@import url('https://fonts.googleapis.com/css2?family=DM+Serif+Display:ital@0;1&family=Space+Mono:ital,wght@0,400;0,700;1,400&display=swap');

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

:root {
  --ink: #1a1a1a;
  --paper: #f5f2ee;
  --paper2: #eee9e2;
  --pink: #e8638c;
  --pink2: #f5a8c0;
  --pink3: #fce8f0;
  --pink4: #c73d6a;
  --mono: 'Space Mono', monospace;
  --serif: 'DM Serif Display', serif;

  --s3-bg: #f8f7f4;
  --s3-card: #ffffff;
  --s3-border: #e0dcd6;
  --s3-label: #888580;
  --s3-ink: #1a1a1a;
  --s3-accent: #e8638c;
  --s3-input-bg: #f2f0ec;
  --s3-result-bg: #f5f2ee;
  --s3-muted: #b0aba5;
}

html, body {
  height: 100%;
  width: 100%;
  overflow: hidden;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--mono);
}

/* ============================================================
   SCREENS
   ============================================================ */

.screen {
  position: fixed;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 2rem;
  transition: opacity 0.3s;
}

#screen-1 {
  background: var(--paper);
  z-index: 10;
}

#screen-2 {
  background: var(--paper);
  z-index: 5;
  opacity: 0;
  pointer-events: none;
  overflow-y: auto;
}

#screen-3 {
  background: var(--s3-bg);
  z-index: 4;
  opacity: 0;
  pointer-events: none;
  overflow-y: auto;
}

/* ============================================================
   WIPE OVERLAY
   ============================================================ */

#wipe-overlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  pointer-events: none;
  clip-path: inset(0 0 100% 0);
  background: var(--pink3);
}

#wipe-overlay.wiping {
  animation: wipeDown 0.7s cubic-bezier(0.77, 0, 0.18, 1) forwards;
}

#wipe-overlay.wiping-s3 {
  background: #f0ede8;
  animation: wipeDown 0.7s cubic-bezier(0.77, 0, 0.18, 1) forwards;
}

@keyframes wipeDown {
  0%   { clip-path: inset(0 0 100% 0); }
  40%  { clip-path: inset(0 0 0% 0); }
  100% { clip-path: inset(0 0 0% 0); }
}

/* ============================================================
   SCREEN 1
   ============================================================ */

.greeting {
  font-family: var(--serif);
  font-size: clamp(2.2rem, 6vw, 4rem);
  text-align: center;
  line-height: 1.2;
  color: var(--ink);
}

.subtext {
  font-family: var(--mono);
  font-size: clamp(0.75rem, 2vw, 1rem);
  color: #555;
  text-align: center;
  margin-top: 0.5rem;
  line-height: 1.6;
}

.tagline {
  font-family: var(--serif);
  font-size: clamp(1rem, 3vw, 1.6rem);
  text-align: center;
  margin-top: 1.5rem;
  color: var(--ink);
}

.tagline .highlight {
  color: var(--pink);
  font-style: italic;
}

.btn-row {
  display: flex;
  gap: 1rem;
  margin-top: 2rem;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  font-family: var(--mono);
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  border: 2px solid var(--ink);
  background: transparent;
  color: var(--ink);
  padding: 0.7rem 2rem;
  cursor: pointer;
  transition: background 0.15s, color 0.15s, transform 0.1s;
  text-transform: lowercase;
}

.btn:hover { background: var(--ink); color: var(--paper); }
.btn:active { transform: scale(0.97); }

.btn-yes { border-color: var(--pink); color: var(--pink); }
.btn-yes:hover { background: var(--pink); color: white; }
.btn-no { font-size: 0.8rem; border-style: dashed; }

/* ============================================================
   SCREEN 2
   ============================================================ */

#screen-2 .s2-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
  max-width: 580px;
  text-align: center;
  animation: fadeInUp 0.5s 0.65s both;
}

#screen-2 .s2-label {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--pink);
  background: var(--pink3);
  padding: 4px 14px;
  display: inline-block;
}

#screen-2 .s2-body {
  font-family: var(--serif);
  font-size: clamp(1.1rem, 3vw, 1.5rem);
  line-height: 1.5;
  color: var(--ink);
}

