/* 美国主要河流分布图 · 样式（卡片体系参照海平面项目 rivers 页） */
:root {
  --panel-bg: rgba(13, 27, 42, 0.88);
  --bg-3: rgba(255, 255, 255, 0.07);
  --bg-2: rgba(255, 255, 255, 0.04);
  --border: rgba(255, 255, 255, 0.12);
  --text: #d7e3f0;
  --text-strong: #f4f8fc;
  --text-muted: #8fa3b8;
  --accent: #38bdf8;
  --shadow: 0 8px 28px rgba(0, 0, 0, 0.45);
  --motion-fast: 0.16s;
  --motion-base: 0.28s;
  --ease-out: cubic-bezier(0.22, 0.9, 0.3, 1);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html, body { height: 100%; overflow: hidden; }
body {
  font-family: "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  color: var(--text);
  background: #0b1220;
}
#map { position: absolute; inset: 0; }
.maplibregl-ctrl-group { background: var(--panel-bg) !important; border: 1px solid var(--border) !important; }
.maplibregl-ctrl-attrib { background: rgba(13, 27, 42, 0.7) !important; color: var(--text-muted) !important; font-size: 10px; }
.maplibregl-ctrl-attrib a { color: var(--text-muted) !important; }

/* ---------- 顶部标题 ---------- */
.topbar {
  position: absolute; top: 12px; left: 324px; z-index: 2;
  pointer-events: none;
}
.topbar h1 {
  font-size: 17px; font-weight: 600; color: var(--text-strong);
  text-shadow: 0 1px 6px rgba(0, 0, 0, 0.8);
}
.topbar .sub {
  font-size: 11px; color: var(--text-muted); margin-top: 2px;
  text-shadow: 0 1px 4px rgba(0, 0, 0, 0.8);
}

/* ---------- 左侧河流目录 ---------- */
.side-panel {
  position: absolute; top: 12px; left: 12px; bottom: 12px;
  width: 300px;
  display: flex; flex-direction: column;
  background: var(--panel-bg);
  backdrop-filter: blur(14px);
  border: 1px solid var(--border);
  border-radius: 14px;
  box-shadow: var(--shadow);
  z-index: 3;
  transition: transform 0.25s ease;
}
.side-panel.collapsed { transform: translateX(calc(-100% - 16px)); }
.panel-head { display: flex; align-items: center; justify-content: space-between; padding: 13px 14px 9px; }
.panel-head h2 { font-size: 15px; color: var(--text-strong); font-weight: 600; }
.panel-close {
  background: none; border: none; color: var(--text-muted);
  font-size: 20px; cursor: pointer; line-height: 1; padding: 2px 6px;
}
.panel-close:hover { color: var(--text-strong); }

.panel-stats {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px;
  padding: 0 14px 12px;
  border-bottom: 1px solid var(--border);
}
.panel-stats > div {
  display: flex; flex-direction: column; align-items: center;
  background: var(--bg-3); border-radius: 9px; padding: 7px 4px;
}
.panel-stats b { font-size: 14px; font-weight: 600; color: var(--accent); font-variant-numeric: tabular-nums; }
.panel-stats span { font-size: 10px; color: var(--text-muted); margin-top: 2px; }

.panel-search { padding: 11px 12px 9px; }
.panel-search input {
  width: 100%;
  background: var(--bg-3); border: 1px solid var(--border); border-radius: 9px;
  padding: 8px 11px; color: var(--text); font-size: 13px; outline: none;
}
.panel-search input:focus { border-color: var(--accent); }
.panel-search input::placeholder { color: var(--text-muted); }

.level-filter {
  display: flex; flex-wrap: wrap; gap: 4px 10px;
  padding: 0 14px 10px;
  border-bottom: 1px solid var(--border);
}
.lv-check {
  display: inline-flex; align-items: center; gap: 5px;
  font-size: 12px; color: var(--text-muted);
  cursor: pointer; user-select: none;
}
.lv-check.off { opacity: 0.45; }
.lv-check input { accent-color: var(--accent); width: 13px; height: 13px; cursor: pointer; }
.lv-check .dot { width: 9px; height: 9px; border-radius: 50%; }
.lv-check .lv-count { font-variant-numeric: tabular-nums; font-size: 10px; opacity: 0.7; }

