/* =========================================================================
   Cragon Education - Stylesheet (Revised)
   ========================================================================= */

/* --- Custom Properties (Design Tokens) --- */
:root {
    --bg-primary: #050a0e;
    --bg-surface: rgba(15, 23, 42, 0.6);
    --bg-surface-solid: #0f172a;
    --bg-surface-hover: #162033;
    --bg-nav: rgba(5, 10, 14, 0.75);
    
    --border: rgba(56, 189, 248, 0.07);
    --border-hover: rgba(56, 189, 248, 0.22);
    
    --accent: #38bdf8;
    --accent-secondary: #0ea5e9;
    --accent-glow: rgba(56, 189, 248, 0.12);
    --accent-gradient: linear-gradient(135deg, #38bdf8, #0ea5e9);
    
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --text-bright: #e2e8f0;

    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    
    --container-width: 1120px;
    --radius: 16px;
    --radius-sm: 10px;
    
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-reveal: 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-secondary);
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

h1, h2, h3, h4 {
    color: var(--text-primary);
    line-height: 1.15;
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: color var(--transition-fast);
}
a:hover { color: var(--text-primary); }

ul { list-style: none; }
img, svg { max-width: 100%; display: block; }

/* --- Layout --- */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 1.5rem;
}

.section {
    padding: clamp(5rem, 10vw, 9rem) 0;
    position: relative;
}

.grid {
    display: grid;
    gap: 1.5rem;
}

.divider {
    border: none;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--border-hover), transparent);
    margin: 0;
}

.visually-hidden {
    position: absolute;
    width: 1px; height: 1px;
    padding: 0; margin: -1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    white-space: nowrap; border: 0;
}

/* --- Subtle Grid Texture Overlay --- */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background-image: radial-gradient(rgba(56, 189, 248, 0.03) 1px, transparent 1px);
    background-size: 40px 40px;
    pointer-events: none;
    z-index: 0;
}

/* --- Header & Navigation --- */
.header {
    position: fixed;
    top: 0; left: 0;
    width: 100%;
    z-index: 100;
    padding: 1rem 0;
    transition: all var(--transition-smooth);
    border-bottom: 1px solid transparent;
}

.header.scrolled {
    background-color: var(--bg-nav);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    padding: 0.75rem 0;
}

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

.logo {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.025em;
    transition: opacity var(--transition-fast);
}
.logo:hover { color: var(--text-primary); opacity: 0.8; }

.logo-tagline {
    font-size: 0.7rem;
    font-weight: 500;
    color: var(--text-muted);
    letter-spacing: 0.06em;
    margin-left: 0.75rem;
    padding-left: 0.75rem;
    border-left: 1px solid var(--border);
    text-transform: uppercase;
}

.nav {
    display: flex;
    gap: 2.25rem;
    align-items: center;
}

.nav-link {
    color: var(--text-muted);
    font-weight: 500;
    font-size: 0.9rem;
    position: relative;
    transition: color var(--transition-fast);
}
.nav-link:hover { color: var(--text-primary); }

.nav-link:not(.btn-nav)::after {
    content: '';
    position: absolute;
    bottom: -4px; left: 0;
    width: 100%; height: 1.5px;
    background: var(--accent-gradient);
    transform: scaleX(0);
    transform-origin: right;
    transition: transform var(--transition-smooth);
}
.nav-link:not(.btn-nav):hover::after {
    transform: scaleX(1);
    transform-origin: left;
}

.btn-nav {
    padding: 0.5rem 1.25rem;
    background: var(--accent-gradient);
    border-radius: 6px;
    color: #fff !important;
    font-weight: 600;
    font-size: 0.85rem;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}
.btn-nav:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(56, 189, 248, 0.25);
}

/* Mobile Menu */
.mobile-menu-btn {
    display: none;
    background: none; border: none;
    cursor: pointer;
    width: 28px; height: 20px;
    position: relative;
    z-index: 101;
}

.mobile-menu-btn .bar {
    display: block;
    width: 100%; height: 2px;
    background-color: var(--text-primary);
    position: absolute; left: 0;
    transition: transform var(--transition-fast), opacity var(--transition-fast);
    border-radius: 2px;
}
.mobile-menu-btn .bar:nth-child(1) { top: 0; }
.mobile-menu-btn .bar:nth-child(2) { top: 9px; }
.mobile-menu-btn .bar:nth-child(3) { top: 18px; }

.mobile-menu-btn.open .bar:nth-child(1) { transform: translateY(9px) rotate(45deg); }
.mobile-menu-btn.open .bar:nth-child(2) { opacity: 0; }
.mobile-menu-btn.open .bar:nth-child(3) { transform: translateY(-9px) rotate(-45deg); }


