/* ============================================================
   BIRTHDAY CAKE — style.css
   Professional, production-grade stylesheet
   ============================================================ */

/* ── Reset & Base ─────────────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* ── Design Tokens ────────────────────────────────────────── */
:root {
  /* Palette */
  --clr-bg:          #0d0a1a;
  --clr-bg-2:        #160d2e;
  --clr-gold:        #e8c97a;
  --clr-gold-light:  #f5e4a8;
  --clr-rose:        #d4607a;
  --clr-rose-light:  #f09ab0;
  --clr-teal:        #4ecdc4;
  --clr-teal-dark:   #2ba89f;
  --clr-lavender:    #a78bfa;
  --clr-cream:       #fef9f0;
  --clr-white:       #ffffff;

  /* Cake tiers */
  --tier-top-a:      #f2c4ce;
  --tier-top-b:      #d4607a;
  --tier-top-shadow: #a03050;
  --tier-mid-a:      #b8a9f5;
  --tier-mid-b:      #7c5fd4;
  --tier-mid-shadow: #5038a8;
  --tier-bot-a:      #f5d99a;
  --tier-bot-b:      #c8960a;
  --tier-bot-shadow: #9a6e00;

  /* Typography */
  --font-display: 'Playfair Display', Georgia, serif;
  --font-body:    'DM Sans', system-ui, sans-serif;

  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 32px;
  --space-xl: 56px;

  /* Timing */
  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
  --ease-out:    cubic-bezier(0.16, 1, 0.3, 1);
}

/* ── Global ───────────────────────────────────────────────── */
html {
  height: 100%;
}

body {
  min-height: 100%;
  background: var(--clr-bg);
  background-image:
    radial-gradient(ellipse 80% 60% at 20% 10%, rgba(167,139,250,0.12) 0%, transparent 60%),
    radial-gradient(ellipse 60% 50% at 80% 90%, rgba(212,96,122,0.10) 0%, transparent 60%);
  font-family: var(--font-body);
  color: var(--clr-white);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  position: relative;
}

/* ── Particle Canvas ──────────────────────────────────────── */
#particleCanvas {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}

/* ── Fireworks Canvas ─────────────────────────────────────── */
#fireworksCanvas {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 50;
  display: none;
}

/* ── Scene ────────────────────────────────────────────────── */
.scene {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-lg);
  padding: var(--space-lg) var(--space-md);
  width: 100%;
  max-width: 440px;
}

/* ── Header ───────────────────────────────────────────────── */
.header {
  text-align: center;
  animation: fadeSlideDown 0.9s var(--ease-out) both;
}

.header__sub {
  font-family: var(--font-body);
  font-weight: 300;
  font-size: 0.75rem;
  letter-spacing: 0.35em;
  text-transform: uppercase;
  color: var(--clr-gold);
  opacity: 0.75;
  margin-bottom: var(--space-xs);
}

.header__title {
  font-family: var(--font-display);
  font-style: italic;
  font-size: clamp(2.4rem, 9vw, 4rem);
  color: var(--clr-gold-light);
  line-height: 1.1;
  text-shadow:
    0 0 40px rgba(232,201,122,0.35),
    0 2px 0 rgba(0,0,0,0.4);
}

/* ── Cake Section ─────────────────────────────────────────── */
.cake {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0;
  animation: fadeSlideUp 1s var(--ease-out) 0.2s both;
}

/* ── Candles ──────────────────────────────────────────────── */
.candles {
  display: flex;
  justify-content: center;
  gap: 20px;
  padding-bottom: 6px;
  position: relative;
  z-index: 10;
}

.candle {
  display: flex;
  flex-direction: column;
  align-items: center;
  position: relative;
}

/* Flame */
.candle__flame-wrap {
  position: relative;
  width: 24px;
  height: 40px;
  transition: opacity 0.4s var(--ease-out);
}

.candle__glow {
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 210, 80, 0.55) 0%, transparent 70%);
  animation: flicker 0.35s ease-in-out infinite alternate;
}

.candle__flame {
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%);
  width: 14px;
  height: 30px;
  border-radius: 50% 50% 30% 30% / 60% 60% 40% 40%;
  background: radial-gradient(ellipse at 50% 85%, #fff 5%, #ffe680 35%, #ffaa00 65%, rgba(255,60,0,0.4) 90%, transparent 100%);
  filter: drop-shadow(0 0 6px #ffd060) drop-shadow(0 0 14px rgba(255,150,0,0.6));
  animation: flicker 0.35s ease-in-out infinite alternate;
}

