/* Proof */

.proof-strip {
  --proof-accent-rgb: 87, 214, 198;
  --proof-accent-strong-rgb: 64, 167, 255;
  --proof-strip-bg:
    radial-gradient(circle at 14% 16%, rgba(236, 251, 250, 0.12), transparent 30%),
    radial-gradient(circle at 86% 72%, rgba(var(--proof-accent-strong-rgb), 0.18), transparent 24%),
    linear-gradient(180deg, rgba(38, 66, 80, 0.992), rgba(30, 56, 69, 0.996));
  --proof-strip-border: rgba(var(--proof-accent-rgb), 0.28);
  --proof-item-bg:
    linear-gradient(180deg, rgba(219, 241, 241, 0.055), rgba(183, 228, 223, 0.03)),
    linear-gradient(145deg, rgba(24, 45, 56, 0.992), rgba(18, 37, 47, 0.995));
  --proof-item-bg-hover:
    linear-gradient(180deg, rgba(231, 248, 248, 0.085), rgba(196, 236, 232, 0.045)),
    linear-gradient(145deg, rgba(29, 53, 66, 0.996), rgba(21, 42, 53, 1));
  --proof-item-border: rgba(var(--proof-accent-rgb), 0.24);
  --proof-item-border-hover: rgba(var(--proof-accent-rgb), 0.36);
  --proof-item-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.12),
    0 24px 52px rgba(0, 0, 0, 0.24);
  --proof-item-shadow-hover:
    0 30px 62px rgba(0, 0, 0, 0.28),
    0 0 0 1px rgba(var(--proof-accent-rgb), 0.14);
  --proof-item-accent: linear-gradient(90deg, rgba(239, 252, 252, 0.96), rgba(var(--proof-accent-rgb), 0.92));
  --proof-title-color: #fbfeff;
  --proof-title-accent: #b6fff4;
  --proof-copy-color: rgba(240, 246, 248, 0.9);
  --proof-link-color: #effcff;
  padding: clamp(3.2rem, 5.4vw, 4.5rem) 0;
  background: var(--proof-strip-bg);
  border-top: 1px solid var(--proof-strip-border);
  border-bottom: 1px solid var(--proof-strip-border);
  position: relative;
  overflow: hidden;
}

.definition-block + .proof-strip {
  padding-top: clamp(2rem, 3.8vw, 3rem);
  padding-bottom: clamp(2.4rem, 4.2vw, 3.4rem);
}

.proof-strip::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(255, 255, 255, 0.024) 1px, transparent 1px),
    linear-gradient(180deg, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
  background-size: 6rem 6rem;
  mask-image: linear-gradient(180deg, transparent, black 12%, black 88%, transparent);
  opacity: 0.12;
  pointer-events: none;
}

.proof-strip .container {
  position: relative;
  z-index: 1;
}

.proof-strip__cta {
  margin-top: 1.5rem;
  text-align: center;
}

.proof-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: clamp(1rem, 1.8vw, 1.25rem);
  align-items: stretch;
}

.proof-item {
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  min-width: 0;
  min-height: 100%;
  padding: clamp(1.15rem, 1.9vw, 1.4rem);
  border: 1px solid var(--proof-item-border);
  border-radius: var(--radius-md);
  text-align: left;
  background: var(--proof-item-bg);
  box-shadow: var(--proof-item-shadow);
  overflow: hidden;
  transition: transform var(--transition-med), border-color var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-fast);
}

.proof-item::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--proof-item-accent);
  opacity: 0.88;
}

.proof-item::before {
  content: "";
  position: absolute;
  inset: auto -10% -24% auto;
  width: 54%;
  aspect-ratio: 1 / 1;
  border-radius: 999px;
  background: radial-gradient(circle, rgba(var(--proof-accent-rgb), 0.08), transparent 72%);
  pointer-events: none;
  opacity: 0.68;
}

.proof-item:hover {
  transform: translateY(-8px);
  border-color: var(--proof-item-border-hover);
  background: var(--proof-item-bg-hover);
  box-shadow: var(--proof-item-shadow-hover);
}

.proof-item + .proof-item::before {
  display: none;
}

.proof-item h4 {
  color: var(--proof-title-color);
  background: none;
  -webkit-text-fill-color: initial;
  font-size: clamp(1.35rem, 1.06rem + 0.95vw, 1.9rem);
  font-weight: 800;
  display: flex;
  align-items: center;
  gap: 0.45rem;
  width: 100%;
  direction: ltr;
  unicode-bidi: isolate;
  line-height: 0.98;
  letter-spacing: -0.035em;
  margin-bottom: 0.7rem;
}

.proof-item h4::before {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.2rem;
  height: 2.2rem;
  flex: 0 0 2.2rem;
  font-size: 2rem;
  font-weight: 900;
  line-height: 1;
  color: var(--proof-title-accent);
  text-shadow: 0 0 18px rgba(var(--proof-accent-rgb), 0.28);
}

.proof-item:first-child h4::before,
.proof-item:nth-child(2) h4::before {
  content: "↓";
}

.proof-item:nth-child(3) h4::before {
  content: "↑";
}

.proof-item:nth-child(4) h4::before {
  content: "✓";
}

.proof-item p {
  font-size: 0.93rem;
  line-height: 1.64;
  margin-bottom: 0;
  color: var(--proof-copy-color);
}

