/* Reset and Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* Cobo-Inspired Industrial Precision Design System */
:root {
    /* Backgrounds - warm taupe (two tones lighter) */
    --background: #3d3a36;                  /* Main background */
    --background-secondary: #4a4642;        /* Cards, panels */
    --background-tertiary: #56524d;         /* Elevated elements */

    /* Foreground - warm cream palette */
    --foreground: #EFECE3;                  /* Primary text - warm cream */
    --foreground-secondary: #D6C8B5;        /* Secondary text - warm beige */
    --foreground-muted: #9a8d7d;            /* Muted text - darker beige */

    /* Accent - earthy terracotta/copper */
    --primary: #AE8466;                     /* Terracotta accent */
    --primary-hover: #75553C;               /* Darker brown hover */

    /* Secondary accent - olive green */
    --accent-secondary: #666E52;            /* Olive/sage green */

    /* Borders */
    --border-color: rgba(214, 200, 181, 0.15);  /* #D6C8B5 with opacity */

    /* Shadows - minimal */
    --shadow-sm: 0 1px 2px hsl(0 0% 0% / 0.2);
    --shadow-md: 0 4px 12px hsl(0 0% 0% / 0.15);

    /* Border radius - angular */
    --radius-none: 0;
    --radius-sm: 2px;
    --radius-md: 4px;
    --radius-full: 9999px;

    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2rem;
    --space-xl: 3rem;
    --space-section: 8vw;
    --space-block: 4vw;
    --container-max: 1400px;
    --container-padding: 5vw;

    /* Transitions */
    --transition-base: 0.35s ease-out;
    --transition-fast: 0.2s ease-out;
}

/* Typography */
@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

body {
    font-family: 'Space Grotesk', -apple-system, BlinkMacSystemFont, sans-serif;
    line-height: 1.6;
    color: var(--foreground);
    background: var(--background);
    -webkit-font-smoothing: antialiased;
}

/* Display typography - light weight, tight tracking */
.display-xl {
    font-size: 4rem;
    font-weight: 300;
    letter-spacing: -0.03em;
    line-height: 1.1;
}

.display-lg {
    font-size: 3rem;
    font-weight: 300;
    letter-spacing: -0.02em;
    line-height: 1.1;
}

/* Headings - bold weight */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.25;
    color: var(--foreground);
}

h1 {
    font-size: 3rem;
    font-weight: 300;
    letter-spacing: -0.02em;
    line-height: 1.1;
}

h2 {
    font-size: 2.25rem;
    font-weight: 600;
    letter-spacing: -0.01em;
}

h3 {
    font-size: 1.5rem;
    font-weight: 600;
}

h4 {
    font-size: 1.25rem;
    font-weight: 600;
}

/* Body text */
p {
    line-height: 1.6;
}

/* Labels - uppercase, spaced */
.label {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--foreground-muted);
}

/* Monospace for data/code */
code, .mono-data {
    font-family: 'JetBrains Mono', monospace;
    font-feature-settings: "tnum";
}

/* Links - Cobo style underline */
a {
    color: var(--foreground);
    text-decoration: underline;
    text-underline-offset: 0.3rem;
    text-decoration-thickness: 1px;
    transition: text-decoration-color var(--transition-base);
}

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

/* Container */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-family: 'Space Grotesk', sans-serif;
    font-size: 0.875rem;
    font-weight: 500;
    text-decoration: none;
    border-radius: var(--radius-sm);
    border: 1px solid transparent;
    cursor: pointer;
    transition: all var(--transition-base);
}

.btn-primary {
    background: var(--primary);
    color: hsl(0 0% 0%);
    border-color: var(--primary);
}

.btn-primary:hover {
    background: var(--primary-hover);
    border-color: var(--primary-hover);
    text-decoration: none;
}

.btn-ghost, .btn-outline {
    background: transparent;
    color: var(--foreground);
    border: 1px solid var(--border-color);
}

.btn-ghost:hover, .btn-outline:hover {
    background: var(--background-tertiary);
    border-color: var(--foreground-muted);
    text-decoration: none;
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1rem;
}

.btn-block {
    width: 100%;
}

/* Navbar - minimal, dark */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--background);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    font-size: 1.25rem;
    font-weight: 600;
    letter-spacing: -0.01em;
    color: var(--foreground);
}

