/*
 * Estilos generales para PixelSurvey.
 * Se utilizan tonos púrpura inspirados en el estilo solicitado por el usuario.
 */

/* Reseteo y tipografía */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Poppins', sans-serif;
    color: #2D2B3A;
    background-color: #FAFAFA;
    line-height: 1.6;
}

/* Botones reutilizables */
.btn {
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-weight: 600;
    text-decoration: none;
    display: inline-block;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
}

/* Variante primaria: se usa en secciones claras y oscuras */
.btn-primary {
    background-color: #ffffff;
    color: #6D28D9;
    box-shadow: 0 4px 12px rgba(109, 40, 217, 0.15);
}

.btn-primary:hover {
    background-color: #F8F6FF;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(109, 40, 217, 0.25);
}

/* Variante secundaria: borde claro sobre fondos oscuros */
.btn-secondary {
    border: 2px solid #ffffff;
    color: #ffffff;
    background-color: transparent;
}

.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

/* Navegación */
nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background: linear-gradient(135deg, #6D28D9 0%, #9333EA 100%);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 4px 20px rgba(109, 40, 217, 0.2);
    backdrop-filter: blur(10px);
}

nav .logo {
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    height: 50px;
    gap: 0.75rem;
}

nav .logo-image {
    height: 100%;
    width: auto;
    transition: transform 0.3s ease;
    display: flex;
    align-self: center;
}

nav .logo-text {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 1.8rem;
    font-weight: 700;
    color: #ffffff;
    text-decoration: none;
    letter-spacing: -0.4px;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    line-height: 1;
}

nav .logo:hover {
    transform: scale(1.05);
}

nav .logo:hover .logo-text {
    text-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

nav .nav-links {
    display: flex;
    gap: 1.5rem;
}

nav .nav-links a {
    color: #ffffff;
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.3s;
    white-space: nowrap;
}

nav .nav-links a:hover {
    opacity: 0.8;
}

/* Hero section */
.hero {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 5rem 2rem;
    margin: 2rem;
    background: linear-gradient(135deg, #6D28D9 0%, #9333EA 50%, #A855F7 100%);
    color: #ffffff;
    position: relative;
    overflow: hidden;
    border-radius: 24px;
    box-shadow: 0 20px 40px rgba(109, 40, 217, 0.25);
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 30% 20%, rgba(255, 255, 255, 0.1) 0%, transparent 50%),
                radial-gradient(circle at 70% 80%, rgba(255, 255, 255, 0.05) 0%, transparent 50%);
    pointer-events: none;
}

.hero-content {
    max-width: 600px;
    text-align: center;
    z-index: 2;
}

.hero h1 {
    font-size: 2.8rem;
    margin-bottom: 1rem;
    font-weight: 700;
    text-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.hero p {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    opacity: 0.95;
    font-weight: 400;
    text-shadow: 0 1px 10px rgba(0, 0, 0, 0.1);
}

.cta {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
}



.hero-image {
    margin-top: 3rem;
    width: 80%;
    max-width: 600px;
    z-index: 1;
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-10px); }
}

.hero-image img {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

/* Features section */
.features {
    padding: 5rem 2rem;
    background: linear-gradient(to bottom, #FAFAFA 0%, #F3F4F6 100%);
    text-align: center;
}

.features h2 {
    font-size: 2.4rem;
    margin-bottom: 3rem;
    color: #6D28D9;
    font-weight: 700;
    position: relative;
}

.features h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, #6D28D9, #9333EA);
    border-radius: 2px;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.feature-item {
    background: linear-gradient(145deg, #ffffff 0%, #fefefe 100%);
    border-radius: 16px;
    padding: 2.5rem;
    box-shadow: 0 8px 25px rgba(109, 40, 217, 0.08);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid rgba(109, 40, 217, 0.05);
    position: relative;
    overflow: hidden;
}

.feature-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, #6D28D9, #9333EA);
    transform: scaleX(0);
    transition: transform 0.4s;
}

.feature-item:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(109, 40, 217, 0.15);
}

