/* ═══════════════════════════════════════════════════════════════
   SAYO UI — DESIGN TOKENS & CORE
   GitHub Primer Dark + Sayo interaction engine
   Zero dependencies. CSS variable driven. Dark-first.
   ═══════════════════════════════════════════════════════════════ */

/* ── TOKENS ─────────────────────────────────────────────────── */
:root {
  /* Backgrounds */
  --syo-bg-base:      #0d1117;
  --syo-bg-surface:   #161b22;
  --syo-bg-elevated:  #1c2129;
  --syo-bg-selection: rgba(31, 111, 235, 0.2);

  /* Borders */
  --syo-border:       #30363d;
  --syo-border-muted: #21262d;

  /* Foregrounds */
  --syo-fg-default: #e6edf3;
  --syo-fg-body:    #c9d1d9;
  --syo-fg-muted:   #8b949e;

  /* Functional */
  --syo-red:    #f85149;
  --syo-orange: #f0883e;
  --syo-yellow: #d29922;
  --syo-green:  #3fb950;
  --syo-teal:   #39d353;
  --syo-cyan:   #79c0ff;
  --syo-blue:   #58a6ff;
  --syo-purple: #bc8cff;
  --syo-pink:   #d2a8ff;

  /* Semantic roles */
  --syo-danger:    var(--syo-red);
  --syo-warning:   var(--syo-yellow);
  --syo-success:   var(--syo-green);
  --syo-info:      var(--syo-blue);
  --syo-accent:    var(--syo-purple);
  --syo-secondary: var(--syo-cyan);
  --syo-special:   var(--syo-orange);
  --syo-subtle:    var(--syo-teal);

  /* Syntax highlight */
  --syo-syn-comment:  #8b949e;
  --syo-syn-keyword:  #ff7b72;
  --syo-syn-string:   #a5d6ff;
  --syo-syn-func:     #d2a8ff;
  --syo-syn-type:     #ffa657;
  --syo-syn-macro:    #f2cc60;
  --syo-syn-operator: #79c0ff;
  --syo-syn-number:   #a5d6ff;

  /* Typography */
  --syo-font-sans:  "Inter", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, sans-serif;
  --syo-font-mono:  "Fira Code", "SF Mono", "Cascadia Code", "JetBrains Mono", monospace;
  --syo-font-size:  15px;
  --syo-line-height: 1.65;

  /* Spacing scale */
  --syo-space-1: 4px;
  --syo-space-2: 8px;
  --syo-space-3: 12px;
  --syo-space-4: 16px;
  --syo-space-5: 20px;
  --syo-space-6: 24px;
  --syo-space-8: 32px;
  --syo-space-10: 40px;
  --syo-space-12: 48px;

  /* Radii */
  --syo-radius-sm: 4px;
  --syo-radius-md: 6px;
  --syo-radius-lg: 8px;
  --syo-radius-full: 999px;

  /* Container */
  --syo-container: 860px;

  /* Nav */
  --syo-nav-height: 52px;

  /* Easing */
  --syo-ease-elastic:  cubic-bezier(0.34, 1.56, 0.64, 1);
  --syo-ease-out:      cubic-bezier(0.4, 0, 0.2, 1);
  --syo-ease-spring:   cubic-bezier(0.25, 0.46, 0.45, 0.94);

  /* Transitions */
  --syo-trans-color:  color 180ms var(--syo-ease-out);
  --syo-trans-spring: transform 250ms var(--syo-ease-elastic), border-color 200ms var(--syo-ease-out), background 200ms var(--syo-ease-out);
  --syo-trans-active: transform 100ms var(--syo-ease-out);
}

/* ── LIGHT THEME ─────────────────────────────────────────────── */
/* Trigger: <html data-syo-theme="light"> or toggle via JS */
html[data-syo-theme="light"] {
  /* Backgrounds */
  --syo-bg-base:      #ffffff;
  --syo-bg-surface:   #f6f8fa;
  --syo-bg-elevated:  #ffffff;
  --syo-bg-selection: rgba(9, 105, 218, 0.15);

  /* Borders */
  --syo-border:       #d0d7de;
  --syo-border-muted: #d8dee4;

  /* Foregrounds */
  --syo-fg-default: #1f2328;
  --syo-fg-body:    #1f2328;
  --syo-fg-muted:   #656d76;

  /* Functional — adjusted for light bg contrast */
  --syo-red:    #cf222e;
  --syo-orange: #bc4c00;
  --syo-yellow: #9a6700;
  --syo-green:  #1a7f37;
  --syo-teal:   #0a8b82;
  --syo-cyan:   #0a85bb;
  --syo-blue:   #0969da;
  --syo-purple: #8250df;
  --syo-pink:   #bf3989;

  /* Syntax highlight */
  --syo-syn-comment:  #6e7781;
  --syo-syn-keyword:  #cf222e;
  --syo-syn-string:   #0a3069;
  --syo-syn-func:     #8250df;
  --syo-syn-type:     #bc4c00;
  --syo-syn-macro:    #9a6700;
  --syo-syn-operator: #0550ae;
  --syo-syn-number:   #0550ae;
}

/* Light-theme select chevron — needs own SVG since data URIs can't inherit var() */
html[data-syo-theme="light"] .syo-select {
  background-image: url("data:image/svg+xml,%3Csvg width='12' height='8' viewBox='0 0 12 8' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1.5l5 5 5-5' stroke='%23656d76' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
}

/* ── RESET ──────────────────────────────────────────────────── */
/* :where() → zero specificity — easy to override in consumer CSS */
:where(*, *::before, *::after) { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  font-size: var(--syo-font-size);
  -webkit-text-size-adjust: 100%;
}

body {
  background: var(--syo-bg-base);
  color: var(--syo-fg-body);
  font-family: var(--syo-font-sans);
  font-weight: 400;
  line-height: var(--syo-line-height);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* custom cursor active — suppress all system cursors */
body[data-syo-cursor],
body[data-syo-cursor] * {
  cursor: none !important;
}

/* ── SCROLLBAR ───────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: var(--syo-border);
  border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover { background: var(--syo-fg-muted); }
/* Firefox */
* { scrollbar-width: thin; scrollbar-color: var(--syo-border) transparent; }

::selection { background: var(--syo-bg-selection); color: var(--syo-fg-default); }

img, svg { display: block; max-width: 100%; }
svg[data-syo-icon] { flex-shrink: 0; }