.logo:hover {
    text-decoration: none;
}

.logo-icon {
    width: 32px;
    height: 32px;
}

.footer-brand .logo-icon {
    width: 40px;
    height: 40px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-links a {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--foreground-secondary);
    text-decoration: none;
    transition: color var(--transition-base);
}

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

/* Numbered Nav Items (Cobo-style) */
.nav-item {
    display: flex;
    align-items: baseline;
    gap: 0.5rem;
}

.nav-item__num {
    font-size: 0.625rem;
    font-weight: 500;
    color: var(--foreground-muted);
}

/* Hero Section */
.hero {
    padding: calc(72px + var(--space-section)) 0 var(--space-section);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.hero-content {
    max-width: 800px;
    margin-bottom: var(--space-section);
}

.hero h1 {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 300;
    letter-spacing: -0.03em;
    line-height: 1.1;
    margin-bottom: var(--space-lg);
}

.hero-tagline {
    font-size: 1.5rem;
    color: var(--accent);
    font-weight: 500;
    margin-bottom: var(--space-md);
    max-width: 600px;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--foreground-secondary);
    line-height: 1.6;
    margin-bottom: var(--space-xl);
    max-width: 600px;
}

.hero-buttons {
    display: flex;
    gap: var(--space-sm);
}

.hero-stats {
    display: flex;
    gap: 5rem;
    padding-top: var(--space-xl);
    border-top: 1px solid var(--border-color);
}

.stat {
    text-align: left;
}

.stat-number {
    display: block;
    font-family: 'JetBrains Mono', monospace;
    font-size: 2rem;
    font-weight: 500;
    color: var(--primary);
    letter-spacing: -0.02em;
}

.stat-label {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--foreground-muted);
    margin-top: 0.25rem;
}

/* Sections */
.section {
    padding: var(--space-section) 0;
}

.section-alt {
    background: var(--background-secondary);
}

.section-header {
    margin-bottom: var(--space-block);
}

.section-header h2 {
    margin-bottom: var(--space-sm);
}

.section-header p {
    color: var(--foreground-secondary);
    font-size: 1.125rem;
}

/* Problem Cards */
.problem-content {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.problem-card {
    padding: var(--space-lg);
    background: var(--background-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

.problem-card:hover {
    background: var(--background-tertiary);
    transform: translateY(-2px);
}

.problem-icon {
    font-size: 2rem;
    margin-bottom: var(--space-md);
}

.problem-card h3 {
    margin-bottom: var(--space-xs);
}

.problem-card p {
    color: var(--foreground-secondary);
    font-size: 0.95rem;
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.feature-card {
    padding: var(--space-lg);
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

.feature-card:hover {
    background: var(--background-tertiary);
    transform: translateY(-2px);
}

.feature-icon {
    font-size: 1.75rem;
    margin-bottom: var(--space-md);
}

.feature-card h3 {
    margin-bottom: var(--space-xs);
    font-size: 1.125rem;
}

.feature-card p {
    color: var(--foreground-secondary);
    font-size: 0.95rem;
}

/* Steps */
.steps {
    display: flex;
    align-items: stretch;
    gap: var(--space-lg);
}

.step {
    flex: 1;
    padding: var(--space-lg);
    background: var(--background-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
}

.step-number {
    width: 40px;
    height: 40px;
    border: 2px solid var(--primary);
    color: var(--primary);
    font-family: 'JetBrains Mono', monospace;
    font-size: 1rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--space-md);
    border-radius: var(--radius-sm);
}

.step h3 {
    margin-bottom: var(--space-xs);
}

.step p {
    color: var(--foreground-secondary);
    margin-bottom: var(--space-md);
    font-size: 0.95rem;
}

.step code {
    display: inline-block;
    padding: 0.5rem 0.75rem;
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    color: var(--primary);
}

.step-arrow {
    font-size: 1.5rem;
    color: var(--foreground-muted);
    padding-top: var(--space-xl);
}

/* Pricing */
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
    align-items: start;
}

.pricing-grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

.pricing-grid-1 {
    grid-template-columns: 1fr;
    max-width: 400px;
    margin: 0 auto;
}

.price-after {
    font-size: 1.1rem;
    color: var(--foreground-secondary);
    margin-top: -0.5rem;
    margin-bottom: var(--space-md);
}

