/* FINAL VERSION YAY */

/* ================================================================
   MECH//KEYS stylesheet
   Dual theme: dark canvas and inverted light mode
   Typography: Share Tech Mono across the site
   ================================================================ */

/* Global Reset */
* { box-sizing: border-box; margin: 0; padding: 0; }

/* Utility Class */
.share-tech-mono-regular {
  font-family: "Share Tech Mono", monospace;
  font-weight: 400;
  font-style: normal;
}

/* Design Tokens */
:root {
  /* Theme Agnostic */
  --radius:    4px;
  --radius-key: 8px;
  --ease:      cubic-bezier(.2,.7,.2,1);
  --mono:      "Share Tech Mono", monospace;

  /* Dark Defaults */
  --bg:            #000000;
  --dot:           rgba(134, 154, 186, 0.55);
  --dark:          #2d2e3b;
  --darker:        #14141c;
  --light:         #869aba;
  --light-2:       #b8c4db;
  --accent:        #a8b8d8;

  --text-strong:   #ffffff;
  --text-soft:     #b8c4db;
  --text-muted:    #869aba;

  --key-top:       #3a4255;
  --key-bottom:    #2d2e3b;
  --key-shadow:    #14141c;
  --key-border:    rgba(134, 154, 186, 0.22);
  --key-border-hi: rgba(134, 154, 186, 0.7);

  --card-top:      rgba(45, 46, 59, 0.9);
  --card-bottom:   rgba(20, 20, 28, 0.9);
  --card-border:   rgba(134, 154, 186, 0.22);
  --card-hover:    rgba(134, 154, 186, 0.55);

  --nav-bg:        rgba(0, 0, 0, 0.78);
  --nav-border:    rgba(134, 154, 186, 0.2);
  --menu-bg:       rgba(0, 0, 0, 0.92);

  --rule:          rgba(134, 154, 186, 0.25);
  --tag-bg:        rgba(45, 46, 59, 0.55);
  --bar-track:     rgba(134, 154, 186, 0.12);

  --ambient-a:     rgba(134, 154, 186, 0.08);
  --ambient-b:     rgba(45, 46, 59, 0.45);

  --shadow-deep:   rgba(0, 0, 0, 0.7);
  --shadow-mid:    rgba(0, 0, 0, 0.6);
  --shadow-soft:   rgba(0, 0, 0, 0.4);

  --cursor-color:  #ffffff;
  --cursor-blend:  difference;

  --active-glow:       rgba(255, 255, 255, 0.38);
  --active-glow-soft:  rgba(255, 255, 255, 0.25);
  --active-border:     rgba(255, 255, 255, 0.6);
}

/* Light Overrides */
[data-theme="light"] {
  --bg:            #ebeef4;
  --dot:           rgba(60, 72, 96, 0.55);
  --dark:          #ffffff;
  --darker:        #b5bccb;
  --light:         #5a6a87;
  --light-2:       #2d2e3b;
  --accent:        #4a5a7a;

  --text-strong:   #14141c;
  --text-soft:     #2d2e3b;
  --text-muted:    #5a6a87;

  --key-top:       #ffffff;
  --key-bottom:    #dfe4ef;
  --key-shadow:    #9aa3b6;
  --key-border:    rgba(60, 72, 96, 0.25);
  --key-border-hi: rgba(60, 72, 96, 0.6);

  --card-top:      rgba(255, 255, 255, 0.95);
  --card-bottom:   rgba(223, 228, 239, 0.95);
  --card-border:   rgba(60, 72, 96, 0.22);
  --card-hover:    rgba(60, 72, 96, 0.55);

  --nav-bg:        rgba(235, 238, 244, 0.82);
  --nav-border:    rgba(60, 72, 96, 0.22);
  --menu-bg:       rgba(255, 255, 255, 0.95);

  --rule:          rgba(60, 72, 96, 0.25);
  --tag-bg:        rgba(255, 255, 255, 0.75);
  --bar-track:     rgba(60, 72, 96, 0.15);

