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

:root {
    --primary: #10b981;
    --primary-dark: #059669;
    --secondary: #6366f1;
    --accent: #f59e0b;
    --danger: #ef4444;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --border: #e5e7eb;
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
}

[data-theme="dark"] {
    --text-dark: #f3f4f6;
    --text-light: #d1d5db;
    --bg-light: #1f2937;
    --bg-white: #111827;
    --border: #374151;
}

html {
    font-size: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, var(--bg-light) 0%, var(--bg-white) 100%);
    color: var(--text-dark);
    line-height: 1.6;
    transition: background 0.3s ease;
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

/* Navigation */
nav {
    display: flex;
    gap: 24px;
    align-items: center;
}

nav a {
    color: var(--text-dark);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    padding: 8px 16px;
    border-radius: 8px;
    transition: all 0.3s ease;
}

nav a:hover {
    color: var(--primary);
    background: rgba(16, 185, 129, 0.05);
}

nav a.active {
    color: var(--primary);
    background: rgba(16, 185, 129, 0.1);
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 40px;
    flex-wrap: wrap;
    gap: 20px;
}

.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    margin-bottom: 20px;
}

.header-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-dark);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
}

.header-logo:hover {
    color: var(--primary);
}

.header-content h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 8px;
}

.header-content p {
    color: var(--text-light);
    font-size: 1.1rem;
}

.theme-toggle,
.lang-toggle {
    background: var(--bg-white);
    border: 2px solid var(--border);
    border-radius: 50px;
    padding: 8px 12px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.2rem;
    transition: all 0.3s ease;
}

.theme-toggle:hover,
.lang-toggle:hover {
    border-color: var(--primary);
    transform: scale(1.05);
}

.header-controls {
    display: flex;
    gap: 12px;
    align-items: center;
}

.lang-buttons {
    display: flex;
    gap: 8px;
    align-items: center;
}

.lang-button {
    background: var(--bg-white);
    border: 2px solid var(--border);
    border-radius: 50px;
    padding: 8px 16px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-dark);
    transition: all 0.3s ease;
    font-family: inherit;
}

.lang-button:hover {
    border-color: var(--primary);
    transform: scale(1.05);
}

.lang-button.active {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    border-color: var(--primary);
}


/* Checkbox styling */
.checkbox-wrapper {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 20px;
}

input[type="checkbox"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
    accent-color: var(--primary);
}

/* Pro mode sections */
.mode-toggle {
    display: flex;
    gap: 8px;
    align-items: center;
    background: var(--bg-white);
    border: 2px solid var(--border);
    border-radius: 50px;
    padding: 4px;
}

.mode-button {
    background: transparent;
    border: none;
    border-radius: 50px;
    padding: 6px 16px;
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-light);
    transition: all 0.3s ease;
    font-family: inherit;
}

.mode-button:hover {
    color: var(--text-dark);
}

.mode-button.active {
    background: linear-gradient(135deg, var(--secondary) 0%, var(--primary) 100%);
    color: white;
}

.pro-section {
    display: none;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 2px solid var(--border);
}

.pro-section.active {
    display: block;
}

/* Advanced metrics card */
.advanced-metrics {
    margin-top: 20px;
    padding: 20px;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.05) 0%, rgba(16, 185, 129, 0.05) 100%);
    border-radius: 12px;
    border: 2px solid var(--border);
}

.main-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin-bottom: 30px;
}

@media (max-width: 900px) {
    .main-grid {
        grid-template-columns: 1fr;
    }
}

.card {
    background: var(--bg-white);
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
    border: 1px solid var(--border);
    transition: all 0.3s ease;
}

.card:hover {
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.12);
    transform: translateY(-2px);
}

.card h2 {
    font-size: 1.5rem;
    margin-bottom: 20px;
    color: var(--text-dark);
    display: flex;
    align-items: center;
    gap: 10px;
}

.form-group {
    margin-bottom: 20px;
}

label {
    display: block;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-dark);
    font-size: 0.95rem;
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

input[type="number"],
input[type="text"] {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--border);
    border-radius: 10px;
    font-size: 1rem;
    background: var(--bg-light);
    color: var(--text-dark);
    transition: all 0.3s ease;
    font-family: inherit;
}

input[type="number"]:focus,
input[type="text"]:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
    background: var(--bg-white);
}

input.money-input {
    text-align: left;
    letter-spacing: 0.5px;
}

.currency {
    position: absolute;
    right: 12px;
    color: var(--text-light);
    font-weight: 600;
    pointer-events: none;
}

input[type="number"] {
    padding-right: 32px;
}

.help-icon {
    display: inline-block;
    width: 20px;
    height: 20px;
    background: var(--primary);
    color: white;
    border-radius: 50%;
    text-align: center;
    line-height: 20px;
    font-size: 0.8rem;
    font-weight: bold;
    cursor: help;
    margin-left: 8px;
    position: relative;
}

