary-color-hover);
}

button:active {
    transform: scale(0.98);
}

#results {
    margin-top: 0;
}

.hidden {
    display: none;
}

h2 {
    color: var(--primary-color);
    text-align: center;
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
}

.chart-container {
    margin-bottom: 2rem;
    height: 300px;
}

.results-summary {
    display: flex;
    justify-content: space-around;
    margin-bottom: 2rem;
    background-color: var(--background-color);
    padding: 1rem;
    border-radius: 4px;
}

.results-summary p {
    margin: 0;
    font-size: 1.1rem;
}

.table-container {
    margin-top: 1rem;
}

table {
    width: 100%;
    border-collapse: collapse;
}

th, td {
    text-align: left;
    padding: 0.2rem; /* Even further reduced padding for smaller row height */
    border-bottom: 1px solid var(--table-border-color);
}

thead th {
    background-color: #87CEEB; /* Azul un poco más oscuro y apagado */
    color: #000000; /* Texto negro para modo día */
    font-weight: 600;
}

tbody tr:nth-child(even) {
    background-color: var(--table-even-row-background);
}

.download-btn {
    margin-top: 1rem;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    display: block;
    width: fit-content;
    margin-left: auto;
    margin-right: auto;
}

.small-download-btn {
    padding: 0.5rem 1rem;
    font-size: 0.85rem;
    margin-top: 0.5rem;
}

.advanced-options-btn {
    background-color: transparent;
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
    margin-bottom: 1rem;
}

.advanced-options-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}

.advanced-options-content.visible {
    max-height: 500px;
}

/* Calculator specific styles */
.calculation-mode-selector {
    margin-bottom: 1.5rem;
    padding: 1rem;
    background-color: var(--background-color);
    border-radius: 8px;
    border: 1px solid var(--input-border-color);
}

.calculation-mode-selector label {
    margin-bottom: 0.5rem;
    font-weight: bold;
}

input[readonly] {
    background-color: var(--table-even-row-background);
    cursor: not-allowed;
    opacity: 0.8;
}

/* Help text styles */
.input-description {
    font-size: 0.85rem;
    color: var(--text-color);
    margin-top: 0.25rem;
    margin-bottom: 1rem;
}

/* How it Works Section */
#news-section {
    background-color: var(--container-background);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: var(--box-shadow);
    max-width: 900px;
    margin: 2rem auto;
}

.article-content h1, .article-content h2, .article-content h3 {
    color: var(--primary-color);
    margin-top: 1.5em;
    margin-bottom: 0.5em;
}

.article-content p {
    line-height: 1.8;
    margin-bottom: 1em;
}

.article-content ul {
    list-style-position: inside;
    padding-left: 0;
}

.article-content li {
    margin-bottom: 0.75em;
}

.article-content strong {
    color: var(--primary-color-hover);
}

.example-box {
    background-color: var(--background-color);
    border-left: 5px solid var(--primary-color);
    padding: 1.5rem;
    margin: 2rem 0;
    border-radius: 8px;
}

.example-box h3 {
    margin-top: 0;
}

#news-articles-container {
    display: block; /* Override grid layout */
}

.error-message {
    color: #dc3545;
}

@media screen and (max-width: 992px) {
    .container {
        grid-template-columns: 1fr;
    }
    #news-articles-container {
        grid-template-columns: 1fr; /* Single column on smaller screens */
    }
}

@media screen and (max-width: 768px) {
    body {
        font-size: 0.9rem;
    }

    .header-container {
        flex-direction: column;
        gap: 1rem;
        padding: 0.5rem 1rem;
    }

    .main-title {
        font-size: 1.5rem;
    }

    .header-controls {
        flex-direction: column;
        gap: 0.5rem;
    }

    .theme-switch-wrapper {
        flex-direction: row;
        gap: 10px;
    }

    .language-switcher {
        margin-top: 0.5rem;
    }

    .lang-btn img {
        width: 25px;
        height: 25px;
    }

    .main-nav ul {
        flex-wrap: wrap;
        padding: 0.5rem;
    }

    .main-nav a {
        padding: 0.75rem 1rem;
        font-size: 0.9rem;
    }

    .main-content {
        padding: 1rem;
    }

    .container {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .calculator-column, .results-column {
        padding: 1.5rem;
    }

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

    label {
        font-size: 0.9rem;
    }

    input, select, button {
        padding: 0.6rem;
        font-size: 0.9rem;
    }

    .input-description {
        font-size: 0.75rem;
    }

    h2 {
        font-size: 1.3rem;
    }

    .chart-container {
        height: 250px;
    }

    .results-summary p {
        font-size: 1rem;
    }

    th, td {
        padding: 0.15rem;
        font-size: 0.85rem;
    }

    .download-btn {
        padding: 0.6rem 1.2rem;
        font-size: 0.9rem;
    }

    .small-download-btn {
        padding: 0.4rem 0.8rem;
        font-size: 0.75rem;
    }

    #news-articles-container {
        grid-template-columns: 1fr; /* Single column on smaller screens */
    }
}

[data-lang-key="calculate"] {
    display: none;
}