  --ambient-a:     rgba(90, 106, 135, 0.1);
  --ambient-b:     rgba(255, 255, 255, 0.4);

  --shadow-deep:   rgba(70, 80, 100, 0.25);
  --shadow-mid:    rgba(70, 80, 100, 0.2);
  --shadow-soft:   rgba(70, 80, 100, 0.15);

  --cursor-color:  #14141c;
  --cursor-blend:  normal;

  --active-glow:       rgba(20, 20, 28, 0.35);
  --active-glow-soft:  rgba(20, 20, 28, 0.22);
  --active-border:     rgba(20, 20, 28, 0.55);
}

/* Base Canvas */
html, body {
  height: 100%;
  width: 100%;
  font-family: var(--mono);
  font-weight: 400;
  color: var(--text-soft);
  background-color: var(--bg);
  overflow-x: hidden;
  line-height: 1.6;
  letter-spacing: 0.01em;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Dotted Grid */
body {
  background-image: radial-gradient(circle, var(--dot) 1px, transparent 1px);
  background-size: 22px 22px;
  background-attachment: fixed;
}

/* Ambient Glow */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(60% 45% at 15% 10%, var(--ambient-a), transparent 70%),
    radial-gradient(50% 40% at 85% 90%, var(--ambient-b), transparent 70%);
  z-index: 0;
}

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

/* ================================================================
   LOADING SCREEN
   ================================================================ */
.loader {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg);
  text-align: center;
  padding: 24px;
  transition: opacity 0.5s ease, visibility 0.5s ease;
}

/* Fade Out */
.loader.loader-gone {
  opacity: 0;
  visibility: hidden;
}

.loader-inner { max-width: 520px; }

/* Loader Key */
.loader-key {
  display: inline-flex;
  gap: 10px;
  padding: 18px 26px;
  border-radius: 5px;
  background: linear-gradient(180deg, var(--key-top) 0%, var(--key-bottom) 100%);
  box-shadow:
    0 6px 0 var(--key-shadow),
    0 0 30px var(--ambient-a),
    inset 0 0 0 1px var(--key-border-hi);
  margin-bottom: 24px;
}

/* Typing Dots */
.loader-dot {
  width: 10px;
  height: 10px;
  background: var(--light);
  border-radius: 50%;
  animation: loaderBounce 1.1s infinite ease-in-out;
}
.loader-dot:nth-child(2) { animation-delay: 0.18s; }
.loader-dot:nth-child(3) { animation-delay: 0.36s; }

@keyframes loaderBounce {
  0%, 60%, 100% { transform: translateY(0); opacity: 0.4; }
  30%           { transform: translateY(-7px); opacity: 1; }
}

/* Loader Copy */
.loader-text {
  color: var(--text-strong);
  font-size: clamp(1.1rem, 2.2vw, 1.5rem);
  letter-spacing: 0.08em;
  margin-bottom: 8px;
}
.loader-sub {
  color: var(--light);
  font-size: clamp(0.9rem, 1.4vw, 1.05rem);
  letter-spacing: 0.04em;
}

/* ================================================================
   CUSTOM CURSOR
   ================================================================ */

/* Cursor Hidden */
@media (hover: hover) and (pointer: fine) {
  html, body, button, a, input, select, textarea { cursor: none; }
}

/* Cursor Dot */
.custom-cursor {
  position: fixed;
  top: 0; left: 0;
  width: 10px;
  height: 10px;
  margin: -5px 0 0 -5px;
  border-radius: 50%;
  background: var(--cursor-color);
  pointer-events: none;
  z-index: 9999;
  mix-blend-mode: var(--cursor-blend);
  box-shadow: 0 0 12px rgba(255, 255, 255, 0.85);
  transition: width 0.15s ease, height 0.15s ease, margin 0.15s ease;
}

/* Trailing Ring */
.custom-cursor-ring {
  position: fixed;
  top: 0; left: 0;
  width: 34px;
  height: 34px;
  margin: -17px 0 0 -17px;
  border-radius: 50%;
  border: 1px solid var(--cursor-color);
  opacity: 0.55;
  pointer-events: none;
  z-index: 9998;
  transition: width 0.2s ease, height 0.2s ease, margin 0.2s ease, opacity 0.2s ease;
}

