*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #ffffff;
  --bg2: #f5f6fa;
  --bg3: #e8eaf0;
  --text: #1a1a2e;
  --text2: #555;
  --accent: #1f77b4;
  --accent2: #e74c3c;
  --border: #ddd;
  --shadow: rgba(0,0,0,0.08);
  --radius: 8px;
  --header-bg: #1a1a2e;
  --header-text: #eee;
}
.theme-dark {
  --bg: #1e1e2e;
  --bg2: #252538;
  --bg3: #2a2a40;
  --text: #e0e0e0;
  --text2: #aaa;
  --accent: #00d4ff;
  --accent2: #ff6b6b;
  --border: #3a3a50;
  --shadow: rgba(0,0,0,0.3);
  --header-bg: #0d0d1a;
  --header-text: #ddd;
}
.theme-navy {
  --bg: #0a1628;
  --bg2: #0f1f38;
  --bg3: #152848;
  --text: #d0e8ff;
  --text2: #7a9cbf;
  --accent: #f0c040;
  --accent2: #e67e22;
  --border: #1a3050;
  --shadow: rgba(0,0,0,0.4);
  --header-bg: #050e1c;
  --header-text: #d0e8ff;
}
.theme-solarized {
  --bg: #fdf6e3;
  --bg2: #eee8d5;
  --bg3: #e0dcc0;
  --text: #657b83;
  --text2: #839496;
  --accent: #268bd2;
  --accent2: #dc322f;
  --border: #d5ccb8;
  --shadow: rgba(0,0,0,0.06);
  --header-bg: #073642;
  --header-text: #eee8d5;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-size: 14px;
  background: var(--bg);
  color: var(--text);
}

header {
  background: var(--header-bg); color: var(--header-text);
  padding: 12px 24px; display: flex; align-items: center; justify-content: space-between;
}
header h1 { font-size: 18px; font-weight: 600; }
header .credit { font-size: 11px; color: var(--text2); white-space: nowrap; display: flex; align-items: center; gap: 4px; }
header .credit a { display: inline-flex; align-items: center; gap: 3px; text-decoration: none; color: var(--accent); }
header .credit a:hover svg { opacity: 0.8; }
header button { -webkit-app-region: no-drag; }
.header-controls { display: flex; gap: 8px; }
.header-controls button, .header-btn {
  background: rgba(255,255,255,0.1); color: var(--header-text); border: 1px solid rgba(255,255,255,0.15);
  padding: 6px 14px; border-radius: 6px; cursor: pointer; font-size: 14px;
}
.header-controls button:hover, .header-btn:hover { background: rgba(255,255,255,0.2); }

.auth-group { display: flex; align-items: center; gap: 6px; margin-right: 8px; }
.auth-btn {
  background: #fff; color: #333; border: none; padding: 6px 14px; border-radius: 6px;
  cursor: pointer; font-size: 13px; font-weight: 500; white-space: nowrap;
}
.auth-btn:hover { background: #f0f0f0; }
.user-info { display: flex; align-items: center; gap: 6px; }
.user-avatar { width: 26px; height: 26px; border-radius: 50%; border: 1px solid rgba(255,255,255,0.2); }
.user-name { font-size: 13px; color: var(--header-text); max-width: 120px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

.main-layout {
  display: flex;
  min-height: calc(100vh - 52px);
}

.sidebar {
  width: 320px; min-width: 320px; padding: 16px;
  background: var(--bg2); border-right: 1px solid var(--border);
  position: sticky; top: 0; height: calc(100vh - 52px); overflow-y: auto;
}
.content {
  flex: 1; display: flex; flex-direction: column; padding: 12px; gap: 16px;
  overflow-y: auto; max-height: calc(100vh - 52px);
}