#screen-2 .s2-body em { color: var(--pink); font-style: italic; }

#screen-2 .s2-caveat {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: #777;
  line-height: 1.8;
  border-left: 2px solid var(--pink2);
  padding-left: 0.8rem;
  text-align: left;
}

#screen-2 .s2-image {
  width: min(100%, 380px);
  border: 2px solid var(--ink);
  display: block;
  margin: 0 auto;
  background: var(--paper2);
}

#screen-2 .s2-image img { width: 100%; display: block; }

#screen-2 .s2-image .img-placeholder {
  width: 100%;
  aspect-ratio: 4/3;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--mono);
  font-size: 0.75rem;
  color: #aaa;
  background: repeating-linear-gradient(
    45deg,
    var(--paper2), var(--paper2) 6px,
    var(--pink3) 6px, var(--pink3) 12px
  );
}

#screen-2 .s2-next {
  font-family: var(--mono);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  border: 2px solid var(--ink);
  background: transparent;
  color: var(--ink);
  padding: 0.65rem 2.2rem;
  cursor: pointer;
  text-transform: lowercase;
  transition: background 0.15s, color 0.15s, transform 0.1s;
  margin-top: 0.5rem;
}

#screen-2 .s2-next:hover { background: var(--ink); color: var(--paper); }
#screen-2 .s2-next:active { transform: scale(0.97); }

/* ============================================================
   SCREEN 3 — height converter (secretly a roast machine)
   ============================================================ */

#screen-3 .s3-inner {
  width: 100%;
  max-width: 480px;
  animation: fadeInUp 0.5s 0.65s both;
}

.sk-header {
  margin-bottom: 2rem;
  text-align: left;
}

.sk-header h2 {
  font-family: var(--serif);
  font-size: 1.8rem;
  font-weight: 400;
  color: var(--s3-ink);
  letter-spacing: -0.02em;
  margin-bottom: 0.3rem;
}

.sk-header p {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--s3-label);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.sk-card {
  background: var(--s3-card);
  border: 1px solid var(--s3-border);
  padding: 2rem;
  margin-bottom: 1rem;
}

.sk-field-label {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--s3-label);
  display: block;
  margin-bottom: 0.6rem;
}

.sk-input-row {
  display: flex;
  gap: 0.75rem;
  align-items: stretch;
}

.sk-input {
  flex: 1;
  font-family: var(--mono);
  font-size: 1rem;
  padding: 0.75rem 1rem;
  background: var(--s3-input-bg);
  border: 1px solid var(--s3-border);
  color: var(--s3-ink);
  outline: none;
  transition: border-color 0.15s;
}

.sk-input:focus { border-color: var(--s3-ink); }

.sk-input::placeholder { color: var(--s3-muted); }

.sk-submit {
  font-family: var(--mono);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: lowercase;
  background: var(--s3-ink);
  color: var(--s3-bg);
  border: none;
  padding: 0.75rem 1.4rem;
  cursor: pointer;
  transition: opacity 0.15s, transform 0.1s;
  white-space: nowrap;
}

.sk-submit:hover { opacity: 0.85; }
.sk-submit:active { transform: scale(0.97); }

.sk-hint {
  font-family: var(--mono);
  font-size: 0.65rem;
  color: var(--s3-muted);
  margin-top: 0.6rem;
  letter-spacing: 0.03em;
}

/* result area */
.sk-result-area {
  margin-top: 1.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--s3-border);
  min-height: 3.5rem;
}

.sk-result-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 0.5rem;
}

.sk-result-key {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--s3-label);
}

.sk-result-val {
  font-family: var(--serif);
  font-size: 1.3rem;
  color: var(--s3-ink);
}

.sk-verdict {
  margin-top: 1rem;
  padding: 0.9rem 1rem;
  background: var(--s3-result-bg);
  border-left: 2px solid var(--s3-accent);
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--s3-ink);
  line-height: 1.6;
  opacity: 0;
  transform: translateY(6px);
  transition: opacity 0.35s, transform 0.35s;
}

.sk-verdict.visible {
  opacity: 1;
  transform: translateY(0);
}

.sk-verdict em {
  color: var(--s3-accent);
  font-style: normal;
}

/* denial row */
.sk-denial {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 1.5rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--s3-border);
  opacity: 0;
  transition: opacity 0.4s 0.2s;
}