:focus-visible {
  outline: 2px solid var(--syo-blue);
  outline-offset: 2px;
}

/* ── BASE ───────────────────────────────────────────────────── */
a {
  color: var(--syo-blue);
  text-decoration: none;
  transition: var(--syo-trans-color);
}
a:hover { color: var(--syo-accent); }

h1, h2, h3, h4, h5, h6 {
  color: var(--syo-fg-default);
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.25;
}

h1 { font-size: clamp(1.5rem, 4vw, 2rem); }
h2 { font-size: clamp(1.25rem, 3vw, 1.5rem); }
h3 { font-size: 1.125rem; }
h4 { font-size: 1rem; }

p + p { margin-top: 0.5em; }

code, pre {
  font-family: var(--syo-font-mono);
  font-size: 0.875em;
}

code {
  background: var(--syo-bg-surface);
  padding: 0.15em 0.4em;
  border-radius: var(--syo-radius-sm);
  border: 1px solid var(--syo-border-muted);
}

pre {
  background: var(--syo-bg-surface);
  border: 1px solid var(--syo-border);
  border-radius: var(--syo-radius-md);
  padding: var(--syo-space-4);
  overflow-x: auto;
  line-height: 1.65;
}

pre code {
  background: none;
  padding: 0;
  border: none;
  font-size: 0.875rem;
}

hr {
  border: none;
  border-top: 1px solid var(--syo-border);
}

/* ── LAYOUT ─────────────────────────────────────────────────── */
.syo-container {
  width: 100%;
  max-width: var(--syo-container);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--syo-space-6);
  padding-right: var(--syo-space-6);
}

.syo-section {
  padding-top: var(--syo-space-12);
  padding-bottom: var(--syo-space-12);
  border-top: 1px solid var(--syo-border);
}

.syo-section-header {
  margin-bottom: var(--syo-space-6);
}

.syo-section-label {
  font-family: var(--syo-font-mono);
  font-size: 0.75rem;
  color: var(--syo-fg-muted);
  text-transform: lowercase;
  letter-spacing: 0.04em;
  margin-bottom: var(--syo-space-1);
}

.syo-grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: var(--syo-space-3); }
.syo-grid-3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: var(--syo-space-3); }
.syo-grid-4 { display: grid; grid-template-columns: 1fr 1fr 1fr 1fr; gap: var(--syo-space-3); }

.syo-flex { display: flex; }
.syo-flex-wrap { flex-wrap: wrap; }
.syo-flex-center { align-items: center; justify-content: center; }
.syo-flex-between { align-items: center; justify-content: space-between; }

.syo-gap-1 { gap: var(--syo-space-1); }
.syo-gap-2 { gap: var(--syo-space-2); }
.syo-gap-3 { gap: var(--syo-space-3); }
.syo-gap-4 { gap: var(--syo-space-4); }
.syo-gap-6 { gap: var(--syo-space-6); }

/* ── COMPONENTS: NAV ────────────────────────────────────────── */
.syo-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--syo-nav-height);
  padding: 0 var(--syo-space-6);
  background: var(--syo-bg-surface);
  border-bottom: 1px solid var(--syo-border);
  overflow: hidden;
}

.syo-nav-brand {
  font-weight: 600;
  font-size: 0.9375rem;
  color: var(--syo-fg-default);
  letter-spacing: -0.01em;
}

.syo-nav-links {
  display: flex;
  gap: var(--syo-space-6);
  list-style: none;
}

.syo-nav-links a {
  display: inline-block;
  font-size: 0.875rem;
  color: var(--syo-fg-muted);
  font-weight: 500;
  transition: var(--syo-trans-spring);
}
.syo-nav-links a:hover { color: var(--syo-fg-default); transform: scale(1.12); }
.syo-nav-links a:active { transform: scale(0.95); transition: var(--syo-trans-active); }

/* ── COMPONENTS: EDITOR ─────────────────────────────────────── */
.syo-editor {
  background: var(--syo-bg-surface);
  border: 1px solid var(--syo-border);
  border-radius: var(--syo-radius-lg);
  overflow: hidden;
  box-shadow: 0 0 80px rgba(88, 166, 255, 0.04), 0 0 160px rgba(121, 192, 255, 0.02);
}

.syo-editor-titlebar {
  display: flex;
  align-items: center;
  height: 36px;
  padding: 0 14px;
  background: var(--syo-bg-elevated);
  border-bottom: 1px solid var(--syo-border-muted);
  gap: var(--syo-space-2);
}

.syo-editor-dots {
  display: flex;
  gap: 6px;
  margin-right: var(--syo-space-3);
}

.syo-editor-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}
.syo-editor-dot--red    { background: var(--syo-red); }
.syo-editor-dot--yellow { background: var(--syo-yellow); }
.syo-editor-dot--green  { background: var(--syo-green); }

.syo-editor-filename {
  font-size: 0.75rem;
  color: var(--syo-fg-muted);
  font-weight: 500;
}

.syo-editor-body {
  display: flex;
  padding: 18px 0;
  font-family: var(--syo-font-mono);
  font-size: 0.875rem;
  line-height: 1.75;
}

.syo-editor-gutter {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  padding: 0 14px 0 16px;
  color: var(--syo-syn-comment);
  /* 字号继承 .syo-editor-body：行高 1.75 是倍数，字号不同会让每行高度差 1.75px，
     行号到末尾整体漂移。行号看着小一点由下一行的 span 负责，不影响行高。 */
  font-size: inherit;
  user-select: none;
  min-width: 38px;
  opacity: 0.5;
}

/* height 用 em：1.75em 落在 body 的字号上，与 .syo-editor-code .line 逐行对齐 */
.syo-editor-gutter span { font-size: 0.8125rem; line-height: 1.75; height: 1.75em; }

.syo-editor-code {
  flex: 1;
  padding-right: var(--syo-space-5);
  overflow-x: auto;
}

.syo-editor-code .line {
  display: block;
  white-space: pre;
  height: 1.75em;
}

.syo-editor-cursor {
  display: inline-block;
  width: 2px;
  height: 1em;
  background: var(--syo-fg-default);
  vertical-align: text-bottom;
  margin-left: 1px;
  animation: syo-blink 1s step-end infinite;
}

/* Syntax token classes (apply to spans inside .syo-editor-body) */
.syn-comment  { color: var(--syo-syn-comment); font-style: italic; }
.syn-keyword  { color: var(--syo-syn-keyword); font-weight: 500; }
.syn-string   { color: var(--syo-syn-string); }
.syn-func     { color: var(--syo-syn-func); }
.syn-type     { color: var(--syo-syn-type); }
.syn-macro    { color: var(--syo-syn-macro); font-weight: 500; }
.syn-operator { color: var(--syo-syn-operator); }
.syn-number   { color: var(--syo-syn-number); }
.syn-lifetime { color: var(--syo-teal); }

/* ── COMPONENTS: CARD ───────────────────────────────────────── */
.syo-card {
  background: var(--syo-bg-surface);
  border: 1px solid var(--syo-border);
  border-radius: var(--syo-radius-md);
  padding: var(--syo-space-5);
  box-shadow: 0 2px 8px rgba(0,0,0,0.25);
  transition: var(--syo-trans-spring), box-shadow 250ms var(--syo-ease-out);
}

.syo-card:hover {
  border-color: var(--syo-accent);
  box-shadow: 0 4px 20px rgba(0,0,0,0.35);
  transform: translateY(-2px) scale(1.02);
}

.syo-card:active {
  transform: translateY(0) scale(0.98);
  transition: var(--syo-trans-active);
}