/* Hover Growth */
.custom-cursor.cursor-hover {
  width: 16px; height: 16px;
  margin: -8px 0 0 -8px;
}
.custom-cursor-ring.cursor-hover {
  width: 54px; height: 54px;
  margin: -27px 0 0 -27px;
  opacity: 0.85;
}

/* Touch Fallback */
@media (hover: none) {
  .custom-cursor, .custom-cursor-ring { display: none; }
}

/* ================================================================
   INTRO PAGE
   ================================================================ */

/* Intro Container */
.intro-page {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 40px 20px;
}

.intro-wrapper {
  text-align: center;
  max-width: 820px;
  width: 100%;
}

/* Hero Title */
.intro-title {
  font-family: var(--mono);
  font-size: clamp(2.4rem, 7.5vw, 5.5rem);
  color: var(--text-strong);
  letter-spacing: 0.04em;
  margin-bottom: 54px;
  line-height: 1.05;
  text-shadow: 0 0 30px var(--ambient-a);
}

/* Space Bar */
.space-bar {
  position: relative;
  width: clamp(280px, 55vw, 560px);
  height: clamp(76px, 11vw, 104px);
  border: none;
  border-radius: 12px;
  cursor: pointer;
  font-family: var(--mono);
  font-size: clamp(1.1rem, 2vw, 1.6rem);
  letter-spacing: 0.45em;
  color: var(--text-soft);
  background: linear-gradient(180deg, var(--key-top) 0%, var(--key-bottom) 100%);
  box-shadow:
    0 9px 0 var(--key-shadow),
    0 14px 26px var(--shadow-deep),
    inset 0 1px 0 rgba(255,255,255,0.06),
    inset 0 0 0 1px var(--key-border);
  transition: transform 0.08s var(--ease), box-shadow 0.08s var(--ease);
}

.space-bar .space-label { display: inline-block; }
.space-bar .space-hint {
  position: absolute;
  right: 22px; top: 50%;
  transform: translateY(-50%);
  color: var(--light);
  font-size: 1rem;
  opacity: 0.7;
  letter-spacing: 0;
}

/* Top Line */
.space-bar::after {
  content: "";
  position: absolute;
  inset: 6px 10px auto 10px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, transparent, var(--key-border-hi), transparent);
  opacity: 0.6;
}

.space-bar:hover {
  transform: translateY(-1px);
  box-shadow:
    0 10px 0 var(--key-shadow),
    0 16px 32px var(--shadow-deep),
    inset 0 1px 0 rgba(255,255,255,0.06),
    inset 0 0 0 1px var(--key-border-hi);
  animation: rgbPulse 2.8s linear infinite;
}

.space-bar:active,
.space-bar.pressed {
  transform: translateY(7px);
  box-shadow:
    0 2px 0 var(--key-shadow),
    0 3px 6px var(--shadow-soft),
    inset 0 1px 0 rgba(255,255,255,0.04),
    inset 0 0 0 1px var(--key-border);
}

/* Start Prompt */
.intro-prompt {
  margin-top: 40px;
  color: var(--light);
  font-family: var(--mono);
  font-size: clamp(0.9rem, 1.2vw, 1.05rem);
  letter-spacing: 0.06em;
}
.intro-prompt kbd {
  display: inline-block;
  padding: 3px 10px;
  margin: 0 4px;
  border-radius: 2px;
  background: var(--dark);
  color: var(--text-soft);
  border: 1px solid var(--key-border);
  box-shadow: 0 2px 0 var(--key-shadow);
  font-family: var(--mono);
  font-size: 0.9rem;
}
.intro-prompt .click-word {
  font-style: italic;
  color: var(--text-soft);
  border-bottom: 1px dashed var(--light);
  padding-bottom: 1px;
}

