/* ==========================================================================
   mulle-core.github.io — pure CSS, no JavaScript, no build step.
   Dark "lava" theme: gradient accents, glow, zero dependencies.
   ========================================================================== */

:root {
   --bg:            #0a0c11;
   --bg-soft:       #10131b;
   --panel:         #12161f;
   --panel-hover:   #171c28;
   --border:        rgba(255, 255, 255, 0.07);
   --border-strong: rgba(255, 255, 255, 0.14);
   --text:          #e8ebf2;
   --muted:         #9aa3b2;
   --faint:         #6b7484;

   --lava-1: #ff5e3a;   /* orange  */
   --lava-2: #ff2e63;   /* pink    */
   --lava-3: #a855f7;   /* purple  */
   --green:  #34d399;

   --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
                "Helvetica Neue", Arial, sans-serif;
   --font-mono: ui-monospace, "SF Mono", "Cascadia Code", "JetBrains Mono",
                Menlo, Consolas, monospace;

   --radius: 14px;
   --maxw: 1080px;
}

/* ------------------------------------------------------------------ reset */
*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
   margin: 0;
   background: var(--bg);
   color: var(--text);
   font-family: var(--font-sans);
   line-height: 1.6;
   -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; }
a { color: var(--lava-1); text-decoration: none; }
a:hover { text-decoration: underline; }
code, pre { font-family: var(--font-mono); }
code { font-size: 0.9em; }

.sr-only {
   position: absolute;
   width: 1px; height: 1px;
   padding: 0; margin: -1px;
   overflow: hidden;
   clip: rect(0 0 0 0);
   white-space: nowrap;
   border: 0;
}

.skip-link {
   position: absolute;
   left: -999px;
   top: 0;
   background: var(--lava-2);
   color: #fff;
   padding: 0.6rem 1rem;
   border-radius: 0 0 8px 0;
   z-index: 100;
}
.skip-link:focus { left: 0; }

/* ------------------------------------------------------------ header/nav */
.site-header {
   position: sticky;
   top: 0;
   z-index: 50;
   background: rgba(10, 12, 17, 0.82);
   backdrop-filter: blur(10px);
   border-bottom: 1px solid var(--border);
}

.nav {
   max-width: var(--maxw);
   margin: 0 auto;
   padding: 0.8rem 1.5rem;
   display: flex;
   align-items: center;
   gap: 1.5rem;
}

.brand {
   display: inline-flex;
   align-items: center;
   gap: 0.5rem;
   color: var(--text);
   font-weight: 700;
   font-size: 1.05rem;
   text-decoration: none;
}
.brand-mark { font-size: 1.3rem; }

.nav-links {
   list-style: none;
   display: flex;
   gap: 1.4rem;
   margin: 0 auto;
   padding: 0;
}
.nav-links a {
   color: var(--muted);
   font-size: 0.92rem;
   text-decoration: none;
}
.nav-links a:hover { color: var(--text); }

.nav > .btn { margin-left: auto; }

/* ----------------------------------------------------------------- buttons */
.btn {
   display: inline-block;
   padding: 0.7rem 1.4rem;
   border-radius: 999px;
   font-weight: 600;
   font-size: 0.95rem;
   text-decoration: none;
   transition: transform 0.15s ease, box-shadow 0.2s ease;
}
.btn:hover { transform: translateY(-1px); text-decoration: none; }

.btn-small { padding: 0.45rem 1rem; font-size: 0.85rem; }

.btn-primary {
   color: #fff;
   background: linear-gradient(135deg, var(--lava-1), var(--lava-2));
   box-shadow: 0 0 0 1px rgba(255, 46, 99, 0.35),
               0 6px 24px rgba(255, 46, 99, 0.35);
   animation: glow-pulse 3s ease-in-out infinite;
}
.btn-primary:hover { box-shadow: 0 0 0 1px rgba(255, 46, 99, 0.5),
                                0 8px 32px rgba(255, 46, 99, 0.5); }

.btn-outline {
   color: var(--text);
   border: 1px solid var(--border-strong);
   background: rgba(255, 255, 255, 0.02);
}
.btn-outline:hover { border-color: var(--lava-1); color: var(--lava-1); }

@keyframes glow-pulse {
   0%, 100% { box-shadow: 0 0 0 1px rgba(255, 46, 99, 0.35),
                          0 6px 24px rgba(255, 46, 99, 0.35); }
   50%      { box-shadow: 0 0 0 1px rgba(255, 46, 99, 0.55),
                          0 6px 34px rgba(255, 46, 99, 0.55); }
}

/* -------------------------------------------------------------------- hero */
.hero {
   position: relative;
   overflow: hidden;
   text-align: center;
   padding: 6.5rem 1.5rem 4rem;
}