.syo-card-head { display: flex; align-items: center; gap: var(--syo-space-2); margin-bottom: var(--syo-space-3); }
.syo-card-icon { color: var(--syo-fg-muted); transition: color 200ms var(--syo-ease-out); }
.syo-card:hover .syo-card-icon { color: var(--syo-accent); }
.syo-card-title { font-size: 0.9375rem; margin: 0; }
.syo-card-title a { color: inherit; display: inline-block; transition: var(--syo-trans-spring); }
.syo-card-title a:hover { color: var(--syo-blue); transform: scale(1.06); }
.syo-card-title a:active { transform: scale(0.95); transition: var(--syo-trans-active); }
.syo-card-desc { font-size: 0.8125rem; color: var(--syo-fg-muted); line-height: 1.55; flex: 1; }
.syo-card-meta { display: flex; align-items: center; gap: 14px; font-family: var(--syo-font-mono); font-size: 0.75rem; color: var(--syo-fg-muted); margin-top: var(--syo-space-3); }

/* ── COMPONENTS: TAG ────────────────────────────────────────── */
.syo-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px var(--syo-space-3);
  background: var(--syo-bg-surface);
  border: 1px solid var(--syo-border);
  border-radius: var(--syo-radius-sm);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--syo-fg-body);
  cursor: default;
  transition: var(--syo-trans-spring);
}

.syo-tag:hover {
  border-color: var(--syo-accent);
  color: var(--syo-fg-default);
  background: var(--syo-bg-elevated);
  transform: scale(1.1);
}

.syo-tag:active {
  transform: scale(0.93);
  transition: var(--syo-trans-active);
}

.syo-tag-dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  flex-shrink: 0;
  vertical-align: middle;
}

.syo-tag-dot--red    { background: var(--syo-red); }
.syo-tag-dot--orange { background: var(--syo-orange); }
.syo-tag-dot--yellow { background: var(--syo-yellow); }
.syo-tag-dot--green  { background: var(--syo-green); }
.syo-tag-dot--blue   { background: var(--syo-blue); }
.syo-tag-dot--purple { background: var(--syo-purple); }
.syo-tag-dot--cyan   { background: var(--syo-cyan); }
.syo-tag-dot--pink   { background: var(--syo-pink); }

/* ── COMPONENTS: BUTTON ─────────────────────────────────────── */
.syo-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--syo-space-2);
  padding: 6px var(--syo-space-4);
  font-family: var(--syo-font-sans);
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: var(--syo-radius-md);
  border: 1px solid var(--syo-border);
  background: var(--syo-bg-surface);
  color: var(--syo-fg-body);
  cursor: pointer;
  transition: var(--syo-trans-spring);
  user-select: none;
}

.syo-btn:hover {
  border-color: var(--syo-accent);
  color: var(--syo-fg-default);
  background: var(--syo-bg-elevated);
  transform: scale(1.05);
}

.syo-btn:active {
  transform: scale(0.95);
  transition: var(--syo-trans-active);
}

.syo-btn--primary {
  background: var(--syo-blue);
  border-color: var(--syo-blue);
  color: #fff;
}
.syo-btn--primary:hover {
  background: var(--syo-cyan);
  border-color: var(--syo-cyan);
  box-shadow: 0 0 14px rgba(88, 166, 255, 0.35);
}

.syo-btn--ghost {
  background: transparent;
  border-color: transparent;
}
.syo-btn--ghost:hover { background: var(--syo-bg-surface); }

/* Size variants */
.syo-btn--sm { padding: 3px var(--syo-space-3); font-size: 0.75rem; }
.syo-btn--lg { padding: 8px var(--syo-space-5); font-size: 1rem; }

/* ── COMPONENTS: FORM ────────────────────────────────────────── */
.syo-form-group {
  display: flex;
  flex-direction: column;
  gap: var(--syo-space-1);
}

.syo-form-label {
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--syo-fg-default);
}

.syo-form-hint {
  font-size: 0.75rem;
  color: var(--syo-fg-muted);
}

.syo-input,
.syo-select {
  display: block;
  width: 100%;
  padding: 6px var(--syo-space-3);
  font-family: var(--syo-font-sans);
  font-size: 0.875rem;
  line-height: 1.55;
  color: var(--syo-fg-default);
  background: var(--syo-bg-surface);
  border: 1px solid var(--syo-border);
  border-radius: var(--syo-radius-md);
  transition: border-color 200ms var(--syo-ease-out),
              box-shadow 200ms var(--syo-ease-out),
              transform 200ms var(--syo-ease-out);
  outline: none;
}

.syo-input::placeholder { color: var(--syo-fg-muted); }

.syo-input:focus,
.syo-select:focus {
  border-color: var(--syo-blue);
  box-shadow: 0 0 0 2px rgba(88, 166, 255, 0.2),
              0 0 20px rgba(88, 166, 255, 0.08);
  outline: none;
  transform: scale(1.01);
  transition: border-color 200ms var(--syo-ease-out),
              box-shadow 250ms var(--syo-ease-out),
              transform 250ms var(--syo-ease-elastic);
}

.syo-input:disabled,
.syo-select:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  background: var(--syo-bg-base);
}

/* Select — custom chevron */
.syo-select {
  appearance: none;
  -webkit-appearance: none;
  padding-right: var(--syo-space-8);
  background-image: url("data:image/svg+xml,%3Csvg width='12' height='8' viewBox='0 0 12 8' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1.5l5 5 5-5' stroke='%238b949e' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 10px center;
  cursor: pointer;
}

/* Input sizes */
.syo-input--sm { padding: 3px var(--syo-space-2); font-size: 0.8125rem; }
.syo-input--lg { padding: 10px var(--syo-space-4); font-size: 1rem; }

/* Input with leading icon */
.syo-input-icon {
  position: relative;
  display: block;
}
.syo-input-icon svg {
  position: absolute;
  left: var(--syo-space-3);
  top: 50%;
  transform: translateY(-50%);
  color: var(--syo-fg-muted);
  pointer-events: none;
  transition: color 200ms var(--syo-ease-out);
}
.syo-input-icon .syo-input { padding-left: var(--syo-space-8); }
.syo-input-icon:focus-within svg { color: var(--syo-blue); }

/* Floating label — label inside input, springs up on focus/fill */
.syo-input-floating {
  position: relative;
  display: block;
}
.syo-input-floating .syo-input {
  padding-top: 18px;
  padding-bottom: 6px;
}
.syo-input-floating .syo-input::placeholder { opacity: 0; }
.syo-input-floating .syo-floating-label {
  position: absolute;
  top: 50%;
  left: var(--syo-space-3);
  transform: translateY(-50%);
  font-size: 0.875rem;
  color: var(--syo-fg-muted);
  pointer-events: none;
  transform-origin: left center;
  transition: transform 220ms var(--syo-ease-elastic),
              top 220ms var(--syo-ease-elastic),
              font-size 220ms var(--syo-ease-elastic),
              color 200ms var(--syo-ease-out);
}
.syo-input-floating .syo-input:focus ~ .syo-floating-label,
.syo-input-floating .syo-input:not(:placeholder-shown) ~ .syo-floating-label {
  top: 5px;
  transform: translateY(0) scale(0.8);
  font-size: 0.75rem;
  color: var(--syo-blue);
}

