/* Root Variables */
:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --accent-color: #0ea5e9;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --dark-color: #1f2937;
    --light-color: #f3f4f6;
    --border-color: #e5e7eb;
    --text-color: #374151;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.08);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: #ffffff;
}

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

/* Navigation Bar */
.navbar {
    background: var(--dark-color);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.logo {
    font-size: 1.8rem;
    font-weight: 700;
    color: white;
    letter-spacing: -0.5px;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.3s ease;
}

.nav-links a:hover,
.nav-links a.active {
    opacity: 0.8;
}

/* Hero Section */
.hero {
    background: var(--primary-color);
    color: white;
    padding: 70px 0;
    text-align: center;
}

.hero h1 {
    font-size: 2.2rem;
    margin-bottom: 0.75rem;
    font-weight: 700;
    line-height: 1.2;
}

.hero p {
    font-size: 1.05rem;
    margin-bottom: 1.5rem;
    opacity: 0.95;
}

.cta-button {
    display: inline-block;
    background-color: white;
    color: var(--primary-color);
    padding: 12px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
}

/* Features Section */
.features {
    padding: 80px 0;
    background-color: var(--light-color);
}

.features h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--dark-color);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    box-shadow: var(--shadow-sm);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    color: var(--dark-color);
}

.feature-card p {
    color: #6b7280;
    line-height: 1.6;
}

/* Calculator Section */
.calculator-section {
    padding: 80px 0;
    background: #f8fafc;
}

.calculator-section h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    color: var(--dark-color);
}

.section-intro {
    max-width: 760px;
    margin: 0 auto 2rem;
    text-align: center;
    color: #4b5563;
    font-size: 1.05rem;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 14px;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    box-shadow: var(--shadow-sm);
}

.calculator-dashboard {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.dashboard-card {
    background: white;
    padding: 1.25rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.dashboard-label {
    color: #6b7280;
    font-size: 0.9rem;
    margin-bottom: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.dashboard-value {
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--dark-color);
}

.calculator-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    background: white;
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.calculator-form h3,
.calculator-results h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--dark-color);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--dark-color);
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.calculate-btn {
    width: 100%;
    padding: 12px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
}

/* Results Section */
.calculator-results {
    display: flex;
    flex-direction: column;
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.business-insights {
    background: linear-gradient(135deg, #eef2ff 0%, #ffffff 100%);
    padding: 1.75rem;
    border-radius: 18px;
    border: 1px solid rgba(99, 102, 241, 0.12);
    margin-top: 1.5rem;
}

.business-insights h4 {
    margin-top: 0;
    margin-bottom: 1rem;
    color: var(--secondary-color);
    font-size: 1.2rem;
}

.business-insights ul {
    padding-left: 1.25rem;
    color: var(--dark-color);
    line-height: 1.8;
}

.business-insights li {
    margin-bottom: 0.75rem;
}

.result-box {
    background: #f8fafc;
    padding: 1rem;
    border-radius: 10px;
    text-align: center;
    border: 1px solid var(--border-color);
}

.result-label {
    font-size: 0.875rem;
    color: #6b7280;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 0.5rem;
}

.result-value {
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--primary-color);
}

.results-summary {
    background: #f8fafc;
    padding: 1rem 1.25rem;
    border-radius: 8px;
    border-left: 3px solid var(--success-color);
    margin-top: 1rem;
}

.results-summary p {
    color: var(--dark-color);
    font-weight: 500;
    margin: 0;
}

/* Multi-Channel Section */
.multi-channel-section {
    margin-top: 3rem;
    padding-top: 3rem;
    border-top: 2px solid var(--border-color);
}

.multi-channel-section h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--dark-color);
}

.channels-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.channel-item {
    background: var(--light-color);
    padding: 1rem;
    border-radius: 8px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: 1px solid var(--border-color);
}

.channel-item-info h4 {
    color: var(--dark-color);
    margin-bottom: 0.25rem;
}

.channel-item-info p {
    font-size: 0.875rem;
    color: #6b7280;
}

.channel-filter {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: flex-start;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.channel-filter label {
    font-weight: 600;
    color: var(--dark-color);
}

.channel-filter select {
    max-width: 250px;
}

.channel-roi {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
}

.comparison-results {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.reset-btn {
    width: 100%;
    padding: 12px;
    background-color: #f3f4f6;
    color: var(--dark-color);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s ease;
}

.reset-btn:hover {
    background-color: var(--light-color);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

/* Guide Section */
.guide-section {
    padding: 80px 0;
    background-color: var(--light-color);
}

.guide-section h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--dark-color);
}

.guide-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.guide-card {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
}

.guide-card:hover {
    box-shadow: var(--shadow);
    transform: translateY(-4px);
}

.guide-card h4 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.guide-card p {
    color: var(--text-color);
    line-height: 1.8;
}

.guide-card strong {
    color: var(--dark-color);
}

/* About Section */
.about-section {
    padding: 80px 0;
    text-align: center;
}

.about-section h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    color: var(--dark-color);
}

.about-section p {
    font-size: 1.1rem;
    max-width: 700px;
    margin: 0 auto;
    line-height: 1.8;
    color: var(--text-color);
}

.performance-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-top: 1rem;
    padding: 0.75rem 1.25rem;
    border-radius: 999px;
    font-weight: 700;
    color: white;
    background: var(--primary-color);
    box-shadow: var(--shadow-sm);
}

.export-btn {
    width: 100%;
    padding: 14px;
    margin-top: 1rem;
    background: #0f172a;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    transition: transform 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease;
}

.export-btn:hover {
    transform: translateY(-2px);
    background-color: #111827;
    box-shadow: var(--shadow);
}