.control-group { margin-bottom: 10px; }
.control-group label { display: block; font-size: 13px; font-weight: 600; color: var(--text2); margin-bottom: 3px; }
.control-group input[type="text"],
.control-group input[type="number"],
.control-group select {
  width: 100%; padding: 8px 10px; border: 1px solid var(--border); border-radius: 6px;
  background: var(--bg); color: var(--text); font-size: 14px;
}
.control-group input:focus, .control-group select:focus {
  outline: none; border-color: var(--accent); box-shadow: 0 0 0 2px rgba(31,119,180,0.15);
}
.num-input { width: 100% !important; }
.control-row { display: flex; gap: 8px; }
.control-row .control-group { flex: 1; }
.extra-controls { display: flex; gap: 4px; margin-bottom: 4px; }
.extra-controls button, .btn-secondary {
  padding: 5px 12px; font-size: 13px; border: 1px solid var(--border); border-radius: 6px;
  background: var(--bg); color: var(--text); cursor: pointer;
}
.extra-controls button:hover, .btn-secondary:hover { background: var(--bg3); }
#extraList { max-height: 120px; overflow-y: auto; }
.extra-item {
  display: flex; align-items: center; gap: 6px; padding: 5px 8px; margin-bottom: 3px;
  background: var(--bg); border: 1px solid var(--border); border-radius: 4px; font-size: 13px;
}
.extra-item .color-dot { width: 10px; height: 10px; border-radius: 50%; flex-shrink: 0; }
.extra-item .extra-label { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.extra-item button { font-size: 11px; padding: 1px 6px; border: none; background: transparent; color: var(--accent2); cursor: pointer; }

.btn-compute {
  width: 100%; padding: 11px; margin-top: 8px;
  background: var(--accent); color: #fff; border: none; border-radius: 8px;
  font-size: 16px; font-weight: 600; cursor: pointer;
}
.btn-compute:hover { filter: brightness(1.1); }

.btn-clear {
  width: 100%; padding: 8px; margin-top: 4px;
  background: #c0392b; color: #fff; border: none; border-radius: 8px;
  font-size: 14px; font-weight: 700; cursor: pointer;
}
.btn-clear:hover { background: #e74c3c; }

.fun-shapes { margin-top: 12px; }
.shape-grid { display: flex; flex-wrap: wrap; gap: 4px; max-height: 160px; overflow-y: auto; }
.shape-btn {
  padding: 5px 11px; font-size: 13px; border: 1px solid var(--border); border-radius: 4px;
  background: var(--bg); color: var(--text); cursor: pointer; white-space: nowrap;
}
.shape-btn:hover { background: var(--accent); color: #fff; border-color: var(--accent); }

#results { margin-top: 16px; padding: 12px; background: var(--bg); border-radius: var(--radius); border: 1px solid var(--border); }
.result-item { display: flex; justify-content: space-between; padding: 4px 0; }
.result-label { font-weight: 600; font-size: 14px; }
.result-value { font-family: 'SF Mono', Consolas, monospace; font-size: 15px; color: var(--accent); }

.plot-container {
  min-height: 300px; display: flex; flex-direction: column;
}
.plot-area {
  flex: 1; min-height: 280px; border-radius: var(--radius); overflow: hidden; background: var(--bg);
  border: 1px solid var(--border);
}

.steps-container {
  display: flex; flex-direction: column;
}
#stepsText {
  padding: 12px; font-family: 'SF Mono', Consolas, monospace; font-size: 14px;
  background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius);
  white-space: pre-wrap; color: var(--text); min-height: 80px; max-height: 240px; overflow-y: auto;
}

.viewer-section {
  display: flex; flex-direction: column;
}
.viewer-area {
  height: 600px; min-height: 400px; border-radius: var(--radius); overflow: hidden;
  background: var(--bg); border: 1px solid var(--border); position: relative;
}
.viewer-area canvas { display: block; width: 100% !important; height: 100% !important; }
.viewer-error { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; color: var(--text2); font-size: 13px; text-align: center; padding: 20px; }
.gizmo-container {
  position: absolute; bottom: 8px; left: 8px; width: 100px; height: 100px;
  pointer-events: none; z-index: 10;
}
.gizmo-container canvas { display: block; width: 100% !important; height: 100% !important; }

.panel-header {
  font-size: 13px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.5px;
  color: var(--text2); padding: 6px 0; display: flex; justify-content: space-between; align-items: center;
}
.viewer-controls { display: flex; gap: 12px; align-items: center; }
.edge-toggle { font-size: 13px; font-weight: 400; text-transform: none; color: var(--text2); cursor: pointer; display: flex; align-items: center; gap: 2px; }
.edge-toggle input[type="checkbox"] { margin: 0; }
.edge-toggle input[type="color"] { width: 22px; height: 22px; padding: 0; border: 1px solid var(--border); border-radius: 3px; cursor: pointer; background: none; }

