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

/* ────────────────────────────────────────────────
   PRESENTAZIONI EFFICACI — Design System tokens
   (allineati a "Corso AI - sezioni argomenti.html")
   ──────────────────────────────────────────────── */
:root {
  /* Brand */
  --brand-blue-900: #0b1037;
  --brand-blue-700: #1d2670;
  --brand-blue-600: #2a3aa5;
  --brand-blue-500: #3a52e4;
  --brand-blue-400: #5b78ff;
  --brand-blue-300: #8aa3ff;
  --brand-violet-900: #2a1366;
  --brand-violet-700: #5024c2;
  --brand-violet-600: #6b3fd9;
  --brand-violet-500: #8a5cff;
  --brand-violet-400: #a983ff;
  --brand-violet-300: #c7adff;

  /* Accento giallo → arancio */
  --accent-200: #ffd36a;
  --accent-300: #ffbf42;
  --accent-400: #ffaa1f;
  --accent-500: #ff8a1f;
  --accent-600: #ef6a14;

  /* Foreground */
  --fg-1: #ffffff;
  --fg-2: rgba(255,255,255,0.78);
  --fg-3: rgba(255,255,255,0.55);
  --fg-4: rgba(255,255,255,0.32);
  --fg-inverse: #0a0d24;

  /* Superfici glass */
  --glass-bg-1: rgba(255,255,255,0.06);
  --glass-bg-2: rgba(255,255,255,0.10);
  --glass-bg-3: rgba(255,255,255,0.16);
  --glass-bg-4: rgba(255,255,255,0.24);
  --glass-stroke-1: rgba(255,255,255,0.12);
  --glass-stroke-2: rgba(255,255,255,0.22);
  --glass-stroke-3: rgba(255,255,255,0.38);
  --glass-blur-sm: 8px;
  --glass-blur-md: 18px;
  --glass-blur-lg: 32px;

  /* Ombre */
  --shadow-xs: 0 1px 2px rgba(10,13,36,0.25);
  --shadow-sm: 0 2px 8px rgba(10,13,36,0.28);
  --shadow-md: 0 8px 24px rgba(10,13,36,0.35);
  --shadow-lg: 0 18px 48px rgba(10,13,36,0.42);
  --shadow-inset-glass: inset 0 1px 0 rgba(255,255,255,0.35), inset 0 -1px 0 rgba(255,255,255,0.06);

  /* Glow */
  --glow-accent-sm: 0 8px 24px -8px rgba(255,170,31,0.55);
  --glow-accent-md: 0 18px 48px -12px rgba(255,138,31,0.55), 0 4px 12px rgba(255,170,31,0.25);
  --glow-violet-sm: 0 8px 24px -8px rgba(138,92,255,0.55);
  --glow-violet-md: 0 18px 48px -12px rgba(138,92,255,0.55), 0 4px 12px rgba(107,63,217,0.25);

  /* Raggi */
  --radius-xs:   6px;
  --radius-sm:   10px;
  --radius-md:   16px;
  --radius-lg:   22px;
  --radius-xl:   32px;
  --radius-pill: 999px;

  /* Spaziatura 4pt */
  --space-4: 16px; --space-6: 24px; --space-8: 32px;
  --space-10: 40px; --space-12: 48px; --space-16: 64px;

  /* Tipografia */
  --font-sans:    'Inter', system-ui, sans-serif;
  --font-display: 'Inter', system-ui, sans-serif;
  --font-mono:    'JetBrains Mono', ui-monospace, monospace;

  /* Motion */
  --ease-out:    cubic-bezier(0.22, 1, 0.36, 1);
  --dur-fast:    120ms;
  --dur-base:    220ms;

  /* Gradiente signature */
  --gradient-app:
    radial-gradient(120% 80% at 8% 0%,  #2a3aa5 0%,  transparent 55%),
    radial-gradient(90%  70% at 100% 100%, #5024c2 0%, transparent 60%),
    linear-gradient(135deg, #0b1037 0%, #1d1156 50%, #2a1366 100%);
  --gradient-accent: linear-gradient(135deg, var(--accent-300) 0%, var(--accent-500) 100%);
}