.sk-denial.visible { opacity: 1; }

.sk-denial-text {
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--s3-label);
  line-height: 1.6;
  flex: 1;
}

.sk-denial-text em {
  color: var(--s3-accent);
  font-style: normal;
}

.sk-deny-btn {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.05em;
  background: transparent;
  border: 1px solid var(--s3-border);
  color: var(--s3-label);
  padding: 0.5rem 1rem;
  cursor: pointer;
  white-space: nowrap;
  transition: border-color 0.15s, color 0.15s, transform 0.1s;
  text-transform: lowercase;
}

.sk-deny-btn:hover { border-color: var(--s3-ink); color: var(--s3-ink); }
.sk-deny-btn:active { transform: scale(0.97); }

.sk-footer-note {
  font-family: var(--mono);
  font-size: 0.62rem;
  color: var(--s3-muted);
  text-align: center;
  margin-top: 1.5rem;
  letter-spacing: 0.04em;
}

/* ============================================================
   SHARED ANIMATIONS
   ============================================================ */

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(18px); }
  to   { opacity: 1; transform: translateY(0); }
}

.shake-active {
  animation: stupidShake 0.4s cubic-bezier(0.36, 0.07, 0.19, 0.97) both;
}

@keyframes stupidShake {
  0%   { transform: translate(0,0) rotate(0deg); }
  20%  { transform: translate(-6px,2px) rotate(-1.5deg); }
  40%  { transform: translate(6px,-3px) rotate(1.5deg); }
  60%  { transform: translate(-4px,2px) rotate(-0.8deg); }
  80%  { transform: translate(4px,-1px) rotate(0.8deg); }
  100% { transform: translate(0,0) rotate(0); }
}

.jittering {
  animation: jitter 0.12s ease-in-out infinite;
}

@keyframes jitter {
  0%,100% { transform: translate(0,0) rotate(0deg); }
  10%  { transform: translate(-3px,2px) rotate(-1deg); }
  20%  { transform: translate(4px,-3px) rotate(1.5deg); }
  30%  { transform: translate(-5px,1px) rotate(-2deg); }
  40%  { transform: translate(3px,4px) rotate(1deg); }
  50%  { transform: translate(-4px,-2px) rotate(-1.5deg); }
  60%  { transform: translate(5px,3px) rotate(2deg); }
  70%  { transform: translate(-3px,-4px) rotate(-1deg); }
  80%  { transform: translate(2px,5px) rotate(1.5deg); }
  90%  { transform: translate(-5px,-1px) rotate(-2deg); }
}

.exploding {
  animation: explode 0.35s ease-in forwards;
}

@keyframes explode {
  0%   { transform: scale(1); opacity: 1; }
  40%  { transform: scale(2.5); opacity: 0.6; }
  100% { transform: scale(0); opacity: 0; }
}

.rainbow {
  animation: colorFlicker 0.08s steps(1) infinite;
}

@keyframes colorFlicker {
  0%   { color: #e8638c; border-color: #e8638c; }
  10%  { color: #f7b731; border-color: #f7b731; }
  20%  { color: #26de81; border-color: #26de81; }
  30%  { color: #45aaf2; border-color: #45aaf2; }
  40%  { color: #fd9644; border-color: #fd9644; }
  50%  { color: #a55eea; border-color: #a55eea; }
  60%  { color: #2bcbba; border-color: #2bcbba; }
  70%  { color: #ff6b81; border-color: #ff6b81; }
  80%  { color: #ffd32a; border-color: #ffd32a; }
  90%  { color: #0be881; border-color: #0be881; }
  100% { color: #e8638c; border-color: #e8638c; }
}

.confetti-piece {
  position: fixed;
  top: -60px;
  pointer-events: none;
  z-index: 9999;
  animation: confettiFall linear forwards;
}

@keyframes confettiFall {
  0%   { transform: translateY(0) rotate(0deg); opacity: 1; }
  80%  { opacity: 1; }
  100% { transform: translateY(110vh) rotate(720deg); opacity: 0; }
}

@media (max-width: 480px) {
  .sk-input-row { flex-direction: column; }
  .greeting { font-size: clamp(1.8rem, 7vw, 3rem); }
}

