/* ==========================================================================
   SO SMALL CIRCLE — EDITORIAL DESIGN SYSTEM (ANTHROPIC AESTHETIC)
   Crafted: Pure Black & White, Editorial Serif & Swiss Sans, Generous Whitespace
   Restrained, intellectual, calm, authoritative. No clutter.
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600&family=Newsreader:ital,opsz,wght@0,6..72,300;0,6..72,400;0,6..72,500;1,6..72,300;1,6..72,400&family=JetBrains+Mono:wght@300;400;500&display=swap');

:root {
  --black: #000000;
  --black-surface: #0a0a0a;
  --black-card: #0f0f0f;
  --gray-border: #1f1f1f;
  --gray-border-subtle: #171717;
  --gray-subtle: #555555;
  --gray-muted: #888888;
  --gray-body: #c4c4c4;
  --white: #ffffff;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

html, body {
  background-color: var(--black);
  color: var(--white);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  overflow-x: hidden;
  line-height: 1.6;
}

::selection {
  background: #ffffff;
  color: #000000;
}

/* Typography Utility */
.font-editorial {
  font-family: 'Newsreader', Georgia, serif;
}

.font-mono {
  font-family: 'JetBrains Mono', monospace;
}

.font-sans {
  font-family: 'Inter', sans-serif;
}

/* Anthropic-style Restrained Buttons */
.btn-primary {
  background-color: var(--white);
  color: var(--black);
  border: 1px solid var(--white);
  padding: 10px 22px;
  font-size: 13px;
  font-weight: 500;
  border-radius: 4px;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  cursor: pointer;
}

.btn-primary:hover {
  background-color: #e5e5e5;
  border-color: #e5e5e5;
  transform: translateY(-1px);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background-color: transparent;
  color: var(--white);
  border: 1px solid var(--gray-border);
  padding: 10px 22px;
  font-size: 13px;
  font-weight: 400;
  border-radius: 4px;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  cursor: pointer;
}

.btn-secondary:hover {
  border-color: #444444;
  background-color: rgba(255, 255, 255, 0.04);
  transform: translateY(-1px);
}

.btn-secondary:active {
  transform: translateY(0);
}

/* Backward-compatible classes */
.btn-invert {
  background-color: var(--white);
  color: var(--black);
  border: 1px solid var(--white);
  padding: 10px 22px;
  font-size: 13px;
  font-weight: 500;
  border-radius: 4px;
  transition: all 0.2s ease;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  cursor: pointer;
}
.btn-invert:hover {
  background-color: #e5e5e5;
}

.btn-outline {
  background-color: transparent;
  color: var(--white);
  border: 1px solid var(--gray-border);
  padding: 10px 22px;
  font-size: 13px;
  font-weight: 400;
  border-radius: 4px;
  transition: all 0.2s ease;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  cursor: pointer;
}
.btn-outline:hover {
  border-color: #555555;
  background-color: rgba(255, 255, 255, 0.04);
}

/* Hairline dividers */
.hairline-b {
  border-bottom: 1px solid var(--gray-border);
}

.hairline-t {
  border-top: 1px solid var(--gray-border);
}

.hairline-all {
  border: 1px solid var(--gray-border);
}

/* Interactive list row (Anthropic research papers style) */
.paper-row {
  transition: background-color 0.2s ease, border-color 0.2s ease;
}

.paper-row:hover {
  background-color: rgba(255, 255, 255, 0.02);
}

/* Interactive Before/After Split Comparison Component */
.compare-container {
  position: relative;
  overflow: hidden;
  user-select: none;
  background: #080808;
  border-radius: 6px;
  border: 1px solid #1f1f1f;
  line-height: 0;
}

.compare-after-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.compare-overlay {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  width: 50%;
  overflow: hidden;
  border-right: 2px solid rgba(255, 255, 255, 0.9);
  z-index: 10;
  transition: width 0.05s ease-out;
}

.compare-before-img {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  width: auto;
  max-width: none;
  object-fit: cover;
}

.compare-handle {
  position: absolute;
  top: 50%;
  right: -13px;
  transform: translateY(-50%);
  width: 26px;
  height: 26px;
  background: #ffffff;
  color: #000000;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.8);
  pointer-events: none;
  font-size: 11px;
}

/* Clean Custom Form Inputs */
input, textarea, select {
  background-color: #0d0d0d;
  color: #ffffff;
  border: 1px solid var(--gray-border);
  border-radius: 4px;
  padding: 12px 16px;
  font-family: inherit;
  font-size: 14px;
  transition: border-color 0.2s ease;
}

input:focus, textarea:focus, select:focus {
  outline: none;
  border-color: #666666;
}

/* Range Slider */
input[type=range] {
  -webkit-appearance: none;
  appearance: none;
  background: #222222;
  height: 4px;
  border-radius: 2px;
  padding: 0;
  border: none;
}

input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: #ffffff;
  cursor: pointer;
  border: 2px solid #000000;
}

input[type=range]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: #ffffff;
  cursor: pointer;
  border: 2px solid #000000;
}

/* Minimalist Scrollbar */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: var(--black);
}

::-webkit-scrollbar-thumb {
  background: #2a2a2a;
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: #444444;
}