/* Reset & Base */
:root {
    --primary-color: #F05A4A;
    /* Incrementic Red/Orange */
    --text-dark: #333333;
    --text-light: #ffffff;
    --bg-light: #f9f9f9;
    --border-color: #e0e0e0;
    --accent-dark: #1a1a1a;
    --font-main: 'Inter', sans-serif;
}

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

body {
    font-family: var(--font-main);
    color: var(--text-dark);
    line-height: 1.6;
    background-color: #fff;
}

a {
    text-decoration: none;
    color: inherit;
    transition: 0.3s;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
header {
    background: #fff;
    padding: 20px 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-area {
    display: flex;
    align-items: center;
    gap: 15px;
}

.logo {
    height: 30px;
}

.divider {
    color: var(--primary-color);
    font-weight: 300;
    font-size: 1.2rem;
}

.tagline {
    font-size: 0.8rem;
    color: var(--primary-color);
    letter-spacing: 1px;
    font-weight: 600;
}

nav {
    display: flex;
    align-items: center;
    gap: 30px;
}

nav a {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-dark);
}

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

.btn-primary {
    background: #000;
    color: #fff;
    padding: 10px 24px;
    border-radius: 4px;
    font-weight: 600;
}

.btn-primary:hover {
    background: var(--primary-color);
    color: #fff;
}

/* Hero Section */
.hero {
    background-color: var(--primary-color);
    color: #fff;
    padding: 100px 0 140px;
    position: relative;
    overflow: hidden;
    text-align: center;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    /* Geometric Pattern using CSS gradients */
    background-image:
        linear-gradient(45deg, rgba(255, 255, 255, 0.1) 25%, transparent 25%, transparent 75%, rgba(255, 255, 255, 0.1) 75%, rgba(255, 255, 255, 0.1)),
        linear-gradient(45deg, rgba(255, 255, 255, 0.1) 25%, transparent 25%, transparent 75%, rgba(255, 255, 255, 0.1) 75%, rgba(255, 255, 255, 0.1));
    background-size: 60px 60px;
    background-position: 0 0, 30px 30px;
    opacity: 0.3;
}

.hero-content {
    position: relative;
    z-index: 2;
}

.hero-title {
    font-size: 4.5rem;
    line-height: .95;
    margin-bottom: 25px;
    font-weight: 300;
    /* Start light */
}

.hero-title .light {
    font-weight: 300;
    font-style: italic;
    opacity: 0.9;
    font-size: 0.6em;
    /* Smaller "the" */
    vertical-align: middle;
}

.hero-title .bold {
    font-weight: 700;
}

.hero-title .italic {
    font-family: serif;
    /* Slight contrast */
    font-style: italic;
}

.hero-subtitle {
    font-size: 1.25rem;
    max-width: 600px;
    margin: 0 auto 40px;
    opacity: 0.9;
}

.btn-hero {
    display: inline-block;
    background: #fff;
    color: var(--primary-color);
    padding: 15px 40px;
    border-radius: 5px;
    font-weight: 700;
    font-size: 1.1rem;
    transition: transform 0.2s;
}

.btn-hero:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
}

/* Sections */
.section {
    padding: 80px 0;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 50px;
    color: var(--text-dark);
    font-weight: 700;
}

/* Calculator Card */
.card {
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.08);
    padding: 40px;
    border: 1px solid var(--border-color);
    max-width: 900px;
}

.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin-bottom: 40px;
}

.form-group {
    display: flex;
    flex-direction: column;
}

label {
    font-weight: 600;
    margin-bottom: 10px;
    display: block;
}

small {
    color: #888;
    margin-top: 8px;
    font-size: 0.85rem;
}

.input-field {
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 1rem;
    font-family: inherit;
    width: 100%;
}

/* Custom Range Slider */
input[type=range] {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    background: transparent;
}

input[type=range]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    height: 20px;
    width: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    margin-top: -8px;
}

input[type=range]::-webkit-slider-runnable-track {
    width: 100%;
    height: 4px;
    cursor: pointer;
    background: #ddd;
    border-radius: 2px;
}

.slider-value {
    font-weight: 700;
    color: var(--primary-color);
    font-size: 1.2rem;
    margin-top: 5px;
    display: block;
}

.result-area {
    background: var(--bg-light);
    padding: 30px;
    border-radius: 8px;
    display: flex;
    justify-content: space-around;
    align-items: center;
    border-top: 4px solid var(--primary-color);
}

.result-item {
    text-align: center;
}

.result-item .label {
    display: block;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: #666;
    margin-bottom: 5px;
}

.result-item .value {
    display: block;
    font-size: 3rem;
    font-weight: 700;
    color: var(--text-dark);
}

/* Guide Grid */
.guide-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.guide-item h3 {
    color: var(--primary-color);
    margin-bottom: 15px;
    font-size: 1.4rem;
}

/* Prompt Box */
.prompt-tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

.tab-btn {
    padding: 12px 24px;
    background: #f8f8f8;
    border: 1px solid #ddd;
    border-top: 3px solid transparent;
    border-radius: 4px 4px 0 0;
    cursor: pointer;
    font-weight: 600;
    color: #666;
    transition: 0.2s;
}

.tab-btn.active {
    background: #fff;
    border-bottom: 1px solid #fff;
    border-top-color: var(--primary-color);
    color: var(--primary-color);
}

.prompt-box {
    background: #f9f9f9;
    border: 1px solid #ddd;
    border-radius: 8px;
    padding: 20px;
    position: relative;
}

.prompt-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.prompt-preview-label {
    font-weight: 600;
    color: #444;
    margin: 0;
}

.preview-content {
    max-height: 400px;
    overflow-y: auto;
    color: #555;
    background: #fff;
    padding: 15px;
    border-radius: 4px;
    border: 1px solid #eee;
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.9rem;
    line-height: 1.4;
    white-space: pre-wrap;
}

.btn-copy {
    background: #fff;
    border: 1px solid #ccc;
    padding: 8px 16px;
    font-size: 0.9rem;
    cursor: pointer;
    border-radius: 4px;
    transition: 0.2s;
    font-weight: 600;
}

.btn-copy:hover {
    background: #f0f0f0;
    border-color: var(--primary-color);
}

.btn-success {
    background: #4CAF50 !important;
    color: white !important;
    border-color: #4CAF50 !important;
}

.prompt-box .btn-copy {
    position: absolute;
    top: 10px;
    right: 10px;
}

.experiment-content {
    max-width: 800px;
    margin-bottom: 40px;
}

.lead {
    font-size: 1.25rem;
    color: #444;
    line-height: 1.6;
    margin-bottom: 30px;
}

.experiment-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.experiment-item h4 {
    color: var(--primary-color);
    margin-bottom: 15px;
    font-size: 1.1rem;
}

.experiment-item p {
    font-size: 0.95rem;
    color: #666;
    line-height: 1.5;
}

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

/* Footer */

footer {
    background: #111;
    color: #666;
    padding: 40px 0;
    text-align: center;
    margin-top: 80px;
}

/* Responsive */
@media (max-width: 768px) {
    .hero-title {
        font-size: 3rem;
    }

    .form-grid {
        grid-template-columns: 1fr;
    }

    .guide-grid {
        grid-template-columns: 1fr;
    }
}