.hero-glow {
   position: absolute;
   inset: -30% -20% auto -20%;
   height: 90%;
   background:
      radial-gradient(40% 60% at 20% 40%, rgba(255, 94, 58, 0.22), transparent 70%),
      radial-gradient(40% 60% at 80% 35%, rgba(168, 85, 247, 0.20), transparent 70%),
      radial-gradient(30% 50% at 50% 80%, rgba(255, 46, 99, 0.14), transparent 70%);
   filter: blur(6px);
   animation: lava-drift 12s ease-in-out infinite alternate;
   pointer-events: none;
}

/* faint blueprint grid for texture — purely decorative */
.hero::before {
   content: "";
   position: absolute;
   inset: 0;
   background-image:
      linear-gradient(rgba(255, 255, 255, 0.022) 1px, transparent 1px),
      linear-gradient(90deg, rgba(255, 255, 255, 0.022) 1px, transparent 1px);
   background-size: 44px 44px;
   pointer-events: none;
}
@keyframes lava-drift {
   from { transform: translate3d(-2%, 0, 0) scale(1); }
   to   { transform: translate3d(2%, 3%, 0) scale(1.06); }
}

.eyebrow {
   display: inline-block;
   margin: 0 0 1.2rem;
   padding: 0.35rem 1rem;
   border: 1px solid var(--border-strong);
   border-radius: 999px;
   background: rgba(255, 255, 255, 0.03);
   color: var(--muted);
   font-family: var(--font-mono);
   font-size: 0.85rem;
   letter-spacing: 0.06em;
}

.hero-title {
   position: relative;
   margin: 0 auto 1.2rem;
   max-width: 20ch;
   font-size: clamp(2.4rem, 6vw, 4.2rem);
   line-height: 1.08;
   letter-spacing: -0.02em;
   background: linear-gradient(100deg, var(--lava-1), var(--lava-2) 55%, var(--lava-3));
   background-size: 200% 200%;
   -webkit-background-clip: text;
   background-clip: text;
   color: transparent;
   animation: gradient-slide 8s ease-in-out infinite alternate;
}
@keyframes gradient-slide {
   from { background-position: 0% 50%; }
   to   { background-position: 100% 50%; }
}

.hero-sub {
   position: relative;
   margin: 0 auto 2rem;
   max-width: 58ch;
   color: var(--muted);
   font-size: 1.08rem;
}
.hero-sub strong { color: var(--text); }

.hero-actions {
   position: relative;
   display: flex;
   justify-content: center;
   gap: 1rem;
   flex-wrap: wrap;
}

.hero-code {
   position: relative;
   max-width: 620px;
   margin: 2.4rem auto 0;
   text-align: left;
   white-space: pre-wrap;       /* wrap instead of scroll on narrow screens */
   word-break: break-word;
}

/* --------------------------------------------------------------- code box */
pre {
   position: relative;
   background: var(--panel);
   border: 1px solid var(--border);
   border-radius: var(--radius);
   padding: 2.3rem 1.3rem 1.1rem;   /* top padding leaves room for the bar */
   overflow-x: auto;
   font-size: 0.88rem;
   line-height: 1.65;
   color: var(--text);
   box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.03);
}

/* traffic-light bar, pure CSS */
pre::before {
   content: "";
   position: absolute;
   top: 0.85rem;
   left: 1.1rem;
   width: 3.4em;
   height: 0.85em;
   background:
      radial-gradient(circle at 0.5em 50%, #ff5f57 0 0.36em, transparent 0.4em),
      radial-gradient(circle at 1.65em 50%, #febc2e 0 0.36em, transparent 0.4em),
      radial-gradient(circle at 2.8em 50%, #28c840 0 0.36em, transparent 0.4em);
   opacity: 0.75;
}

pre code { font-size: inherit; }

.c  { color: var(--lava-1); }   /* keywords-ish  */
.k  { color: var(--lava-2); }   /* calls         */
.s  { color: var(--green);  }   /* strings       */
.v  { color: #7dd3fc;       }   /* variables     */
.cm { color: var(--faint);  }   /* comments      */

/* ----------------------------------------------------------------- section */
.section {
   max-width: var(--maxw);
   margin: 0 auto;
   padding: 4.5rem 1.5rem;
}