.proof-strip__link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  padding: 0;
  border: none;
  background: none;
  border-radius: 0;
  color: var(--proof-link-color) !important;
  font-weight: 700 !important;
  text-decoration: none;
  transition: transform var(--transition-fast), color var(--transition-fast), opacity var(--transition-fast);
}

.proof-strip__link:hover {
  transform: translateY(-2px);
  color: rgb(var(--proof-accent-rgb)) !important;
}

:root[data-theme="light"] .proof-strip {
  --proof-accent-rgb: var(--brand-color-rgb);
  --proof-accent-strong-rgb: var(--brand-color-deep-rgb);
  --proof-strip-bg:
    radial-gradient(circle at 14% 18%, rgba(255, 232, 239, 0.38), transparent 30%),
    radial-gradient(circle at 84% 76%, rgba(var(--proof-accent-strong-rgb), 0.16), transparent 24%),
    radial-gradient(circle at 52% 110%, rgba(var(--proof-accent-rgb), 0.18), transparent 34%),
    linear-gradient(180deg, rgba(106, 36, 59, 0.94), rgba(163, 61, 92, 0.92) 44%, rgba(230, 178, 196, 0.94) 100%);
  --proof-strip-border: rgba(var(--proof-accent-rgb), 0.22);
  --proof-item-bg:
    radial-gradient(circle at 16% 14%, rgba(255, 255, 255, 0.9), transparent 34%),
    radial-gradient(circle at 86% 84%, rgba(var(--proof-accent-rgb), 0.08), transparent 30%),
    linear-gradient(180deg, rgba(255, 251, 252, 0.995), rgba(255, 242, 246, 0.992)),
    linear-gradient(145deg, rgba(255, 255, 255, 0.98), rgba(255, 244, 248, 0.985));
  --proof-item-bg-hover:
    radial-gradient(circle at 18% 12%, rgba(255, 255, 255, 0.96), transparent 34%),
    radial-gradient(circle at 84% 82%, rgba(var(--proof-accent-strong-rgb), 0.1), transparent 30%),
    linear-gradient(180deg, rgba(255, 255, 255, 1), rgba(255, 238, 244, 0.998)),
    linear-gradient(145deg, rgba(255, 255, 255, 0.995), rgba(255, 241, 246, 0.99));
  --proof-item-border: rgba(var(--proof-accent-rgb), 0.18);
  --proof-item-border-hover: rgba(var(--proof-accent-rgb), 0.28);
  --proof-item-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.94),
    0 18px 40px rgba(28, 68, 81, 0.12);
  --proof-item-shadow-hover:
    0 22px 50px rgba(28, 68, 81, 0.16),
    0 0 0 1px rgba(var(--proof-accent-rgb), 0.1);
  --proof-item-accent: linear-gradient(90deg, rgba(var(--proof-accent-rgb), 0.94), rgba(var(--proof-accent-strong-rgb), 0.78));
  --proof-title-color: #0d222b;
  --proof-title-accent: #2f8f86;
  --proof-copy-color: rgba(31, 51, 60, 0.84);
  --proof-link-color: #10222b;
}

:root[data-theme="light"] .proof-item {
  box-shadow: var(--proof-item-shadow);
}

:root[data-theme="light"] .proof-item:hover {
  border-color: rgba(var(--proof-accent-strong-rgb), 0.24);
  background:
    radial-gradient(circle at 14% 12%, rgba(255, 255, 255, 0.98), transparent 34%),
    radial-gradient(circle at 86% 82%, rgba(var(--proof-accent-strong-rgb), 0.14), transparent 30%),
    linear-gradient(180deg, rgba(255, 255, 255, 1), rgba(255, 236, 243, 0.998)),
    linear-gradient(145deg, rgba(255, 255, 255, 0.998), rgba(255, 238, 244, 0.992));
  box-shadow: var(--proof-item-shadow-hover);
}

:root[data-theme="light"] .proof-item::before {
  background: radial-gradient(circle, rgba(var(--proof-accent-rgb), 0.09), transparent 72%);
}

:root[data-theme="light"] .proof-item h4::before {
  color: #2f8f86;
  text-shadow: 0 0 16px rgba(47, 143, 134, 0.16);
}

:root[data-theme="light"] .proof-item:hover::before {
  background: radial-gradient(circle, rgba(var(--proof-accent-strong-rgb), 0.12), transparent 72%);
  opacity: 0.84;
}

:root[data-theme="light"] .proof-strip__link:hover {
  color: #811245 !important;
  text-shadow: 0 0 18px rgba(var(--proof-accent-strong-rgb), 0.12);
}

@media (max-width: 1024px) {
  .definition-block + .proof-strip {
      padding-top: 2rem;
      padding-bottom: 2.5rem;
    }

  .proof-grid {
      grid-template-columns: repeat(2, minmax(0, 1fr));
    }

  .proof-item:nth-child(2n + 1)::before {
      display: none;
    }

  .proof-item + .proof-item::before {
      display: none;
    }
}

@media (max-width: 768px) {
  .proof-grid {
      grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 640px) {
  .proof-strip {
      padding-block: 2.4rem;
    }

  .definition-block + .proof-strip {
      padding-top: 2rem;
      padding-bottom: 2.4rem;
    }

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

  .proof-item::before {
      display: none;
    }

  .proof-item h4 {
      margin-bottom: 0.55rem;
    }

  .proof-item {
      text-align: left;
      padding: 1.2rem 1rem;
    }
}