.river-list {
  flex: 1; overflow-y: auto;
  padding: 10px;
  scrollbar-width: thin; scrollbar-color: var(--bg-3) transparent;
  display: flex; flex-direction: column; gap: 8px;
}
/* 河流目录卡片：左缘等级色条 + 等级徽章 + 元信息 */
.river-item {
  position: relative; isolation: isolate;
  display: block; width: 100%; text-align: left;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-left: 3px solid var(--c, var(--accent));
  border-radius: 10px;
  padding: 9px 11px;
  cursor: pointer; color: var(--text); font-family: inherit;
  transition: transform var(--motion-fast) var(--ease-out),
              border-color var(--motion-fast) var(--ease-out),
              background-color var(--motion-fast) var(--ease-out);
}
.river-item::after {
  content: ""; position: absolute; inset: 0; z-index: -1;
  border-radius: inherit;
  box-shadow: 0 7px 18px rgba(0, 0, 0, 0.35);
  opacity: 0; pointer-events: none;
  transition: opacity var(--motion-fast) var(--ease-out);
}
.river-item:hover, .river-item:focus-visible, .river-item.is-selected {
  background: var(--bg-3);
  border-color: var(--c, var(--accent));
  transform: translateX(2px);
}
.river-item:hover::after, .river-item:focus-visible::after, .river-item.is-selected::after { opacity: 1; }
.river-item.is-selected { outline: 1px solid color-mix(in srgb, var(--c) 70%, transparent); outline-offset: -1px; }
.ri-top { display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.ri-name {
  font-size: 13.5px; font-weight: 500; color: var(--text-strong);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.ri-level {
  flex: none; font-size: 10.5px; color: var(--c);
  border: 1px solid var(--c); border-radius: 6px; padding: 1px 6px;
}
.ri-meta { margin-top: 3px; font-size: 11.5px; color: var(--text-muted); }
.list-empty { padding: 24px 12px; text-align: center; color: var(--text-muted); font-size: 13px; }
.list-count {
  padding: 9px 14px; border-top: 1px solid var(--border);
  font-size: 11px; color: var(--text-muted); font-variant-numeric: tabular-nums;
}
.panel-open {
  position: absolute; top: 12px; left: 12px; z-index: 2;
  background: var(--panel-bg); backdrop-filter: blur(14px);
  border: 1px solid var(--border); border-radius: 9px;
  color: var(--text); font-size: 13px; padding: 8px 14px; cursor: pointer;
  display: none;
}
.side-panel.collapsed + .panel-open { display: block; }

/* ---------- 右上角：触发钮 + 设置图例面板 ---------- */
.mp-trigger {
  position: absolute; top: 12px; right: 12px; z-index: 4;
  width: 40px; height: 40px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  background: var(--panel-bg); backdrop-filter: blur(14px);
  border: 1px solid var(--border); box-shadow: var(--shadow);
  color: var(--accent); font-size: 18px; cursor: pointer; line-height: 1;
  transition: opacity var(--motion-fast) var(--ease-out), transform var(--motion-fast) var(--ease-out), color var(--motion-fast) var(--ease-out), border-color var(--motion-fast) var(--ease-out);
}
.mp-trigger:hover { color: var(--text-strong); border-color: var(--accent); }
.mp-trigger.is-hidden { opacity: 0; transform: scale(0.9); pointer-events: none; }

.map-panel {
  position: absolute; top: 12px; right: 12px;
  width: 252px; max-height: calc(100% - 24px);
  display: flex; flex-direction: column;
  background: var(--panel-bg); backdrop-filter: blur(14px);
  border: 1px solid var(--border); border-radius: 12px; box-shadow: var(--shadow);
  z-index: 4; overflow: hidden;
  transform-origin: top right;
  transition: opacity var(--motion-fast) var(--ease-out), transform var(--motion-base) var(--ease-out), visibility 0s linear 0s;
}
.map-panel.collapsed {
  opacity: 0; visibility: hidden;
  transform: translate3d(8px, -6px, 0) scale(0.97);
  pointer-events: none;
  transition: opacity var(--motion-fast) var(--ease-out), transform var(--motion-base) var(--ease-out), visibility 0s linear var(--motion-base);
}
.mp-head { display: flex; align-items: center; justify-content: space-between; padding: 10px 12px; border-bottom: 1px solid var(--border); }
.mp-title { font-size: 12.5px; font-weight: 600; color: var(--text-strong); }
.mp-close { background: none; border: none; color: var(--text-muted); font-size: 18px; line-height: 1; cursor: pointer; padding: 0 4px; }
.mp-close:hover { color: var(--text-strong); }
.mp-body {
  padding: 10px 12px 12px; overflow-y: auto;
  display: flex; flex-direction: column; gap: 10px;
  scrollbar-width: thin;
}
.mp-group { display: flex; flex-direction: column; gap: 6px; }
.mp-label { font-size: 11px; color: var(--text-muted); letter-spacing: 0.4px; }
.base-grid { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 6px; }
.mp-row { display: flex; gap: 6px; flex-wrap: wrap; }
.tool-btn {
  background: var(--bg-3); border: 1px solid var(--border); border-radius: 8px;
  color: var(--text-muted); font-size: 12px; padding: 7px 9px; cursor: pointer; white-space: nowrap;
  font-family: inherit;
}
.tool-btn:hover { color: var(--text-strong); border-color: var(--accent); }
.tool-btn.active { color: #0b1220; background: var(--accent); border-color: var(--accent); font-weight: 500; }
.tool-btn[aria-pressed="false"] { opacity: 0.55; }
.mp-legend { border-top: 1px solid var(--border); padding-top: 8px; gap: 4px; }
.legend-row { display: flex; align-items: center; gap: 7px; font-size: 11.5px; color: var(--text-muted); white-space: nowrap; }
.lk { width: 22px; height: 0; border-top: 2px solid; border-radius: 2px; flex: none; }
.lk1 { border-color: #ef4444; border-top-width: 3px; }
.lk2 { border-color: #38bdf8; border-top-width: 2.5px; }
.lk3 { border-color: #fbbf24; }
.lk4 { border-color: #34d399; }
.lk5 { border-color: #9ca3af; }
.lk6 { border-color: #cbd5e1; }
.mp-note { font-size: 10.5px; line-height: 1.6; color: var(--text-muted); border-top: 1px solid var(--border); padding-top: 8px; }
.mp-nav { display: flex; gap: 10px; }
.mp-nav a { font-size: 11.5px; color: var(--accent); text-decoration: none; }
.mp-nav a:hover { text-decoration: underline; }

