/* ===================================
   CSS Variables & Reset
   =================================== */
:root {
    --color-dark-bg: #0a0a0f;
    --color-dark-secondary: #1a1a24;
    --color-gray-dark: #2a2a3a;
    --color-blue-primary: #3b82f6;
    --color-blue-dark: #1e3a8a;
    --color-blue-light: #60a5fa;
    --color-purple: #8b5cf6;
    --color-text-primary: #ffffff;
    --color-text-secondary: #b4b4c8;
    --color-text-muted: #6b7280;
    --spacing-section: 120px;
    --spacing-large: 80px;
    --spacing-medium: 48px;
    --spacing-small: 24px;
    --transition-smooth: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: all 0.3s ease;
}

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

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background-color: var(--color-dark-bg);
    color: var(--color-text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 40px;
}

/* ===================================
   Header
   =================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 20px 0;
    background: rgba(10, 10, 15, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

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

.logo {
    font-size: 18px;
    font-weight: 700;
    color: var(--color-text-primary);
    letter-spacing: -0.3px;
}

.nav {
    display: flex;
    gap: 20px;
    align-items: center;
}

.contact-link {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: 13px;
    transition: var(--transition-fast);
}

.contact-link:hover {
    color: var(--color-blue-light);
}

.linkedin-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 6px;
    color: var(--color-text-secondary);
    transition: var(--transition-fast);
    text-decoration: none;
}

.linkedin-btn:hover {
    background: var(--color-blue-primary);
    color: var(--color-text-primary);
    transform: translateY(-2px);
}

/* ===================================
   Screen Layout
   =================================== */
.screen {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    padding: var(--spacing-section) 0;
}

/* ===================================
   Hero Screen (Screen 1)
   =================================== */
.hero-screen {
    background: #000;
    overflow: hidden;
    padding: 0;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

.hero-bg-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, rgba(0, 0, 0, 0.6) 0%, rgba(0, 0, 0, 0.8) 100%);
}

.hero-content {
    position: relative;
    z-index: 2;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
    min-height: 100vh;
    padding-top: 80px;
}

.hero-text {
    max-width: 700px;
}

.hero-headline {
    font-size: 64px;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 24px;
    letter-spacing: -2px;
    color: var(--color-text-primary);
}

.hero-subheadline {
    font-size: 22px;
    font-weight: 400;
    color: var(--color-text-secondary);
    margin-bottom: 16px;
    line-height: 1.5;
}

.hero-supporting {
    font-size: 14px;
    color: var(--color-text-muted);
    margin-bottom: 40px;
    letter-spacing: 0.5px;
}

.cta-button {
    display: inline-block;
    padding: 14px 40px;
    background: transparent;
    color: var(--color-text-primary);
    text-decoration: none;
    border: 2px solid var(--color-text-primary);
    border-radius: 6px;
    font-weight: 600;
    font-size: 15px;
    transition: var(--transition-fast);
}

.cta-button:hover {
    background: var(--color-text-primary);
    color: var(--color-dark-bg);
    transform: translateY(-2px);
}

.hero-visual {
    position: absolute;
    right: 80px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 3;
}

.visionventory-text {
    font-size: 72px;
    font-weight: 900;
    color: rgba(255, 255, 255, 0.08);
    letter-spacing: -3px;
    writing-mode: vertical-rl;
    text-orientation: mixed;
    white-space: nowrap;
}

/* ===================================
   Problem Screen (Screen 2)
   =================================== */
.problem-screen {
    background: var(--color-gray-dark);
}

.problem-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.problem-image img {
    width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 16px 64px rgba(0, 0, 0, 0.4);
}

.problem-text {
    max-width: 500px;
}

.section-headline {
    font-size: 48px;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 32px;
    letter-spacing: -1px;
}

.section-body {
    font-size: 18px;
    color: var(--color-text-secondary);
    line-height: 1.7;
    margin-bottom: 48px;
}

.pain-points {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.pain-point {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px;
    background: rgba(26, 26, 36, 0.5);
    border-radius: 8px;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.pain-icon {
    font-size: 28px;
}

.pain-text {
    font-size: 17px;
    font-weight: 500;
    color: var(--color-text-primary);
}

/* ===================================
   Solution Screen (Screen 3)
   =================================== */
.solution-screen {
    background: linear-gradient(135deg, #1e3a8a 0%, #3b82f6 50%, #60a5fa 100%);
    position: relative;
}

.solution-screen::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.3);
    z-index: 1;
}

.solution-content {
    position: relative;
    z-index: 2;
    text-align: center;
    max-width: 1200px;
    margin: 0 auto;
}

.solution-text {
    margin-bottom: 64px;
}

.solution-text .section-headline {
    font-size: 52px;
    margin-bottom: 24px;
}

.highlight {
    color: var(--color-text-primary);
}

.section-description {
    font-size: 20px;
    color: rgba(255, 255, 255, 0.9);
    line-height: 1.6;
}

.solution-visual {
    margin: 64px 0;
    display: flex;
    justify-content: center;
}

.layer-diagram {
    position: relative;
    width: 450px;
    perspective: 1000px;
}

.diagram-layer {
    padding: 48px 60px;
    border-radius: 12px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 2px solid rgba(255, 255, 255, 0.2);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.top-layer {
    margin-bottom: 0;
}

.bottom-layer {
    background: rgba(26, 26, 36, 0.6);
    border: 2px solid rgba(180, 180, 200, 0.3);
}

.layer-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 64px;
    height: 64px;
    color: var(--color-text-primary);
}