.candle__flame::after {
  content: '';
  position: absolute;
  bottom: 4px;
  left: 50%;
  transform: translateX(-50%);
  width: 5px;
  height: 10px;
  background: rgba(255, 255, 255, 0.85);
  border-radius: 50%;
  filter: blur(2px);
}

/* Smoke (shown after candle is out) */
.candle__smoke {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  width: 4px;
  pointer-events: none;
  opacity: 0;
}

/* Candle body */
.candle__wick {
  width: 2px;
  height: 9px;
  background: #2a1a00;
  border-radius: 1px;
}

.candle__body {
  width: 16px;
  height: 56px;
  border-radius: 5px 5px 3px 3px;
  position: relative;
  overflow: hidden;
  box-shadow: inset -3px 0 6px rgba(0,0,0,0.25);
}

.candle__body::after {
  content: '';
  position: absolute;
  top: 0;
  left: 28%;
  width: 3px;
  height: 100%;
  background: rgba(255,255,255,0.22);
  border-radius: 2px;
}

/* Candle colour variants */
.candle:nth-child(1) .candle__body { background: linear-gradient(175deg, #f9b4c8 0%, #c73060 100%); }
.candle:nth-child(2) .candle__body { background: linear-gradient(175deg, #b8d9ff 0%, #2060c8 100%); }
.candle:nth-child(3) .candle__body { background: linear-gradient(175deg, #a8f5e0 0%, #10a07a 100%); }
.candle:nth-child(4) .candle__body { background: linear-gradient(175deg, #fde9a2 0%, #c89000 100%); }
.candle:nth-child(5) .candle__body { background: linear-gradient(175deg, #e0b4ff 0%, #8830d0 100%); }

/* Out state */
.candle--out .candle__flame-wrap {
  opacity: 0;
  pointer-events: none;
}

.candle--out .candle__smoke {
  animation: smokeRise 1.8s var(--ease-out) forwards;
}

/* ── Cake Tiers ───────────────────────────────────────────── */
.tier {
  position: relative;
  border-radius: 10px 10px 6px 6px;
  overflow: visible;
}

.tier--top {
  width: 220px;
  height: 72px;
  background: linear-gradient(180deg, var(--tier-top-a) 0%, var(--tier-top-b) 100%);
  box-shadow: 0 5px 0 var(--tier-top-shadow), inset 0 2px 8px rgba(255,255,255,0.25);
}

.tier--mid {
  width: 268px;
  height: 82px;
  background: linear-gradient(180deg, var(--tier-mid-a) 0%, var(--tier-mid-b) 100%);
  box-shadow: 0 5px 0 var(--tier-mid-shadow), inset 0 2px 8px rgba(255,255,255,0.2);
  margin-top: 5px;
}

.tier--bottom {
  width: 316px;
  height: 92px;
  background: linear-gradient(180deg, var(--tier-bot-a) 0%, var(--tier-bot-b) 100%);
  box-shadow: 0 6px 0 var(--tier-bot-shadow), inset 0 2px 8px rgba(255,255,255,0.15);
  margin-top: 5px;
}

/* Frosting drip */
.tier__frosting {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 22px;
  pointer-events: none;
  z-index: 2;
}

.tier__frosting svg {
  width: 100%;
  height: 100%;
}

/* Pearl gems on top tier */
.tier__gems {
  position: absolute;
  top: 22px;
  left: 0;
  right: 0;
  display: flex;
  justify-content: center;
  gap: 14px;
  padding-top: 8px;
}

.gem {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  box-shadow: 0 0 8px currentColor;
}

/* Plate */
.plate {
  margin-top: 6px;
  width: 360px;
  height: 22px;
  background: linear-gradient(180deg, #e8e8e8 0%, #c0bfc0 100%);
  border-radius: 50%;
  box-shadow:
    0 8px 24px rgba(0,0,0,0.5),
    inset 0 2px 4px rgba(255,255,255,0.5);
  position: relative;
}

.plate__shadow {
  position: absolute;
  bottom: -10px;
  left: 10%;
  right: 10%;
  height: 14px;
  background: rgba(0,0,0,0.35);
  border-radius: 50%;
  filter: blur(8px);
}