.pricing-card {
    position: relative;
    padding: var(--space-xl) var(--space-lg);
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
}

.pricing-card:hover {
    background: var(--background-tertiary);
}

.pricing-card.featured {
    border-color: var(--primary);
}

.featured-badge {
    position: absolute;
    top: -1px;
    right: var(--space-lg);
    background: var(--primary);
    color: hsl(0 0% 0%);
    padding: 0.25rem 0.75rem;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.pricing-card h3 {
    margin-bottom: var(--space-md);
    font-size: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--foreground-secondary);
}

.price {
    font-family: 'JetBrains Mono', monospace;
    font-size: 2.5rem;
    font-weight: 500;
    color: var(--foreground);
    margin-bottom: var(--space-lg);
}

.price span {
    font-size: 0.875rem;
    font-weight: 400;
    color: var(--foreground-muted);
}

.pricing-card ul {
    list-style: none;
    margin-bottom: var(--space-lg);
}

.pricing-card li {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-color);
    color: var(--foreground-secondary);
    font-size: 0.95rem;
}

.pricing-card li:last-child {
    border-bottom: none;
}

/* Signup Section */
.signup-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-section);
    align-items: start;
}

.signup-info h2 {
    margin-bottom: var(--space-md);
}

.signup-info p {
    color: var(--foreground-secondary);
    margin-bottom: var(--space-lg);
}

.signup-benefits {
    list-style: none;
}

.signup-benefits li {
    padding: 0.5rem 0;
    color: var(--foreground-secondary);
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.signup-benefits li::before {
    content: "";
    width: 4px;
    height: 4px;
    background: var(--primary);
    border-radius: 50%;
}

/* Form Styles */
.signup-form-container {
    background: var(--background-secondary);
    padding: var(--space-xl);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
}

.form-group {
    margin-bottom: var(--space-md);
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--foreground);
}

.form-group input[type="text"],
.form-group input[type="email"] {
    width: 100%;
    padding: 0.75rem 1rem;
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-family: 'Space Grotesk', sans-serif;
    font-size: 1rem;
    color: var(--foreground);
    transition: border-color var(--transition-base);
}

.form-group input::placeholder {
    color: var(--foreground-muted);
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary);
}

.checkbox-group {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.checkbox-group input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: var(--primary);
}

.checkbox-group label {
    margin-bottom: 0;
    font-weight: 400;
    font-size: 0.875rem;
    color: var(--foreground-secondary);
}

.form-note {
    margin-top: var(--space-md);
    font-size: 0.75rem;
    color: var(--foreground-muted);
    text-align: center;
}

/* Success State */
.signup-success {
    text-align: center;
}

.success-icon {
    font-size: 3rem;
    margin-bottom: var(--space-md);
}

.signup-success h3 {
    margin-bottom: 0.5rem;
}

.signup-success > p {
    color: var(--foreground-secondary);
    margin-bottom: var(--space-lg);
}

.credentials-box {
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    margin-bottom: var(--space-lg);
    text-align: left;
}

.credential {
    margin-bottom: var(--space-md);
}

.credential:last-child {
    margin-bottom: 0;
}

.credential label {
    display: block;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--foreground-muted);
    margin-bottom: 0.5rem;
}

.credential-value {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.credential-value code {
    flex: 1;
    padding: 0.75rem;
    background: var(--background-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 0.8rem;
    word-break: break-all;
    color: var(--foreground);
}

.copy-btn {
    padding: 0.5rem 1rem;
    background: var(--primary);
    color: hsl(0 0% 0%);
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-family: 'Space Grotesk', sans-serif;
    font-size: 0.75rem;
    font-weight: 500;
    transition: background var(--transition-base);
}

.copy-btn:hover {
    background: var(--primary-hover);
}

/* Footer */
.footer {
    background: var(--background-secondary);
    border-top: 1px solid var(--border-color);
    padding: var(--space-section) 0 var(--space-xl);
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--space-section);
    margin-bottom: var(--space-xl);
}

.footer-brand .logo {
    margin-bottom: var(--space-sm);
}

.footer-brand p {
    color: var(--foreground-muted);
    font-size: 0.95rem;
    max-width: 300px;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.footer-column h4 {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--foreground-muted);
    margin-bottom: var(--space-md);
    font-weight: 500;
}

