:root {
    --color-bg-dark: #020c1b;
    --color-bg-light: #0a192f;
    --color-text-primary: #ccd6f6;
    --color-text-secondary: #8892b0;
    --color-border: #172a45;
    --color-accent-inc: #64ffda;
    --color-accent-spi: #ff6489;
    --color-accent-proto: #64d1ff;
    --font-primary: 'Manrope', sans-serif;
    --shadow-light: 0 10px 30px -15px rgba(2, 12, 27, 0.7);
    --transition-main: all 0.3s cubic-bezier(0.645, 0.045, 0.355, 1);
}

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

html {
    scroll-behavior: smooth;
    scrollbar-width: thin;
    scrollbar-color: var(--color-text-secondary) var(--color-bg-dark);
}

body {
    background-color: var(--color-bg-dark);
    color: var(--color-text-primary);
    font-family: var(--font-primary);
    line-height: 1.6;
    cursor: none;
}

body::-webkit-scrollbar {
    width: 10px;
}
body::-webkit-scrollbar-track {
    background: var(--color-bg-dark);
}
body::-webkit-scrollbar-thumb {
    background-color: var(--color-text-secondary);
    border-radius: 10px;
    border: 3px solid var(--color-bg-dark);
}

.cursor {
    width: 24px;
    height: 24px;
    border: 2px solid var(--color-text-primary);
    border-radius: 50%;
    position: fixed;
    transform: translate(-50%, -50%);
    pointer-events: none;
    z-index: 9999;
    transition: all 0.1s ease-out;
    mix-blend-mode: difference;
    opacity: 0;
}
.cursor.hovered {
    transform: translate(-50%, -50%) scale(2.5);
    background-color: var(--color-text-primary);
    opacity: 0.5;
}
body:hover > .cursor { opacity: 1; }
@media (pointer: coarse) {
    .cursor { display: none; }
    body { cursor: auto; }
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 25px;
}

.content-section {
    padding: 120px 0;
    position: relative;
}
.content-section.alt-bg {
    background-color: var(--color-bg-light);
}

h1, h2, h3, h4 {
    color: var(--color-text-primary);
    font-weight: 600;
    line-height: 1.2;
}

h2 { font-size: 2.8rem; margin-bottom: 20px; text-align: center; }
h3 { font-size: 1.7rem; margin-bottom: 15px; }
h4 { font-size: 1.2rem; margin-bottom: 10px; }
p { font-size: 1.1rem; color: var(--color-text-secondary); margin-bottom: 20px; max-width: 700px; }
section h2 + p { text-align: center; margin-left: auto; margin-right: auto; }
ul { list-style: none; }
a { text-decoration: none; color: var(--color-accent-inc); cursor: none; }
button { cursor: none; }

.back-to-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: var(--color-text-secondary);
    color: var(--color-bg-dark);
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    opacity: 0;
    transform: translateY(100px);
    transition: var(--transition-main);
}
.back-to-top svg { width: 24px; height: 24px; }
.back-to-top:hover {
    background-color: var(--color-accent-inc);
}
.back-to-top.visible {
    opacity: 1;
    transform: translateY(0);
}

.main-nav {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: rgba(2, 12, 27, 0.85);
    backdrop-filter: blur(10px);
    z-index: 100;
    display: flex;
    justify-content: center;
    padding: 20px 0;
    border-bottom: 1px solid var(--color-border);
    transition: top 0.4s cubic-bezier(0.645, 0.045, 0.355, 1);
}
.main-nav.nav-hidden {
   top: -100px;
}
/* --- ESTILOS PARA EL ICONO HOME EN NAV --- */
.main-nav ul {
    display: flex;
    align-items: center; /* Centra verticalmente los elementos, incluido el icono */
    gap: 30px; /* Ajusta el espacio si es necesario */
}

.home-link svg {
    display: block; /* Elimina espacio extra debajo del SVG */
    transition: fill 0.3s ease; /* Transición suave para el color */
}

.home-link:hover svg {
    fill: var(--color-accent-inc); /* Cambia el color del icono al pasar el ratón */
}

/* Ajuste responsive si es necesario */
@media (max-width: 768px) {
    .main-nav ul {
        gap: 10px; /* Menos espacio en móvil */
    }
    .home-link svg {
        width: 18px; /* Icono ligeramente más pequeño en móvil */
        height: 18px;
    }
}