/* ================================================================
   MAIN PAGE
   ================================================================ */
.main-page {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Sticky Nav */
.nav {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px clamp(20px, 4vw, 48px);
  background: var(--nav-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--nav-border);
  flex-wrap: nowrap;
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

/* Left Cluster */
.nav-left {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: nowrap;
}

/* Theme Toggle */
.theme-toggle {
  position: relative;
  min-width: 76px;
  padding: 9px 14px 11px;
  border: none;
  cursor: pointer;
  font-family: var(--mono);
  color: var(--text-soft);
  background: linear-gradient(180deg, var(--key-top) 0%, var(--key-bottom) 100%);
  border-radius: 8px;
  text-align: center;
  box-shadow:
    0 4px 0 var(--key-shadow),
    0 6px 12px var(--shadow-mid),
    inset 0 1px 0 rgba(255,255,255,0.06),
    inset 0 0 0 1px var(--key-border);
  transition: transform 0.07s var(--ease), color 0.2s;
}
.theme-toggle::after {
  content: "";
  position: absolute;
  left: 8px; right: 8px; top: 4px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--key-border-hi), transparent);
  border-radius: 1px;
}
.theme-toggle .theme-top {
  display: block;
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  color: var(--light);
}
.theme-toggle .theme-sub {
  display: block;
  font-size: 0.95rem;
  letter-spacing: 0.12em;
  margin-top: 2px;
}
.theme-toggle:hover {
  color: var(--text-strong);
  animation: rgbPulse 3s linear infinite;
  transform: translateY(-1px);
}
.theme-toggle:active,
.theme-toggle.pressed {
  transform: translateY(3px);
  animation: none;
  box-shadow:
    0 1px 0 var(--key-shadow),
    0 2px 4px var(--shadow-soft),
    inset 0 1px 0 rgba(255,255,255,0.04),
    inset 0 0 0 1px var(--key-border);
}

/* Logo Button */
.nav-logo {
  border: none;
  background: transparent;
  cursor: pointer;
  padding: 6px 8px;
  font-family: var(--mono);
  font-size: 1.2rem;
  letter-spacing: 0.14em;
  color: var(--text-soft);
  white-space: nowrap;
  border-radius: 2px;
  transition: color 0.2s, background-color 0.2s, transform 0.08s var(--ease);
}
.nav-logo .slash { color: var(--light); transition: color 0.2s; }
.nav-logo:hover {
  color: var(--text-strong);
  background-color: var(--tag-bg);
}
.nav-logo:hover .slash { color: var(--text-strong); }
.nav-logo:active,
.nav-logo.pressed {
  transform: translateY(1px);
}

/* Nav Row */
.nav-keys {
  display: flex;
  gap: 10px;
  align-items: flex-end;
  flex-wrap: nowrap;
}

/* Key Button */
.key-btn {
  position: relative;
  min-width: 110px;
  padding: 11px 18px 13px;
  border: none;
  cursor: pointer;
  font-family: var(--mono);
  color: var(--text-soft);
  background: linear-gradient(180deg, var(--key-top) 0%, var(--key-bottom) 100%);
  border-radius: 8px;
  text-align: center;
  box-shadow:
    0 5px 0 var(--key-shadow),
    0 8px 14px var(--shadow-mid),
    inset 0 1px 0 rgba(255,255,255,0.06),
    inset 0 0 0 1px var(--key-border);
  transition: transform 0.07s var(--ease), color 0.2s;
}
.key-btn .key-top {
  display: block;
  font-size: 0.95rem;
  letter-spacing: 0.12em;
}
.key-btn .key-sub {
  display: block;
  font-size: 0.58rem;
  color: var(--light);
  margin-top: 3px;
  letter-spacing: 0.1em;
}

/* Top Bevel */
.key-btn::after {
  content: "";
  position: absolute;
  left: 8px; right: 8px; top: 4px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--key-border-hi), transparent);
  border-radius: 1px;
}