.feature-item:hover::before {
    transform: scaleX(1);
}

.feature-item i {
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, #6D28D9, #9333EA);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    filter: drop-shadow(0 2px 4px rgba(109, 40, 217, 0.2));
}

.feature-emoji {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    text-align: center;
    filter: drop-shadow(0 2px 8px rgba(0, 0, 0, 0.1));
    animation: bounce 2s ease-in-out infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-8px); }
}

.feature-item h3 {
    font-size: 1.4rem;
    margin-bottom: 1rem;
    color: #2D2B3A;
    font-weight: 600;
}

.feature-item p {
    font-size: 0.95rem;
    color: #6B7280;
    line-height: 1.6;
}

/* Contribute section */
.call-to-action {
    padding: 5rem 2rem;
    background: linear-gradient(135deg, #6D28D9 0%, #9333EA 100%);
    color: #ffffff;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.call-to-action::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 70% 30%, rgba(255, 255, 255, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.call-to-action h2 {
    font-size: 2.2rem;
    margin-bottom: 1rem;
}

.call-to-action p {
    font-size: 1rem;
    max-width: 700px;
    margin: 0 auto 2rem;
}

.call-to-action .btn-primary {
    background-color: #ffffff;
    color: #6D28D9;
    display: inline-block;
    margin-top: 1rem;
    padding: 1rem 2rem;
    border-radius: 8px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.4s;
    box-shadow: 0 4px 15px rgba(255, 255, 255, 0.2);
    position: relative;
    z-index: 2;
}

.call-to-action .btn-primary:hover {
    background-color: #F8F6FF;
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(255, 255, 255, 0.3);
}

.cityai-link {
    color: #ffffff;
    text-decoration: underline;
    text-decoration-color: rgba(255, 255, 255, 0.5);
    transition: all 0.3s ease;
    font-weight: 600;
}

.cityai-link:hover {
    text-decoration-color: #ffffff;
    color: #F3E8FF;
}

/* Footer */
.footer {
    background: linear-gradient(135deg, #6D28D9 0%, #9333EA 100%);
    color: #ffffff;
    padding: 2.5rem;
    text-align: center;
    font-size: 0.9rem;
}

.footer .heart {
    color: #F3E8FF;
    animation: heartbeat 2s ease-in-out infinite;
}

.footer .tudelft-logo {
    height: 1.2rem;
    width: auto;
    margin: 0 0.5rem;
    vertical-align: middle;
    filter: invert(1) brightness(1);
    opacity: 0.9;
    transition: opacity 0.3s ease;
}

.footer .tudelft-logo:hover {
    opacity: 1;
}

@keyframes heartbeat {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

/* Simple hamburger menu */
.hamburger {
    display: none;
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
}

@media (max-width: 768px) {
    nav {
        position: relative;
    }
    
    .hamburger {
        display: block;
    }
    
    nav .nav-links {
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: linear-gradient(135deg, #6D28D9 0%, #9333EA 100%);
        flex-direction: column;
        gap: 0;
        display: none;
        box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        z-index: 1000;
    }
    
    nav .nav-links.show {
        display: flex;
    }
    
    nav .nav-links a {
        padding: 1rem;
        border-bottom: 1px solid rgba(255,255,255,0.1);
        text-align: center;
        display: block;
    }
    
    nav .nav-links a:last-child {
        border-bottom: none;
    }

    .hero {
        padding: 3rem 1rem;
        margin: 1rem;
        border-radius: 16px;
    }
    .hero h1 {
        font-size: 2.2rem;
    }
    .features {
        padding: 3rem 1rem;
    }
    .feature-item {
        padding: 2rem;
    }
}@media (min-width: 769px) {
    .hero {
        flex-direction: row;
        justify-content: space-between;
        padding: 6rem 4rem;
        margin: 2rem;
    }
    .hero-content {
        text-align: left;
        max-width: 50%;
    }
    .hero-image {
        margin-top: 0;
        max-width: 45%;
    }
    .hero h1 {
        font-size: 3.2rem;
    }
    .hero p {
        font-size: 1.2rem;
    }
}