:root {
  --bg: #111111;
  --surface: #1B1B1B;
  --card: #222222;
  --elevated: #2A2A2A;
  --border: rgba(255, 255, 255, 0.07);
  --border-md: rgba(255, 255, 255, 0.12);
  --text: #FFFFFF;
  --text-2: rgba(255, 255, 255, 0.5);
  --text-3: rgba(255, 255, 255, 0.28);
}

body {
  min-height: 100vh;
}

header {
  height: 56px;
}

.hdr-left {
  gap: 10px;
}

.hdr-school {
  font-size: 1rem;
}

.hdr-title {
  font-size: 0.85rem;
  color: var(--text-2);
}

.content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 28px 80px;
}

/* 안내 카드 */
.intro-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px 32px;
  margin-bottom: 28px;
}

.intro-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.intro-desc {
  font-size: 0.88rem;
  color: var(--text-2);
  line-height: 1.8;
}

.algo-box {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px 20px;
  margin-top: 16px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.78rem;
  color: var(--text-2);
  line-height: 2;
}

.algo-red {
  color: var(--red);
}

.algo-blue {
  color: var(--blue);
}

.algo-comment {
  color: var(--text-3);
  font-style: italic;
}

/* 알고리즘 단계 섹션 */
.algo-section {
  margin-top: 20px;
}

.algo-section-label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.6rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--text-3);
  margin-bottom: 8px;
}

.algo-steps {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.algo-step {
  display: flex;
  gap: 14px;
  align-items: flex-start;
}

.algo-step-num {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: rgba(95, 163, 191, 0.12);
  border: 1px solid rgba(95, 163, 191, 0.3);
  color: var(--blue);
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.68rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-top: 3px;
}

.algo-step-body {
  flex: 1;
}

.algo-step-title {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-2);
  margin-bottom: 6px;
}

/* 결정론적 보장 박스 */
.algo-guarantee {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  background: rgba(195, 0, 52, 0.05);
  border: 1px solid rgba(195, 0, 52, 0.18);
  border-left: 3px solid rgba(195, 0, 52, 0.5);
  border-radius: 10px;
  padding: 14px 16px;
  margin-top: 20px;
  font-size: 0.82rem;
  color: var(--text-2);
  line-height: 1.75;
}

.algo-guarantee-icon {
  font-size: 1rem;
  flex-shrink: 0;
  margin-top: 1px;
}

.algo-guarantee code {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.8em;
  color: var(--blue);
}

/* 폼 */
.form-row {
  display: flex;
  gap: 10px;
  align-items: flex-end;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
  flex: 1;
}

#seed-input {
  background: var(--surface);
  border: 1px solid var(--border-md);
  border-radius: 10px;
  color: var(--red);
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.05rem;
  font-weight: 600;
  padding: 12px 16px;
  outline: none;
  transition: border-color 0.2s;
  width: 100%;
}

#seed-input:focus {
  border-color: var(--blue);
}

#seed-error {
  font-size: 0.78rem;
  color: #F43F5E;
  display: none;
  margin-top: 4px;
}

#verify-btn {
  background: var(--red);
  border: none;
  border-radius: 10px;
  color: #fff;
  font-family: 'Noto Sans KR', sans-serif;
  font-size: 0.95rem;
  font-weight: 700;
  padding: 12px 28px;
  cursor: pointer;
  transition: background 0.15s;
  white-space: nowrap;
}

#verify-btn:hover:not(:disabled) {
  background: #a8002c;
}

#verify-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

/* 결과 */
#result-section {
  display: none;
  margin-top: 32px;
}

#result-banner {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--red);
  border-radius: 10px;
  padding: 14px 18px;
  font-size: 0.88rem;
  color: var(--text-2);
  margin-bottom: 24px;
  line-height: 1.6;
}

#verify-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

@media (max-width: 900px) {
  #verify-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 560px) {
  #verify-grid {
    grid-template-columns: 1fr;
  }
}

.v-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid transparent;
  border-radius: 12px;
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.v-num {
  font-size: 0.95rem;
  font-weight: 700;
}

.v-leader {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--card);
  border-radius: 8px;
  padding: 8px 12px;
  font-size: 0.88rem;
}

.v-name {
  font-weight: 700;
}

.v-member {
  border-radius: 6px;
  background: var(--card);
  overflow: hidden;
}

.v-minfo {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  font-size: 0.88rem;
}

details.v-hash-wrap {
  border-top: 1px solid var(--border);
}

summary.v-hash-toggle {
  padding: 4px 12px;
  font-size: 0.62rem;
  font-family: 'JetBrains Mono', monospace;
  color: var(--text-3);
  cursor: pointer;
  list-style: none;
}

summary.v-hash-toggle::-webkit-details-marker {
  display: none;
}

summary.v-hash-toggle::before {
  content: '▶ ';
}

details[open] summary.v-hash-toggle::before {
  content: '▼ ';
}

.v-hash-val {
  display: block;
  padding: 6px 12px 8px;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.58rem;
  color: var(--blue);
  word-break: break-all;
  line-height: 1.5;
}