/* Glow Pulse */
@keyframes rgbPulse {
  0%   { box-shadow:
           0 5px 0 var(--key-shadow),
           0 8px 14px var(--shadow-mid),
           inset 0 0 0 1px rgba(255, 90, 110, 0.9),
           0 0 14px rgba(255, 90, 110, 0.55); }
  20%  { box-shadow:
           0 5px 0 var(--key-shadow),
           0 8px 14px var(--shadow-mid),
           inset 0 0 0 1px rgba(255, 200, 90, 0.9),
           0 0 14px rgba(255, 200, 90, 0.55); }
  40%  { box-shadow:
           0 5px 0 var(--key-shadow),
           0 8px 14px var(--shadow-mid),
           inset 0 0 0 1px rgba(120, 240, 150, 0.9),
           0 0 14px rgba(120, 240, 150, 0.55); }
  60%  { box-shadow:
           0 5px 0 var(--key-shadow),
           0 8px 14px var(--shadow-mid),
           inset 0 0 0 1px rgba(90, 200, 255, 0.9),
           0 0 14px rgba(90, 200, 255, 0.55); }
  80%  { box-shadow:
           0 5px 0 var(--key-shadow),
           0 8px 14px var(--shadow-mid),
           inset 0 0 0 1px rgba(210, 130, 255, 0.9),
           0 0 14px rgba(210, 130, 255, 0.55); }
  100% { box-shadow:
           0 5px 0 var(--key-shadow),
           0 8px 14px var(--shadow-mid),
           inset 0 0 0 1px rgba(255, 90, 110, 0.9),
           0 0 14px rgba(255, 90, 110, 0.55); }
}

/* Hover Glow */
.key-btn:hover {
  color: var(--text-strong);
  animation: rgbPulse 3s linear infinite;
  transform: translateY(-1px);
}

/* Press State */
.key-btn:active,
.key-btn.pressed {
  transform: translateY(4px);
  animation: none;
  box-shadow:
    0 1px 0 var(--key-shadow),
    0 2px 4px var(--shadow-soft),
    inset 0 1px 0 rgba(255,255,255,0.04),
    inset 0 0 0 1px var(--key-border);
}

/* Active Key */
.key-btn.is-current {
  color: var(--text-strong);
  box-shadow:
    0 5px 0 var(--key-shadow),
    0 16px 32px var(--active-glow-soft),
    0 0 28px var(--active-glow),
    0 0 60px var(--active-glow-soft),
    inset 0 1px 0 rgba(255,255,255,0.14),
    inset 0 0 0 1px var(--active-border);
}
.key-btn.is-current .key-sub { color: var(--text-strong); opacity: 0.85; }

/* Menu Toggle */
.menu-toggle {
  display: none;
  position: relative;
  min-width: 96px;
  padding: 11px 18px 13px;
  border: none;
  cursor: pointer;
  font-family: var(--mono);
  color: var(--text-soft);
  background: linear-gradient(180deg, var(--key-top) 0%, var(--key-bottom) 100%);
  border-radius: 8px;
  text-align: center;
  box-shadow:
    0 5px 0 var(--key-shadow),
    0 8px 14px var(--shadow-mid),
    inset 0 1px 0 rgba(255,255,255,0.06),
    inset 0 0 0 1px var(--key-border);
  transition: transform 0.07s var(--ease);
}
.menu-toggle::after {
  content: "";
  position: absolute;
  left: 8px; right: 8px; top: 4px;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--key-border-hi), transparent);
  border-radius: 1px;
}
.menu-toggle-top {
  display: block;
  font-size: 0.92rem;
  letter-spacing: 0.12em;
}
.menu-toggle-sub {
  display: block;
  font-size: 0.9rem;
  color: var(--light);
  margin-top: 2px;
}
.menu-toggle:hover {
  color: var(--text-strong);
  animation: rgbPulse 3s linear infinite;
  transform: translateY(-1px);
}
.menu-toggle:active {
  transform: translateY(4px);
  animation: none;
}

/* Content Area */
.content {
  flex: 1;
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding: clamp(32px, 5vw, 72px) clamp(20px, 4vw, 48px) 96px;
}

