/* ==========================================================================
   FuelZen — Dark Vibrant Neon Design System (Mobile Responsive)
   ========================================================================== */

:root {
    --bg-dark: #050806;
    --bg-card: rgba(15, 23, 19, 0.75);
    --bg-card-hover: rgba(22, 36, 29, 0.9);
    --border-color: rgba(57, 211, 83, 0.15);
    --border-glow: rgba(57, 211, 83, 0.4);
    
    --primary-green: #39D353;
    --primary-green-dark: #22c55e;
    --green-glow: rgba(57, 211, 83, 0.35);
    --green-subtle: rgba(57, 211, 83, 0.1);
    
    --text-main: #FFFFFF;
    --text-muted: #94A3B8;
    --text-dim: #64748B;
    
    --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-body: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    
    --radius-sm: 8px;
    --radius-md: 14px;
    --radius-lg: 24px;
    --radius-full: 9999px;
    
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Reset & Base Styles */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    -webkit-tap-highlight-color: transparent;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    background-color: var(--bg-dark);
    color: var(--text-main);
    font-family: var(--font-body);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
    min-height: 100vh;
    width: 100%;
}

/* Background Ambient Lighting */
.bg-glow {
    position: absolute;
    pointer-events: none;
    z-index: 0;
}

/* Top curved header shape matching app splash screen */
.bg-glow.top-curve {
    top: -120px;
    left: 50%;
    transform: translateX(-50%);
    width: 140%;
    max-width: 1600px;
    height: 380px;
    background: radial-gradient(ellipse at top, rgba(57, 211, 83, 0.45) 0%, rgba(34, 197, 94, 0.15) 45%, transparent 75%);
    border-radius: 0 0 50% 50%;
    filter: blur(20px);
}

.bg-glow.radial-center {
    top: 35%;
    right: -10%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(57, 211, 83, 0.12) 0%, transparent 70%);
    filter: blur(80px);
}

.bg-glow.radial-bottom {
    bottom: 5%;
    left: -10%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(34, 197, 94, 0.1) 0%, transparent 70%);
    filter: blur(90px);
}

/* Layout Utilities */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    position: relative;
    z-index: 1;
}

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

.text-green {
    color: var(--primary-green);
    text-shadow: 0 0 20px rgba(57, 211, 83, 0.4);
}

/* Navbar */
.navbar {
    padding: 1.25rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    background: rgba(5, 8, 6, 0.8);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

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

.brand {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    text-decoration: none;
}

.brand-logo {
    width: 34px;
    height: 34px;
    object-fit: contain;
    filter: drop-shadow(0 0 8px rgba(57, 211, 83, 0.5));
}

.brand-name {
    font-family: var(--font-heading);
    font-size: 1.4rem;
    font-weight: 800;
    color: var(--text-main);
    letter-spacing: -0.5px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    text-decoration: none;
    font-family: var(--font-heading);
    font-weight: 700;
    border-radius: var(--radius-full);
    transition: var(--transition-smooth);
    cursor: pointer;
    border: none;
}

.btn-sm {
    padding: 0.55rem 1.15rem;
    font-size: 0.88rem;
}

.btn-xl {
    padding: 1.1rem 2rem;
    font-size: 1.15rem;
    width: 100%;
    min-height: 60px;
}

.btn-outline {
    background: rgba(57, 211, 83, 0.08);
    color: var(--primary-green);
    border: 1px solid rgba(57, 211, 83, 0.3);
}

.btn-outline:hover, .btn-outline:active {
    background: rgba(57, 211, 83, 0.18);
    border-color: var(--primary-green);
    box-shadow: 0 0 15px rgba(57, 211, 83, 0.3);
    transform: translateY(-2px);
}

.btn-primary {
    background: linear-gradient(135deg, #39D353 0%, #22C55E 100%);
    color: #030805;
    box-shadow: 0 10px 30px rgba(57, 211, 83, 0.4), 0 0 15px rgba(57, 211, 83, 0.2);
    position: relative;
    overflow: hidden;
}

