:root {
  --bg: #f4f6f9;
  --bg-elevated: #ffffff;
  --border: #e2e8f0;
  --text-primary: #0f172a;
  --text-secondary: #64748b;
  --text-muted: #94a3b8;
  --accent: #0891b2;
  --accent-soft: #e0f7fa;
  --success: #16a34a;
  --success-soft: #dcfce7;
  --danger: #dc2626;
  --danger-soft: #fee2e2;
  --custom: #7c3aed;
  --custom-soft: #ede9fe;
  --row-hover: #f1f5f9;
  --shadow: 0 1px 2px rgba(15, 23, 42, 0.06), 0 1px 1px rgba(15, 23, 42, 0.04);
  --mono: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
}

:root[data-theme="dark"] {
  --bg: #0a0e1a;
  --bg-elevated: #0f1729;
  --border: #1e293b;
  --text-primary: #e2e8f0;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent: #22d3ee;
  --accent-soft: rgba(34, 211, 238, 0.12);
  --success: #4ade80;
  --success-soft: rgba(74, 222, 128, 0.12);
  --danger: #f87171;
  --danger-soft: rgba(248, 113, 113, 0.12);
  --custom: #a78bfa;
  --custom-soft: rgba(167, 139, 250, 0.14);
  --row-hover: #131c31;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text-primary);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

.app {
  max-width: 1100px;
  margin: 0 auto;
  padding: 24px 20px 64px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: var(--shadow);
}

.mono {
  font-family: var(--mono);
}

.hidden {
  display: none !important;
}

/* Header */
.header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 4px 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-icon {
  width: 40px;
  height: 40px;
  object-fit: contain;
  flex-shrink: 0;
}

.brand-text h1 {
  margin: 0;
  font-size: 18px;
  letter-spacing: 0.06em;
}

.brand-text span {
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

.theme-toggle {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  cursor: pointer;
  font-size: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.theme-toggle:hover {
  background: var(--row-hover);
}

/* Chain tip */
.chain-tip {
  display: flex;
  gap: 40px;
  padding: 18px 22px;
  flex-wrap: wrap;
}

.chain-tip-item {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.chain-tip-item.grow {
  flex: 1;
  min-width: 260px;
}

.label {
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
  font-weight: 600;
}

.value-lg {
  font-size: 28px;
  font-weight: 700;
}

.hash-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

.hash-row .mono {
  font-size: 14px;
  word-break: break-all;
}

.copy-btn {
  border: none;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 14px;
  padding: 2px 4px;
  border-radius: 6px;
  flex-shrink: 0;
}

.copy-btn:hover {
  background: var(--row-hover);
  color: var(--accent);
}

/* Search */
.search {
  padding: 4px;
}

#search-form {
  display: flex;
  align-items: center;
}

#search-input {
  flex: 1;
  border: none;
  background: transparent;
  padding: 14px 16px;
  font-size: 14px;
  color: var(--text-primary);
  outline: none;
}

#search-input::placeholder {
  color: var(--text-muted);
}

#search-form button[type="submit"] {
  border: none;
  background: transparent;
  cursor: pointer;
  font-size: 15px;
  padding: 10px 16px;
  color: var(--text-secondary);
}

/* Search result / block detail shared bits */
.search-result {
  padding: 16px 18px;
}

.search-result-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.search-result-header h3 {
  margin: 0;
  font-size: 14px;
  letter-spacing: 0.06em;
}

.close-btn {
  border: none;
  background: transparent;
  cursor: pointer;
  font-size: 14px;
  color: var(--text-secondary);
  padding: 4px 8px;
  border-radius: 6px;
}

.close-btn:hover {
  background: var(--row-hover);
}

.loading,
.error {
  padding: 16px;
  font-size: 13px;
  color: var(--text-secondary);
}

.error {
  color: var(--danger);
}

/* Blocks list */
.blocks {
  padding: 0;
  overflow: hidden;
}

.blocks-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 18px 12px;
}

.blocks-header h2 {
  margin: 0;
  font-size: 14px;
  letter-spacing: 0.04em;
}

.blocks-header .muted {
  color: var(--text-secondary);
  font-weight: 400;
}

.badge {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 4px 10px;
  border-radius: 999px;
}

.blocks-columns,
.block-summary {
  display: grid;
  grid-template-columns: 24px 90px 1fr 90px 170px;
  gap: 12px;
  align-items: center;
  padding: 10px 18px;
}

.blocks-columns {
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.blocks-list {
  max-height: 640px;
  overflow-y: auto;
}

.block-row {
  border-bottom: 1px solid var(--border);
}

.block-row:last-child {
  border-bottom: none;
}

.block-summary {
  cursor: pointer;
}

.block-summary:hover {
  background: var(--row-hover);
}

.block-row.expanded .block-summary {
  background: var(--accent-soft);
}

.chevron {
  transition: transform 0.15s ease;
  color: var(--text-secondary);
  font-size: 14px;
}

.block-row.expanded > .block-summary .chevron {
  transform: rotate(90deg);
  color: var(--accent);
}

