:root {
    --bg: #FFFFFF;
    --bg-alt: #F6FAF6;
    --text-main: #0A0A0A;
    --text-body: #4A4A4A;
    --text-muted: #8A8A8A;
    --brand: #0F3D2E;
    --action: #277A00;
    --accent: #E6F2E2;
    --hover-bg: #F2F9F0;
    --border: #E4E7E4;
    --warn: #B45309;
    --error: #B03227;

    --nav-height: 76px;
    --font-heading: 'Poppins', sans-serif;
    --font-body: 'Poppins', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
}

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

html { scroll-behavior: smooth; }

body {
    font-family: var(--font-body);
    background-color: var(--bg);
    color: var(--text-body);
    line-height: 1.55;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
    font-size: 16px;
    font-weight: 500;
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    color: var(--text-main);
    letter-spacing: -0.03em;
    line-height: 1.1;
}

a { text-decoration: none; color: inherit; }
ul { list-style: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }

.numeric {
    font-family: var(--font-mono);
    font-variant-numeric: tabular-nums;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

:focus-visible {
    outline: 2px solid var(--action);
    outline-offset: 2px;
}

/* Butonlar */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0 24px;
    height: 48px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 15px;
    transition: all 0.2s ease;
}

.btn-primary { background-color: var(--brand); color: var(--bg); }
.btn-primary:hover { background-color: var(--text-main); }
.btn-outline { border: 1px solid var(--border); color: var(--brand); background-color: transparent; }
.btn-outline:hover { border-color: var(--brand); background-color: var(--hover-bg); }

/* Navigasyon & Mega Menu */
.navbar {
    position: sticky;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--nav-height);
    background-color: var(--bg);
    border-bottom: 1px solid var(--border);
    z-index: 100;
    transition: height 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    align-items: center;
}

.navbar.scrolled {
    height: 60px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.05);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
}

.logo {
    font-family: var(--font-heading);
    font-size: 24px;
    font-weight: 800;
    color: var(--brand);
    letter-spacing: -0.05em;
}

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-item {
    position: relative;
    padding: 24px 0; /* Increase hit area for hover */
}

.nav-link {
    color: var(--brand);
    font-weight: 600;
    font-size: 15px;
    position: relative;
}

/* Hover alt çizgi efekti */
.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--action);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 180ms ease;
}
.nav-item:hover .nav-link::after, .nav-link.active::after {
    transform: scaleX(1);
}

/* Mega Menü */
.mega-menu {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(10px);
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.08);
    width: 800px;
    padding: 32px;
    opacity: 0;
    visibility: hidden;
    transition: all 0.2s ease;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    pointer-events: none;
}

.nav-item.has-mega:hover .mega-menu {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
    pointer-events: auto;
}

.mega-item {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    padding: 16px;
    border-radius: 8px;
    transition: background 0.2s ease;
}
.mega-item:hover { background: var(--hover-bg); }
.mega-icon {
    width: 40px; height: 40px;
    border-radius: 8px; background: var(--accent); color: var(--action);
    display: flex; align-items: center; justify-content: center;
    flex-shrink: 0;
}
.mega-text h4 { font-size: 16px; margin-bottom: 4px; color: var(--brand); }
.mega-text p { font-size: 13px; color: var(--text-muted); }

.mobile-menu-btn { display: none; font-size: 24px; color: var(--brand); }

/* Hero ERP Odaklı */
.hero {
    padding: 120px 0 80px;
    text-align: left;
    position: relative;
}

.hero-inner {
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.eyebrow {
    display: inline-block;
    background-color: var(--accent);
    color: var(--action);
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 24px;
}

.hero h1 { font-size: clamp(48px, 6vw, 76px); margin-bottom: 24px; }
.hero h1 span { color: var(--action); }

.hero-desc {
    font-size: 20px;
    color: var(--text-body);
    max-width: 60ch;
    margin-bottom: 40px;
}

/* Referanslar & Sonsuz Slider (Marquee) */
.references-section {
    padding: 60px 0 80px;
    border-bottom: 1px solid var(--border);
    overflow: hidden;
    background: var(--bg-alt);
}
.ref-title {
    text-align: center;
    font-size: 14px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 32px;
    font-weight: 600;
}
.marquee {
    display: flex;
    width: 200%;
    animation: scroll-left 40s linear infinite;
}
.marquee:hover {
    animation-play-state: paused;
}
.marquee-content {
    display: flex;
    justify-content: space-around;
    width: 50%;
    align-items: center;
}
.ref-logo {
    height: 40px;
    filter: grayscale(100%) opacity(0.5);
    transition: all 0.3s ease;
    padding: 0 32px;
}
.ref-logo:hover {
    filter: grayscale(0%) opacity(1);
    transform: scale(1.05);
}
@keyframes scroll-left {
    0% { transform: translateX(0); }
    100% { transform: translateX(-50%); }
}