.footer-column a {
    display: block;
    color: var(--foreground-secondary);
    text-decoration: none;
    padding: 0.5rem 0;
    font-size: 0.95rem;
    transition: color var(--transition-base);
}

.footer-column a:hover {
    color: var(--foreground);
}

.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding-top: var(--space-lg);
    color: var(--foreground-muted);
    font-size: 0.875rem;
}

/* Alert / Error Messages */
.alert {
    padding: var(--space-md);
    border-radius: var(--radius-sm);
    margin-bottom: var(--space-md);
    border: 1px solid;
}

.alert-error {
    background: rgba(117, 85, 60, 0.2);       /* #75553C with opacity */
    border-color: rgba(117, 85, 60, 0.4);
    color: #D6C8B5;
}

.alert-success {
    background: rgba(102, 110, 82, 0.2);      /* #666E52 with opacity */
    border-color: rgba(102, 110, 82, 0.4);
    color: #EFECE3;
}

/* Data Entry Rules Section */
.rules-intro {
    margin-bottom: var(--space-xl);
}

.important-notice {
    background: rgba(174, 132, 102, 0.15);    /* Terracotta background */
    border: 1px solid rgba(174, 132, 102, 0.3);
    border-left: 4px solid var(--primary);
    padding: var(--space-lg);
    border-radius: var(--radius-md);
}

.important-notice h3 {
    color: var(--primary);
    margin-bottom: var(--space-sm);
    font-size: 1.125rem;
}

.important-notice p {
    color: var(--foreground-secondary);
    margin: 0;
}

.important-notice strong {
    color: var(--foreground);
}

.rules-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-lg);
    margin-bottom: var(--space-xl);
}

.rule-card {
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.rule-header {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md) var(--space-lg);
    background: var(--background-tertiary);
    border-bottom: 1px solid var(--border-color);
}

.rule-icon {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--primary);
    background: rgba(174, 132, 102, 0.2);
    padding: 0.5rem 0.75rem;
    border-radius: var(--radius-sm);
    letter-spacing: 0.05em;
}

.rule-header h3 {
    font-size: 1rem;
    margin: 0;
}

.rule-content {
    padding: var(--space-lg);
}

.rule-critical {
    font-weight: 600;
    color: var(--foreground);
    margin-bottom: var(--space-sm);
    font-size: 0.95rem;
}

.rule-list {
    list-style: none;
    margin-bottom: var(--space-md);
}

.rule-list li {
    padding: 0.4rem 0;
    padding-left: 1.25rem;
    position: relative;
    color: var(--foreground-secondary);
    font-size: 0.9rem;
}

.rule-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0.75rem;
    width: 4px;
    height: 4px;
    background: var(--foreground-muted);
    border-radius: 50%;
}

.rule-examples {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.rule-examples .example {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.5rem 0.75rem;
    border-radius: var(--radius-sm);
}

.rule-examples .example.correct {
    background: rgba(102, 110, 82, 0.15);
}

.rule-examples .example.incorrect {
    background: rgba(117, 85, 60, 0.15);
}

.rule-examples .label {
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 500;
    min-width: 50px;
}

.rule-examples .correct .label {
    color: var(--accent-secondary);
}

.rule-examples .incorrect .label {
    color: #AE8466;
}

.rule-examples code {
    font-size: 0.85rem;
    padding: 0.25rem 0.5rem;
    background: var(--background-tertiary);
    border-radius: var(--radius-sm);
    color: var(--foreground);
}

/* Hash Levels Table */
.hash-levels-section {
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
}

.hash-levels-section h3 {
    margin-bottom: var(--space-sm);
}

.hash-levels-section > p {
    color: var(--foreground-secondary);
    margin-bottom: var(--space-md);
}

.hash-levels-table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: var(--space-md);
}

.hash-levels-table th,
.hash-levels-table td {
    padding: 0.75rem 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.hash-levels-table th {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--foreground-muted);
    font-weight: 500;
    background: var(--background-secondary);
}

.hash-levels-table td {
    font-size: 0.9rem;
    color: var(--foreground-secondary);
}

.hash-levels-table tbody tr:hover {
    background: var(--background-secondary);
}

.level-badge {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: var(--radius-sm);
    min-width: 32px;
    text-align: center;
}