/* ── BASE ─────────────────────────────────────── */
html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--gradient-app);
  background-attachment: fixed;
  color: var(--fg-1);
  min-height: 100vh;
  overflow-x: hidden;
}

/* ── AURORA AMBIENT BLOBS ─────────────────────── */
.aurora-ambient {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}
.aurora-ambient::before,
.aurora-ambient::after {
  content: '';
  position: absolute;
  width: 60vmax; height: 60vmax;
  border-radius: 50%;
  filter: blur(80px);
  mix-blend-mode: screen;
}
.aurora-ambient::before {
  background: radial-gradient(circle, var(--brand-violet-500), transparent 60%);
  top: -20vmax; left: -20vmax;
  opacity: 0.45;
  animation: blob-a 18s ease-in-out infinite alternate;
}
.aurora-ambient::after {
  background: radial-gradient(circle, var(--accent-500), transparent 60%);
  bottom: -25vmax; right: -20vmax;
  opacity: 0.25;
  animation: blob-b 22s ease-in-out infinite alternate;
}
@keyframes blob-a {
  from { transform: translate(0,0) scale(1); }
  to   { transform: translate(8vw, 6vh) scale(1.15); }
}
@keyframes blob-b {
  from { transform: translate(0,0) scale(1); }
  to   { transform: translate(-6vw,-4vh) scale(1.1); }
}

.page { position: relative; z-index: 1; }

/* ── TOPBAR ───────────────────────────────────── */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 56px;
  background: var(--glass-bg-1);
  backdrop-filter: blur(var(--glass-blur-sm)) saturate(140%);
  -webkit-backdrop-filter: blur(var(--glass-blur-sm)) saturate(140%);
  border-bottom: 1px solid var(--glass-stroke-1);
}
.topbar-logo { display: flex; align-items: center; gap: 12px; }
.topbar-mark {
  width: 40px; height: 40px;
  flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  padding: 6px;
  border-radius: var(--radius-md);
  background: #ffffff;
  box-shadow: var(--shadow-sm), var(--shadow-inset-glass);
}
.topbar-mark img { width: 100%; height: 100%; object-fit: contain; display: block; }
.topbar-wordmark { display: flex; flex-direction: column; line-height: 1; }
.topbar-wordmark .line-1 {
  font-size: 10px; font-weight: 700; letter-spacing: 0.18em;
  text-transform: uppercase; color: var(--fg-1);
}
.topbar-wordmark .line-2 {
  font-size: 16px; font-weight: 900; letter-spacing: -0.01em; text-transform: uppercase;
  background: var(--gradient-accent);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.topbar-wordmark .line-2 .tld {
  background: none; -webkit-background-clip: initial; background-clip: initial;
  color: var(--fg-1); -webkit-text-fill-color: var(--fg-1);
}
.topbar-links { display: flex; align-items: center; gap: 12px; }
.topbar-pill {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 7px 16px;
  border-radius: var(--radius-pill);
  background: var(--glass-bg-3);
  border: 1px solid var(--glass-stroke-2);
  box-shadow: var(--shadow-sm), var(--shadow-inset-glass);
  font-size: 12px; font-weight: 600; color: var(--fg-2); letter-spacing: 0.02em;
  text-decoration: none;
  transition: background var(--dur-base) var(--ease-out), border-color var(--dur-base) var(--ease-out), color var(--dur-base) var(--ease-out);
}
.topbar-pill:hover { background: var(--glass-bg-4); border-color: var(--glass-stroke-3); color: var(--fg-1); }

/* ── HERO ─────────────────────────────────────── */
.hero { padding: 72px 56px 56px; max-width: 1160px; margin: 0 auto; }

.hero-overline {
  font-size: 12px; font-weight: 700; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--fg-3); margin-bottom: 28px;
}

.hero-profile { display: flex; align-items: center; gap: 36px; }

.hero-avatar {
  width: 132px; height: 132px;
  border-radius: 50%;
  object-fit: cover;
  object-position: center top;
  flex-shrink: 0;
  border: 2px solid var(--glass-stroke-2);
  box-shadow: var(--shadow-md), var(--glow-violet-md);
}