/* ── Controls ─────────────────────────────────────────────── */
.controls {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
  animation: fadeSlideUp 1s var(--ease-out) 0.45s both;
  width: 100%;
}

/* Volume meter */
.volume-meter {
  width: 220px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}

.volume-meter__track {
  width: 100%;
  height: 8px;
  background: rgba(255,255,255,0.1);
  border-radius: 99px;
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.08);
}

.volume-meter__fill {
  height: 100%;
  width: 0%;
  border-radius: 99px;
  background: linear-gradient(90deg, var(--clr-teal), var(--clr-gold));
  box-shadow: 0 0 10px rgba(78,205,196,0.6);
  transition: width 0.08s linear;
}

.volume-meter__label {
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.4);
  font-weight: 600;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  border: none;
  border-radius: 50px;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.2s, opacity 0.2s;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  transform: none !important;
}

.btn--primary {
  padding: 14px 36px;
  background: linear-gradient(135deg, var(--clr-rose) 0%, var(--clr-lavender) 100%);
  color: var(--clr-white);
  box-shadow: 0 4px 24px rgba(212,96,122,0.45);
}

.btn--primary:not(:disabled):hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 32px rgba(212,96,122,0.6);
}

.btn--primary:not(:disabled):active {
  transform: translateY(0) scale(0.97);
}

.btn--ghost {
  padding: 11px 28px;
  background: transparent;
  color: rgba(255,255,255,0.65);
  border: 1.5px solid rgba(255,255,255,0.2);
}

.btn--ghost:hover {
  border-color: var(--clr-gold);
  color: var(--clr-gold);
  transform: translateY(-2px);
}

.btn__icon {
  font-size: 1.1rem;
}

/* Hint text */
.controls__hint {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.35);
  text-align: center;
  max-width: 280px;
  line-height: 1.6;
}

/* ── Celebration Overlay ──────────────────────────────────── */
.celebration {
  position: fixed;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-md);
  background: rgba(13,10,26,0.88);
  backdrop-filter: blur(12px);
  z-index: 100;
  animation: fadeIn 0.6s var(--ease-out) both;
}

.celebration[hidden] {
  display: none;
}

.celebration__emoji {
  font-size: 5rem;
  animation: bounceIn 0.8s var(--ease-spring) both;
  line-height: 1;
}

.celebration__text {
  font-family: var(--font-display);
  font-style: italic;
  font-size: clamp(2rem, 9vw, 3.6rem);
  color: var(--clr-gold-light);
  text-shadow: 0 0 40px rgba(232,201,122,0.5);
  animation: bounceIn 0.8s var(--ease-spring) 0.15s both;
}

/* ── Confetti pieces (injected by JS) ─────────────────────── */
.confetti {
  position: fixed;
  top: -16px;
  pointer-events: none;
  z-index: 200;
  border-radius: 2px;
  animation: confettiFall linear forwards;
}

/* ── Keyframes ────────────────────────────────────────────── */
@keyframes flicker {
  0%   { transform: translateX(-50%) scaleX(1)    scaleY(1)    rotate(-2deg); }
  100% { transform: translateX(-50%) scaleX(0.82) scaleY(1.09) rotate(2deg); }
}

@keyframes smokeRise {
  0%   { opacity: 0.9; transform: translateX(-50%) translateY(0)    scaleX(1); }
  40%  { opacity: 0.6; transform: translateX(-58%) translateY(-20px) scaleX(1.5); }
  100% { opacity: 0;   transform: translateX(-42%) translateY(-56px) scaleX(2.5); }
}

@keyframes fadeSlideDown {
  from { opacity: 0; transform: translateY(-20px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeSlideUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes bounceIn {
  from { opacity: 0; transform: scale(0.5) rotate(-4deg); }
  to   { opacity: 1; transform: scale(1) rotate(0deg); }
}

@keyframes confettiFall {
  0%   { transform: translateY(0)     rotate(0deg);   opacity: 1; }
  80%  { opacity: 1; }
  100% { transform: translateY(105vh) rotate(720deg); opacity: 0; }
}

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 380px) {
  .tier--top    { width: 180px;  height: 60px; }
  .tier--mid    { width: 220px;  height: 70px; }
  .tier--bottom { width: 264px;  height: 78px; }
  .plate        { width: 300px; }
  .candles      { gap: 14px; }
}