/* ---------- 河流名称标注 ---------- */
#labels { position: absolute; inset: 0; pointer-events: none; z-index: 1; overflow: hidden; }
.lbl {
  position: absolute; transform: translate(-50%, -50%);
  font-size: 13px; line-height: 1; white-space: nowrap;
  padding: 2px 6px; border-radius: 4px;
  background: rgba(2, 6, 23, 0.55); color: #fff;
  text-shadow: 0 1px 2px #000; will-change: transform;
  pointer-events: none;
}
.lbl.l1 { color: #fecaca; font-size: 12.5px; font-weight: 700; letter-spacing: 1px; }
.lbl.l2 { color: #bae6fd; font-size: 11.5px; }
.lbl.l3 { color: #fde68a; font-size: 11px; }
.lbl.l4 { color: #bbf7d0; font-size: 10.5px; font-weight: 500; }
.lbl.l5 { color: #e5e7eb; font-size: 10px; font-weight: 500; }
.lbl.l6 { color: #d1d5db; font-size: 9.5px; font-weight: 400; }

/* ---------- 悬停/点击详情卡（cn-rivers 内容结构 + 海平面动效与质感）---------- */
.river-popup { z-index: 30 !important; }   /* 必须高于 #labels(1)，避免被河流名称遮挡 */
.river-popup .maplibregl-popup-content {
  background: var(--panel-bg);
  backdrop-filter: blur(10px);
  border: none; border-radius: 12px; padding: 0; overflow: hidden;
  color: var(--text);
  box-shadow: var(--shadow);
  min-width: 196px;
  transform-origin: center bottom;
  animation: river-popup-in var(--motion-base) var(--ease-out) both;
}
@keyframes river-popup-in {
  from { opacity: 0; transform: translate3d(0, 5px, 0) scale(0.97); }
  to { opacity: 1; transform: translate3d(0, 0, 0) scale(1); }
}
.river-popup .maplibregl-popup-close-button { color: var(--text-muted); font-size: 17px; padding: 5px 9px; z-index: 2; }
.river-popup .maplibregl-popup-close-button:hover { color: var(--text-strong); }
.river-popup .maplibregl-popup-tip { display: none !important; }
.pop { padding: 12px 14px; border-left: 3px solid var(--c, var(--accent)); }
.pop h3 { margin: 0 0 6px; font-size: 15px; color: var(--text-strong); padding-right: 16px; line-height: 1.35; }
.pop .lv { font-size: 11px; padding: 1px 7px; border-radius: 999px; margin-left: 6px; white-space: nowrap; }
.pop .lv.l1 { background: rgba(239,68,68,0.25); color: #fecaca; }
.pop .lv.l2 { background: rgba(56,189,248,0.25); color: #bae6fd; }
.pop .lv.l3 { background: rgba(251,191,36,0.25); color: #fde68a; }
.pop .lv.l4 { background: rgba(52,211,153,0.25); color: #bbf7d0; }
.pop .lv.l5 { background: rgba(156,163,175,0.28); color: #e5e7eb; }
.pop .lv.l6 { background: rgba(203,213,225,0.22); color: #d1d5db; }
.pop table { border-collapse: collapse; margin-top: 4px; }
.pop td { padding: 2px 0; vertical-align: top; }
.pop td.k { color: var(--text-muted); padding-right: 10px; white-space: nowrap; }
.pop table.kv { width: 100%; }
.pop table.kv td.k { text-align: left; font-variant-numeric: tabular-nums; }
.pop table.kv td:not(.k) { font-variant-numeric: tabular-nums; max-width: 190px; word-break: break-word; }
@media (prefers-reduced-motion: reduce) {
  .river-popup .maplibregl-popup-content { animation: none; }
}

/* ---------- 移动端 ---------- */
@media (max-width: 760px) {
  .topbar { left: 14px; top: 10px; }
  .topbar h1 { font-size: 14px; }
  .topbar .sub { display: none; }
  .side-panel { width: calc(100% - 24px); max-width: 320px; }
  .map-panel { width: 210px; }
  .mp-legend { display: none; }
}