.hero-text { flex: 1; min-width: 0; }

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(32px, 4.4vw, 52px);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: -0.02em;
  text-transform: uppercase;
  margin-bottom: 14px;
  text-wrap: pretty;
}
.hero-title .line-white { display: block; color: var(--fg-1); }
.hero-title .line-accent {
  display: block;
  background: var(--gradient-accent);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
  filter: drop-shadow(0 0 32px rgba(255,138,31,0.4));
}

.hero-body { font-size: 15px; line-height: 1.65; color: var(--fg-2); max-width: 520px; }

.hero-divider { height: 1px; background: var(--glass-stroke-1); }

/* ── SECTION WRAPPER ──────────────────────────── */
.section { max-width: 1160px; margin: 0 auto; padding: 48px 56px 100px; }

/* ── FILTER BAR ───────────────────────────────── */
.filter-bar { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 48px; }

.filter-btn {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 8px 18px;
  border-radius: var(--radius-pill);
  background: var(--glass-bg-2);
  border: 1px solid var(--glass-stroke-2);
  box-shadow: var(--shadow-xs), var(--shadow-inset-glass);
  font-family: var(--font-sans);
  font-size: 12px; font-weight: 600; color: var(--fg-2); letter-spacing: 0.02em;
  cursor: pointer;
  transition: background var(--dur-base) var(--ease-out), border-color var(--dur-base) var(--ease-out),
              color var(--dur-base) var(--ease-out), box-shadow var(--dur-base) var(--ease-out);
}
.filter-btn svg { width: 14px; height: 14px; flex-shrink: 0; }
.filter-btn:hover { background: var(--glass-bg-3); border-color: var(--glass-stroke-3); color: var(--fg-1); }
.filter-btn.active {
  background: var(--glass-bg-4);
  border-color: var(--btn-color, var(--accent-400));
  color: var(--btn-color, var(--fg-1));
  box-shadow: var(--shadow-sm), 0 0 16px var(--btn-glow, rgba(255,170,31,0.35));
}

/* ── CATEGORY SECTION ─────────────────────────── */
.category-section { margin-bottom: 56px; }

.category-header { display: flex; align-items: center; gap: 12px; margin-bottom: 16px; }

.category-icon {
  width: 28px; height: 28px;
  border-radius: var(--radius-xs);
  display: flex; align-items: center; justify-content: center;
  color: var(--cat-color, var(--accent-300));
  background: var(--glass-bg-1);
  border: 1px solid var(--glass-stroke-1);
  flex-shrink: 0;
}
.category-icon svg { width: 16px; height: 16px; }

.category-title {
  font-size: 11px; font-weight: 700; letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--cat-color, var(--fg-3));
  white-space: nowrap;
}

.category-line {
  flex: 1; height: 1px;
  background: linear-gradient(90deg, var(--cat-color, var(--glass-stroke-2)), transparent);
  opacity: 0.55;
}

/* ── CARDS GRID ───────────────────────────────── */
.cards-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(270px, 1fr)); gap: 12px; }

.tool-card {
  position: relative;
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 18px;
  background: var(--cat-bg, var(--glass-bg-2));
  border: 1px solid var(--glass-stroke-2);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(var(--glass-blur-md)) saturate(140%);
  -webkit-backdrop-filter: blur(var(--glass-blur-md)) saturate(140%);
  box-shadow: var(--shadow-sm), var(--shadow-inset-glass);
  text-decoration: none;
  color: inherit;
  overflow: hidden;
  transition: background var(--dur-base) var(--ease-out), border-color var(--dur-base) var(--ease-out),
              transform var(--dur-base) var(--ease-out), box-shadow var(--dur-base) var(--ease-out);
}

.tool-card::before {
  content: '';
  position: absolute;
  top: 0; left: 16px; right: 16px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--cat-color, var(--accent-400)), transparent);
  opacity: 0;
  transition: opacity var(--dur-base) var(--ease-out);
}
.tool-card:hover::before { opacity: 0.9; }