/* Checkbox / Radio — custom visual, hidden native */
.syo-checkbox,
.syo-radio {
  display: inline-flex;
  align-items: center;
  gap: var(--syo-space-2);
  font-size: 0.875rem;
  color: var(--syo-fg-body);
  cursor: pointer;
  user-select: none;
}

.syo-checkbox input,
.syo-radio input {
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
}

/* Custom checkbox box */
.syo-checkbox .syo-checkmark {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 16px; height: 16px;
  border: 1.5px solid var(--syo-border);
  border-radius: var(--syo-radius-sm);
  background: var(--syo-bg-surface);
  flex-shrink: 0;
  transition: background 150ms var(--syo-ease-out),
              border-color 150ms var(--syo-ease-out);
}

.syo-checkbox:hover .syo-checkmark { border-color: var(--syo-blue); }

.syo-checkbox input:checked + .syo-checkmark {
  background: var(--syo-blue);
  border-color: var(--syo-blue);
  animation: syo-check-pop 280ms var(--syo-ease-elastic);
}

.syo-checkbox input:checked + .syo-checkmark::after {
  content: '';
  width: 5px; height: 9px;
  border: solid #fff;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg) translateY(-1px);
  animation: syo-check-mark 280ms var(--syo-ease-elastic);
}

.syo-checkbox input:focus-visible + .syo-checkmark {
  outline: 2px solid var(--syo-blue);
  outline-offset: 2px;
}

/* Custom radio circle */
.syo-radio .syo-radiomark {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 16px; height: 16px;
  border: 1.5px solid var(--syo-border);
  border-radius: 50%;
  background: var(--syo-bg-surface);
  flex-shrink: 0;
  transition: border-color 150ms var(--syo-ease-out);
}

.syo-radio:hover .syo-radiomark { border-color: var(--syo-blue); }

.syo-radio input:checked + .syo-radiomark {
  border-color: var(--syo-blue);
  animation: syo-check-pop 280ms var(--syo-ease-elastic);
}

.syo-radio input:checked + .syo-radiomark::after {
  content: '';
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--syo-blue);
  animation: syo-radio-dot 280ms var(--syo-ease-elastic);
}

.syo-radio input:focus-visible + .syo-radiomark {
  outline: 2px solid var(--syo-blue);
  outline-offset: 2px;
}

/* Disabled checkbox / radio */
.syo-checkbox input:disabled ~ .syo-checkmark,
.syo-radio input:disabled ~ .syo-radiomark {
  opacity: 0.4;
  cursor: not-allowed;
}
.syo-checkbox input:disabled,
.syo-radio input:disabled,
.syo-checkbox input:disabled ~ *,
.syo-radio input:disabled ~ * {
  cursor: not-allowed;
}

/* ── COMPONENTS: STAT ───────────────────────────────────────── */
.syo-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--syo-space-1);
  padding: var(--syo-space-4);
  background: var(--syo-bg-surface);
  border: 1px solid var(--syo-border);
  border-radius: var(--syo-radius-md);
}

.syo-stat-value {
  font-family: var(--syo-font-mono);
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--syo-fg-default);
}

.syo-stat-label {
  font-size: 0.75rem;
  color: var(--syo-fg-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* ── COMPONENTS: TOGGLE ──────────────────────────────────────── */
/*
   Generic pill toggle switch. Pure CSS, checkbox-driven.
   Variants:
     .syo-toggle             — base: clean pill, blue when checked
     .syo-toggle--theme       — day/night: sky gradient, stars, sun↔moon
     .syo-toggle.syo-toggle--sm  — compact (36×20)
*/

/* ── Base pill ── */
.syo-toggle {
  --st-width: 44px;
  --st-height: 24px;
  --st-knob: 18px;
  --st-gap: 3px;
  --st-travel: 20px;

  position: relative;
  display: inline-flex;
  align-items: center;
  width: var(--st-width);
  height: var(--st-height);
  cursor: pointer;
  user-select: none;
  vertical-align: middle;
}

.syo-toggle input {
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
}

/* Track */
.syo-toggle-track {
  width: 100%; height: 100%;
  border-radius: 999px;
  background: var(--syo-bg-elevated);
  border: 1px solid var(--syo-border);
  transition: background 300ms var(--syo-ease-out),
              border-color 300ms var(--syo-ease-out),
              box-shadow 300ms var(--syo-ease-out);
}
.syo-toggle input:checked ~ .syo-toggle-track {
  background: var(--syo-accent);
  border-color: var(--syo-accent);
  box-shadow: 0 0 12px rgba(188, 140, 255, 0.25);
}

/* Knob */
.syo-toggle-knob {
  position: absolute;
  top: var(--st-gap);
  left: var(--st-gap);
  width: var(--st-knob);
  height: var(--st-knob);
  border-radius: 50%;
  background: var(--syo-fg-default);
  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
  transition: transform 350ms var(--syo-ease-elastic),
              box-shadow 300ms var(--syo-ease-out),
              background 200ms var(--syo-ease-out);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2;
}
.syo-toggle input:checked ~ .syo-toggle-knob {
  transform: translateX(var(--st-travel));
  box-shadow: 0 1px 4px rgba(0,0,0,0.2), 0 0 10px rgba(188, 140, 255, 0.3);
}
.syo-toggle input:focus-visible ~ .syo-toggle-knob {
  outline: 2px solid var(--syo-blue);
  outline-offset: 2px;
}

/* Disabled */
.syo-toggle input:disabled ~ .syo-toggle-track { opacity: 0.4; }
.syo-toggle input:disabled ~ .syo-toggle-knob { opacity: 0.6; }
.syo-toggle input:disabled { cursor: not-allowed; }

/* ── Size: small ── */
.syo-toggle--sm {
  --st-width: 36px;
  --st-height: 20px;
  --st-knob: 14px;
  --st-gap: 3px;
  --st-travel: 16px;
}

/* ═══════════════════════════════════════════════════════════════
   VARIANT: Theme (day ↔ night)
   Extends base toggle with sky gradient track, stars,
   and sun/moon icons inside the knob.
   ═══════════════════════════════════════════════════════════════ */
.syo-toggle--theme {
  --st-width: 52px;
  --st-height: 28px;
  --st-knob: 22px;
  --st-gap: 3px;
  --st-travel: 24px;
}

/* Night sky (unchecked — dark theme) → Day sky (checked — light theme) */
.syo-toggle--theme .syo-toggle-track {
  background: linear-gradient(135deg, #0d1b3e 0%, #1a237e 40%, #283593 100%);
  border: none;
  box-shadow: inset 0 1px 3px rgba(0,0,0,0.3);
  transition: background 500ms ease;
}
.syo-toggle--theme input:checked ~ .syo-toggle-track {
  background: linear-gradient(135deg, #81d4fa 0%, #4fc3f7 50%, #ffcc80 100%);
}