/* ============================================================
   SCREEN 4 — PHYSICS BF SIMULATOR
   ============================================================ */

#screen-4 {
  background: var(--paper);
  z-index: 3;
  opacity: 0;
  pointer-events: none;
  overflow-y: auto;
}

#screen-4 .s4-inner {
  width: 100%;
  max-width: 520px;
  animation: fadeInUp 0.5s 0.65s both;
}

.s4-header {
  margin-bottom: 1.8rem;
  text-align: left;
}

.s4-header h2 {
  font-family: var(--serif);
  font-size: 1.8rem;
  font-weight: 400;
  color: var(--ink);
  letter-spacing: -0.02em;
  margin-bottom: 0.3rem;
}

.s4-header p {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: #999;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* tab bar */
.s4-tabs {
  display: flex;
  gap: 0;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid #ddd;
}

.s4-tab {
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: lowercase;
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  color: #aaa;
  padding: 0.6rem 1.2rem;
  cursor: pointer;
  margin-bottom: -1px;
  transition: color 0.15s, border-color 0.15s;
}

.s4-tab:hover { color: var(--ink); }

.s4-tab.active {
  color: var(--ink);
  border-bottom-color: var(--pink);
}

/* tab panes */
.s4-pane { display: none; }
.s4-pane.active { display: block; }

/* shared card */
.s4-card {
  background: #fff;
  border: 1px solid #e0dcd6;
  padding: 1.5rem;
  margin-bottom: 1rem;
}

.s4-field-label {
  font-family: var(--mono);
  font-size: 0.65rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #999;
  display: block;
  margin-bottom: 0.8rem;
}

/* output boxes */
.s4-output {
  font-family: var(--mono);
  font-size: 0.78rem;
  line-height: 1.7;
  color: var(--ink);
  background: var(--paper);
  border: 1px solid #e0dcd6;
  padding: 1rem;
  min-height: 3.5rem;
  margin-top: 1rem;
}

.s4-output em { color: var(--pink); font-style: normal; }

/* action buttons */
.s4-btn {
  font-family: var(--mono);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: lowercase;
  background: var(--ink);
  color: var(--paper);
  border: none;
  padding: 0.65rem 1.4rem;
  cursor: pointer;
  transition: opacity 0.15s, transform 0.1s;
}

.s4-btn:hover { opacity: 0.8; }
.s4-btn:active { transform: scale(0.97); }

.s4-btn-ghost {
  background: transparent;
  color: var(--ink);
  border: 1px solid #ccc;
}

.s4-btn-ghost:hover { border-color: var(--ink); }

.s4-btn-row {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: 0.8rem;
}

/* loading bar */
.s4-bar-wrap {
  margin-top: 1rem;
  display: none;
}

.s4-bar-track {
  background: #eee;
  height: 3px;
  width: 100%;
}

.s4-bar-fill {
  height: 3px;
  width: 0%;
  background: var(--pink);
  transition: width 0.1s linear;
}

.s4-bar-label {
  font-family: var(--mono);
  font-size: 0.62rem;
  color: #aaa;
  margin-top: 0.4rem;
  letter-spacing: 0.04em;
}

/* equation display */
.s4-equation {
  font-family: var(--mono);
  font-size: 1.1rem;
  text-align: center;
  padding: 1.2rem;
  background: var(--paper);
  border: 1px solid #e0dcd6;
  margin: 1rem 0;
  letter-spacing: 0.04em;
  color: var(--ink);
}

/* pickup line */
.s4-pickup {
  font-family: var(--serif);
  font-size: 1rem;
  font-style: italic;
  line-height: 1.5;
  color: var(--ink);
  padding: 1rem 0 0;
  border-top: 1px solid #e0dcd6;
  margin-top: 1rem;
  display: none;
}

.s4-pickup em { color: var(--pink); font-style: italic; }

/* hatred counter */
.s4-counter {
  font-family: var(--mono);
  font-size: 0.65rem;
  color: #aaa;
  margin-top: 0.5rem;
  letter-spacing: 0.06em;
}

.s4-footer-note {
  font-family: var(--mono);
  font-size: 0.62rem;
  color: #bbb;
  text-align: center;
  margin-top: 1.2rem;
  letter-spacing: 0.04em;
}