:root {
  /* Molten dark theme */
  --bg: #16101a;
  --bg-2: #1e1624;
  --panel: #1e1624;
  --panel-border: #322640;
  --field-bg: #16101a;
  --field-border: #3a2d44;
  --text: #e8dff0;
  --text-muted: #9a8ba6;
  --accent: #ff7ab0;
  --accent-2: #ffae3d;
  --accent-grad: linear-gradient(135deg, #ff3d8b, #ffae3d);
  --glow: 0 0 18px rgba(255, 61, 139, .45);
  --danger: #ff5d73;
  /* light surface for technical drawings */
  --draw-bg: #fffdf8;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg); color: var(--text); min-height: 100vh; line-height: 1.5;
}

/* Header */
.app-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 1rem 1.5rem; background: var(--bg-2); border-bottom: 1px solid var(--panel-border);
}
.app-header h1 {
  font-size: 1.25rem; font-weight: 800;
  background: var(--accent-grad); -webkit-background-clip: text;
  background-clip: text; color: transparent;
}

/* Top dimension bar */
.dim-bar {
  display: flex; gap: .6rem; flex-wrap: wrap; align-items: flex-end;
  padding: .8rem 1.5rem; background: var(--bg-2);
  border-bottom: 1px solid var(--panel-border); position: sticky; top: 0; z-index: 20;
}
.dim-field { display: flex; flex-direction: column; }
.dim-field label {
  font-size: .65rem; font-weight: 700; color: var(--text-muted);
  text-transform: uppercase; letter-spacing: .04em; margin-bottom: .2rem;
}
.dim-field input, .dim-field select {
  padding: .4rem .55rem; border: 1px solid var(--field-border); border-radius: 6px;
  background: var(--field-bg); color: var(--accent-2); font-size: .85rem; width: 6.5rem;
}
.dim-field input:focus, .dim-field select:focus { outline: none; border-color: var(--accent); }

/* Tabs */
.tabs { display: flex; gap: .3rem; padding: .6rem 1.5rem 0; background: var(--bg-2); }
.tab-btn {
  padding: .55rem 1.1rem; border: 1px solid var(--panel-border); border-bottom: none;
  border-radius: 8px 8px 0 0; background: transparent; color: var(--text-muted);
  font-size: .85rem; font-weight: 700; cursor: pointer;
}
.tab-btn.active { background: var(--panel); color: var(--accent-2); }
.tab-panel { display: none; padding: 1.5rem; max-width: 1400px; margin: 0 auto; }
.tab-panel.active { display: block; }

/* Generic surfaces */
.card {
  background: var(--panel); border: 1px solid var(--panel-border);
  border-radius: 10px; padding: 1.2rem; margin-bottom: 1.2rem;
}
.card h2 { font-size: 1rem; color: var(--accent-2); margin-bottom: .8rem; }

/* Buttons */
.btn {
  padding: .5rem 1rem; border: none; border-radius: 7px; cursor: pointer;
  font-size: .85rem; font-weight: 700;
}
.btn-primary { background: var(--accent-grad); color: #16101a; box-shadow: var(--glow); }
.btn-ghost { background: var(--bg); color: var(--accent-2); border: 1px solid var(--field-border); }
.btn-danger { background: var(--danger); color: #fff; font-size: .75rem; padding: .25rem .55rem; }

/* Drawing canvas stays light */
.draw-card { background: var(--draw-bg); border-radius: 8px; padding: 1rem; }
.draw-card svg { width: 100%; height: auto; }

/* Tables */
.data-table { width: 100%; border-collapse: collapse; font-size: .82rem; }
.data-table th {
  text-align: left; padding: .45rem .6rem; color: var(--text-muted);
  font-size: .68rem; text-transform: uppercase; letter-spacing: .04em;
  border-bottom: 1px solid var(--panel-border);
}
.data-table td { padding: .4rem .6rem; border-bottom: 1px solid var(--panel-border); }
.data-table input, .data-table select {
  padding: .3rem .4rem; border: 1px solid var(--field-border); border-radius: 5px;
  background: var(--field-bg); color: var(--text); font-size: .8rem; width: 100%;
}