:root {
    --mit-red: #A31F34;
    --black: #000000;
    --dark-gray: #121212;
    --light-gray: #E5E5E5;
    --white: #FFFFFF;
    --border-width: 1px;
    --border-color: #000;
}

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

body {
    font-family: 'Noto Sans', Helvetica, Arial, sans-serif;
    color: var(--black);
    background-color: var(--white);
    line-height: 1.4;
    text-align: left !important;
}

/* --- CLASES CON PREFIJO --- */
.retos26_mono {
    font-family: 'JetBrains Mono', monospace;

    font-size: 14px;
    letter-spacing: 0.5px;

}

/* --- NAVIGATION --- */
.retos26_nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    border-bottom: 2px solid var(--black);
    position: sticky;
    top: 0;
    background: var(--white);
    z-index: 1000;
    height: 90px;
    position: fixed;
    top: 80px;
    width: 100%;
    top: 80px;
    width: 100%;
}

.retos26_logo img {
    width: 70%;
}

@media (max-width: 768px) {
    .retos26_logo img {
        width: 100%;
    }
}

.retos26_nav-wrapper {
    display: flex;
    align-items: center;
}

.retos26_nav-items {
    display: flex;
    gap: 2rem;
}

.retos26_nav-items a {
    font-weight: 600;
    font-size: 14px;
    text-decoration: none;
    color: var(--black);
}

.retos26_nav-items a:hover {
    color: var(--mit-red);
    text-decoration: underline;
}

.retos26_nav-items a.retos26_nav-highlight {
    color: var(--mit-red);
}

#menu-toggle {
    display: none;
}

.retos26_hamburger {
    display: none;
    cursor: pointer;
    padding: 10px;
    z-index: 1001;
}

.retos26_hamburger span {
    display: block;
    width: 25px;
    height: 2px;
    background: var(--black);
    margin: 5px 0;
    transition: 0.3s;
}

/* --- LAYOUT COMPONENTS --- */
.retos26_hero-grid {
    display: grid;
    grid-template-columns: 60% 40%;
    border-bottom: 1px solid var(--black);
}

.retos26_hero-text {
    padding: 4rem 2rem;
}

.retos26_hero-text .retos26_mono {
    margin-bottom: 10px;
    display: block;
}

.retos26_hero-text p {
    font-size: 25px;
    max-width: 500px;
    font-weight: 400;
}

.retos26_hero-image {
    /*background-color: var(--dark-gray); 
         border-left: 1px solid var(--black); */
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    text-align: center;

    background-size: cover;
}

.retos26_hero-year {
    font-size: 40px;
    font-weight: 800;
}

.retos26_h1 {
    font-size: clamp(5.5rem, 8vw, 7.5rem);
    font-weight: 800;
    line-height: 0.9;
    margin-bottom: 2rem;
    letter-spacing: -2px;
    color: black;
    font-family: sans-serif;
}

.retos26_h2 {
    font-size: 40px;
    font-weight: 800;
    line-height: 0.9;
    margin-bottom: 2rem;
    letter-spacing: -2px;
    color: black;
    font-family: sans-serif;
}

.retos26_section-container {
    display: grid;
    grid-template-columns: repeat(12, 1fr);
    border-top: 1px solid var(--black);
}

.retos26_section-no-top-border {
    border-top: none;
}

.retos26_sidebar {
    grid-column: span 3;
    background-color: var(--light-gray);
    padding: 2rem;
    border-right: 1px solid var(--black);
}

.retos26_sidebar .retos26_mono {
    margin-bottom: 1rem;
    color: var(--mit-red);
}

.retos26_sidebar p {
    font-size: 15px;
    font-weight: 400;
}

.retos26_main-content {
    grid-column: span 9;
}

.retos26_module-header {
    padding: 2rem;
    border-bottom: 1px solid var(--black);
}

.retos26_module-header .retos26_mono {
    margin-bottom: 10px;
}

.retos26_module-header h2 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--mit-red);
}