.main-nav a {
    color: var(--color-text-secondary);
    font-weight: 400;
    font-size: 1rem;
    transition: color 0.3s ease;
}
.main-nav a:hover,
.main-nav a.active {
    color: var(--color-accent-inc);
}

.hero-section {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
    overflow: hidden;
}
#hero-canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}
.hero-content { z-index: 2; }

.animated-gradient-text {
    font-size: 4.5rem;
    font-weight: 700;
    background: linear-gradient(90deg, var(--color-accent-inc), #fff, var(--color-accent-spi));
    background-size: 200% 200%;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: gradient-flow 5s ease infinite;
}
@keyframes gradient-flow {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.hero-content h2 {
    font-size: 3rem;
    font-weight: 600;
    margin-bottom: 20px;
    color: var(--color-text-primary);
}
.hero-content p {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}
.hero-btn {
    display: inline-block;
    margin-top: 40px;
    color: var(--color-accent-inc);
    background-color: transparent;
    border: 2px solid var(--color-accent-inc);
    padding: 14px 28px;
    border-radius: 4px;
    font-weight: 600;
    font-size: 1rem;
    transition: var(--transition-main);
}
.hero-btn:hover {
    background-color: rgba(100, 255, 218, 0.1);
    box-shadow: 0 0 15px rgba(100, 255, 218, 0.3);
}

.fade-in {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}
.fade-in.is-visible {
    opacity: 1;
    transform: translateY(0);
}

#waterfall h3 {
    text-align: center;
    color: var(--color-accent-spi);
    margin-top: 60px;
    margin-bottom: 20px;
}

.waterfall-diagram {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
    margin-top: 40px;
}

.waterfall-stage {
    background-color: var(--color-bg-dark);
    color: var(--color-text-secondary);
    font-weight: 600;
    padding: 12px 20px;
    border-radius: 6px;
    border: 1px solid var(--color-border);
    position: relative;
    cursor: help;
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.waterfall-arrow {
    font-size: 1.5rem;
    color: var(--color-text-secondary);
    opacity: 0;
    transform: scale(0);
    transition: all 0.3s ease;
}

.waterfall-stage.visible {
    opacity: 1;
    transform: translateY(0);
}
.waterfall-arrow.visible {
    opacity: 0.5;
    transform: scale(1);
}

.waterfall-stage::before,
.waterfall-stage::after {
    opacity: 0;
    visibility: hidden;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    transition: all 0.3s ease;
    z-index: 10;
}
.waterfall-stage::after {
    content: attr(data-tooltip);
    background-color: var(--color-bg-dark);
    color: var(--color-text-primary);
    font-size: 0.85rem;
    font-weight: 400;
    padding: 8px 12px;
    border-radius: 4px;
    border: 1px solid var(--color-border);
    bottom: calc(100% + 10px);
    width: 150px;
    text-align: center;
    line-height: 1.4;
    transform: translateX(-50%) translateY(10px);
}
.waterfall-stage::before {
    content: '';
    border-style: solid;
    border-width: 6px 6px 0 6px;
    border-color: var(--color-border) transparent transparent transparent;
    bottom: 100%;
    transform: translateX(-50%) translateY(10px);
}
.waterfall-stage:hover::before,
.waterfall-stage:hover::after {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

.problems-list-wrapper {
    max-width: 800px;
    margin: 40px auto 0 auto;
    background-color: var(--color-bg-dark);
    padding: 30px;
    border-radius: 8px;
    border-left: 4px solid var(--color-accent-spi);
}

.problems-list {
    list-style-type: disc;
    padding-left: 30px;
}
.problems-list li {
    display: list-item;
    font-size: 1.05rem;
    padding-left: 10px;
    margin-bottom: 10px;
    color: var(--color-text-primary);
}
.problems-list li::marker {
    color: var(--color-accent-spi);
    font-size: 1.2rem;
}