.btn-primary::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: 0.6s ease;
}

.btn-primary:hover::after {
    left: 100%;
}

.btn-primary:hover, .btn-primary:focus {
    transform: translateY(-3px) scale(1.01);
    box-shadow: 0 15px 40px rgba(57, 211, 83, 0.6), 0 0 25px rgba(57, 211, 83, 0.4);
}

.btn-primary:active {
    transform: translateY(-1px) scale(0.99);
}

.btn-text {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    text-align: left;
}

.btn-title {
    font-size: clamp(1.05rem, 3.5vw, 1.25rem);
    line-height: 1.2;
    font-weight: 800;
}

.btn-sub {
    font-size: clamp(0.72rem, 2.5vw, 0.8rem);
    font-weight: 500;
    opacity: 0.9;
}

.btn-icon {
    display: flex;
    align-items: center;
    flex-shrink: 0;
}

/* Hero Section */
.hero-section {
    padding: 3rem 0 4.5rem;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3.5rem;
    align-items: center;
}

.hero-text {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.badge-pill {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.4rem 0.9rem;
    background: rgba(57, 211, 83, 0.1);
    border: 1px solid rgba(57, 211, 83, 0.25);
    border-radius: var(--radius-full);
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--primary-green);
    margin-bottom: 1.25rem;
}

.badge-dot {
    width: 8px;
    height: 8px;
    background-color: var(--primary-green);
    border-radius: 50%;
    box-shadow: 0 0 10px var(--primary-green);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(57, 211, 83, 0.7); }
    70% { transform: scale(1); box-shadow: 0 0 0 8px rgba(57, 211, 83, 0); }
    100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(57, 211, 83, 0); }
}

.hero-brand-circle {
    width: 80px;
    height: 80px;
    background: #0d1611;
    border: 2px solid rgba(57, 211, 83, 0.4);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 0 30px rgba(57, 211, 83, 0.35);
    margin-bottom: 1.25rem;
}

.hero-emblem {
    width: 48px;
    height: 48px;
    object-fit: contain;
}

.hero-title {
    font-family: var(--font-heading);
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 800;
    line-height: 1.08;
    letter-spacing: -1px;
    margin-bottom: 0.5rem;
}

.hero-tagline {
    font-family: var(--font-heading);
    font-size: clamp(1.15rem, 3.2vw, 1.4rem);
    font-weight: 600;
    color: var(--text-muted);
    margin-bottom: 1.1rem;
}

.hero-description {
    font-size: clamp(0.95rem, 2.5vw, 1.05rem);
    color: var(--text-muted);
    margin-bottom: 1.75rem;
    max-width: 520px;
}

/* Download Box */
.download-box {
    width: 100%;
    max-width: 460px;
}

.download-btn {
    animation: floatingGlow 3s ease-in-out infinite;
}

@keyframes floatingGlow {
    0%, 100% { box-shadow: 0 10px 30px rgba(57, 211, 83, 0.4); }
    50% { box-shadow: 0 15px 45px rgba(57, 211, 83, 0.65); }
}

.download-meta {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.6rem;
    margin-top: 0.85rem;
    font-size: 0.82rem;
    color: var(--text-muted);
    flex-wrap: wrap;
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 0.35rem;
}

.meta-item svg {
    color: var(--primary-green);
    flex-shrink: 0;
}

.meta-divider {
    color: var(--text-dim);
}

/* Phone Visual */
.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
}

.phone-mockup-wrapper {
    position: relative;
    padding: 10px;
}

.phone-glow {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 90%;
    height: 90%;
    background: radial-gradient(circle, rgba(57, 211, 83, 0.3) 0%, transparent 70%);
    filter: blur(50px);
    z-index: 0;
}

.phone-mockup {
    position: relative;
    z-index: 1;
    width: 280px;
    height: 570px;
    background: #090e0b;
    border-radius: 40px;
    border: 7px solid #1a2920;
    box-shadow: 0 25px 60px rgba(0, 0, 0, 0.8), 0 0 30px rgba(57, 211, 83, 0.25);
    overflow: hidden;
    transition: var(--transition-smooth);
}