.help-icon {
  display: inline-flex; align-items: center; justify-content: center;
  width: 16px; height: 16px; border-radius: 50%; font-size: 11px; line-height: 16px;
  background: var(--border); color: var(--text2); cursor: help; flex-shrink: 0;
  font-weight: 700; text-align: center; position: relative;
}
.help-icon:hover { background: var(--accent); color: #fff; }

.help-tip {
  display: none; position: absolute; top: 22px; left: 50%; transform: translateX(-50%);
  width: 260px; padding: 10px 12px; border-radius: 6px;
  background: var(--bg3); color: var(--text); font-size: 12px; font-weight: 400; line-height: 1.5;
  border: 1px solid var(--border); box-shadow: 0 4px 12px var(--shadow); z-index: 100;
  text-align: left; white-space: normal;
}
.help-icon:hover .help-tip { display: block; }
.btn-reset {
  font-size: 12px; padding: 4px 9px; border: 1px solid var(--border); border-radius: 4px;
  background: var(--bg2); color: var(--text); cursor: pointer;
}
.btn-reset:hover { background: var(--bg3); }

/* Modal styles */
.modal-overlay {
  position: fixed; top: 0; left: 0; right: 0; bottom: 0; background: rgba(0,0,0,0.5);
  display: flex; align-items: center; justify-content: center; z-index: 1000;
}
.modal {
  background: var(--bg); border-radius: 12px; padding: 24px; min-width: 400px;
  max-width: 90vw; max-height: 85vh; overflow-y: auto; box-shadow: 0 10px 40px rgba(0,0,0,0.3);
}
.modal h2 { margin-bottom: 16px; font-size: 16px; }
.modal label { display: block; font-size: 12px; font-weight: 600; color: var(--text2); margin-top: 10px; margin-bottom: 3px; }
.modal input[type="text"], .modal input[type="number"], .modal select {
  width: 100%; padding: 7px 10px; border: 1px solid var(--border); border-radius: 6px;
  background: var(--bg2); color: var(--text); font-size: 13px;
}
.modal-btn-row { display: flex; gap: 8px; margin-top: 16px; justify-content: flex-end; }
.modal-btn-row button { padding: 8px 16px; border-radius: 6px; cursor: pointer; font-size: 13px; }
.modal-btn-row .primary { background: var(--accent); color: #fff; border: none; }
.modal-btn-row .secondary { background: var(--bg3); color: var(--text); border: 1px solid var(--border); }

.theme-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(80px, 1fr)); gap: 6px; margin: 10px 0; }
.theme-btn {
  padding: 8px; border-radius: 6px; border: 2px solid transparent; cursor: pointer;
  font-size: 11px; text-align: center; font-weight: 600;
}
.theme-btn.active { border-color: var(--accent); }

.radio-label { font-size: 12px; font-weight: 400; cursor: pointer; display: flex; align-items: center; gap: 4px; }
.radio-label input { margin: 0; }

.btn-small {
  padding: 4px 9px; font-size: 13px; border: 1px solid var(--border); border-radius: 4px;
  background: var(--bg); color: var(--text); cursor: pointer; margin-top: 4px;
}
.btn-small:hover { background: var(--bg3); }
.btn-apply { background: var(--accent); color: #fff; border-color: var(--accent); margin-left: 4px; }
.btn-apply:hover { filter: brightness(1.1); }

.pw-table-header {
  display: flex; gap: 4px; font-size: 10px; font-weight: 600; color: var(--text2);
  padding: 2px 0; margin-top: 4px;
}
.pw-col-expr { flex: 1; }
.pw-col-range { width: 60px; text-align: center; }
.pw-col-color { width: 50px; text-align: center; }
.pw-col-btn { width: 22px; }

