:root {
    --primary-color: #000;
    --accent-color: #ff3b30;
    --background-color: #f9f9f9;
    --card-background: #ffffff;
    --text-color: #111;
    --text-secondary: #555;
    --border-color: #eaeaea;
    --box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    --border-radius: 12px;
    --transition: all 0.3s ease;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

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

body {
    font-family: var(--font-sans);
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 0.5em;
}

h1 {
    font-size: 3.5rem;
    letter-spacing: -0.03em;
}

h2 {
    font-size: 2.25rem;
    letter-spacing: -0.02em;
    margin-bottom: 1rem;
}

h3 {
    font-size: 1.5rem;
    letter-spacing: -0.01em;
}

p {
    margin-bottom: 1.5rem;
    font-size: 1.125rem;
    color: var(--text-secondary);
}

/* Header */
header {
    background-color: var(--primary-color);
    color: white;
    padding: 100px 0 80px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

header::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at center, rgba(255, 59, 48, 0.1) 0%, rgba(0, 0, 0, 0) 70%);
    z-index: 1;
}

header .container {
    position: relative;
    z-index: 2;
}

header h1 {
    font-size: 4rem;
    font-weight: 900;
    margin-bottom: 16px;
    letter-spacing: -0.04em;
    line-height: 1.1;
}

.tagline {
    font-size: 1.25rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto 20px;
    color: rgba(255, 255, 255, 0.9);
}

/* Main Content */
main {
    padding: 80px 0;
}

section {
    margin-bottom: 80px;
}

.intro {
    max-width: 800px;
    margin: 0 auto 80px;
    text-align: center;
    padding-top: 20px;
}

.intro h2 {
    font-size: 2.5rem;
    margin-bottom: 24px;
    margin-top: 40px;
    position: relative;
    display: inline-block;
}

.intro h2::before {
    content: '';
    position: absolute;
    top: -30px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background-color: var(--accent-color);
    border-radius: 2px;
}

.intro p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

/* Stats Section */
.stat-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    margin-bottom: 60px;
}

.stat-box {
    background-color: var(--card-background);
    padding: 40px 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    text-align: center;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.stat-box:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

.stat-number {
    font-size: 3.5rem;
    font-weight: 800;
    color: var(--primary-color);
    margin: 16px 0;
    line-height: 1;
}

/* Create Code Section */
.code-generator {
    background-color: var(--card-background);
    padding: 40px;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    margin-bottom: 40px;
    border: 1px solid var(--border-color);
}

.form-group {
    margin-bottom: 24px;
}

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

input, select {
    width: 100%;
    padding: 14px 16px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    font-family: var(--font-sans);
    transition: var(--transition);
    background-color: white;
}

input:focus, select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 0, 0, 0.1);
}

.hint {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-top: 8px;
}

.btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 14px 28px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
    display: inline-block;
    text-decoration: none;
}

.btn:hover {
    background-color: #333;
    transform: translateY(-2px);
}

/* QR Result */
.qr-result {
    background-color: var(--card-background);
    padding: 40px;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    text-align: center;
    border: 1px solid var(--border-color);
}

.qr-code-container {
    position: relative;
    width: 350px;
    height: auto;
    margin: 0 auto 30px;
    padding: 30px;
    background-color: white;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
    overflow: visible;
    box-sizing: content-box;
}

#qrCode {
    margin: 0 auto;
    position: relative;
    width: 100%;
    max-width: 256px;
    height: auto;
    display: block;
}

#qrCode canvas, 
#qrCode img {
    width: 100%;
    height: auto;
    display: block;
    image-rendering: pixelated;
    image-rendering: -moz-crisp-edges;
    image-rendering: crisp-edges;
}

.qr-warning {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: var(--accent-color);
    color: white;
    padding: 8px 16px;
    font-weight: 700;
    border-radius: 6px;
    font-size: 0.9rem;
    white-space: nowrap;
    box-shadow: 0 2px 10px rgba(255, 59, 48, 0.3);
    z-index: 10;
}

/* How It Works */
.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.step {
    background-color: var(--card-background);
    padding: 40px 30px;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    text-align: center;
    transition: var(--transition);
    border: 1px solid var(--border-color);
    position: relative;
}

.step:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

.step-number {
    background-color: var(--primary-color);
    color: white;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 24px;
    font-weight: 700;
    font-size: 1.25rem;
}

/* About Section */
.about {
    background-color: var(--card-background);
    padding: 40px;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    border: 1px solid var(--border-color);
}

.about h2 {
    margin-bottom: 24px;
}

.about p {
    margin-bottom: 20px;
}

.about a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

.about a:hover {
    text-decoration: underline;
}

/* Footer */
footer {
    background-color: var(--primary-color);
    color: white;
    padding: 60px 0;
    text-align: center;
}

footer a {
    color: white;
    text-decoration: none;
    transition: var(--transition);
}

footer a:hover {
    text-decoration: underline;
    opacity: 0.9;
}

/* Responsive */
@media (max-width: 768px) {
    header {
        padding: 60px 0 50px;
    }
    
    header h1 {
        font-size: 2.5rem;
    }
    
    .stat-container, .steps {
        grid-template-columns: 1fr;
    }
    
    .code-generator, .qr-result, .about {
        padding: 30px 20px;
    }
    
    main {
        padding: 50px 0;
    }
    
    section {
        margin-bottom: 50px;
    }
}

/* Add Inter font */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800;900&display=swap');