.layer-label {
    font-size: 20px;
    font-weight: 600;
    color: var(--color-text-primary);
}

.connection-line {
    width: 2px;
    height: 60px;
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.5) 0%, rgba(255, 255, 255, 0.2) 100%);
    margin: -2px auto -2px;
    position: relative;
    z-index: 1;
}

.benefits-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
    margin-top: 80px;
}

.benefit-card {
    padding: 40px 32px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 12px;
    transition: var(--transition-fast);
}

.benefit-card:hover {
    transform: translateY(-4px);
    background: rgba(255, 255, 255, 0.15);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.benefit-icon {
    color: var(--color-text-primary);
    margin-bottom: 24px;
}

.benefit-title {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--color-text-primary);
}

.benefit-text {
    font-size: 15px;
    color: rgba(255, 255, 255, 0.85);
    line-height: 1.6;
}

/* ===================================
   CTA Screen (Screen 4)
   =================================== */
.cta-screen {
    background: var(--color-dark-bg);
    position: relative;
    overflow: hidden;
}

.cta-background-effect {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 1000px;
    height: 1000px;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.08) 0%, transparent 70%);
    pointer-events: none;
}

.cta-content {
    text-align: center;
    position: relative;
    z-index: 2;
}

.cta-headline {
    font-size: 64px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 32px;
    letter-spacing: -1.5px;
}

.highlight-gradient {
    background: linear-gradient(135deg, var(--color-blue-light) 0%, var(--color-purple) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.cta-description {
    font-size: 20px;
    color: var(--color-text-secondary);
    line-height: 1.7;
    margin-bottom: 48px;
}

.cta-button-large {
    display: inline-block;
    padding: 18px 56px;
    background: transparent;
    color: var(--color-text-primary);
    text-decoration: none;
    border: 2px solid var(--color-text-primary);
    border-radius: 8px;
    font-weight: 600;
    font-size: 17px;
    transition: var(--transition-fast);
}

.cta-button-large:hover {
    background: var(--color-text-primary);
    color: var(--color-dark-bg);
    transform: translateY(-3px);
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: var(--color-dark-secondary);
    padding: 48px 0 24px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 32px;
}

.footer-logo {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 8px;
}

.footer-email {
    color: var(--color-text-secondary);
    font-size: 13px;
}

.social-links {
    display: flex;
    gap: 16px;
}

.social-link {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 8px;
    color: var(--color-text-secondary);
    transition: var(--transition-fast);
    text-decoration: none;
}

.social-link:hover {
    background: var(--color-blue-primary);
    color: var(--color-text-primary);
}

.footer-bottom {
    text-align: center;
    padding-top: 24px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-bottom p {
    color: var(--color-text-muted);
    font-size: 13px;
}

/* ===================================
   Animations
   =================================== */
.fade-in {
    animation: fadeIn 1s ease-out;
}

.fade-in-delay-1 {
    animation: fadeIn 1s ease-out 0.2s both;
}

.fade-in-delay-2 {
    animation: fadeIn 1s ease-out 0.4s both;
}

.fade-in-delay-3 {
    animation: fadeIn 1s ease-out 0.6s both;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===================================
   Responsive Design - Tablet
   =================================== */
@media (max-width: 1024px) {
    .container {
        padding: 0 32px;
    }

    .hero-headline {
        font-size: 52px;
    }

    .hero-subheadline {
        font-size: 20px;
    }

    .visionventory-text {
        font-size: 56px;
        right: 40px;
    }

    .problem-content {
        grid-template-columns: 1fr;
        gap: 48px;
    }

    .section-headline {
        font-size: 40px;
    }

    .benefits-grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    .cta-headline {
        font-size: 52px;
    }
}

/* ===================================
   Responsive Design - Mobile
   =================================== */
@media (max-width: 768px) {
    .container {
        padding: 0 24px;
    }

    .header {
        padding: 16px 0;
    }

    .logo {
        font-size: 16px;
    }

    .contact-link {
        font-size: 11px;
    }

    .hero-headline {
        font-size: 40px;
        letter-spacing: -1px;
    }

    .hero-subheadline {
        font-size: 18px;
    }

    .hero-supporting {
        font-size: 12px;
    }

    .cta-button {
        padding: 12px 32px;
        font-size: 14px;
    }

    .hero-visual {
        display: none;
    }

    .section-headline {
        font-size: 32px;
    }

    .section-body {
        font-size: 16px;
    }

    .solution-text .section-headline {
        font-size: 36px;
    }

    .section-description {
        font-size: 16px;
    }

    .layer-diagram {
        width: 100%;
        max-width: 300px;
    }

    .diagram-layer {
        padding: 32px 40px;
    }

    .cta-headline {
        font-size: 36px;
    }

    .cta-description {
        font-size: 16px;
    }

    .cta-button-large {
        padding: 16px 40px;
        font-size: 15px;
    }

    .footer-content {
        flex-direction: column;
        gap: 24px;
        text-align: center;
    }

    .screen {
        padding: 80px 0;
    }
}

@media (max-width: 480px) {
    .hero-headline {
        font-size: 32px;
    }

    .hero-subheadline {
        font-size: 16px;
    }

    .section-headline {
        font-size: 28px;
    }

    .cta-headline {
        font-size: 28px;
    }

    .pain-icon {
        font-size: 24px;
    }

    .pain-text {
        font-size: 15px;
    }

    .benefit-title {
        font-size: 18px;
    }

    .benefit-text {
        font-size: 14px;
    }
}