.secondary-btn {
    width: 100%;
    padding: 12px;
    margin-top: 0.75rem;
    background: white;
    color: var(--dark-color);
    border: 2px solid rgba(15, 23, 42, 0.12);
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 700;
    cursor: pointer;
    transition: transform 0.3s ease, border-color 0.3s ease, background-color 0.3s ease;
}

.secondary-btn:hover {
    transform: translateY(-1px);
    border-color: var(--primary-color);
    background-color: #f8fafc;
}

.export-btn:disabled,
.secondary-btn:disabled {
    opacity: 0.55;
    cursor: not-allowed;
}

.chart-card {
    background: white;
    padding: 1.75rem;
    border-radius: 18px;
    box-shadow: var(--shadow-sm);
    border: 1px solid rgba(15, 23, 42, 0.06);
    margin-bottom: 1.5rem;
}

.chart-card h4 {
    margin-top: 0;
    margin-bottom: 1rem;
    color: var(--dark-color);
    font-size: 1.1rem;
}

.chart-bars {
    display: grid;
    gap: 1rem;
}

.chart-bar-item {
    display: grid;
    gap: 0.4rem;
}

.chart-bar-label {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
    color: #374151;
    font-weight: 600;
}

.chart-bar-track {
    width: 100%;
    height: 14px;
    border-radius: 999px;
    background: #e5e7eb;
    overflow: hidden;
}

.chart-bar-fill {
    height: 100%;
    border-radius: 999px;
}

.chart-empty {
    color: #6b7280;
    line-height: 1.75;
}

footer {
    background-color: var(--dark-color);
    color: #d1d5db;
    padding: 2rem 0;
    text-align: center;
}

footer p {
    margin: 0.5rem 0;
    color: #d1d5db;
}

@media (max-width: 960px) {
    .calculator-wrapper {
        grid-template-columns: 1fr;
        padding: 2rem;
    }

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

    .comparison-results {
        grid-template-columns: 1fr;
    }

    .nav-links {
        gap: 1rem;
        flex-wrap: wrap;
        justify-content: center;
    }
}

@media (max-width: 640px) {
    .navbar .container,
    .hero-content,
    .features-grid,
    .guide-grid,
    .calculator-wrapper {
        padding-left: 10px;
        padding-right: 10px;
    }

    .hero h1 {
        font-size: 2.4rem;
    }

    .hero p,
    .features h2,
    .calculator-section h2,
    .guide-section h2,
    .about-section h2,
    .contact-section h2 {
        font-size: 2rem;
    }

    .cta-button,
    .calculate-btn,
    .export-btn,
    .reset-btn {
        font-size: 0.95rem;
    }

    .channel-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
    }
}

/* Contact Section */
.contact-section {
    padding: 80px 0;
    background: linear-gradient(135deg, #f3f4f6 0%, #ffffff 100%);
}

.contact-section h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--dark-color);
}

.contact-form {
    max-width: 500px;
    margin: 0 auto;
}

.contact-form .form-group {
    margin-bottom: 1.5rem;
}

.contact-form input,
.contact-form textarea {
    width: 100%;
    padding: 12px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.3s ease;
}

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

footer {
    background-color: var(--dark-color);
    color: #d1d5db;
    padding: 2rem 0;
    text-align: center;
}

footer p {
    margin: 0.5rem 0;
    color: #d1d5db;
}

@media (max-width: 960px) {
    .calculator-wrapper {
        grid-template-columns: 1fr;
        padding: 2rem;
    }

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

    .comparison-results {
        grid-template-columns: 1fr;
    }

    .nav-links {
        gap: 1rem;
        flex-wrap: wrap;
        justify-content: center;
    }
}

@media (max-width: 640px) {
    .navbar .container,
    .hero-content,
    .features-grid,
    .guide-grid,
    .calculator-wrapper {
        padding-left: 10px;
        padding-right: 10px;
    }

    .hero h1 {
        font-size: 2.4rem;
    }

    .hero p,
    .features h2,
    .calculator-section h2,
    .guide-section h2,
    .about-section h2,
    .contact-section h2 {
        font-size: 2rem;
    }

    .cta-button,
    .calculate-btn,
    .export-btn,
    .reset-btn {
        font-size: 0.95rem;
    }

    .channel-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
    }
}

.submit-btn {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.submit-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.contact-status {
    margin-top: 1rem;
    font-size: 0.95rem;
    color: var(--text-color);
}

/* Footer */
.footer {
    background: var(--dark-color);
    color: white;
    padding: 3rem 0;
    text-align: center;
}

.footer p {
    margin-bottom: 0.5rem;
}

.footer p:last-child {
    margin-bottom: 0;
    opacity: 0.8;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-links {
        flex-direction: column;
        gap: 1rem;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .hero p {
        font-size: 1.1rem;
    }

    .features h2,
    .calculator-section h2,
    .guide-section h2,
    .about-section h2,
    .contact-section h2 {
        font-size: 1.8rem;
    }

    .calculator-wrapper {
        grid-template-columns: 1fr;
        padding: 2rem;
        gap: 2rem;
    }

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

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

    .calculator-form,
    .calculator-results {
        padding: 0;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .hero {
        padding: 50px 0;
    }

    .hero h1 {
        font-size: 1.5rem;
    }

    .logo {
        font-size: 1.5rem;
    }

    .nav-links {
        gap: 0.5rem;
        font-size: 0.9rem;
    }

    .features,
    .calculator-section,
    .guide-section,
    .about-section,
    .contact-section {
        padding: 40px 0;
    }

    .result-value {
        font-size: 1.5rem;
    }
}