/* Section Swap */
.section {
  display: none;
  animation: fadeUp 0.45s var(--ease);
}
.section.active { display: block; }

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* Type Hierarchy */
.section-head { margin-bottom: 44px; }

/* Section Tag */
.section-tag {
  display: inline-block;
  font-size: 0.78rem;
  letter-spacing: 0.25em;
  color: var(--light);
  padding: 5px 12px;
  border: 1px solid var(--key-border-hi);
  border-radius: 2px;
  margin-bottom: 22px;
  background: var(--tag-bg);
}

/* Section Headline */
.section-head h2 {
  font-family: var(--mono);
  font-weight: 400;
  font-size: clamp(2rem, 4.2vw, 3.4rem);
  color: var(--text-strong);
  line-height: 1.1;
  letter-spacing: 0.005em;
  max-width: 900px;
}

/* Section Kicker */
.section-kicker {
  color: var(--light);
  margin-top: 18px;
  max-width: 760px;
  font-size: clamp(1rem, 1.3vw, 1.2rem);
  letter-spacing: 0.02em;
}

/* Extra Spacing */
.section-kicker-spaced {
  margin-bottom: 40px;
}

/* Sub Heading */
.sub-heading {
  font-family: var(--mono);
  font-weight: 400;
  color: var(--text-strong);
  font-size: clamp(1.4rem, 2.2vw, 1.9rem);
  letter-spacing: 0.02em;
  margin: 56px 0 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--rule);
}

/* Card Titles */
.card-title-sm { font-size: 1.05rem; color: var(--text-strong); margin-bottom: 8px; font-weight: 400; letter-spacing: 0.02em; }
.card-title-md { font-size: 1.25rem; color: var(--text-strong); margin-bottom: 10px; font-weight: 400; letter-spacing: 0.02em; }
.card-title-lg { font-size: 1.5rem;  color: var(--text-strong); margin-bottom: 14px; font-weight: 400; letter-spacing: 0.02em; }

/* Two Column */
.two-col {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 40px;
  align-items: start;
}
.two-col p { margin-bottom: 18px; color: var(--text-soft); font-size: 1.02rem; }
.two-col .lead {
  font-size: clamp(1.15rem, 1.7vw, 1.35rem);
  color: var(--text-strong);
  line-height: 1.5;
}

/* Card Base */
.card {
  position: relative;
  background: linear-gradient(180deg, var(--card-top) 0%, var(--card-bottom) 100%);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 26px;
  transition: border-color 0.25s, transform 0.25s;
}
.card:hover {
  border-color: var(--card-hover);
  transform: translateY(-2px);
}
.card p { color: var(--text-soft); font-size: 0.98rem; }

/* Card List */
.card ul { list-style: none; padding: 0; }
.card ul li {
  padding: 9px 0;
  border-bottom: 1px solid var(--rule);
  color: var(--text-soft);
  font-size: 1rem;
  position: relative;
  padding-left: 20px;
  letter-spacing: 0.01em;
}
.card ul li::before {
  content: "\203A";
  position: absolute;
  left: 2px;
  color: var(--light);
}
.card ul li:last-child { border-bottom: none; }

/* Glow Card */
.glow-card {
  background:
    linear-gradient(180deg, var(--card-top), var(--card-bottom)),
    radial-gradient(circle at top left, var(--ambient-a), transparent 70%);
  box-shadow: 0 0 40px var(--ambient-a);
}

/* Timeline Accordion */
.timeline {
  position: relative;
  margin-left: 14px;
  padding-left: 30px;
  border-left: 1px solid var(--rule);
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.timeline-item { position: relative; }
.timeline-item::before {
  content: "";
  position: absolute;
  left: -37px;
  top: 22px;
  width: 10px; height: 10px;
  background: var(--light);
  border-radius: 50%;
  box-shadow: 0 0 0 4px var(--ambient-a);
  transition: background 0.25s, box-shadow 0.25s;
}
.timeline-item.open::before {
  background: var(--text-strong);
  box-shadow: 0 0 0 4px var(--ambient-a), 0 0 12px var(--ambient-a);
}

