/* ===========================================
   Open Problems — Teaser Page
   Minimalist dot/ASCII aesthetic
   =========================================== */

:root {
    --color-ink: #0B0B0C;
    --color-paper: #FFFFFF;
    --color-muted: #888;
    --font-body: -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    --font-mono: 'SF Mono', SFMono-Regular, ui-monospace, Menlo, Monaco, 'Cascadia Mono', monospace;
}

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

html {
    font-size: 18px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    background: var(--color-paper);
    color: var(--color-ink);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    line-height: 1.6;
    overflow-x: hidden;
}

/* ----------------------------------------
   Header
   ---------------------------------------- */
.header {
    position: fixed;
    top: 0;
    left: 0;
    padding: 1.5rem;
    z-index: 100;
}

.logo {
    display: block;
    width: 40px;
    height: 40px;
    transition: transform 0.3s ease;
}

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

.logo img {
    width: 100%;
    height: 100%;
}

/* Accessibility: screen-reader only */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

/* ----------------------------------------
   Background dot field — "connecting the dots"
   ---------------------------------------- */
.dot-field {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: -1;
    background-image: radial-gradient(circle, rgba(0, 0, 0, 0.06) 0.8px, transparent 0.8px);
    background-size: 12px 12px;
}


/* ----------------------------------------
   Hero
   ---------------------------------------- */
.hero {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 2rem 1.5rem 4rem;
    gap: 1.5rem;
}

.title {
    font-size: clamp(2rem, 6vw, 3.5rem);
    font-weight: 600;
    line-height: 1.15;
    letter-spacing: -0.02em;
    max-width: 14ch;
}

.title em {
    font-style: normal;
    font-weight: 700;
}

.teaser {
    max-width: 52ch;
    color: var(--color-muted);
    font-size: 1rem;
    text-align: center;
}

/* Disciplines inline list */
.disciplines-list {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.25rem 1rem;
    list-style: none;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-muted);
}

.disciplines-list li {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.disciplines-list li:not(:last-child)::after {
    content: '·';
    color: var(--color-muted);
}

/* ----------------------------------------
   Stage (animated SVG container)
   ---------------------------------------- */
.stage {
    position: relative;
    width: min(300px, 75vw);
    height: min(300px, 75vw);
    margin: 2.5rem 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon-container {
    position: absolute;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    filter: blur(12px);
    transform: scale(0.92);
    transition: 
        opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1),
        filter 0.6s cubic-bezier(0.4, 0, 0.2, 1),
        transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.icon-container svg {
    width: 100%;
    height: 100%;
}

/* Transition states */
.icon-container.visible {
    opacity: 1;
    filter: blur(0);
    transform: scale(1);
}

.icon-container.entering {
    opacity: 0;
    filter: blur(12px);
    transform: scale(1.08);
}

.icon-container.leaving {
    opacity: 0;
    filter: blur(12px);
    transform: scale(0.92);
}


/* ----------------------------------------
   Footer
   ---------------------------------------- */
.footer {
    text-align: center;
    padding: 2rem;
    font-family: var(--font-mono);
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-muted);
}

/* ----------------------------------------
   Responsive
   ---------------------------------------- */
@media (max-width: 600px) {
    html {
        font-size: 16px;
    }

    .header {
        padding: 1rem;
    }

    .hero {
        padding: 1.5rem 1rem 3rem;
    }
}

/* ----------------------------------------
   Reduced motion
   ---------------------------------------- */
@media (prefers-reduced-motion: reduce) {
    .layer {
        transition: none;
    }

    .layer.fade-out,
    .layer.hidden {
        filter: none;
        transform: none;
    }
}