.col-height {
  font-weight: 600;
}

.col-hash {
  font-size: 13px;
  color: var(--text-primary);
}

.col-txcount {
  font-size: 13px;
  color: var(--accent);
  font-weight: 600;
}

.col-time {
  font-size: 13px;
  color: var(--text-secondary);
}

.block-detail {
  padding: 16px 18px 20px 46px;
  background: var(--bg);
  border-top: 1px solid var(--border);
}

.block-detail-header {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 14px;
  margin-bottom: 16px;
}

.block-detail-header .value {
  font-size: 14px;
  font-weight: 600;
  margin-top: 2px;
  word-break: break-all;
}

.tx-list h3,
.io-col h4 {
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--text-secondary);
  margin: 0 0 8px;
}

.tx-row {
  border: 1px solid var(--border);
  border-radius: 8px;
  margin-bottom: 8px;
  background: var(--bg-elevated);
  overflow: hidden;
}

.tx-summary {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  cursor: pointer;
}

.tx-summary:hover {
  background: var(--row-hover);
}

.tx-id {
  font-size: 13px;
  flex: 1;
}

.tx-amount {
  font-size: 13px;
  font-weight: 600;
}

.badge-coinbase {
  background: var(--success-soft);
  color: var(--success);
}

.tx-detail {
  padding: 14px 14px 16px;
  border-top: 1px solid var(--border);
}

.tx-meta {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 4px 12px;
  font-size: 13px;
  margin-bottom: 14px;
  align-items: center;
}

.tx-meta .label {
  align-self: start;
  padding-top: 2px;
}

.tx-meta .value.mono {
  word-break: break-all;
}

.tx-detail-grid {
  display: grid;
  gap: 16px;
}

.io-col {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.io-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-size: 13px;
  padding: 6px 10px;
  background: var(--bg);
  border-radius: 6px;
}

.io-addr {
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 0;
}

.io-row .amount {
  font-weight: 600;
  white-space: nowrap;
}

.addr-tag {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 2px 7px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  white-space: nowrap;
  flex-shrink: 0;
}

.addr-tag-burn {
  background: var(--danger-soft);
  color: var(--danger);
}

.addr-tag-custom {
  background: var(--custom-soft);
  color: var(--custom);
}

/* Tags modal */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  z-index: 50;
}

.modal {
  width: 100%;
  max-width: 480px;
  max-height: 80vh;
  overflow-y: auto;
  padding: 20px 22px;
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}

.modal-header h3 {
  margin: 0;
  font-size: 14px;
  letter-spacing: 0.06em;
}

.modal-desc {
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.5;
  margin: 0 0 16px;
}

.modal-desc strong {
  color: var(--text-primary);
}

.tag-form {
  display: flex;
  gap: 8px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.tag-form input {
  flex: 1;
  min-width: 140px;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 10px;
  font-size: 13px;
  background: var(--bg);
  color: var(--text-primary);
}

.tag-form button {
  border: none;
  background: var(--accent);
  color: #fff;
  padding: 8px 16px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 13px;
  font-weight: 600;
}

.tag-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.tag-list-row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 13px;
}

.tag-list-row .mono {
  flex: 1;
  min-width: 0;
}

.tag-list-label {
  font-weight: 600;
  color: var(--custom);
}

.tag-remove-btn {
  border: none;
  background: transparent;
  cursor: pointer;
  font-size: 13px;
  color: var(--text-secondary);
  padding: 4px 6px;
  border-radius: 6px;
}

.tag-remove-btn:hover {
  background: var(--danger-soft);
  color: var(--danger);
}

.tag-list-empty {
  font-size: 12px;
  color: var(--text-muted);
  padding: 8px 0;
}

.coinbase-row {
  color: var(--text-secondary);
  font-style: italic;
}

@media (min-width: 720px) {
  .tx-detail-grid {
    grid-template-columns: 1fr 1fr;
    grid-template-areas:
      "meta meta"
      "in out";
  }
  .tx-meta {
    grid-area: meta;
    grid-template-columns: max-content 1fr;
  }
  .io-col:nth-of-type(1) {
    grid-area: in;
  }
  .io-col:nth-of-type(2) {
    grid-area: out;
  }
}

/* Footer */
.site-footer {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 40;
  background: var(--bg-elevated);
  border-top: 1px solid var(--border);
  padding: 5px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 2px 16px;
  font-size: 10px;
  line-height: 1.4;
  color: var(--text-muted);
}

.site-footer a {
  color: inherit;
}

/* Mobile */
@media (max-width: 640px) {
  .chain-tip {
    gap: 20px;
  }

  .blocks-columns {
    display: none;
  }

  .block-summary {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 4px 10px;
  }

  .block-summary .chevron {
    order: 1;
  }

  .block-summary .col-height {
    order: 2;
  }

  .block-summary .col-txcount {
    order: 3;
    margin-left: auto;
    font-size: 12px;
  }

  .block-summary .col-hash {
    order: 4;
    flex-basis: 100%;
    margin-left: 30px;
    font-size: 12px;
  }

  .block-summary .col-time {
    order: 5;
    flex-basis: 100%;
    margin-left: 30px;
    font-size: 12px;
  }

  .block-detail {
    padding-left: 18px;
  }
}