/* Stars — visible at night (unchecked), fade out for day (checked) */
.syo-toggle--theme .syo-toggle-track::after {
  content: '';
  position: absolute;
  inset: 3px 6px;
  border-radius: 999px;
  opacity: 1;
  transition: opacity 400ms ease;
  background-image:
    radial-gradient(1px 1px at 20% 35%, #fff 50%, transparent 50%),
    radial-gradient(1.4px 1.4px at 50% 25%, #fff 50%, transparent 50%),
    radial-gradient(1px 1px at 65% 50%, #fff 50%, transparent 50%),
    radial-gradient(1.2px 1.2px at 35% 60%, #fff 50%, transparent 50%);
  background-repeat: no-repeat;
}
.syo-toggle--theme input:checked ~ .syo-toggle-track::after { opacity: 0; }

/* Theme knob — moon (unchecked) → sun (checked) */
.syo-toggle--theme .syo-toggle-knob {
  background: #e8eaf6;
  box-shadow: 0 1px 6px rgba(0,0,0,0.25), 0 0 14px rgba(121,192,255,0.2);
  transition: transform 400ms var(--syo-ease-elastic),
              background 300ms ease,
              box-shadow 300ms ease;
}
.syo-toggle--theme input:checked ~ .syo-toggle-knob {
  background: #fff8e1;
  box-shadow: 0 1px 4px rgba(0,0,0,0.18), 0 0 8px rgba(255,183,77,0.3);
}

/* Icons — moon visible by default, sun on checked */
.syo-toggle--theme .syo-toggle-knob svg {
  position: absolute;
  width: 13px; height: 13px;
  transition: opacity 250ms ease, transform 300ms var(--syo-ease-elastic);
}
.syo-toggle-sun  { opacity: 0; transform: rotate(90deg); }
.syo-toggle-moon { opacity: 1; transform: rotate(0); }
.syo-toggle--theme input:checked ~ .syo-toggle-knob .syo-toggle-sun {
  opacity: 1; transform: rotate(0);
}
.syo-toggle--theme input:checked ~ .syo-toggle-knob .syo-toggle-moon {
  opacity: 0; transform: rotate(-60deg);
}

/* ── VARIANT: Language (text labels inside knob) ── */
.syo-toggle--lang {
  --st-width: 48px;
  --st-height: 26px;
  --st-knob: 22px;
  --st-gap: 2px;
  --st-travel: 22px;
}
/* Track: purple → deep blue */
.syo-toggle--lang .syo-toggle-track {
  background: linear-gradient(135deg, #2d1b69 0%, #4c249f 50%, #6d35d1 100%);
  border: none;
  box-shadow: inset 0 1px 3px rgba(0,0,0,0.3);
  transition: background 400ms ease, box-shadow 400ms ease;
}
.syo-toggle--lang input:checked ~ .syo-toggle-track {
  background: linear-gradient(135deg, #0d1b3e 0%, #122a5c 50%, #1a3a7a 100%);
  box-shadow: inset 0 1px 3px rgba(0,0,0,0.2), 0 0 10px rgba(88, 166, 255, 0.15);
}
/* Knob: light, works on both purple and blue */
.syo-toggle--lang .syo-toggle-knob {
  font-size: 0.625rem;
  font-weight: 700;
  color: #7c3aed;
  background: #f5f0ff;
  box-shadow: 0 1px 4px rgba(0,0,0,0.15), 0 0 8px rgba(124, 58, 237, 0.2);
  line-height: 1;
  transition: transform 350ms var(--syo-ease-elastic),
              box-shadow 300ms var(--syo-ease-out),
              color 250ms ease, background 250ms ease;
}
.syo-toggle--lang input:checked ~ .syo-toggle-knob {
  color: #3b82f6;
  background: #eff6ff;
  box-shadow: 0 1px 4px rgba(0,0,0,0.15), 0 0 10px rgba(59, 130, 246, 0.25);
}
.syo-toggle--lang .syo-toggle-knob .syo-lang-zh,
.syo-toggle--lang .syo-toggle-knob .syo-lang-en {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity 200ms ease, transform 200ms var(--syo-ease-elastic);
}
.syo-toggle--lang .syo-lang-zh { opacity: 1; transform: scale(1); }
.syo-toggle--lang .syo-lang-en { opacity: 0; transform: scale(0.6); }
.syo-toggle--lang input:checked ~ .syo-toggle-knob .syo-lang-zh {
  opacity: 0; transform: scale(0.6);
}
.syo-toggle--lang input:checked ~ .syo-toggle-knob .syo-lang-en {
  opacity: 1; transform: scale(1);
}

/* ── COMPONENTS: TOAST ─────────────────────────────────────── */
.syo-toast-container {
  position: fixed;
  bottom: calc(var(--syo-space-6) + env(safe-area-inset-bottom, 0px));
  right: var(--syo-space-6);
  z-index: 10000;
  display: flex;
  flex-direction: column-reverse;
  gap: var(--syo-space-2);
  pointer-events: none;
}

.syo-toast {
  pointer-events: auto;
  display: flex;
  align-items: flex-start;
  gap: var(--syo-space-3);
  padding: var(--syo-space-3) var(--syo-space-4);
  background: var(--syo-bg-elevated);
  border: 1px solid var(--syo-border);
  border-radius: var(--syo-radius-md);
  min-width: 280px;
  max-width: 400px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.4);
  opacity: 1;
  animation: syo-toast-in 400ms cubic-bezier(0.34,1.56,0.64,1) backwards;
}

.syo-toast.is-dismissing {
  animation: syo-toast-out 250ms cubic-bezier(0.4,0,1,1) forwards;
}

.syo-toast-icon {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  margin-top: 1px;
}

.syo-toast-body {
  flex: 1;
  font-size: 0.8125rem;
  line-height: 1.45;
  color: var(--syo-fg-body);
}

.syo-toast-close {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  border: none;
  background: none;
  color: var(--syo-fg-muted);
  cursor: pointer;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--syo-radius-sm);
  transition: color 180ms var(--syo-ease-out);
  margin-top: 1px;
}

.syo-toast-close:hover,
.syo-toast-close:focus-visible { color: var(--syo-fg-default); }

/* Toast variants */
.syo-toast--success { border-left: 3px solid var(--syo-green); }
.syo-toast--error   { border-left: 3px solid var(--syo-red); }
.syo-toast--info    { border-left: 3px solid var(--syo-blue); }
.syo-toast--warning { border-left: 3px solid var(--syo-yellow); }

@keyframes syo-toast-in {
  from { opacity: 0; transform: translateY(24px) scale(0.92); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

@keyframes syo-toast-out {
  from { opacity: 1; transform: translateY(0) scale(1); }
  to   { opacity: 0; transform: translateY(-12px) scale(0.94); }
}

/* ── COMPONENTS: TABLE ──────────────────────────────────────── */
.syo-table {
  width: 100%;
  border-collapse: collapse;
}

.syo-table th {
  padding: 8px 0;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--syo-fg-muted);
  text-align: left;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-bottom: 1px solid var(--syo-border);
}

.syo-table td {
  padding: 10px 0;
  font-size: 0.8125rem;
  border-bottom: 1px solid var(--syo-border-muted);
}

.syo-table code {
  font-size: 0.8125rem;
}

/* ── COMPONENTS: DIALOG ──────────────────────────────────────── */
.syo-dialog-overlay {
  position: fixed;
  inset: 0;
  z-index: 10001;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--syo-space-6);
  background: rgba(0, 0, 0, 0.55);
  animation: syo-fade-in 180ms ease-out;
}