.phone-mockup:hover {
    transform: translateY(-6px) rotate(-1deg);
    box-shadow: 0 35px 70px rgba(0, 0, 0, 0.9), 0 0 45px rgba(57, 211, 83, 0.4);
}

.phone-notch {
    position: absolute;
    top: 12px;
    left: 50%;
    transform: translateX(-50%);
    width: 85px;
    height: 16px;
    background: #000000;
    border-radius: 10px;
    z-index: 10;
}

.phone-screen {
    width: 100%;
    height: 100%;
    overflow: hidden;
}

.app-screenshot {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: top center;
}

/* Sections General */
.section {
    padding: 4.5rem 0;
    position: relative;
}

.section-header {
    margin-bottom: 3rem;
}

.section-title {
    font-family: var(--font-heading);
    font-size: clamp(1.8rem, 5vw, 2.4rem);
    font-weight: 800;
    letter-spacing: -0.5px;
    margin-bottom: 0.5rem;
}

.section-subtitle {
    font-size: clamp(0.95rem, 2.5vw, 1.1rem);
    color: var(--text-muted);
}

/* Steps Grid */
.steps-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.step-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 2rem 1.5rem;
    position: relative;
    overflow: hidden;
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    transition: var(--transition-smooth);
}

.step-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--border-glow);
    transform: translateY(-4px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.5), 0 0 20px rgba(57, 211, 83, 0.15);
}

.step-number {
    position: absolute;
    top: 0.75rem;
    right: 1.1rem;
    font-family: var(--font-heading);
    font-size: 3.2rem;
    font-weight: 800;
    color: rgba(57, 211, 83, 0.08);
}

.step-icon {
    width: 52px;
    height: 52px;
    background: rgba(57, 211, 83, 0.12);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-green);
    margin-bottom: 1.25rem;
}

.step-title {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.4rem;
}

.step-desc {
    font-size: 0.92rem;
    color: var(--text-muted);
}

.step-desc code {
    background: rgba(57, 211, 83, 0.15);
    color: var(--primary-green);
    padding: 0.15rem 0.4rem;
    border-radius: 4px;
    font-size: 0.85rem;
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 2rem;
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    transition: var(--transition-smooth);
}

.feature-card:hover {
    border-color: var(--border-glow);
    background: var(--bg-card-hover);
    transform: translateY(-4px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.4), 0 0 25px rgba(57, 211, 83, 0.15);
}

.feature-icon {
    font-size: 2.3rem;
    margin-bottom: 0.85rem;
}

.feature-title {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.4rem;
}

.feature-desc {
    font-size: 0.95rem;
    color: var(--text-muted);
}

/* CTA Banner Section */
.cta-banner-section {
    padding: 2.5rem 0 5rem;
}

.cta-banner {
    background: linear-gradient(135deg, rgba(20, 36, 26, 0.9) 0%, rgba(8, 16, 11, 0.95) 100%);
    border: 1px solid var(--border-glow);
    border-radius: var(--radius-lg);
    padding: 3.5rem 1.75rem;
    text-align: center;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.6), 0 0 35px rgba(57, 211, 83, 0.2);
    position: relative;
    overflow: hidden;
}

.cta-banner::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 350px;
    height: 350px;
    background: radial-gradient(circle, rgba(57, 211, 83, 0.2) 0%, transparent 70%);
    filter: blur(60px);
    pointer-events: none;
}

.cta-banner-content {
    max-width: 580px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.cta-logo {
    width: 56px;
    height: 56px;
    margin-bottom: 0.85rem;
    filter: drop-shadow(0 0 15px rgba(57, 211, 83, 0.6));
}

.cta-title {
    font-family: var(--font-heading);
    font-size: clamp(1.8rem, 5vw, 2.4rem);
    font-weight: 800;
    margin-bottom: 0.6rem;
}

.cta-desc {
    font-size: clamp(0.95rem, 2.5vw, 1.05rem);
    color: var(--text-muted);
    margin-bottom: 2rem;
}