#incremental h3 { color: var(--color-accent-inc); }
.incremental-layout {
    margin-top: 60px;
    display: grid;
    grid-template-columns: 1fr;
    gap: 30px;
}
.increment-card {
    background-color: var(--color-bg-light);
    border-radius: 8px;
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-light);
    transition: var(--transition-main);
    overflow: hidden;
}
.increment-card:hover {
    transform: translateY(-8px);
    border-color: var(--color-accent-inc);
}
.increment-header {
    background-color: var(--color-border);
    padding: 20px 30px;
    border-bottom: 1px solid var(--color-border);
}
.increment-header h4 {
    color: var(--color-accent-inc);
}
.mini-waterfall {
    display: flex;
    align-items: center;
    justify-content: space-around;
    padding: 30px;
}
.mini-waterfall .stage {
    background-color: var(--color-bg-dark);
    color: var(--color-text-secondary);
    font-weight: 600;
    padding: 10px 15px;
    border-radius: 6px;
    border: 1px solid var(--color-border);
    opacity: 0;
    transform: scale(0.8);
    transition: all 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
    cursor: help;
}
.mini-waterfall .stage span {
    display: none;
}
.mini-waterfall .arrow {
    font-size: 1.5rem;
    color: var(--color-text-secondary);
    opacity: 0;
    transform: scale(0);
    transition: all 0.3s ease;
}
.mini-waterfall .stage.visible {
    opacity: 1;
    transform: scale(1);
    border-color: var(--color-accent-inc);
    color: var(--color-accent-inc);
}
.mini-waterfall .arrow.visible {
    opacity: 0.5;
    transform: scale(1);
}

.mini-waterfall .stage::before,
.mini-waterfall .stage::after {
    opacity: 0;
    visibility: hidden;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    transition: all 0.3s ease;
    z-index: 10;
}
.mini-waterfall .stage::after {
    content: attr(data-tooltip);
    background-color: var(--color-bg-dark);
    color: var(--color-text-primary);
    font-size: 0.85rem;
    font-weight: 400;
    padding: 8px 12px;
    border-radius: 4px;
    border: 1px solid var(--color-border);
    bottom: calc(100% + 10px);
    width: 150px;
    text-align: center;
    line-height: 1.4;
    transform: translateX(-50%) translateY(10px);
}
.mini-waterfall .stage::before {
    content: '';
    border-style: solid;
    border-width: 6px 6px 0 6px;
    border-color: var(--color-border) transparent transparent transparent;
    bottom: 100%;
    transform: translateX(-50%) translateY(10px);
}
.mini-waterfall .stage:hover::before,
.mini-waterfall .stage:hover::after {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}


.spiral-section {
    position: relative;
    background-color: var(--color-bg-light);
}
#spiral-scroll-trigger {
    height: 350vh;
}
.sticky-container {
    position: sticky;
    top: 0;
    height: 100vh;
    overflow: hidden;
}
.spiral-content-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    gap: 50px;
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}
.spiral-text-content {
    flex: 1;
    z-index: 10;
}
.spiral-text-content h3 { color: var(--color-accent-spi); }
.quadrant-text-group { margin-top: 30px; }
.quadrant-text {
    padding: 15px;
    border-radius: 5px;
    margin-bottom: 15px;
    border-left: 3px solid var(--color-border);
    opacity: 0.3;
    transition: var(--transition-main);
}
.quadrant-text.active {
    opacity: 1;
    background-color: var(--color-bg-dark);
    transform: scale(1.05);
    border-left-color: var(--color-accent-spi);
    box-shadow: var(--shadow-light);
}
.quadrant-text h4 { color: var(--color-text-primary); }
.quadrant-text p { font-size: 0.95rem; margin-bottom: 0; }

.spiral-animation-container {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}
#spiral-svg {
    width: 100%;
    max-width: 450px;
    height: auto;
    transform-origin: center center;
}
#spiral-path-bg {
    fill: none;
    stroke: var(--color-border);
    stroke-width: 5;
}
#spiral-path {
    fill: none;
    stroke: var(--color-accent-spi);
    stroke-width: 6;
    stroke-linecap: round;
}
#spiral-marker {
    fill: var(--color-accent-inc);
    stroke: var(--color-bg-dark);
    stroke-width: 3;
    filter: drop-shadow(0 0 5px var(--color-accent-inc));
    transition: all 0.05s linear;
}