.syo-dialog {
  background: var(--syo-bg-elevated);
  border: 1px solid var(--syo-border);
  border-radius: var(--syo-radius-lg);
  width: 100%;
  max-width: 420px;
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.3);
  animation: syo-dialog-in 350ms var(--syo-ease-elastic);
}

.syo-dialog-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--syo-space-4) var(--syo-space-5);
  border-bottom: 1px solid var(--syo-border-muted);
}

.syo-dialog-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--syo-fg-default);
}

.syo-dialog-close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px; height: 28px;
  border: none;
  background: none;
  color: var(--syo-fg-muted);
  cursor: pointer;
  border-radius: var(--syo-radius-sm);
  font-size: 1.125rem;
  line-height: 1;
  transition: color 150ms var(--syo-ease-out),
              background 150ms var(--syo-ease-out);
}
.syo-dialog-close:hover,
.syo-dialog-close:focus-visible {
  color: var(--syo-fg-default);
  background: var(--syo-bg-surface);
}

.syo-dialog-body {
  padding: var(--syo-space-5);
  font-size: 0.875rem;
  color: var(--syo-fg-body);
  line-height: 1.6;
}

.syo-dialog-footer {
  display: flex;
  justify-content: flex-end;
  gap: var(--syo-space-2);
  padding: var(--syo-space-3) var(--syo-space-5) var(--syo-space-4);
}

/* Dialog closing */
.syo-dialog-overlay.is-closing {
  animation: syo-fade-in 200ms ease-out reverse both;
}
.syo-dialog-overlay.is-closing .syo-dialog {
  animation: syo-dialog-out 200ms ease-in forwards;
}

@keyframes syo-dialog-in {
  from { opacity: 0; transform: scale(0.92) translateY(16px); }
  to   { opacity: 1; transform: scale(1) translateY(0); }
}
@keyframes syo-dialog-out {
  from { opacity: 1; transform: scale(1) translateY(0); }
  to   { opacity: 0; transform: scale(0.94) translateY(-8px); }
}

/* ── COMPONENTS: INERTIA SCROLL ────────────────────────────── */
.syo-inertia {
  display: flex;
  gap: var(--syo-space-3);
  overflow-x: auto;
  overflow-y: hidden;
  cursor: grab;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
  scrollbar-color: var(--syo-border) transparent;
}

.syo-inertia::-webkit-scrollbar { height: 6px; }
.syo-inertia::-webkit-scrollbar-track { background: transparent; }
.syo-inertia::-webkit-scrollbar-thumb { background: var(--syo-border); border-radius: 3px; }

.syo-inertia > * {
  flex-shrink: 0;
  white-space: normal;
}

/* ── COMPONENTS: SKELETON ─────────────────────────────────── */
.syo-skeleton {
  display: block;
  border-radius: var(--syo-radius-sm);
  animation: syo-shimmer 1.8s ease-in-out infinite;
  background: linear-gradient(
    90deg,
    var(--syo-bg-surface) 25%,
    var(--syo-bg-elevated) 50%,
    var(--syo-bg-surface) 75%
  );
  background-size: 200% 100%;
}

.syo-skeleton--text {
  display: inline-block;
  height: 0.875em;
  border-radius: var(--syo-radius-sm);
  vertical-align: middle;
}

.syo-skeleton--circle {
  border-radius: 50%;
}

.syo-skeleton--btn {
  height: 34px;
  border-radius: var(--syo-radius-md);
}

@keyframes syo-shimmer {
  0%   { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* ── COMPONENTS: TOOLTIP ──────────────────────────────────── */
.syo-tooltip {
  position: relative;
  display: inline-flex;
  cursor: help;
}

.syo-tooltip::after {
  content: attr(data-syo-tooltip);
  position: absolute;
  bottom: calc(100% + 10px);
  left: 50%;
  transform: translateX(-50%) scale(0.7) translateY(6px);
  transform-origin: bottom center;
  padding: 5px var(--syo-space-3);
  font-family: var(--syo-font-sans);
  font-size: 0.75rem;
  font-weight: 500;
  line-height: 1.45;
  color: var(--syo-fg-default);
  background: radial-gradient(ellipse at 50% 130%, rgba(188,140,255,0.12) 0%, transparent 65%),
              var(--syo-bg-elevated);
  border: 1px solid var(--syo-accent);
  border-radius: var(--syo-radius-sm);
  box-shadow:
    0 4px 24px rgba(0,0,0,0.35),
    0 0 18px rgba(188,140,255,0.28),
    0 0 45px rgba(188,140,255,0.10),
    inset 0 1px 0 rgba(255,255,255,0.03);
  white-space: nowrap;
  pointer-events: none;
  opacity: 0;
  transition: opacity 180ms var(--syo-ease-out),
              transform 350ms cubic-bezier(0.34, 1.56, 0.64, 1),
              box-shadow 300ms var(--syo-ease-out);
  z-index: 9999;
}

/* Arrow */
.syo-tooltip::before {
  content: '';
  position: absolute;
  bottom: calc(100% + 4px);
  left: 50%;
  transform: translateX(-50%) rotate(45deg) scale(0.7);
  width: 8px; height: 8px;
  background: var(--syo-bg-elevated);
  border-right: 1px solid var(--syo-accent);
  border-bottom: 1px solid var(--syo-accent);
  border-radius: 0 0 2px 0;
  box-shadow: 0 0 8px rgba(188,140,255,0.35), 0 0 16px rgba(188,140,255,0.12);
  opacity: 0;
  pointer-events: none;
  transition: opacity 120ms var(--syo-ease-out),
              transform 300ms cubic-bezier(0.34, 1.56, 0.64, 1),
              box-shadow 250ms var(--syo-ease-out);
  z-index: 9999;
}

.syo-tooltip:hover::after,
.syo-tooltip:focus-visible::after {
  opacity: 1;
  transform: translateX(-50%) scale(1) translateY(0);
}

.syo-tooltip:hover::before,
.syo-tooltip:focus-visible::before {
  opacity: 1;
  transform: translateX(-50%) rotate(45deg) scale(1);
}

/* Position variants */
.syo-tooltip--bottom::after {
  bottom: auto;
  top: calc(100% + 10px);
  transform: translateX(-50%) scale(0.7) translateY(-6px);
  transform-origin: top center;
}
.syo-tooltip--bottom::before {
  bottom: auto;
  top: calc(100% + 4px);
  transform: translateX(-50%) rotate(45deg) scale(0.7);
}
.syo-tooltip--bottom:hover::after,
.syo-tooltip--bottom:focus-visible::after {
  transform: translateX(-50%) scale(1) translateY(0);
}
.syo-tooltip--bottom:hover::before,
.syo-tooltip--bottom:focus-visible::before {
  transform: translateX(-50%) rotate(45deg) scale(1);
}