.pw-row {
  display: flex; gap: 4px; align-items: center; margin-bottom: 3px;
}
.pw-row input[type="text"] {
  flex: 1; padding: 4px 6px; border: 1px solid var(--border); border-radius: 4px;
  background: var(--bg); color: var(--text); font-size: 12px; font-family: 'SF Mono', Consolas, monospace;
}
.pw-row input[type="number"] {
  width: 60px; padding: 4px 6px; border: 1px solid var(--border); border-radius: 4px;
  background: var(--bg); color: var(--text); font-size: 12px;
}
.pw-row input[type="color"] {
  width: 50px; height: 26px; padding: 1px; border: 1px solid var(--border); border-radius: 4px;
  background: none; cursor: pointer;
}
.pw-row .pw-del-btn {
  width: 22px; height: 26px; font-size: 13px; padding: 0; border: none;
  background: transparent; color: var(--accent2); cursor: pointer; line-height: 26px; text-align: center;
}
.pw-row .pw-del-btn:hover { background: var(--bg3); border-radius: 4px; }
.pw-error { color: var(--accent2); font-size: 11px; margin-top: 4px; display: none; }

.bound-slider {
  width: 100%; height: 3px; -webkit-appearance: none; appearance: none;
  background: var(--border); border-radius: 2px; outline: none; cursor: pointer; margin-top: 4px;
}
.bound-slider::-webkit-slider-thumb {
  -webkit-appearance: none; width: 12px; height: 12px; border-radius: 50%;
  background: var(--accent); cursor: pointer; border: none;
}
.bound-slider::-moz-range-thumb {
  width: 12px; height: 12px; border-radius: 50%;
  background: var(--accent); cursor: pointer; border: none;
}

.steps-modal { min-width: 500px; max-width: 80vw; }
.steps-modal .katex-display { margin: 0.5em 0; }

.project-card {
  display: flex; align-items: center; justify-content: space-between;
  padding: 10px 12px; margin-bottom: 6px;
  background: var(--bg2); border: 1px solid var(--border); border-radius: 6px;
}
.project-card-info { flex: 1; min-width: 0; }
.project-card-name { font-weight: 600; font-size: 14px; color: var(--text); }
.project-card-date { font-size: 11px; color: var(--text2); margin-top: 2px; }
.project-card-actions { display: flex; gap: 6px; flex-shrink: 0; margin-left: 12px; }
.project-load-btn {
  padding: 4px 12px; font-size: 12px; border: none; border-radius: 4px;
  background: var(--accent); color: #fff; cursor: pointer;
}
.project-load-btn:hover { filter: brightness(1.1); }
.project-del-btn {
  padding: 4px 12px; font-size: 12px; border: 1px solid var(--border); border-radius: 4px;
  background: transparent; color: var(--accent2); cursor: pointer;
}
.project-del-btn:hover { background: var(--accent2); color: #fff; }

.toast {
  position: fixed; top: 60px; right: 20px; z-index: 9999;
  background: var(--accent); color: #fff; padding: 12px 20px; border-radius: 8px;
  font-size: 14px; font-weight: 500; box-shadow: 0 4px 16px rgba(0,0,0,0.2);
  transition: opacity 0.3s;
}

.color-row { display: flex; align-items: center; gap: 10px; margin-top: 6px; }
.color-swatch {
  width: 30px; height: 30px; border-radius: 6px; border: 2px solid var(--border); cursor: pointer;
}

/* Animation controls */
.anim-controls {
  display: flex; align-items: center; gap: 8px; margin-top: 4px;
}
.btn-play {
  width: 28px; height: 26px; padding: 0; font-size: 13px; line-height: 26px; text-align: center;
  border: 1px solid var(--border); border-radius: 4px; background: var(--accent); color: #fff;
  cursor: pointer; flex-shrink: 0;
}
.btn-play:hover { filter: brightness(1.1); }
.anim-slider {
  flex: 1; height: 4px; -webkit-appearance: none; appearance: none;
  background: var(--border); border-radius: 2px; outline: none; cursor: pointer;
}
.anim-slider::-webkit-slider-thumb {
  -webkit-appearance: none; width: 14px; height: 14px; border-radius: 50%;
  background: var(--accent); cursor: pointer; border: none;
}
.anim-slider::-moz-range-thumb {
  width: 14px; height: 14px; border-radius: 50%;
  background: var(--accent); cursor: pointer; border: none;
}
.anim-label {
  font-size: 11px; font-family: 'SF Mono', Consolas, monospace; color: var(--text2);
  width: 42px; text-align: right; flex-shrink: 0;
}

/* KaTeX steps */
#stepsText .katex { font-size: 1.1em; }
#stepsText code { font-size: 12px; color: var(--accent); }