/* ===== CSS Variables ===== */
:root {
    --color-primary: #0ea5e9;
    --color-primary-dark: #0284c7;
    --color-primary-light: #38bdf8;
    --color-secondary: #1e293b;
    --color-accent: #06b6d4;
    --color-success: #22c55e;
    --color-warning: #f59e0b;
    --color-danger: #ef4444;
    --color-bg: #ffffff;
    --color-bg-alt: #f8fafc;
    --color-bg-dark: #0f172a;
    --color-text: #334155;
    --color-text-light: #64748b;
    --color-text-dark: #0f172a;
    --color-border: #e2e8f0;
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: 16px;
    line-height: 1.6;
    color: var(--color-text);
    background: var(--color-bg);
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color 0.2s;
}

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

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
}

/* ===== Layout ===== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-primary {
    background: var(--color-primary);
    color: white;
}

.btn-primary:hover {
    background: var(--color-primary-dark);
    color: white;
}

.btn-secondary {
    background: var(--color-bg-alt);
    color: var(--color-text-dark);
    border: 1px solid var(--color-border);
}

.btn-secondary:hover {
    background: var(--color-border);
    color: var(--color-text-dark);
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.btn-block {
    width: 100%;
}

.apple-icon {
    width: 1.25em;
    height: 1.25em;
}

/* ===== Navigation ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid transparent;
    transition: all 0.3s;
}

.navbar.scrolled {
    border-bottom-color: var(--color-border);
    box-shadow: var(--shadow-sm);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 4rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text-dark);
}

.logo:hover {
    color: var(--color-text-dark);
}

.logo-icon {
    width: 1.75rem;
    height: 1.75rem;
    border-radius: 0.375rem;
    object-fit: contain;
}

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

.nav-links a {
    color: var(--color-text);
    font-weight: 500;
}

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

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 0.5rem;
    background: none;
    border: none;
    cursor: pointer;
}

.mobile-menu-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text-dark);
    transition: all 0.3s;
}

/* ===== Hero Section ===== */
.hero {
    padding: 8rem 0 4rem;
    background: linear-gradient(135deg, var(--color-bg) 0%, var(--color-bg-alt) 100%);
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-content h1 {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.1;
    color: var(--color-text-dark);
    margin-bottom: 1rem;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--color-primary);
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--color-text-light);
    margin-bottom: 2rem;
    max-width: 540px;
}

.hero-cta {
    margin-bottom: 1rem;
}

.hero-note {
    font-size: 0.875rem;
    color: var(--color-text-light);
}

/* Phone Mockup */
.phone-mockup {
    width: 280px;
    height: 580px;
    background: #1a1a1a;
    border-radius: 40px;
    padding: 12px;
    box-shadow: var(--shadow-xl);
    margin: 0 auto;
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: var(--color-bg);
    border-radius: 30px;
    overflow: hidden;
}

.app-preview {
    padding: 1rem;
}

.preview-header {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text-dark);
    margin-bottom: 1rem;
}

.preview-tank {
    background: var(--color-bg-alt);
    border-radius: var(--radius-lg);
    padding: 1rem;
    margin-bottom: 1rem;
}

.tank-name {
    font-weight: 600;
    color: var(--color-text-dark);
    margin-bottom: 0.75rem;
}

.tank-stats {
    display: flex;
    gap: 1.5rem;
}

.stat {
    display: flex;
    flex-direction: column;
}

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

.stat-value.good {
    color: var(--color-success);
}

.stat-label {
    font-size: 0.75rem;
    color: var(--color-text-light);
}

.preview-alerts .alert {
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    font-weight: 500;
}

.alert.success {
    background: #dcfce7;
    color: #166534;
}

/* ===== Features Section ===== */
.features {
    padding: 6rem 0;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-text-dark);
    text-align: center;
    margin-bottom: 0.5rem;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--color-text-light);
    text-align: center;
    margin-bottom: 3rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.feature-card {
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: 2rem;
    transition: all 0.3s;
}

.feature-card:hover {
    border-color: var(--color-primary-light);
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.feature-icon {
    width: 2.5rem;
    height: 2.5rem;
    margin-bottom: 1rem;
    color: var(--color-primary);
}

.feature-icon svg {
    width: 100%;
    height: 100%;
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text-dark);
    margin-bottom: 0.75rem;
}

.feature-card p {
    color: var(--color-text-light);
    font-size: 0.9375rem;
}

/* ===== Why Shoalr Section ===== */
.why-shoalr {
    padding: 4rem 0;
    background: var(--color-bg-alt);
}

.comparison {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 2rem;
    max-width: 800px;
    margin: 0 auto;
}

