/* ===== DESIGN SYSTEM - BluKloud Technologies ===== */

/* CSS Variables */
:root {
    /* Colors */
    --blue-50: #EFF6FF;
    --blue-100: #DBEAFE;
    --blue-200: #BFDBFE;
    --blue-400: #60A5FA;
    --blue-500: #3B82F6;
    --blue-600: #2563EB;
    --blue-700: #1D4ED8;
    --blue-900: #1E3A8A;

    --purple-400: #A78BFA;
    --purple-500: #8B5CF6;
    --purple-600: #7C3AED;

    --amber-400: #FBBF24;
    --amber-500: #F59E0B;
    --amber-600: #D97706;

    --emerald-400: #34D399;
    --emerald-500: #10B981;
    --emerald-600: #059669;

    --gray-50: #F9FAFB;
    --gray-100: #F3F4F6;
    --gray-200: #E5E7EB;
    --gray-300: #D1D5DB;
    --gray-400: #9CA3AF;
    --gray-500: #6B7280;
    --gray-600: #4B5563;
    --gray-700: #374151;
    --gray-800: #1F2937;
    --gray-900: #111827;
    --gray-950: #030712;

    --white: #FFFFFF;
    --black: #000000;

    /* Gradient */
    --gradient-primary: linear-gradient(135deg, #2563EB 0%, #7C3AED 100%);
    --gradient-hero: linear-gradient(135deg, #0F172A 0%, #1E293B 50%, #0F172A 100%);
    --gradient-card: linear-gradient(135deg, rgba(255,255,255,0.05) 0%, rgba(255,255,255,0.02) 100%);
    --gradient-cta: linear-gradient(135deg, #1D4ED8 0%, #6D28D9 100%);

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-xs: 0.75rem;
    --font-sm: 0.875rem;
    --font-base: 1rem;
    --font-lg: 1.125rem;
    --font-xl: 1.25rem;
    --font-2xl: 1.5rem;
    --font-3xl: 1.875rem;
    --font-4xl: 2.25rem;
    --font-5xl: 3rem;
    --font-6xl: 3.75rem;

    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    --space-24: 6rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;

    /* Shadows */
    --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 -2px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -4px rgba(0,0,0,0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.1), 0 8px 10px -6px rgba(0,0,0,0.1);
    --shadow-glow: 0 0 40px rgba(37,99,235,0.15);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;

    /* Z-index */
    --z-nav: 100;
    --z-overlay: 50;
}

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

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-base);
    line-height: 1.6;
    color: var(--gray-800);
    background-color: var(--white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

img { max-width: 100%; height: auto; display: block; }
a { text-decoration: none; color: inherit; }
ul, ol { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
input, textarea, select { font-family: inherit; }

/* ===== LAYOUT ===== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.section {
    padding: var(--space-20) 0;
}

@media (min-width: 768px) {
    .section { padding: var(--space-24) 0; }
}

/* ===== TYPOGRAPHY ===== */
.gradient-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-header {
    text-align: center;
    max-width: 640px;
    margin: 0 auto var(--space-16);
}

.section-tag {
    display: inline-block;
    font-size: var(--font-sm);
    font-weight: 600;
    color: var(--blue-600);
    background: var(--blue-50);
    padding: var(--space-2) var(--space-4);
    border-radius: var(--radius-full);
    margin-bottom: var(--space-4);
    letter-spacing: 0.02em;
}

.section-title {
    font-size: var(--font-3xl);
    font-weight: 800;
    color: var(--gray-900);
    line-height: 1.2;
    margin-bottom: var(--space-4);
}

.section-desc {
    font-size: var(--font-lg);
    color: var(--gray-500);
    line-height: 1.7;
}

@media (min-width: 768px) {
    .section-title { font-size: var(--font-4xl); }
}

/* ===== NAVBAR ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-nav);
    background: rgba(255,255,255,0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0,0,0,0.06);
    transition: all var(--transition-base);
}

.navbar.scrolled {
    background: rgba(255,255,255,0.95);
    box-shadow: var(--shadow-sm);
}

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

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    z-index: calc(var(--z-nav) + 1);
}

.logo-text {
    font-size: var(--font-xl);
    font-weight: 700;
    color: var(--gray-900);
}