.retos26_module-header h2 span {
    color: var(--black);
}

.retos26_module-header h2.retos26_small-title {
    font-size: 1.5rem;
    color: var(--black);
}

.retos26_content-split {
    display: grid;
    grid-template-columns: 1fr 1fr;
}

.retos26_media-box {
    background: black;
    border-right: 1px solid var(--black);
    aspect-ratio: 16/9;
    position: relative;
}

.retos26_media-box iframe {
    width: 100%;
    height: 100%;
    border: none;
    position: absolute;
    top: 0;
    left: 0;
}

.retos26_padlet-container {
    width: 100%;
    height: 600px;
    background: #eee;
}

.retos26_padlet-embed {
    height: 90%;
}

.retos26_padlet-embed iframe {
    width: 100%;
    height: 608px;
    display: block;
    padding: 0;
    margin: 0;
    border: none;
}

.retos26_text-box {
    padding: 2rem;
}

.retos26_btn-square {
    display: inline-block;
    background: var(--black);
    color: var(--white);
    padding: 1rem 2rem;
    font-weight: 600;
    font-size: 17px;
    border: 1px solid var(--black);
    text-decoration: none;
    margin-top: 2rem;
    transition: 0.2s;
    cursor: pointer;
    max-width: 300px;
    width: 100%;
}

/* Explicitly force white text on all interaction states */
.retos26_btn-square:visited,
.retos26_btn-square:hover,
.retos26_btn-square:focus,
.retos26_btn-square:active {
    color: var(--white) !important;
    text-decoration: none !important;
    /* Optional: Ensure background stays dark on hover so white text is visible */
    background: var(--black);
    border-color: var(--black);
}

.retos26_mono a {
    text-decoration: none;
}

.retos26_btn-square:hover {
    background: var(--mit-red);
    border-color: var(--mit-red);
}

#registro {
    position: relative;
    padding: 4rem 2rem;
    border-top: 2px solid var(--black);
    background: var(--light-gray);
}

.retos26_registro-inner {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.retos26_registro-inner h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.retos26_registro-inner p {
    margin-bottom: 2rem;
}

.retos26_registro-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.retos26_registro-actions .retos26_btn-square {
    margin: 0;
}

.retos26_btn-outline {
    background: transparent;
    color: black;
    border: 1px solid black;
}

footer {
    background: var(--black);
    color: white;
    padding: 3rem 2rem;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    border-top: 1px solid var(--black);
}

footer .retos26_mono {
    margin-bottom: 1rem;
}

footer .retos26_mono.retos26_highlight {
    color: var(--mit-red);
}

footer p {
    font-size: 0.8rem;
}

footer p.retos26_faded {
    opacity: 0.7;
}

footer a {
    color: white;
    text-decoration: none;
}

/* --- MOBILE RESPONSIVE --- */
@media (max-width: 900px) {
    .retos26_hamburger {
        display: block;
    }

    .retos26_nav-items {
        position: fixed;
        top: 0;
        right: -100%;
        height: 100vh;
        width: 100%;
        background: var(--white);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        transition: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
        z-index: 1000;
    }

    #menu-toggle:checked~.retos26_nav-items {
        right: 0;
    }

    #menu-toggle:checked~.retos26_hamburger span:nth-child(1) {
        transform: translateY(7px) rotate(45deg);
    }

    #menu-toggle:checked~.retos26_hamburger span:nth-child(2) {
        opacity: 0;
    }

    #menu-toggle:checked~.retos26_hamburger span:nth-child(3) {
        transform: translateY(-7px) rotate(-45deg);
    }

    .retos26_nav-items a {
        font-size: 1.5rem;
    }

    .retos26_hero-grid {
        grid-template-columns: 1fr;
    }

    .retos26_hero-image {
        display: none;
    }

    .retos26_section-container {
        display: flex;
        flex-direction: column;
    }

    .retos26_sidebar {
        border-right: none;
        border-bottom: 1px solid var(--black);
    }

    .retos26_content-split {
        grid-template-columns: 1fr;
    }

    .retos26_media-box {
        border-right: none;
        border-bottom: 1px solid var(--black);
    }
}