.tooltip {
    display: none;
    position: absolute;
    background: var(--text-dark);
    color: white;
    padding: 10px 12px;
    border-radius: 8px;
    font-size: 0.85rem;
    white-space: nowrap;
    z-index: 1000;
    bottom: 130%;
    left: 50%;
    transform: translateX(-50%);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.tooltip::after {
    content: '';
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    border: 5px solid transparent;
    border-top-color: var(--text-dark);
}

.help-icon:hover .tooltip {
    display: block;
}

.buttons-group {
    display: flex;
    gap: 12px;
    margin-top: 30px;
    flex-wrap: wrap;
}

button {
    padding: 12px 24px;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    font-family: inherit;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    flex: 1;
    min-width: 150px;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(16, 185, 129, 0.3);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-secondary {
    background: var(--bg-light);
    color: var(--text-dark);
    border: 2px solid var(--border);
}

.btn-secondary:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: rgba(16, 185, 129, 0.05);
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin-top: 20px;
}

@media (max-width: 600px) {
    .results-grid {
        grid-template-columns: 1fr;
    }
}

.result-item {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.05) 0%, rgba(99, 102, 241, 0.05) 100%);
    padding: 16px;
    border-radius: 12px;
    border-left: 4px solid var(--primary);
}

.result-label {
    font-size: 0.85rem;
    color: var(--text-light);
    margin-bottom: 6px;
    font-weight: 500;
}

.result-value {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary);
}

.result-value.warning {
    color: var(--warning);
}

.result-value.error {
    color: var(--error);
}

.result-value.info {
    color: var(--secondary);
}

.result-value.success {
    color: var(--success);
}

.history-list {
    max-height: 300px;
    overflow-y: auto;
    border: 1px solid var(--border);
    border-radius: 10px;
    background: var(--bg-light);
}

.history-item {
    padding: 12px 16px;
    border-bottom: 1px solid var(--border);
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.history-item:last-child {
    border-bottom: none;
}

.history-item:hover {
    background: rgba(16, 185, 129, 0.1);
}

.history-item-text {
    font-size: 0.9rem;
    color: var(--text-dark);
}

.history-item-value {
    font-weight: 700;
    color: var(--primary);
}

.history-delete {
    background: none;
    border: none;
    color: var(--error);
    cursor: pointer;
    padding: 0;
    font-size: 1.2rem;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.history-delete:hover {
    transform: scale(1.2);
}

.comparison-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-top: 20px;
}

@media (max-width: 600px) {
    .comparison-grid {
        grid-template-columns: 1fr;
    }
}

.comparison-card {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.05) 0%, rgba(16, 185, 129, 0.05) 100%);
    padding: 16px;
    border-radius: 12px;
    border: 2px solid var(--border);
}

.comparison-title {
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-dark);
}

.pie-chart-container {
    position: relative;
    width: 200px;
    height: 200px;
    margin: 20px auto;
}

.no-data {
    text-align: center;
    padding: 30px;
    color: var(--text-light);
    font-style: italic;
}

.alert {
    padding: 12px 16px;
    border-radius: 8px;
    margin-bottom: 16px;
    font-weight: 500;
}

.alert-warning {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning);
    border-left: 4px solid var(--warning);
}

.alert-success {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success);
    border-left: 4px solid var(--success);
}

.footer {
    text-align: center;
    margin-top: 60px;
    padding-top: 30px;
    border-top: 1px solid var(--border);
    color: var(--text-light);
    font-size: 0.9rem;
}

/* Blog styles */
.blog-header {
    text-align: center;
    margin-bottom: 40px;
}

.blog-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 12px;
}

.blog-header p {
    font-size: 1.1rem;
    color: var(--text-light);
}

.blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 24px;
    margin-bottom: 40px;
}

.blog-card {
    background: var(--bg-white);
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
    border: 1px solid var(--border);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.blog-card:hover {
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.12);
    transform: translateY(-2px);
}

.blog-card h3 {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 12px;
    line-height: 1.4;
}

.blog-card .blog-date {
    font-size: 0.85rem;
    color: var(--text-light);
    margin-bottom: 12px;
}

.blog-card .blog-excerpt {
    font-size: 0.95rem;
    color: var(--text-dark);
    line-height: 1.6;
    margin-bottom: 16px;
    flex-grow: 1;
}

.blog-card .blog-link {
    display: inline-block;
    padding: 10px 20px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s ease;
    text-align: center;
}

.blog-card .blog-link:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(16, 185, 129, 0.3);
}

/* Article page styles */
.article-header {
    margin-bottom: 40px;
}

.article-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 16px;
    line-height: 1.3;
}