.logo-highlight {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--space-1);
}

.nav-link {
    padding: var(--space-2) var(--space-4);
    font-size: var(--font-sm);
    font-weight: 500;
    color: var(--gray-600);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    position: relative;
}

.nav-link:hover { color: var(--gray-900); background: var(--gray-50); }
.nav-link.active { color: var(--blue-600); background: var(--blue-50); }

.nav-link.cta-link {
    background: var(--gradient-primary);
    color: var(--white);
    padding: var(--space-2) var(--space-5);
    border-radius: var(--radius-full);
    margin-left: var(--space-2);
}

.nav-link.cta-link:hover { opacity: 0.9; box-shadow: 0 4px 12px rgba(37,99,235,0.3); }
.nav-link.cta-link.active { background: var(--gradient-primary); color: var(--white); }

.nav-toggle { display: none; }

.hamburger {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--gray-700);
    position: relative;
    transition: all var(--transition-base);
}

.hamburger::before, .hamburger::after {
    content: '';
    display: block;
    width: 24px;
    height: 2px;
    background: var(--gray-700);
    position: absolute;
    transition: all var(--transition-base);
}

.hamburger::before { top: -7px; }
.hamburger::after { top: 7px; }

/* Mobile Nav */
@media (max-width: 767px) {
    .nav-toggle {
        display: flex;
        align-items: center;
        justify-content: center;
        width: 44px;
        height: 44px;
        z-index: calc(var(--z-nav) + 1);
    }

    .nav-links {
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background: rgba(255,255,255,0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        justify-content: center;
        gap: var(--space-2);
        opacity: 0;
        pointer-events: none;
        transition: opacity var(--transition-base);
    }

    .nav-links.active {
        opacity: 1;
        pointer-events: all;
    }

    .nav-link {
        font-size: var(--font-xl);
        padding: var(--space-4) var(--space-8);
    }

    .nav-link.cta-link { margin-left: 0; margin-top: var(--space-4); }

    .nav-toggle.active .hamburger { background: transparent; }
    .nav-toggle.active .hamburger::before { top: 0; transform: rotate(45deg); }
    .nav-toggle.active .hamburger::after { top: 0; transform: rotate(-45deg); }
}

/* ===== BUTTONS ===== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    font-weight: 600;
    font-size: var(--font-sm);
    padding: var(--space-3) var(--space-6);
    border-radius: var(--radius-lg);
    transition: all var(--transition-base);
    white-space: nowrap;
}

.btn-lg {
    padding: var(--space-4) var(--space-8);
    font-size: var(--font-base);
    border-radius: var(--radius-xl);
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--white);
    box-shadow: 0 4px 14px rgba(37,99,235,0.25);
}

.btn-primary:hover {
    box-shadow: 0 6px 20px rgba(37,99,235,0.4);
    transform: translateY(-2px);
}

.btn-ghost {
    color: var(--gray-700);
    border: 1px solid var(--gray-200);
    background: var(--white);
}

.btn-ghost:hover {
    border-color: var(--gray-300);
    background: var(--gray-50);
    transform: translateY(-2px);
}

.btn-white {
    background: var(--white);
    color: var(--blue-700);
    box-shadow: 0 4px 14px rgba(0,0,0,0.15);
}

.btn-white:hover {
    box-shadow: 0 6px 20px rgba(0,0,0,0.2);
    transform: translateY(-2px);
}

.btn-outline-white {
    border: 2px solid rgba(255,255,255,0.3);
    color: var(--white);
}

.btn-outline-white:hover {
    background: rgba(255,255,255,0.1);
    border-color: rgba(255,255,255,0.5);
    transform: translateY(-2px);
}

.btn-amber {
    background: linear-gradient(135deg, var(--amber-500) 0%, var(--amber-600) 100%);
    color: var(--white);
    box-shadow: 0 4px 14px rgba(245,158,11,0.25);
}

.btn-amber:hover {
    box-shadow: 0 6px 20px rgba(245,158,11,0.4);
    transform: translateY(-2px);
}

.btn-emerald {
    background: linear-gradient(135deg, var(--emerald-500) 0%, var(--emerald-600) 100%);
    color: var(--white);
    box-shadow: 0 4px 14px rgba(16,185,129,0.25);
}