.tool-card:hover {
  background: var(--glass-bg-3);
  border-color: var(--cat-color, var(--glass-stroke-3));
  transform: translateY(-3px);
  box-shadow: var(--shadow-md), var(--shadow-inset-glass), 0 12px 32px -10px var(--cat-glow-strong, rgba(0,0,0,0.4));
}

.tool-icon {
  width: 40px; height: 40px;
  border-radius: var(--radius-sm);
  background: var(--glass-bg-2);
  border: 1px solid var(--glass-stroke-1);
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0;
  overflow: hidden;
  color: var(--cat-color, var(--accent-300));
}
.tool-icon img { width: 24px; height: 24px; object-fit: contain; border-radius: 4px; }
.tool-icon svg { width: 20px; height: 20px; }

.tool-body { flex: 1; min-width: 0; }

.tool-name {
  font-size: 13.5px; font-weight: 700; color: var(--fg-1);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
  margin-bottom: 2px;
}

.tool-meta { display: flex; align-items: center; gap: 8px; min-width: 0; }

.tool-desc {
  font-size: 11.5px; color: var(--fg-3);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}

.tool-note {
  font-family: var(--font-mono);
  font-size: 9.5px; font-weight: 600; letter-spacing: 0.02em;
  color: var(--accent-300);
  background: rgba(255,170,31,0.12);
  border: 1px solid rgba(255,170,31,0.28);
  border-radius: var(--radius-xs);
  padding: 2px 6px;
  white-space: nowrap;
  flex-shrink: 0;
}

.tool-arrow {
  font-family: var(--font-mono);
  font-size: 13px; color: var(--fg-4);
  flex-shrink: 0;
  transition: transform var(--dur-fast) var(--ease-out), color var(--dur-fast) var(--ease-out);
}
.tool-card:hover .tool-arrow { transform: translateX(3px); color: var(--cat-color, var(--accent-300)); }

/* ── LOADING / ERRORE ─────────────────────────── */
.loading { text-align: center; padding: 96px 0; color: var(--fg-3); }
.spinner {
  width: 34px; height: 34px;
  border: 2.5px solid var(--glass-stroke-1);
  border-top-color: var(--accent-400);
  border-radius: 50%;
  animation: spin 0.75s linear infinite;
  margin: 0 auto 18px;
}
@keyframes spin { to { transform: rotate(360deg); } }
.loading p { font-size: 13px; }

.error { text-align: center; padding: 96px 0; color: var(--fg-3); font-size: 13px; }

/* ── FOOTER ───────────────────────────────────── */
.footer {
  background: var(--glass-bg-1);
  backdrop-filter: blur(var(--glass-blur-sm)) saturate(140%);
  -webkit-backdrop-filter: blur(var(--glass-blur-sm)) saturate(140%);
  border-top: 1px solid var(--glass-stroke-1);
  padding: 32px 56px;
  display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 16px;
}
.footer-brand { font-size: 12px; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; color: var(--fg-3); }
.footer-links { font-size: 12px; color: var(--fg-4); }
.footer-cta {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 22px;
  border-radius: var(--radius-pill);
  background: var(--gradient-accent);
  border: none;
  font-family: var(--font-sans);
  font-size: 13px; font-weight: 600; color: var(--fg-inverse);
  text-decoration: none; cursor: pointer;
  box-shadow: var(--shadow-sm), var(--glow-accent-md);
  transition: box-shadow var(--dur-base) var(--ease-out), transform var(--dur-base) var(--ease-out);
}
.footer-cta:hover { box-shadow: var(--shadow-md), var(--glow-accent-md); transform: translateY(-1px); }

/* ── RESPONSIVE ───────────────────────────────── */
@media (max-width: 680px) {
  .topbar { padding: 16px 24px; }
  .hero { padding: 48px 24px 40px; }
  .hero-profile { flex-direction: column; align-items: flex-start; gap: 20px; }
  .section { padding: 32px 24px 72px; }
  .footer { padding: 28px 24px; }
  .cards-grid { grid-template-columns: 1fr; }
}