:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --bg-color: #f8fafc;
    --panel-bg: #ffffff;
    --text-main: #0f172a;
    --text-light: #64748b;
    --border-color: #e2e8f0;

    /* Interactive Visualizer Colors */
    --vis-bg: #e2e8f0;
    --vis-primary: #cbd5e1;
    --vis-accent: #d97706;
    /* Wood */
    --vis-soil: #78350f;
    /* Soil */
    --vis-mulch: #451a03;
    /* Mulch */
}

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

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Nav */
nav {
    background: var(--panel-bg);
    padding: 15px 0;
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-main);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
}

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

.nav-links a {
    color: var(--text-light);
    text-decoration: none;
    margin-left: 20px;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links a:hover {
    color: var(--primary);
}

/* Hero */
.hero {
    background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
    color: white;
    padding: 60px 0 40px;
    text-align: center;
}

.hero h1 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 15px;
}

.hero p {
    color: #cbd5e1;
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto;
}

/* Base Calculator Layout */
.calculator-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin: 40px 0;
}

@media (max-width: 768px) {
    .calculator-wrapper {
        grid-template-columns: 1fr;
    }
}

.panel {
    background: var(--panel-bg);
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.05);
    border: 1px solid var(--border-color);
}

.panel h2 {
    font-size: 1.3rem;
    margin-bottom: 25px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--bg-color);
}

/* Form Elements */
.input-group {
    margin-bottom: 20px;
}

label {
    display: block;
    font-weight: 600;
    margin-bottom: 8px;
}

input[type="number"],
input[type="text"] {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    transition: all 0.2s;
}

input[type="number"]:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

small {
    display: block;
    color: var(--text-light);
    margin-top: 5px;
    font-size: 0.85rem;
}

.unit-select {
    padding: 12px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    background: var(--bg-color);
    font-size: 1rem;
    cursor: pointer;
    color: var(--text-main);
}

.unit-select:focus {
    outline: none;
    border-color: var(--primary);
}

/* Toggles */
.toggle-group {
    display: flex;
    gap: 10px;
}

.toggle-group input[type="radio"] {
    display: none;
}

.toggle-btn {
    flex: 1;
    text-align: center;
    padding: 10px;
    background: var(--bg-color);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-light);
    transition: all 0.2s;
}

.toggle-group input[type="radio"]:checked+.toggle-btn {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

.toggle-group input[type="radio"]:checked+.toggle-btn small {
    color: rgba(255, 255, 255, 0.9);
}

/* Result Cards */
.result-card {
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
    border: 1px solid #bfdbfe;
    border-radius: 12px;
    padding: 25px;
    text-align: center;
    margin-bottom: 20px;
}

.result-card h3 {
    color: var(--primary-hover);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 10px;
}

.big-number {
    font-size: 3rem;
    font-weight: 800;
    color: var(--primary-hover);
    line-height: 1;
    margin-bottom: 5px;
}

/* SEO Content */
.seo-content {
    background: var(--panel-bg);
    padding: 40px;
    border-radius: 16px;
    margin-bottom: 60px;
    border: 1px solid var(--border-color);
}

.seo-content h2 {
    color: var(--primary-hover);
    margin-top: 30px;
    margin-bottom: 15px;
}

.seo-content h2:first-child {
    margin-top: 0;
}

.seo-content h3 {
    margin-top: 25px;
    margin-bottom: 10px;
    color: var(--text-main);
}

.seo-content p {
    margin-bottom: 15px;
}

/* Homepage Grid */
.silo-section {
    margin: 40px 0;
}

.silo-section h2 {
    margin-bottom: 20px;
}

.calc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}

.calc-card {
    background: var(--panel-bg);
    border: 1px solid var(--border-color);
    padding: 20px;
    border-radius: 12px;
    text-decoration: none;
    color: var(--text-main);
    transition: transform 0.2s, box-shadow 0.2s;
}

.calc-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.05);
    border-color: var(--primary);
}

.calc-card h3 {
    color: var(--primary);
    margin-bottom: 10px;
}

.calc-card p {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* Header Search */
.nav-search {
    flex-grow: 1;
    max-width: 400px;
    margin: 0 20px;
}

.search-input {
    width: 100%;
    padding: 10px 15px;
    border: 1px solid var(--border-color);
    border-radius: 20px;
    background: var(--bg-color);
    font-size: 0.95rem;
    transition: all 0.2s;
}

.search-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
    background: #fff;
}

@media (max-width: 768px) {
    .nav-inner {
        flex-direction: column;
        gap: 15px;
    }
    .nav-search {
        width: 100%;
    }
    .nav-search form {
        width: 100%;
    }
    .nav-search input {
        width: 100%;
        text-align: center;
    }
    .nav-links {
        margin-bottom: 5px;
    }
}

/* Footer */
.site-footer {
    text-align: center;
    padding: 40px 20px;
    border-top: 1px solid var(--border-color);
    margin-top: 60px;
    color: var(--text-light);
    font-size: 0.9rem;
}

/* Global fix for horizontal centering */
.calculator-wrapper,
.calculator-container,
.app-container,
.wrapper,
main {
    margin-left: auto !important;
    margin-right: auto !important;
}