/* Scrollytelling Video */
.scrollytelling { position: relative; background-color: var(--bg); }
.sticky-stage {
    position: sticky; top: 0; height: 100vh;
    display: flex; align-items: center; justify-content: center;
    overflow: hidden; border-top: 1px solid var(--border); border-bottom: 1px solid var(--border);
}
.video-container {
    width: 100%; max-width: 1000px; aspect-ratio: 16/10;
    border: 1px solid var(--border); border-radius: 12px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.05); background: var(--bg-alt);
    overflow: hidden; position: relative; z-index: 1;
}
.video-container video, .video-container canvas { width: 100%; height: 100%; object-fit: cover; display: block; }
.captions {
    position: absolute; left: max(5%, calc((100vw - 1200px)/2 + 24px));
    top: 50%; transform: translateY(-50%); width: 320px; z-index: 2; pointer-events: none;
}
.caption-item {
    position: absolute; top: 0; left: 0; opacity: 0; transform: translateY(12px);
    transition: opacity 0.3s ease, transform 0.3s ease;
    background: rgba(255, 255, 255, 0.9); backdrop-filter: blur(8px);
    padding: 24px; border: 1px solid var(--border); border-radius: 12px; box-shadow: 0 10px 30px rgba(0,0,0,0.08);
}
.caption-item.active { opacity: 1; transform: translateY(0); }
.caption-item strong { display: block; color: var(--text-main); font-size: 18px; margin-bottom: 8px; font-family: var(--font-heading); }
.step-indicator {
    position: absolute; right: max(5%, calc((100vw - 1200px)/2 + 24px));
    top: 50%; transform: translateY(-50%); display: flex; flex-direction: column; gap: 12px; z-index: 2;
}
.step-dot { width: 4px; height: 24px; background-color: var(--border); border-radius: 2px; transition: all 0.3s ease; }
.step-dot.passed { background-color: var(--brand); }
.step-dot.active { background-color: var(--action); height: 40px; }

/* Problem, Modüller, Sektörler, vs. (Genel Sınıflar) */
.section { padding: 120px 0; }
.section-header { text-align: center; margin-bottom: 64px; }
.section-header h2 { font-size: 40px; margin-bottom: 16px; }

/* Modüller (ERP Sayfası için de kullanılabilir) */
.page-header {
    background: var(--bg-alt);
    padding: 120px 0 80px;
    border-bottom: 1px solid var(--border);
    text-align: center;
}
.page-header h1 { font-size: 56px; margin-bottom: 24px; }
.page-header p { font-size: 18px; max-width: 700px; margin: 0 auto; color: var(--text-muted); }

.feature-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
    margin-top: 64px;
}
.feat-card {
    border: 1px solid var(--border);
    padding: 40px;
    border-radius: 16px;
    background: var(--bg);
}
.feat-card h3 { font-size: 24px; margin-bottom: 16px; }
.feat-card ul li { display: flex; gap: 12px; margin-bottom: 12px; }
.feat-card ul li svg { color: var(--action); flex-shrink: 0; margin-top: 4px; }

/* SSS ve Footer */
.faq-list { max-width: 800px; margin: 0 auto; border-top: 1px solid var(--border); }
.faq-item { border-bottom: 1px solid var(--border); }
.faq-q { width: 100%; text-align: left; padding: 24px 0; font-size: 18px; font-weight: 600; color: var(--text-main); display: flex; justify-content: space-between; align-items: center; }
.faq-a { max-height: 0; overflow: hidden; transition: max-height 0.3s ease; color: var(--text-body); max-width: 70ch; }
.faq-a p { padding-bottom: 24px; }
.faq-item.active .faq-icon { transform: rotate(45deg); }

footer { border-top: 1px solid var(--border); padding: 80px 0 24px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 48px; margin-bottom: 64px; }
.footer-col h5 { font-size: 16px; margin-bottom: 24px; }
.footer-col ul { display: flex; flex-direction: column; gap: 12px; }
.footer-col a { color: var(--text-muted); font-size: 14px; transition: color 0.2s; }
.footer-col a:hover { color: var(--brand); }
.footer-bottom { border-top: 1px solid var(--border); padding-top: 24px; display: flex; justify-content: space-between; align-items: center; font-size: 13px; color: var(--text-muted); }
.footer-links { display: flex; gap: 24px; }

/* Responsive */
@media (max-width: 992px) {
    .feature-grid { grid-template-columns: 1fr; }
    .mega-menu { width: 100%; grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
    .nav-links { display: none; }
    .mobile-menu-btn { display: block; }
    .hero { padding: 80px 0 40px; }
    .scrollytelling { height: auto !important; padding: 40px 0; }
    .sticky-stage { position: relative; height: auto; border: none; flex-direction: column; }
    .captions, .step-indicator { display: none; }
    .video-container { margin: 0 24px; width: calc(100% - 48px); }
    .footer-grid { grid-template-columns: 1fr; gap: 32px; }
    .footer-bottom { flex-direction: column; gap: 16px; text-align: center; }
}
@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; scroll-behavior: auto !important; }
    .scrollytelling { height: auto !important; padding: 60px 0; }
    .sticky-stage { position: relative; height: auto; }
    .captions, .step-indicator { display: none; }
}