/* Footer */
.footer {
    padding: 2.25rem 0;
    border-top: 1px solid rgba(255, 255, 255, 0.06);
    background: rgba(3, 5, 4, 0.95);
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.85rem;
    text-align: center;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.footer-logo {
    width: 24px;
    height: 24px;
}

.footer-name {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.05rem;
}

.footer-copy {
    font-size: 0.85rem;
    color: var(--text-dim);
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: #0f1c14;
    border: 1px solid var(--primary-green);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.85), 0 0 20px rgba(57, 211, 83, 0.4);
    border-radius: var(--radius-md);
    padding: 0.9rem 1.25rem;
    display: flex;
    align-items: center;
    gap: 0.85rem;
    z-index: 1000;
    transition: var(--transition-smooth);
    transform: translateY(0);
    opacity: 1;
}

.toast.hidden {
    transform: translateY(100px);
    opacity: 0;
    pointer-events: none;
}

.toast-icon {
    font-size: 1.4rem;
    flex-shrink: 0;
}

.toast-text {
    display: flex;
    flex-direction: column;
    font-size: 0.85rem;
}

.toast-text strong {
    color: var(--primary-green);
}

.toast-text span {
    color: var(--text-muted);
}

/* ==========================================================================
   Responsive Breakpoints & Touch Mobile Optimization
   ========================================================================== */

/* Tablets & Small Laptops (max-width: 992px) */
@media (max-width: 992px) {
    .container {
        padding: 0 1.25rem;
    }

    .hero-grid {
        grid-template-columns: 1fr;
        gap: 3rem;
        text-align: center;
    }
    
    .hero-text {
        align-items: center;
    }

    .hero-description {
        max-width: 100%;
    }

    .btn-text {
        align-items: center;
        text-align: center;
    }

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

/* Smartphones (max-width: 768px) */
@media (max-width: 768px) {
    .section {
        padding: 3.5rem 0;
    }

    .navbar {
        padding: 0.9rem 0;
    }

    .brand-name {
        font-size: 1.25rem;
    }

    .brand-logo {
        width: 28px;
        height: 28px;
    }

    .nav-cta {
        padding: 0.45rem 0.95rem;
        font-size: 0.8rem;
    }

    .hero-brand-circle {
        width: 70px;
        height: 70px;
        margin-bottom: 1rem;
    }

    .hero-emblem {
        width: 40px;
        height: 40px;
    }

    .steps-grid {
        grid-template-columns: 1fr;
        gap: 1.25rem;
    }

    .step-card {
        padding: 1.5rem 1.25rem;
        border-radius: 18px;
    }

    .step-number {
        font-size: 2.8rem;
    }

    .feature-card {
        padding: 1.5rem 1.25rem;
        border-radius: 18px;
    }

    .phone-mockup {
        width: 240px;
        height: 490px;
        border-width: 6px;
        border-radius: 34px;
    }

    .phone-notch {
        width: 75px;
        height: 14px;
        top: 10px;
    }

    .cta-banner {
        padding: 2.5rem 1.25rem;
        border-radius: 20px;
    }

    .toast {
        left: 1rem;
        right: 1rem;
        bottom: 1.25rem;
        max-width: calc(100vw - 2rem);
        padding: 0.85rem 1rem;
    }
}

/* Extra Small Screens / Older Mobile Devices (max-width: 480px) */
@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }

    .badge-pill {
        font-size: 0.76rem;
        padding: 0.35rem 0.75rem;
    }

    .btn-xl {
        padding: 0.9rem 1.1rem;
        gap: 0.6rem;
    }

    .btn-title {
        font-size: 1.05rem;
    }

    .btn-sub {
        font-size: 0.7rem;
    }

    .download-meta {
        font-size: 0.78rem;
        gap: 0.4rem;
    }

    .meta-divider {
        display: none;
    }

    .meta-item {
        width: 100%;
        justify-content: center;
    }

    .phone-mockup {
        width: 220px;
        height: 450px;
        border-width: 5px;
        border-radius: 30px;
    }
}