.section-title {
   position: relative;
   margin: 0 0 0.6rem;
   padding-bottom: 0.45rem;
   font-size: clamp(1.6rem, 3.5vw, 2.2rem);
   letter-spacing: -0.01em;
}
.section-title::after {
   content: "";
   position: absolute;
   left: 0;
   bottom: 0;
   width: 3.2rem;
   height: 3px;
   border-radius: 2px;
   background: linear-gradient(90deg, var(--lava-1), var(--lava-2));
}
.section-lead {
   margin: 0 0 2.5rem;
   max-width: 72ch;
   color: var(--muted);
   font-size: 1.02rem;
}

/* ------------------------------------------------------------------- cards */
.cards {
   display: grid;
   grid-template-columns: repeat(auto-fit, minmax(290px, 1fr));
   gap: 1.2rem;
}

.card {
   background: var(--panel);
   border: 1px solid var(--border);
   border-radius: var(--radius);
   padding: 1.6rem 1.5rem;
   transition: transform 0.18s ease, border-color 0.18s ease,
               box-shadow 0.18s ease;
}
.card:hover {
   transform: translateY(-3px);
   border-color: var(--border-strong);
   box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4),
               0 0 24px rgba(255, 46, 99, 0.08);
}
/* full-width highlight card (e.g. mulle-objc) */
.card-spotlight {
   grid-column: 1 / -1;
   border-color: rgba(168, 85, 247, 0.35);
   background: linear-gradient(180deg, rgba(168, 85, 247, 0.07), var(--panel) 60%);
}
.card-spotlight:hover {
   border-color: rgba(168, 85, 247, 0.6);
   box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4),
               0 0 28px rgba(168, 85, 247, 0.12);
}
.card-spotlight h3 { display: inline-block; }
.card-spotlight .card-emoji { display: inline-block; margin: 0 0.6rem 0 0; }

.card-emoji { font-size: 1.6rem; display: block; margin-bottom: 0.6rem; }
.card h3 { margin: 0 0 0.5rem; font-size: 1.05rem; }
.card p { margin: 0; color: var(--muted); font-size: 0.94rem; }

/* call-to-action row inside a card */
.card p.guide-actions { margin-top: 1.1rem; }

/* monospace library tags under a demo card */
.card p.card-tags {
   margin-top: 0.6rem;
   color: var(--faint);
   font-family: var(--font-mono);
   font-size: 0.74rem;
   letter-spacing: 0.01em;
}

/* ------------------------------------------------ split feature layouts (A) */
.split {
   display: grid;
   grid-template-columns: 0.85fr 1.15fr;
   gap: 3rem;
   align-items: start;
}

.split-pull {
   margin: 0 0 1.1rem;
   max-width: 16ch;
   font-size: 1.4rem;
   font-weight: 700;
   line-height: 1.22;
   letter-spacing: -0.01em;
   background: linear-gradient(100deg, var(--lava-1), var(--lava-3));
   -webkit-background-clip: text;
   background-clip: text;
   color: transparent;
}

.split-code { margin: 0.4rem 0; font-family: var(--font-mono); font-size: 0.85rem; }
.split-code code {
   display: inline-block;
   padding: 0.3rem 0.75rem;
   border: 1px solid var(--border);
   border-radius: 8px;
   background: var(--panel);
   color: var(--text);
}

.split-note {
   margin: 1.3rem 0 0;
   padding-left: 1.1rem;
   border-left: 2px solid var(--lava-2);
   color: var(--muted);
   font-size: 0.92rem;
}
.split-note code { color: var(--text); }

/* --------------------------------------------------- next-step callout (F) */
.next-step {
   margin-top: 2.5rem;
   padding: 1.5rem 1.6rem;
   border: 1px solid var(--border);
   border-left: 3px solid var(--lava-2);
   border-radius: var(--radius);
   background: var(--panel);
}
.next-step h3 { margin: 0 0 0.5rem; font-size: 1.05rem; }
.next-step p { margin: 0 0 0.9rem; color: var(--muted); font-size: 0.95rem; }
.next-step p:last-child { margin-bottom: 0; }

/* ----------------------------------------------------------------- modules */
.module-group { margin-bottom: 2.2rem; }

.group-title {
   margin: 0 0 0.9rem;
   font-size: 0.95rem;
   text-transform: uppercase;
   letter-spacing: 0.08em;
   color: var(--muted);
}

.modules {
   display: grid;
   grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
   gap: 0.8rem;
}

.module {
   background: var(--panel);
   border: 1px solid var(--border);
   border-radius: 12px;
   padding: 0.9rem 1.1rem;
   font-size: 0.9rem;
   transition: border-color 0.15s ease, background 0.15s ease;
}
.module:hover {
   border-color: var(--border-strong);
   background: var(--panel-hover);
}
.module > span { margin-right: 0.5rem; }
.module a { font-family: var(--font-mono); font-weight: 600; color: var(--text); }
.module a:hover { color: var(--lava-1); }
.module p { margin: 0.2rem 0 0 1.4rem; color: var(--faint); font-size: 0.82rem; }
.links .module p { margin-left: 0; }