.comparison-toggle-wrapper {
    display: flex;
    justify-content: center;
    margin-top: 40px;
    margin-bottom: 40px;
    background-color: var(--color-bg-dark);
    border-radius: 8px;
    padding: 8px;
    width: fit-content;
    margin-left: auto;
    margin-right: auto;
    position: relative;
    border: 1px solid var(--color-border);
}
.toggle-highlight {
    position: absolute;
    top: 8px;
    left: 8px;
    height: calc(100% - 16px);
    background-color: var(--color-accent-inc);
    border-radius: 6px;
    transition: all 0.4s cubic-bezier(0.23, 1, 0.32, 1);
}
.toggle-btn {
    padding: 12px 30px;
    border: none;
    background-color: transparent;
    color: var(--color-text-secondary);
    font-size: 1rem;
    font-weight: 600;
    font-family: var(--font-primary);
    border-radius: 6px;
    z-index: 2;
    transition: color 0.3s ease;
}
.toggle-btn.active {
    color: var(--color-bg-dark);
}

.comparison-content-wrapper {
    position: relative;
    min-height: 350px;
}
.comparison-content {
    background-color: var(--color-bg-dark);
    padding: 30px;
    border-radius: 8px;
    border: 1px solid var(--color-border);
    transition: opacity 0.5s ease, transform 0.5s ease, visibility 0.5s;
    position: absolute;
    width: 100%;
    opacity: 0;
    transform: translateY(20px);
    visibility: hidden;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}
.comparison-content.active {
    opacity: 1;
    transform: translateY(0);
    visibility: visible;
    position: relative;
}
.comparison-content h3 {
    text-align: left;
    margin-bottom: 30px;
}
#incremental-content h3 { color: var(--color-accent-inc); }
#spiral-content h3 { color: var(--color-accent-spi); }

.comparison-content ul {
    display: flex;
    flex-direction: column;
    gap: 20px;
    list-style-type: disc;
    padding-left: 30px;
}
.comparison-content li {
    display: list-item;
    font-size: 1.05rem;
    padding-left: 10px;
}
.comparison-content li::marker {
    font-size: 1.2rem;
}
#incremental-content li::marker {
    color: var(--color-accent-inc);
}
#spiral-content li::marker {
    color: var(--color-accent-spi);
}
.comparison-content li strong {
    color: var(--color-text-primary);
}

#quiz-container {
    background-color: var(--color-bg-light);
    border-radius: 8px;
    padding: 40px;
    margin-top: 40px;
    position: relative;
    min-height: 250px;
}
.quiz-question, .quiz-result {
    transition: opacity 0.4s ease, transform 0.4s ease;
    text-align: center;
}
.quiz-question {
    opacity: 0;
    visibility: hidden;
    position: absolute;
    top: 40px;
    left: 40px;
    right: 40px;
    transform: translateY(20px);
}
.quiz-question.active {
    opacity: 1;
    visibility: visible;
    position: relative;
    top: 0;
    left: 0;
    right: 0;
    transform: translateY(0);
}
.quiz-question h3 {
    font-size: 1.5rem;
    color: var(--color-text-primary);
    margin-bottom: 30px;
}
.quiz-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}
.quiz-btn {
    border: 2px solid var(--color-border);
    background-color: var(--color-bg-dark);
    color: var(--color-text-secondary);
    padding: 12px 24px;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: 600;
    transition: var(--transition-main);
}
.quiz-btn:hover {
    border-color: var(--color-accent-inc);
    color: var(--color-accent-inc);
    transform: translateY(-5px);
}
.quiz-result {
    opacity: 0;
    visibility: hidden;
    position: absolute;
    top: 40px;
    left: 40px;
    right: 40px;
    transform: translateY(20px);
}
.quiz-result.active {
    opacity: 1;
    visibility: visible;
    position: relative;
    top: 0;
    left: 0;
    right: 0;
    transform: translateY(0);
}
.result-box {
    padding: 30px;
    border-radius: 6px;
    text-align: left;
}
.result-box.incremental {
    background-color: rgba(100, 255, 218, 0.05);
    border: 1px solid rgba(100, 255, 218, 0.2);
}
.result-box.spiral {
    background-color: rgba(255, 100, 137, 0.05);
    border: 1px solid rgba(255, 100, 137, 0.2);
}
.result-box.prototype {
    background-color: rgba(100, 209, 255, 0.05);
    border: 1px solid rgba(100, 209, 255, 0.2);
}
.result-box h3 {
    margin-bottom: 20px;
}
.result-box.incremental h3 { color: var(--color-accent-inc); }
.result-box.spiral h3 { color: var(--color-accent-spi); }
.result-box.prototype h3 { color: var(--color-accent-proto); }
.result-box h4 {
    color: var(--color-text-primary);
    font-size: 1.1rem;
    margin-top: 20px;
}
.result-box p {
    font-size: 1.05rem;
    margin-bottom: 10px;
}
.quiz-reset-btn {
    margin-top: 20px;
    border: 1px solid var(--color-text-secondary);
    background: transparent;
    color: var(--color-text-secondary);
    padding: 8px 16px;
    border-radius: 4px;
    font-weight: 600;
    transition: var(--transition-main);
}
.quiz-reset-btn:hover {
    border-color: var(--color-accent-inc);
    color: var(--color-accent-inc);
}