.article-meta {
    display: flex;
    gap: 16px;
    align-items: center;
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 8px;
}

.article-subtitle {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 32px;
}

.article-content {
    max-width: 800px;
    margin: 0 auto;
}

.article-content h2 {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-top: 40px;
    margin-bottom: 16px;
}

.article-content h3 {
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--text-dark);
    margin-top: 32px;
    margin-bottom: 12px;
}

.article-content p {
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text-dark);
    margin-bottom: 16px;
}

.article-content ul,
.article-content ol {
    margin-left: 24px;
    margin-bottom: 16px;
    line-height: 1.8;
}

.article-content li {
    margin-bottom: 8px;
    color: var(--text-dark);
}

.article-cta {
    margin-top: 48px;
    padding: 24px;
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.05) 0%, rgba(99, 102, 241, 0.05) 100%);
    border-radius: 12px;
    border: 2px solid var(--border);
    text-align: center;
}

.article-cta h3 {
    font-size: 1.3rem;
    margin-bottom: 16px;
    margin-top: 0;
}

.related-articles {
    margin-top: 48px;
    padding-top: 32px;
    border-top: 2px solid var(--border);
}

.related-articles h3 {
    font-size: 1.5rem;
    margin-bottom: 24px;
    margin-top: 0;
}

.related-articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.related-article-card {
    background: var(--bg-white);
    border-radius: 12px;
    padding: 20px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    border: 1px solid var(--border);
    transition: all 0.3s ease;
}

.related-article-card:hover {
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
    transform: translateY(-2px);
}

.related-article-card h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.related-article-card a {
    color: var(--text-dark);
    text-decoration: none;
}

.related-article-card a:hover {
    color: var(--primary);
}

/* From blog section on homepage */
.from-blog {
    margin-top: 60px;
    margin-bottom: 40px;
}

.from-blog h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 24px;
    text-align: center;
}

.from-blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

@media (max-width: 600px) {
    .header-content h1 {
        font-size: 1.8rem;
    }

    header {
        margin-bottom: 30px;
    }

    .card {
        padding: 20px;
    }

    .main-grid {
        gap: 20px;
        margin-bottom: 20px;
    }

    .blog-header h1 {
        font-size: 2rem;
    }

    .article-header h1 {
        font-size: 2rem;
    }

    nav {
        order: 3;
        width: 100%;
        margin-top: 16px;
        flex-direction: row;
        justify-content: center;
        gap: 12px;
    }

    .header-top {
        flex-wrap: wrap;
    }

    .header-logo {
        order: 1;
    }

    .header-controls {
        order: 2;
    }

    nav a {
        flex: 1;
        text-align: center;
        padding: 10px;
        background: var(--bg-light);
        border: 1px solid var(--border);
    }

    nav a.active {
        background: rgba(16, 185, 129, 0.1);
        border-color: var(--primary);
    }
}

/* Pro Mode Styles */
.form-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.form-header h2 {
    margin-bottom: 0;
}

.mode-toggle {
    display: flex;
    align-items: center;
    gap: 8px;
    background: var(--bg-light);
    padding: 4px 8px;
    border-radius: 20px;
    border: 1px solid var(--border);
}

.mode-label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-light);
}

/* Toggle Switch */
.switch {
    position: relative;
    display: inline-block;
    width: 40px;
    height: 24px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #ccc;
    transition: .4s;
}

.slider:before {
    position: absolute;
    content: "";
    height: 18px;
    width: 18px;
    left: 3px;
    bottom: 3px;
    background-color: white;
    transition: .4s;
}

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

input:focus+.slider {
    box-shadow: 0 0 1px var(--primary);
}

.checkbox-container {
    display: block;
    position: relative;
    padding-left: 30px;
    margin-bottom: 12px;
    cursor: pointer;
    font-size: 1rem;
    user-select: none;
    color: var(--text-dark);
}

.checkbox-container input {
    position: absolute;
    opacity: 0;
    cursor: pointer;
    height: 0;
    width: 0;
}

.checkmark {
    position: absolute;
    top: 2px;
    left: 0;
    height: 20px;
    width: 20px;
    background-color: var(--bg-light);
    border: 1px solid var(--border);
    border-radius: 4px;
}

.checkbox-container:hover input~.checkmark {
    background-color: #ccc;
}

.checkbox-container input:checked~.checkmark {
    background-color: var(--primary);
    border-color: var(--primary);
}

.checkmark:after {
    content: "";
    position: absolute;
    display: none;
}

.checkbox-container input:checked~.checkmark:after {
    display: block;
}

.checkbox-container .checkmark:after {
    left: 7px;
    top: 3px;
    width: 5px;
    height: 10px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}