.level-badge.l0 {
    background: rgba(174, 132, 102, 0.25);
    color: #D6C8B5;
}

.level-badge.l1 {
    background: rgba(102, 110, 82, 0.3);
    color: #D6C8B5;
}

.level-badge.l2 {
    background: rgba(102, 110, 82, 0.5);
    color: #EFECE3;
}

.level-badge.l3 {
    background: rgba(174, 132, 102, 0.4);
    color: #EFECE3;
}

.level-badge.l4 {
    background: rgba(174, 132, 102, 0.6);
    color: #EFECE3;
}

.hash-note {
    font-size: 0.85rem;
    color: var(--foreground-muted);
    font-style: italic;
    margin: 0;
}

/* Animations */
@keyframes fade-up {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-in {
    animation: fade-up 0.6s ease-out forwards;
}

.animate-in:nth-child(1) { animation-delay: 0s; }
.animate-in:nth-child(2) { animation-delay: 0.1s; }
.animate-in:nth-child(3) { animation-delay: 0.2s; }
.animate-in:nth-child(4) { animation-delay: 0.3s; }

/* Responsive */
@media (max-width: 1024px) {
    :root {
        --container-padding: 2rem;
    }

    .features-grid,
    .problem-content,
    .pricing-grid,
    .rules-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .steps {
        flex-direction: column;
    }

    .step-arrow {
        transform: rotate(90deg);
        padding: var(--space-sm) 0;
    }

    .signup-container {
        grid-template-columns: 1fr;
        gap: var(--space-xl);
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: var(--space-xl);
    }
}

/* Mobile Menu Button */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 32px;
    height: 32px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.mobile-menu-btn span {
    display: block;
    width: 100%;
    height: 2px;
    background: var(--foreground);
    transition: all var(--transition-fast);
}

.mobile-menu-btn.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* Mobile Menu Overlay */
.mobile-menu {
    display: none;
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--background);
    z-index: 999;
    padding: var(--space-lg);
    flex-direction: column;
    gap: var(--space-md);
}

.mobile-menu.active {
    display: flex;
}

.mobile-menu a {
    display: block;
    padding: var(--space-md);
    color: var(--foreground);
    text-decoration: none;
    font-size: 1.125rem;
    border-bottom: 1px solid var(--border-color);
}

.mobile-menu a:hover {
    background: var(--background-secondary);
}

.mobile-menu .btn {
    margin-top: var(--space-md);
}

@media (max-width: 1200px) {
    .pricing-grid-4 {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    h1 { font-size: 2.25rem; }
    h2 { font-size: 1.75rem; }

    .nav-links {
        display: none;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .hero {
        padding-top: calc(72px + var(--space-xl));
    }

    .hero-buttons {
        flex-direction: column;
    }

    .hero-stats {
        flex-direction: column;
        gap: var(--space-lg);
    }

    .features-grid,
    .problem-content,
    .pricing-grid,
    .rules-grid {
        grid-template-columns: 1fr;
    }

    .footer-links {
        grid-template-columns: 1fr;
    }

    .hash-levels-table {
        font-size: 0.8rem;
    }

    .hash-levels-table th,
    .hash-levels-table td {
        padding: 0.5rem;
    }
}

/* Modal Styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-backdrop {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    background: var(--background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--space-xl);
    width: 100%;
    max-width: 420px;
    margin: var(--space-md);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
}

.modal-content h2 {
    margin-bottom: var(--space-xs);
    color: var(--foreground);
}

.modal-subtitle {
    color: var(--foreground-muted);
    margin-bottom: var(--space-lg);
}

.modal-close {
    position: absolute;
    top: var(--space-md);
    right: var(--space-md);
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--foreground-muted);
    cursor: pointer;
    padding: 0;
    line-height: 1;
    transition: color var(--transition-base);
}

.modal-close:hover {
    color: var(--foreground);
}

.modal-footer {
    margin-top: var(--space-lg);
    padding-top: var(--space-md);
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--foreground-muted);
}

.modal-footer a {
    color: var(--primary);
}

.error-message {
    background: rgba(220, 53, 69, 0.1);
    border: 1px solid rgba(220, 53, 69, 0.3);
    color: #dc3545;
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-sm);
    margin-top: var(--space-md);
    font-size: 0.875rem;
}