/* Timeline Trigger */
.timeline-trigger {
  width: 100%;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 18px;
  padding: 16px 22px;
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  background: linear-gradient(180deg, var(--card-top) 0%, var(--card-bottom) 100%);
  font-family: var(--mono);
  color: var(--text-soft);
  cursor: pointer;
  text-align: left;
  transition: border-color 0.25s, transform 0.15s;
}
.timeline-trigger:hover {
  border-color: var(--card-hover);
  animation: rgbPulse 3s linear infinite;
}

.timeline-year {
  color: var(--light);
  font-size: 1rem;
  letter-spacing: 0.14em;
  white-space: nowrap;
}
.timeline-title {
  color: var(--text-strong);
  font-size: 1.05rem;
  letter-spacing: 0.02em;
}
.timeline-caret {
  color: var(--light);
  font-size: 1.5rem;
  line-height: 1;
  transition: transform 0.3s ease;
  width: 1em;
  text-align: center;
}
.timeline-item.open .timeline-caret {
  transform: rotate(45deg);
  color: var(--text-strong);
}

/* Sliding Panel */
.timeline-panel {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.35s var(--ease);
}
.timeline-panel-inner {
  overflow: hidden;
}
.timeline-item.open .timeline-panel {
  grid-template-rows: 1fr;
}
.timeline-panel-inner p {
  padding: 18px 22px 22px;
  color: var(--text-soft);
  font-size: 0.98rem;
}

/* Parts Grid */
.parts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
  gap: 18px;
}
.parts-grid .card-num {
  font-family: var(--mono);
  color: var(--light);
  font-size: 0.85rem;
  letter-spacing: 0.2em;
}

/* Reveal Card */
.card.reveal-item {
  padding: 0;
  overflow: hidden;
}
.reveal-trigger {
  width: 100%;
  border: none;
  background: transparent;
  cursor: pointer;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 14px;
  padding: 22px 24px;
  font-family: var(--mono);
  color: var(--text-soft);
  text-align: left;
  transition: background-color 0.2s, color 0.2s;
}
.reveal-trigger-switch {
  grid-template-columns: auto 1fr auto;
}
.reveal-trigger:hover {
  background-color: var(--tag-bg);
  color: var(--text-strong);
}
.reveal-title {
  color: var(--text-strong);
  font-size: 1.1rem;
  letter-spacing: 0.02em;
  font-weight: 400;
}
.reveal-caret {
  color: var(--light);
  font-size: 1.4rem;
  line-height: 1;
  transition: transform 0.3s ease, color 0.2s;
  width: 1em;
  text-align: center;
}
.reveal-item.open .reveal-caret {
  transform: rotate(45deg);
  color: var(--text-strong);
}
.reveal-item.open {
  border-color: var(--card-hover);
}
.reveal-panel {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.35s var(--ease);
}
.reveal-panel-inner { overflow: hidden; }
.reveal-item.open .reveal-panel { grid-template-rows: 1fr; }
.reveal-panel-inner p {
  padding: 4px 24px 22px;
  color: var(--text-soft);
  font-size: 0.98rem;
}

/* Layouts Grid */
.layouts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin-bottom: 28px;
}
.layout-card {
  position: relative;
  padding: 22px 22px 26px;
}
.layout-pct {
  position: absolute;
  top: 16px;
  right: 18px;
  font-family: var(--mono);
  color: var(--light);
  font-size: 0.85rem;
  letter-spacing: 0.08em;
}
.layout-bar {
  margin-top: 14px;
  height: 6px;
  background: var(--bar-track);
  border-radius: 3px;
  overflow: hidden;
}
.layout-bar > span {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--light), var(--text-soft));
  border-radius: 3px;
  box-shadow: 0 0 8px var(--ambient-a);
}