.comparison-item {
    flex: 1;
    padding: 2rem;
    background: var(--color-bg);
    border-radius: var(--radius-xl);
    border: 1px solid var(--color-border);
}

.comparison-item.highlight {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-lg);
}

.comparison-item h4 {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-text-dark);
    margin-bottom: 0.75rem;
}

.comparison-item p {
    color: var(--color-text-light);
    font-size: 0.9375rem;
}

.comparison-divider {
    font-weight: 600;
    color: var(--color-text-light);
}

/* ===== Pricing Section ===== */
.pricing {
    padding: 6rem 0;
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
    max-width: 800px;
    margin: 0 auto 2rem;
}

.pricing-card {
    position: relative;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: 2rem;
}

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

.pricing-badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--color-primary);
    color: white;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.25rem 1rem;
    border-radius: 9999px;
}

.pricing-header {
    text-align: center;
    margin-bottom: 1.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--color-border);
}

.pricing-header h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-text-dark);
    margin-bottom: 0.5rem;
}

.price {
    display: flex;
    align-items: baseline;
    justify-content: center;
    gap: 0.25rem;
}

.price .amount {
    font-size: 3rem;
    font-weight: 700;
    color: var(--color-text-dark);
}

.price .period {
    font-size: 1rem;
    color: var(--color-text-light);
}

.price-alt {
    font-size: 0.875rem;
    color: var(--color-text-light);
    margin-top: 0.5rem;
}

.pricing-features {
    margin-bottom: 2rem;
}

.pricing-features li {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 0.5rem 0;
    color: var(--color-text);
}

.pricing-features .check-icon {
    width: 1.25rem;
    height: 1.25rem;
    color: var(--color-success);
    flex-shrink: 0;
}

.pricing-note {
    text-align: center;
    color: var(--color-text-light);
    font-size: 0.9375rem;
    max-width: 600px;
    margin: 0 auto;
}

/* ===== Support Section ===== */
.support {
    padding: 6rem 0;
    background: var(--color-bg-alt);
}

.support-content {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.support-card {
    background: var(--color-bg);
    border-radius: var(--radius-xl);
    padding: 2rem;
    text-align: center;
    border: 1px solid var(--color-border);
}

.support-icon {
    width: 2.5rem;
    height: 2.5rem;
    margin: 0 auto 1rem;
    color: var(--color-primary);
}

.support-icon svg {
    width: 100%;
    height: 100%;
}

.support-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text-dark);
    margin-bottom: 0.75rem;
}

.support-card p {
    color: var(--color-text-light);
    margin-bottom: 1rem;
    font-size: 0.9375rem;
}

.support-link {
    font-weight: 600;
    color: var(--color-primary);
}

/* ===== CTA Section ===== */
.cta {
    padding: 6rem 0;
    background: var(--color-bg-dark);
    text-align: center;
}

.cta h2 {
    font-size: 2.5rem;
    font-weight: 700;
    color: white;
    margin-bottom: 1rem;
}

.cta p {
    font-size: 1.125rem;
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 2rem;
}

/* ===== Footer ===== */
.footer {
    padding: 4rem 0 2rem;
    background: var(--color-bg-dark);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 3fr;
    gap: 4rem;
}

.footer-brand .logo {
    color: white;
    margin-bottom: 1rem;
}

.footer-brand p {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9375rem;
}

.footer-brand .copyright {
    margin-top: 1.5rem;
    font-size: 0.875rem;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.footer-column h4 {
    color: white;
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 1rem;
}

.footer-column ul li {
    margin-bottom: 0.5rem;
}

.footer-column a {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9375rem;
}

.footer-column a:hover {
    color: white;
}

/* ===== Mobile Responsive ===== */
@media (max-width: 1024px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-description {
        margin-left: auto;
        margin-right: auto;
    }

    .hero-image {
        order: -1;
    }

    .phone-mockup {
        width: 240px;
        height: 500px;
    }

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

@media (max-width: 768px) {
    .mobile-menu-btn {
        display: flex;
    }

    .nav-links {
        position: fixed;
        top: 4rem;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 1.5rem;
        gap: 1rem;
        border-bottom: 1px solid var(--color-border);
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s;
    }

    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .hero h1 {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.25rem;
    }

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

    .comparison {
        flex-direction: column;
    }

    .comparison-divider {
        transform: rotate(90deg);
    }

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

    .support-content {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .footer-links {
        grid-template-columns: repeat(2, 1fr);
    }

    .section-title {
        font-size: 2rem;
    }

    .cta h2 {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 2rem;
    }

    .btn-lg {
        padding: 0.875rem 1.5rem;
        font-size: 1rem;
    }

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