/* --- Buttons --- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.9rem 2rem;
    border-radius: 8px;
    font-weight: 600;
    font-size: 1rem;
    text-align: center;
    cursor: pointer;
    border: none;
    font-family: inherit;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.btn-primary {
    background: var(--accent-gradient);
    background-size: 200% 200%;
    color: #fff;
    box-shadow: 0 4px 20px rgba(56, 189, 248, 0.2);
}
.btn-primary:hover {
    color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(56, 189, 248, 0.3);
}
.btn-primary:active { transform: translateY(0); }

.btn-primary .btn-arrow {
    transition: transform var(--transition-fast);
}
.btn-primary:hover .btn-arrow {
    transform: translateX(3px);
}

.btn-block {
    width: 100%;
    justify-content: center;
    padding: 1rem;
}

/* --- Section Titles --- */
.section-label {
    display: inline-block;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--accent);
    margin-bottom: 1rem;
}

.section-title {
    font-size: clamp(1.85rem, 3.5vw, 2.75rem);
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: 1rem;
}

.section-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 560px;
    line-height: 1.7;
}


/* ========================================================================
   HERO SECTION
   ======================================================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 5rem;
    position: relative;
    overflow: hidden;
}

.hero-content {
    max-width: 780px;
    position: relative;
    z-index: 2;
}

.hero-title {
    font-size: clamp(2.6rem, 5.5vw, 4.2rem);
    font-weight: 700;
    letter-spacing: -0.035em;
    line-height: 1.08;
    margin-bottom: 1.75rem;
}

.hero-title .line-accent {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: clamp(1.05rem, 1.8vw, 1.2rem);
    max-width: 600px;
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

.hero-audience {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-style: italic;
    margin-top: 1.5rem;
    margin-bottom: 0;
}

/* Hero pillars */
.hero-pillars {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-top: 3rem;
    padding-top: 2.5rem;
    border-top: 1px solid var(--border);
}

.pillar {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: rgba(15, 23, 42, 0.4);
    transition: all var(--transition-fast);
}

.pillar:hover {
    border-color: var(--border-hover);
    background: rgba(15, 23, 42, 0.7);
}

.pillar-icon {
    font-size: 1.15rem;
    line-height: 1.4;
    flex-shrink: 0;
}

.pillar-text {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* Background Glows */
.glow {
    position: absolute;
    border-radius: 50%;
    filter: blur(100px);
    z-index: 1;
    pointer-events: none;
}

.glow-1 {
    top: 5%;
    left: -15%;
    width: 55vw; height: 55vw;
    max-width: 700px; max-height: 700px;
    background: radial-gradient(circle, rgba(14,165,233,0.12) 0%, transparent 70%);
}

.glow-2 {
    bottom: -20%;
    right: -15%;
    width: 45vw; height: 45vw;
    max-width: 550px; max-height: 550px;
    background: radial-gradient(circle, rgba(56,189,248,0.08) 0%, transparent 70%);
}


/* ========================================================================
   CARDS (Shared)
   ======================================================================== */
.card {
    background: var(--bg-surface);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    transition: all var(--transition-smooth);
    display: flex;
    flex-direction: column;
    position: relative;
    overflow: hidden;
}

/* Accent top-border on hover */
.card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 2px;
    background: var(--accent-gradient);
    opacity: 0;
    transition: opacity var(--transition-smooth);
}

.card:hover {
    background: var(--bg-surface-hover);
    border-color: var(--border-hover);
    transform: translateY(-4px);
    box-shadow: 
        0 8px 30px rgba(0,0,0,0.25),
        0 0 40px rgba(56, 189, 248, 0.04);
}

.card:hover::before { opacity: 1; }

.card-title {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 0.6rem;
}

.card-list {
    margin-top: 1.25rem;
    flex-grow: 1;
}

.card-list li {
    position: relative;
    padding-left: 1.4rem;
    margin-bottom: 0.7rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.card-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.55em;
    width: 6px; height: 6px;
    border-radius: 50%;
    background: var(--accent);
    opacity: 0.6;
}


/* ========================================================================
   SERVICES
   ======================================================================== */
.services .section-header {
    margin-bottom: 3rem;
}

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

.card-icon {
    width: 44px; height: 44px;
    border-radius: var(--radius-sm);
    background: rgba(56, 189, 248, 0.06);
    color: var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.25rem;
    border: 1px solid rgba(56, 189, 248, 0.1);
    transition: background var(--transition-smooth), border-color var(--transition-smooth);
}

.card:hover .card-icon {
    background: rgba(56, 189, 248, 0.1);
    border-color: rgba(56, 189, 248, 0.2);
}

.service-card .card-summary {
    color: var(--text-muted);
    font-size: 0.9rem;
    font-style: italic;
}