/* --------------------------------------------------------------- quick start */
.steps {
   list-style: none;
   margin: 0;
   padding: 0;
   display: grid;
   gap: 1.6rem;
   counter-reset: step;
}

/* grid items must be allowed to shrink below their content's min-width,
   otherwise long code lines blow out the layout on narrow screens */
.steps li,
.steps pre { min-width: 0; }

.steps li h3 {
   display: flex;
   align-items: center;
   gap: 0.7rem;
   margin: 0 0 0.7rem;
   font-size: 1.05rem;
}
.step-num {
   display: inline-flex;
   align-items: center;
   justify-content: center;
   width: 1.8rem;
   height: 1.8rem;
   border-radius: 50%;
   font-family: var(--font-mono);
   font-size: 0.85rem;
   font-weight: 700;
   color: #fff;
   background: linear-gradient(135deg, var(--lava-1), var(--lava-2));
   box-shadow: 0 0 14px rgba(255, 46, 99, 0.4);
}
.steps pre { max-width: 640px; }

.section-note { margin-top: 2rem; color: var(--faint); font-size: 0.92rem; }

/* ------------------------------------------------------------- concurrency */
.section-feature {
   position: relative;
   max-width: none;
   padding: 5rem 1.5rem;
   border-top: 1px solid var(--border);
   border-bottom: 1px solid var(--border);
   background: linear-gradient(180deg, var(--bg-soft), var(--bg));
   overflow: hidden;
}
.section-feature .section-title,
.section-feature .section-lead {
   max-width: var(--maxw);
   margin-left: auto;
   margin-right: auto;
}

.feature-glow {
   position: absolute;
   top: -40%;
   left: 50%;
   transform: translateX(-50%);
   width: 70%;
   height: 120%;
   background: radial-gradient(50% 50% at 50% 50%, rgba(52, 211, 153, 0.10), transparent 70%);
   pointer-events: none;
}

.feature-grid {
   position: relative;
   max-width: var(--maxw);
   margin: 0 auto;
   display: grid;
   grid-template-columns: 1.1fr 1fr;
   gap: 2.5rem;
   align-items: center;
}

.feature-code {
   border-color: rgba(52, 211, 153, 0.25);
   box-shadow: 0 0 40px rgba(52, 211, 153, 0.07),
               inset 0 1px 0 rgba(255, 255, 255, 0.03);
   margin: 0;
}

.feature-list {
   list-style: none;
   margin: 0;
   padding: 0;
   display: grid;
   gap: 1rem;
}
.feature-list li {
   padding-left: 1.4rem;
   border-left: 2px solid var(--lava-2);
   color: var(--muted);
   font-size: 0.96rem;
}
.feature-list strong { color: var(--text); }

/* ---------------------------------------------------------------- platforms */
.platform-grid {
   display: grid;
   grid-template-columns: 1fr;
   gap: 1.5rem;
   align-items: start;
}

.matrix {
   width: 100%;
   border-collapse: collapse;
   background: var(--panel);
   border: 1px solid var(--border);
   border-radius: var(--radius);
   overflow: hidden;
   font-size: 0.92rem;
}
.matrix th, .matrix td {
   text-align: left;
   padding: 0.7rem 1.1rem;
   border-bottom: 1px solid var(--border);
}
.matrix thead th {
   background: var(--bg-soft);
   color: var(--muted);
   font-size: 0.8rem;
   text-transform: uppercase;
   letter-spacing: 0.06em;
}
.matrix tbody tr:last-child td { border-bottom: none; }
.matrix tbody tr:hover td { background: var(--panel-hover); }
.matrix td:first-child { color: var(--text); font-weight: 600; }
.matrix td:nth-child(2) { font-family: var(--font-mono); color: var(--lava-1); }

/* ------------------------------------------------------------------ footer */
.site-footer {
   border-top: 1px solid var(--border);
}

/* ------------------------------------------------------------- responsive */
@media (max-width: 860px) {
   .feature-grid { grid-template-columns: 1fr; }
   .split { grid-template-columns: 1fr; gap: 2rem; }
   .split-pull { max-width: none; }
   .nav-links { display: none; }
   .hero { padding-top: 4.5rem; }
}

/* --------------------------------------------------------- reduced motion */
@media (prefers-reduced-motion: reduce) {
   html { scroll-behavior: auto; }
   *, *::before, *::after {
      animation-duration: 0.01ms !important;
      animation-iteration-count: 1 !important;
      transition-duration: 0.01ms !important;
   }
}