.syo-tooltip--left::after {
  left: auto;
  right: calc(100% + 10px);
  bottom: auto;
  top: 50%;
  transform: translateY(-50%) scale(0.7) translateX(6px);
  transform-origin: right center;
}
.syo-tooltip--left::before {
  left: auto;
  right: calc(100% + 4px);
  bottom: auto;
  top: 50%;
  transform: translateY(-50%) rotate(45deg) scale(0.7);
}
.syo-tooltip--left:hover::after,
.syo-tooltip--left:focus-visible::after {
  transform: translateY(-50%) scale(1) translateX(0);
}
.syo-tooltip--left:hover::before,
.syo-tooltip--left:focus-visible::before {
  transform: translateY(-50%) rotate(45deg) scale(1);
}

.syo-tooltip--right::after {
  left: calc(100% + 10px);
  bottom: auto;
  top: 50%;
  transform: translateY(-50%) scale(0.7) translateX(-6px);
  transform-origin: left center;
}
.syo-tooltip--right::before {
  left: calc(100% + 4px);
  bottom: auto;
  top: 50%;
  transform: translateY(-50%) rotate(45deg) scale(0.7);
}
.syo-tooltip--right:hover::after,
.syo-tooltip--right:focus-visible::after {
  transform: translateY(-50%) scale(1) translateX(0);
}
.syo-tooltip--right:hover::before,
.syo-tooltip--right:focus-visible::before {
  transform: translateY(-50%) rotate(45deg) scale(1);
}

/* Color variants */
.syo-tooltip--info::after {
  border-color: var(--syo-blue);
  background: radial-gradient(ellipse at 50% 130%, rgba(88,166,255,0.10) 0%, transparent 65%),
              var(--syo-bg-elevated);
  box-shadow:
    0 4px 24px rgba(0,0,0,0.35),
    0 0 18px rgba(88,166,255,0.28),
    0 0 45px rgba(88,166,255,0.10),
    inset 0 1px 0 rgba(255,255,255,0.03);
}
.syo-tooltip--info::before {
  background: var(--syo-bg-elevated);
  border-color: var(--syo-blue);
  box-shadow: 0 0 8px rgba(88,166,255,0.35), 0 0 16px rgba(88,166,255,0.12);
}

.syo-tooltip--success::after {
  border-color: var(--syo-green);
  background: radial-gradient(ellipse at 50% 130%, rgba(63,185,80,0.10) 0%, transparent 65%),
              var(--syo-bg-elevated);
  box-shadow:
    0 4px 24px rgba(0,0,0,0.35),
    0 0 18px rgba(63,185,80,0.28),
    0 0 45px rgba(63,185,80,0.10),
    inset 0 1px 0 rgba(255,255,255,0.03);
}
.syo-tooltip--success::before {
  background: var(--syo-bg-elevated);
  border-color: var(--syo-green);
  box-shadow: 0 0 8px rgba(63,185,80,0.35), 0 0 16px rgba(63,185,80,0.12);
}

.syo-tooltip--warning::after {
  border-color: var(--syo-yellow);
  background: radial-gradient(ellipse at 50% 130%, rgba(210,153,34,0.10) 0%, transparent 65%),
              var(--syo-bg-elevated);
  box-shadow:
    0 4px 24px rgba(0,0,0,0.35),
    0 0 18px rgba(210,153,34,0.28),
    0 0 45px rgba(210,153,34,0.10),
    inset 0 1px 0 rgba(255,255,255,0.03);
}
.syo-tooltip--warning::before {
  background: var(--syo-bg-elevated);
  border-color: var(--syo-yellow);
  box-shadow: 0 0 8px rgba(210,153,34,0.35), 0 0 16px rgba(210,153,34,0.12);
}

.syo-tooltip--danger::after {
  border-color: var(--syo-red);
  background: radial-gradient(ellipse at 50% 130%, rgba(248,81,73,0.10) 0%, transparent 65%),
              var(--syo-bg-elevated);
  box-shadow:
    0 4px 24px rgba(0,0,0,0.35),
    0 0 18px rgba(248,81,73,0.28),
    0 0 45px rgba(248,81,73,0.10),
    inset 0 1px 0 rgba(255,255,255,0.03);
}
.syo-tooltip--danger::before {
  background: var(--syo-bg-elevated);
  border-color: var(--syo-red);
  box-shadow: 0 0 8px rgba(248,81,73,0.35), 0 0 16px rgba(248,81,73,0.12);
}

/* ── COMPONENTS: TABS ─────────────────────────────────────── */
.syo-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  border-bottom: 1px solid var(--syo-border);
}

.syo-tabs input {
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
}

.syo-tab {
  position: relative;
  padding: 8px var(--syo-space-4);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--syo-fg-muted);
  cursor: pointer;
  user-select: none;
  border-radius: var(--syo-radius-sm) var(--syo-radius-sm) 0 0;
  transition: color 200ms var(--syo-ease-out),
              background 200ms var(--syo-ease-out);
}

.syo-tab:hover,
.syo-tab:focus-visible {
  color: var(--syo-fg-default);
  background: rgba(188, 140, 255, 0.04);
}

/* Glowing underline via ::after */
.syo-tab::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--syo-accent);
  border-radius: 2px;
  transform: translateX(-50%);
  transition: width 300ms var(--syo-ease-elastic),
              box-shadow 300ms var(--syo-ease-out);
}

.syo-tabs input:checked + .syo-tab {
  color: var(--syo-accent);
  /* gradient bleeding up from the glowing line */
  background: linear-gradient(to top, rgba(188,140,255,0.14) 0%, rgba(188,140,255,0.04) 60%, transparent 100%);
}

.syo-tabs input:checked + .syo-tab::after {
  width: calc(100% - var(--syo-space-3));
  box-shadow: 0 0 12px rgba(188, 140, 255, 0.55),
              0 0 4px rgba(188, 140, 255, 0.35);
}

.syo-tab-panel {
  display: none;
  padding: var(--syo-space-4) 0;
}

/* Show panel when corresponding radio is checked */
.syo-tabs:has(input:nth-of-type(1):checked) ~ .syo-tabs-panels .syo-tab-panel:nth-of-type(1),
.syo-tabs:has(input:nth-of-type(2):checked) ~ .syo-tabs-panels .syo-tab-panel:nth-of-type(2),
.syo-tabs:has(input:nth-of-type(3):checked) ~ .syo-tabs-panels .syo-tab-panel:nth-of-type(3),
.syo-tabs:has(input:nth-of-type(4):checked) ~ .syo-tabs-panels .syo-tab-panel:nth-of-type(4),
.syo-tabs:has(input:nth-of-type(5):checked) ~ .syo-tabs-panels .syo-tab-panel:nth-of-type(5),
.syo-tabs:has(input:nth-of-type(6):checked) ~ .syo-tabs-panels .syo-tab-panel:nth-of-type(6) {
  display: block;
  animation: syo-fade-up 300ms var(--syo-ease-out);
}

/* ── COMPONENTS: DROPDOWN ─────────────────────────────────── */
.syo-dropdown {
  position: relative;
  display: inline-block;
}

.syo-dropdown-toggle {
  display: inline-flex;
  align-items: center;
  gap: var(--syo-space-1);
  cursor: pointer;
  user-select: none;
}