.btn-emerald:hover {
    box-shadow: 0 6px 20px rgba(16,185,129,0.4);
    transform: translateY(-2px);
}

.btn-full { width: 100%; justify-content: center; }

/* ===== PAGE HERO (inner pages) ===== */
.page-hero {
    padding: 140px 0 80px;
    text-align: center;
    background: var(--gradient-hero);
    position: relative;
    overflow: hidden;
}

.page-hero-title {
    font-size: var(--font-4xl);
    font-weight: 800;
    color: var(--white);
    line-height: 1.15;
    margin-bottom: var(--space-4);
}

.page-hero-desc {
    font-size: var(--font-lg);
    color: rgba(255,255,255,0.6);
    max-width: 560px;
    margin: 0 auto;
}

@media (min-width: 768px) {
    .page-hero { padding: 160px 0 100px; }
    .page-hero-title { font-size: var(--font-5xl); }
}

/* ===== FOOTER ===== */
.footer {
    background: var(--gray-950);
    padding: var(--space-16) 0 0;
    color: var(--gray-400);
}

.footer-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-10);
    padding-bottom: var(--space-12);
    border-bottom: 1px solid rgba(255,255,255,0.08);
}

@media (min-width: 768px) {
    .footer-grid { grid-template-columns: 2fr 1fr 1fr 1fr; }
}

.footer-brand { max-width: 320px; }
.footer-brand .nav-logo .logo-text { color: var(--white); }

.footer-tagline {
    margin-top: var(--space-4);
    font-size: var(--font-sm);
    line-height: 1.7;
    color: var(--gray-500);
}

.footer-social {
    display: flex;
    gap: var(--space-3);
    margin-top: var(--space-6);
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-lg);
    background: rgba(255,255,255,0.06);
    color: var(--gray-400);
    transition: all var(--transition-base);
}

.social-link:hover {
    background: rgba(37,99,235,0.2);
    color: var(--blue-400);
    transform: translateY(-2px);
}

.footer-heading {
    font-size: var(--font-sm);
    font-weight: 600;
    color: var(--white);
    margin-bottom: var(--space-4);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.footer-links li { margin-bottom: var(--space-3); }

.footer-links a {
    font-size: var(--font-sm);
    color: var(--gray-500);
    transition: color var(--transition-fast);
}

.footer-links a:hover { color: var(--white); }

.footer-bottom {
    padding: var(--space-6) 0;
    text-align: center;
    font-size: var(--font-sm);
    color: var(--gray-600);
}

/* ===== ANIMATIONS ===== */
@keyframes fadeUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

.animate-fade-up {
    opacity: 0;
    animation: fadeUp 0.8s ease forwards;
}

.delay-1 { animation-delay: 0.15s; }
.delay-2 { animation-delay: 0.3s; }
.delay-3 { animation-delay: 0.45s; }
.delay-4 { animation-delay: 0.6s; }

.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.7s ease, transform 0.7s ease;
}

.animate-on-scroll.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===== HERO BG ORBS ===== */
.hero-bg {
    position: absolute;
    inset: 0;
    overflow: hidden;
    pointer-events: none;
}

.hero-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.5;
}

.hero-orb-1 {
    width: 400px;
    height: 400px;
    background: rgba(37,99,235,0.3);
    top: -100px;
    right: -100px;
    animation: float 8s ease-in-out infinite;
}

.hero-orb-2 {
    width: 300px;
    height: 300px;
    background: rgba(124,58,237,0.2);
    bottom: -50px;
    left: -50px;
    animation: float 10s ease-in-out infinite reverse;
}

.hero-orb-3 {
    width: 200px;
    height: 200px;
    background: rgba(59,130,246,0.2);
    top: 50%;
    left: 50%;
    animation: float 12s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0); }
    33% { transform: translate(20px, -20px); }
    66% { transform: translate(-10px, 15px); }
}

/* ===== FOCUS / ACCESSIBILITY ===== */
:focus-visible {
    outline: 2px solid var(--blue-500);
    outline-offset: 2px;
}

/* Screen reader only */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    white-space: nowrap;
    border: 0;
}