/* ========================================================================
   PORTFOLIO
   ======================================================================== */
.portfolio .section-header {
    margin-bottom: 3rem;
}

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

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 0.75rem;
    margin-bottom: 0.35rem;
}

.card-type {
    color: var(--accent);
    font-size: 0.85rem;
    font-weight: 500;
    margin-bottom: 0;
    opacity: 0.85;
}

.badge {
    font-size: 0.7rem;
    padding: 0.2rem 0.65rem;
    border-radius: 100px;
    background: rgba(52, 211, 153, 0.08);
    color: #34d399;
    border: 1px solid rgba(52, 211, 153, 0.15);
    white-space: nowrap;
    font-weight: 500;
    letter-spacing: 0.01em;
}

.badge-secondary {
    background: rgba(148, 163, 184, 0.06);
    color: var(--text-muted);
    border-color: rgba(148, 163, 184, 0.12);
}

.portfolio-footer {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
    max-width: 780px;
}

.portfolio-footer p {
    font-size: 0.875rem;
    color: var(--text-muted);
    line-height: 1.7;
}

.portfolio-references {
    margin-top: 1rem;
    font-style: italic;
    color: var(--text-secondary) !important;
}


/* ========================================================================
   ABOUT
   ======================================================================== */
.about-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
    max-width: 780px;
}

.about-content p {
    margin-bottom: 1.5rem;
    font-size: 1.05rem;
}

/* Tech stack pills */
.tech-stack {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1.5rem;
}

.tech-pill {
    font-size: 0.78rem;
    padding: 0.3rem 0.75rem;
    border-radius: 100px;
    background: rgba(56, 189, 248, 0.06);
    color: var(--text-secondary);
    border: 1px solid var(--border);
    font-weight: 500;
    transition: all var(--transition-fast);
}

.tech-pill:hover {
    background: rgba(56, 189, 248, 0.1);
    border-color: var(--border-hover);
    color: var(--text-primary);
}


/* ========================================================================
   CONTACT
   ======================================================================== */
.contact {
    background: linear-gradient(180deg, var(--bg-primary) 0%, rgba(15, 23, 42, 0.3) 100%);
}

.contact-container {
    max-width: 560px;
    margin: 0 auto;
}

.contact-header {
    text-align: center;
    margin-bottom: 2.5rem;
}

.contact-header .section-subtitle {
    margin: 0 auto;
}

.form-group {
    margin-bottom: 1rem;
}

.form-input {
    width: 100%;
    padding: 0.9rem 1.15rem;
    background: var(--bg-surface-solid);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.95rem;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

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

.form-input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

textarea.form-input {
    resize: vertical;
    min-height: 130px;
}

.form-result {
    margin-top: 1rem;
    text-align: center;
    font-size: 0.9rem;
    opacity: 0;
    transition: opacity var(--transition-smooth);
}
.form-result.show { opacity: 1; }
.form-result.success { color: #34d399; }
.form-result.error { color: #f87171; }

.form-note {
    text-align: center;
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 1.25rem;
}


/* ========================================================================
   FOOTER
   ======================================================================== */
.footer {
    padding: 2.5rem 0;
    border-top: 1px solid var(--border);
}

.footer-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--text-muted);
    font-size: 0.8rem;
}


/* ========================================================================
   ANIMATIONS
   ======================================================================== */
.reveal, .reveal-stagger {
    opacity: 0;
    transform: translateY(25px);
    transition: opacity var(--transition-reveal), transform var(--transition-reveal);
    will-change: opacity, transform;
}

.reveal.active, .reveal-stagger.active {
    opacity: 1;
    transform: translateY(0);
}


/* ========================================================================
   RESPONSIVE
   ======================================================================== */
@media (max-width: 1024px) {
    .services-grid,
    .portfolio-grid {
        grid-template-columns: 1fr 1fr;
    }
}

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

    .nav {
        position: fixed;
        top: 0; right: -100%;
        width: 100%; height: 100vh;
        background-color: var(--bg-surface-solid);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        transition: right var(--transition-smooth);
        z-index: 100;
        gap: 1.5rem;
    }
    .nav.open { right: 0; }
    .nav-link { font-size: 1.35rem; color: var(--text-secondary); }
    .btn-nav { margin-top: 0.5rem; font-size: 1rem; padding: 0.75rem 1.75rem; }

    .services-grid,
    .portfolio-grid {
        grid-template-columns: 1fr;
    }

    .hero-pillars {
        grid-template-columns: 1fr;
    }

    .logo-tagline { display: none; }

    .hero-title br { display: none; }
}




/* ========================================================================
   ACCESSIBILITY
   ======================================================================== */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
    .reveal, .reveal-stagger {
        opacity: 1 !important;
        transform: none !important;
    }
}