/* ===== RESET & BASE ===== */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg: #0f0f14;
  --bg-alt: #16161e;
  --surface: #1e1e2a;
  --surface-hover: #282838;
  --text: #e8e8f0;
  --text-dim: #9999aa;
  --accent: #ff6b2b;
  --accent-glow: #ff6b2b55;
  --uran-green: #39ff14;
  --uran-dim: #39ff1433;
  --danger: #ff3b3b;
  --radius: 16px;
}

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  overflow-x: hidden;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ===== HERO ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: radial-gradient(ellipse at 50% 30%, #1a1030 0%, var(--bg) 70%);
  padding: 2rem;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: repeating-conic-gradient(from 0deg at 50% 50%, transparent 0deg, transparent 3deg, #ff6b2b08 3deg, #ff6b2b08 6deg);
  animation: spin 120s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

.hero-inner { position: relative; z-index: 1; }

.hero-emoji {
  font-size: 5rem;
  display: block;
  margin-bottom: 1rem;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.15) rotate(5deg); }
}

.hero h1 {
  font-size: clamp(2.2rem, 6vw, 4rem);
  font-weight: 800;
  background: linear-gradient(135deg, #ff6b2b, #ff9a5c);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.5rem;
}

.subtitle {
  font-size: clamp(1rem, 2.5vw, 1.35rem);
  color: var(--text-dim);
  margin-bottom: 2rem;
}

/* ===== BUTTON ===== */
.btn {
  display: inline-block;
  padding: 0.75rem 1.8rem;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 999px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  text-decoration: none;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px var(--accent-glow);
  text-decoration: none;
}

/* ===== SECTIONS ===== */
.section {
  padding: 5rem 1.5rem;
  max-width: 1100px;
  margin: 0 auto;
}

.section.alt { background: var(--bg-alt); }
.section > h2 {
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  text-align: center;
  margin-bottom: 0.5rem;
}

.section-desc {
  text-align: center;
  color: var(--text-dim);
  margin-bottom: 2.5rem;
  font-size: 1.05rem;
}

/* ===== CARD GRID ===== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.card {
  background: var(--surface);
  border: 1px solid #ffffff10;
  border-radius: var(--radius);
  padding: 2rem 1.5rem;
  transition: transform 0.3s, box-shadow 0.3s, border-color 0.3s;
  opacity: 0;
  transform: translateY(30px);
  animation: fadeInUp 0.6s forwards;
}

.card:nth-child(1) { animation-delay: 0s; }
.card:nth-child(2) { animation-delay: 0.1s; }
.card:nth-child(3) { animation-delay: 0.2s; }
.card:nth-child(4) { animation-delay: 0.3s; }
.card:nth-child(5) { animation-delay: 0.4s; }
.card:nth-child(6) { animation-delay: 0.5s; }

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

.card:hover {
  transform: translateY(-6px);
  box-shadow: 0 8px 32px #ff6b2b22;
  border-color: var(--accent);
}

.card-icon {
  font-size: 2.5rem;
  margin-bottom: 0.8rem;
}

.card h3 {
  font-size: 1.15rem;
  margin-bottom: 0.5rem;
  color: #fff;
}

.card p { color: var(--text-dim); font-size: 0.95rem; }

/* ===== CALCULATOR ===== */
.calc-box {
  max-width: 420px;
  margin: 0 auto;
  background: var(--surface);
  border-radius: var(--radius);
  padding: 2rem;
  border: 1px solid #ffffff10;
}

.calc-row {
  margin-bottom: 1rem;
}

.calc-row label {
  display: block;
  margin-bottom: 0.3rem;
  font-weight: 600;
  font-size: 0.95rem;
}

.calc-row select,
.calc-row input {
  width: 100%;
  padding: 0.65rem 0.8rem;
  border-radius: 10px;
  border: 1px solid #ffffff20;
  background: var(--bg);
  color: var(--text);
  font-size: 1rem;
  outline: none;
  transition: border-color 0.2s;
}

.calc-row select:focus,
.calc-row input:focus {
  border-color: var(--accent);
}

#calc-btn {
  width: 100%;
  margin-top: 0.5rem;
}

.calc-result {
  margin-top: 1.2rem;
  text-align: center;
  font-size: 1.1rem;
  min-height: 2rem;
  color: var(--uran-green);
  font-weight: 600;
}

/* ===== URAN SECTION ===== */
.uran-section {
  background: linear-gradient(180deg, var(--bg) 0%, #0a1a0a 100%);
  text-align: center;
}

.uran-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
  text-align: left;
}

.uran-card {
  background: #0d1a0d;
  border: 1px solid var(--uran-dim);
  border-radius: var(--radius);
  padding: 2rem 1.5rem;
  position: relative;
  overflow: hidden;
  transition: border-color 0.3s, box-shadow 0.3s;
}

.uran-card:hover {
  border-color: var(--uran-green);
  box-shadow: 0 0 30px #39ff1422;
}

.uran-number {
  position: absolute;
  top: -10px;
  right: -5px;
  font-size: 6rem;
  font-weight: 900;
  color: #39ff1415;
  line-height: 1;
  pointer-events: none;
  user-select: none;
}

.uran-card h3 {
  color: var(--uran-green);
  margin-bottom: 0.5rem;
  font-size: 1.1rem;
}

.uran-card p { color: var(--text-dim); font-size: 0.95rem; }

.fun-fact {
  margin-top: 3rem;
  background: #1a1a2e;
  border-left: 4px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 1.5rem 2rem;
  text-align: left;
  max-width: 750px;
  margin-left: auto;
  margin-right: auto;
  color: var(--text-dim);
}

.fun-fact strong { color: #fff; }

/* ===== CHECKLIST ===== */
.checklist-box {
  max-width: 520px;
  margin: 0 auto;
  background: var(--surface);
  border-radius: var(--radius);
  padding: 2rem;
  border: 1px solid #ffffff10;
}

.check-item {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  padding: 0.65rem 0;
  border-bottom: 1px solid #ffffff08;
  font-size: 1.05rem;
  cursor: pointer;
  transition: color 0.2s;
}

.check-item:last-child { border-bottom: none; }

.check-item input[type="checkbox"] {
  width: 20px;
  height: 20px;
  accent-color: var(--accent);
  cursor: pointer;
  flex-shrink: 0;
}

.check-item.checked {
  color: var(--uran-green);
}

/* ===== FOOTER ===== */
.footer {
  text-align: center;
  padding: 3rem 1.5rem;
  color: var(--text-dim);
  border-top: 1px solid #ffffff10;
}

.footer .small {
  font-size: 0.8rem;
  margin-top: 0.5rem;
  color: #666;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 640px) {
  .card-grid, .uran-grid { grid-template-columns: 1fr; }
  .hero-emoji { font-size: 3.5rem; }
}