/* Switch Grid */
.switch-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 18px;
}
.switch-card { padding: 24px; }
.switch-tag {
  display: inline-block;
  font-size: 0.75rem;
  letter-spacing: 0.25em;
  color: var(--light);
  padding: 3px 10px;
  border: 1px solid var(--key-border-hi);
  border-radius: 2px;
  margin-bottom: 0;
  background: var(--tag-bg);
}
.switch-linear  .switch-tag { color: #c25a5a; border-color: rgba(194,90,90,0.45); }
.switch-tactile .switch-tag { color: #a07a40; border-color: rgba(160,122,64,0.45); }
.switch-clicky  .switch-tag { color: #3a6bb0; border-color: rgba(58,107,176,0.45); }
.switch-special .switch-tag { color: var(--light); border-color: var(--key-border-hi); }

/* Sources List */
.sources-list {
  list-style: none;
  display: grid;
  gap: 16px;
  max-width: 840px;
}
.sources-list li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 20px 24px;
  background: linear-gradient(180deg, var(--card-top) 0%, var(--card-bottom) 100%);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  transition: border-color 0.25s;
}
.sources-list li:hover { border-color: var(--card-hover); }
.sources-list a {
  color: var(--text-strong);
  font-size: 1.15rem;
  text-decoration: none;
  border-bottom: 1px dashed var(--key-border-hi);
  padding-bottom: 2px;
  width: fit-content;
  letter-spacing: 0.02em;
}
.sources-list a:hover { color: var(--text-soft); }
.sources-list span { color: var(--light); font-size: 0.95rem; }

/* Footer Note */
.footer-note {
  margin-top: 42px;
  text-align: center;
  font-family: var(--mono);
  font-size: 0.82rem;
  letter-spacing: 0.22em;
  color: var(--light);
  opacity: 0.7;
}

/* ================================================================
   RESPONSIVE BREAKPOINTS
   ================================================================ */

/* Menu Collapse */
@media (max-width: 860px) {
  .nav-keys {
    position: absolute;
    top: calc(100% + 8px);
    right: clamp(20px, 4vw, 48px);
    flex-direction: column;
    gap: 8px;
    background: var(--menu-bg);
    padding: 14px;
    border: 1px solid var(--card-border);
    border-radius: 4px;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    display: none;
    align-items: stretch;
    min-width: 180px;
  }
  .nav-keys.open { display: flex; }

  .menu-toggle { display: inline-block; }

  .key-btn {
    min-width: 100%;
    padding: 10px 14px 12px;
  }

  .nav-left { gap: 10px; }
  .nav-logo { font-size: 1.05rem; letter-spacing: 0.1em; }
  .theme-toggle { min-width: 68px; padding: 8px 10px 10px; }
  .theme-toggle .theme-top { font-size: 0.7rem; }
  .theme-toggle .theme-sub { font-size: 0.85rem; }
}

/* Tablet Tweaks */
@media (max-width: 820px) {
  .two-col { grid-template-columns: 1fr; }
  .timeline-trigger {
    grid-template-columns: auto 1fr auto;
    gap: 12px;
    padding: 14px 18px;
  }
  .timeline-title { font-size: 0.98rem; }
}

/* Phone Tweaks */
@media (max-width: 480px) {
  .intro-prompt { font-size: 0.85rem; }
  .space-bar { letter-spacing: 0.28em; }
  .section-head h2 { font-size: 1.7rem; }
  .sub-heading { font-size: 1.25rem; margin-top: 44px; }
  .timeline { padding-left: 22px; margin-left: 6px; }
  .timeline-item::before { left: -29px; }
  .timeline-trigger {
    grid-template-columns: 1fr auto;
    row-gap: 4px;
  }
  .timeline-year { grid-column: 1 / 2; }
  .timeline-caret { grid-column: 2 / 3; grid-row: 1 / 3; }
  .timeline-title { grid-column: 1 / 2; }

  .nav-logo { font-size: 0.95rem; }
  .theme-toggle { min-width: 60px; }
  .theme-toggle .theme-top { font-size: 0.65rem; }
  .theme-toggle .theme-sub { font-size: 0.78rem; }
}

/* Motion Preference */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}