#epilogue {
    border-top: 1px solid var(--color-border);
}
.epilogue-layout {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-top: 40px;
}
.epilogue-card {
    background-color: var(--color-bg-dark);
    padding: 25px;
    border-radius: 6px;
    border: 1px solid var(--color-border);
}
.epilogue-card h4 {
    color: var(--color-accent-inc);
    font-size: 1.1rem;
    margin-bottom: 10px;
}
.epilogue-card p {
    font-size: 1rem;
    margin-bottom: 0;
}
.other-models {
    margin-top: 60px;
    text-align: center;
}
.other-models h3 {
    color: var(--color-text-primary);
}
.other-models p {
    text-align: center; /* Add this line */
    margin-top: 10px;
    margin-left: auto; /* Helps ensure centering if max-width is applied */
    margin-right: auto; /* Helps ensure centering if max-width is applied */
}
.other-models ul {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
    margin-top: 20px;
}
.other-models li {
    background-color: var(--color-bg-dark);
    border: 1px solid var(--color-border);
    color: var(--color-text-secondary);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
}


.main-footer {
    padding: 50px 20px;
    text-align: center;
    background-color: var(--color-bg-dark);
    border-top: 1px solid var(--color-border);
}
.main-footer p {
    color: var(--color-text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0;
}

@media (max-width: 900px) {
    .comparison-content {
        grid-template-columns: 1fr;
    }
    .tree-branches { 
        flex-direction: column; 
        gap: 20px; 
        align-items: center;
    }
    .tree-branch { 
        width: 100%; 
        max-width: 400px;
    }
    .connector-branch-wrapper { display: none; }
    .connector-line { height: 0 !important; }
    .fade-in.is-visible .connector-line.vertical { height: 20px; }
}

@media (max-width: 768px) {
    h2 { font-size: 2rem; }
    .hero-content h1 { font-size: 2.8rem; }
    .hero-content h2 { font-size: 2.2rem; }
    
    .main-nav { padding: 6px; }
    .main-nav ul { gap: 6px; }
    .main-nav a { font-size: 0.5rem; padding: 5px; }

    .waterfall-diagram {
        flex-direction: column;
        gap: 15px;
    }
    .waterfall-arrow {
        transform: rotate(90deg) scale(0);
    }
    .waterfall-arrow.visible {
        transform: rotate(90deg) scale(1);
    }

    .mini-waterfall {
        flex-direction: column;
        gap: 15px;
    }
    .mini-waterfall .arrow {
        transform: rotate(90deg) scale(0);
    }
    .mini-waterfall .arrow.visible {
        transform: rotate(90deg) scale(1);
    }
    .mini-waterfall .stage::after {
        width: 120px;
        font-size: 0.8rem;
    }

    .spiral-content-wrapper {
        flex-direction: column;
        gap: 20px;
        padding: 40px 20px;
    }
    .spiral-text-content { order: 1; text-align: center; }
    .spiral-animation-container { order: 2; width: 100%; max-width: 300px; }
    .quadrant-text { text-align: left; }
    #spiral-scroll-trigger { height: 400vh; }
    
    .quiz-buttons {
        flex-direction: column;
    }
}