.syo-dropdown-menu {
  position: absolute;
  top: calc(100% + 4px);
  left: 0;
  min-width: 160px;
  padding: var(--syo-space-1);
  background: var(--syo-bg-elevated);
  border: 1px solid var(--syo-border);
  border-radius: var(--syo-radius-md);
  box-shadow: 0 4px 16px rgba(0,0,0,0.3);
  opacity: 0;
  visibility: hidden;
  transform: scale(0.92) translateY(-4px);
  transform-origin: top left;
  transition: opacity 150ms var(--syo-ease-out),
              transform 250ms var(--syo-ease-elastic),
              visibility 0ms linear 200ms;
  z-index: 9998;
}

.syo-dropdown.open > .syo-dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: scale(1) translateY(0);
  transition: opacity 150ms var(--syo-ease-out),
              transform 250ms var(--syo-ease-elastic),
              visibility 0ms linear 0ms;
}

.syo-dropdown-item {
  display: block;
  width: 100%;
  padding: 6px var(--syo-space-3);
  font-size: 0.8125rem;
  color: var(--syo-fg-body);
  border-radius: var(--syo-radius-sm);
  cursor: pointer;
  text-align: left;
  background: none;
  border: none;
  transition: background 120ms var(--syo-ease-out),
              color 120ms var(--syo-ease-out);
}

.syo-dropdown-item:hover,
.syo-dropdown-item:focus-visible {
  background: var(--syo-bg-surface);
  color: var(--syo-fg-default);
}

.syo-dropdown-divider {
  height: 1px;
  margin: var(--syo-space-1) 0;
  background: var(--syo-border-muted);
}

/* ── UTILITY CLASSES ────────────────────────────────────────── */
/* Text */
.syo-text-default { color: var(--syo-fg-default); }
.syo-text-muted   { color: var(--syo-fg-muted); }
.syo-text-sm      { font-size: 0.8125rem; }
.syo-text-xs      { font-size: 0.75rem; }
.syo-text-lg      { font-size: 1.125rem; }
.syo-text-mono    { font-family: var(--syo-font-mono); }
.syo-text-center  { text-align: center; }
.syo-text-weight-400 { font-weight: 400; }
.syo-text-weight-600 { font-weight: 600; }

/* Padding / Margin helpers */
.syo-p-4 { padding: var(--syo-space-4); }
.syo-p-6 { padding: var(--syo-space-6); }
.syo-py-4 { padding-top: var(--syo-space-4); padding-bottom: var(--syo-space-4); }
.syo-py-12 { padding-top: var(--syo-space-12); padding-bottom: var(--syo-space-12); }
.syo-mt-1 { margin-top: var(--syo-space-1); }
.syo-mt-2 { margin-top: var(--syo-space-2); }
.syo-mt-3 { margin-top: var(--syo-space-3); }
.syo-mt-4 { margin-top: var(--syo-space-4); }
.syo-mt-6 { margin-top: var(--syo-space-6); }
.syo-mb-1 { margin-bottom: var(--syo-space-1); }
.syo-mb-2 { margin-bottom: var(--syo-space-2); }
.syo-mb-3 { margin-bottom: var(--syo-space-3); }
.syo-mb-4 { margin-bottom: var(--syo-space-4); }
.syo-mb-6 { margin-bottom: var(--syo-space-6); }

/* Border */
.syo-border-top    { border-top: 1px solid var(--syo-border); }
.syo-border-bottom { border-bottom: 1px solid var(--syo-border); }

/* Hidden */
.syo-hidden { display: none !important; }

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

/* Skip link — sr-only until focused */
.syo-skip-link {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}
.syo-skip-link:focus {
  position: fixed;
  top: 0; left: 0;
  z-index: 10001;
  display: flex;
  align-items: center;
  height: 36px;
  padding: 0 var(--syo-space-4);
  background: var(--syo-blue);
  color: #fff;
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
  clip: auto;
  width: auto;
  height: auto;
  margin: 0;
}

/* ── LINK TYPES ─────────────────────────────────────────────── */
.syo-link-spring {
  display: inline-block;
  transition: var(--syo-trans-spring);
}
.syo-link-spring:hover { transform: scale(1.12); }
.syo-link-spring:active { transform: scale(0.93); transition: var(--syo-trans-active); }

/* ── MOTION ─────────────────────────────────────────────────── */
.syo-reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 500ms var(--syo-ease-out),
              transform 500ms var(--syo-ease-elastic);
}

.syo-reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ── ANIMATIONS ─────────────────────────────────────────────── */
@keyframes syo-blink {
  0%, 49%  { opacity: 1; }
  50%, 100% { opacity: 0; }
}

@keyframes syo-fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes syo-fade-up {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes syo-ripple-expand {
  0%   { width: 0; height: 0; opacity: 0.7; }
  100% { width: 120px; height: 120px; opacity: 0; }
}

@keyframes syo-flash-pulse {
  0%   { transform: translate(-50%, -50%) scale(0); opacity: 0.6; }
  100% { transform: translate(-50%, -50%) scale(1); opacity: 0; }
}

/* Form — spring-pop for checkbox / radio */
@keyframes syo-check-pop {
  0%   { transform: scale(0.7); }
  60%  { transform: scale(1.1); }
  100% { transform: scale(1); }
}
@keyframes syo-check-mark {
  0%   { opacity: 0; transform: rotate(45deg) translateY(-1px) scale(0); }
  70%  { opacity: 1; transform: rotate(45deg) translateY(-1px) scale(1.2); }
  100% { transform: rotate(45deg) translateY(-1px) scale(1); }
}
@keyframes syo-radio-dot {
  0%   { transform: scale(0); }
  60%  { transform: scale(1.3); }
  100% { transform: scale(1); }
}

/* ── REDUCED MOTION ─────────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0ms !important;
    animation-delay: 0ms !important;
    transition-duration: 0ms !important;
  }
  .syo-reveal { opacity: 1; transform: none; }
  .syo-editor-cursor { animation: none; opacity: 1; }
}

/* ── RESPONSIVE ─────────────────────────────────────────────── */
@media (max-width: 768px) {
  :root { --syo-container: 100%; }

  .syo-grid-2,
  .syo-grid-3,
  .syo-grid-4 {
    grid-template-columns: repeat(auto-fill, minmax(min(100%, 240px), 1fr));
  }

  .syo-nav { padding: 0 var(--syo-space-3); }
  .syo-nav-links { gap: var(--syo-space-3); }
  .syo-nav-links a { font-size: 0.8125rem; }

  .syo-container { padding-left: var(--syo-space-4); padding-right: var(--syo-space-4); }
  .syo-section { padding-top: var(--syo-space-8); padding-bottom: var(--syo-space-8); }
  .syo-editor-code { font-size: 0.75rem; }

  .syo-inertia { -webkit-overflow-scrolling: touch; }
}

@media (max-width: 480px) {
  .syo-nav-links { gap: var(--syo-space-2); }
  .syo-nav-brand { font-size: 0.875rem; }
  .syo-btn--lg { padding: 6px var(--syo-space-4); font-size: 0.9375rem; }
  .syo-toast { min-width: auto; max-width: calc(100vw - var(--syo-space-8)); }
}