:root {
  --bg: #e7ebf3;
  --bg-elev: #ffffff;
  --bg-soft: #eaeef6;
  --border: #c9d1e0;
  --border-strong: #a9b4ca;
  --text: #0d1424;
  --text-soft: #414c63;
  --text-faint: #69738a;
  --accent: #3a55f0;
  --accent-soft: rgba(58, 85, 240, 0.14);
  --accent-strong: #2a3fd0;
  --success: #0e9d63;
  --success-soft: rgba(14, 157, 99, 0.16);
  --danger: #d3363b;
  --danger-soft: rgba(211, 54, 59, 0.14);
  --shadow: 0 1px 2px rgba(20, 30, 60, 0.08), 0 10px 28px rgba(20, 30, 60, 0.10);
  --shadow-sm: 0 1px 3px rgba(20, 30, 60, 0.12);
  --radius: 16px;
  --radius-sm: 10px;
  --mono: "SFMono-Regular", ui-monospace, "JetBrains Mono", Menlo, Consolas, monospace;
}

[data-theme="dark"] {
  --bg: #0e1118;
  --bg-elev: #171b26;
  --bg-soft: #1e2331;
  --border: #262c3b;
  --border-strong: #333b4f;
  --text: #eaeef7;
  --text-soft: #a5adc0;
  --text-faint: #6f7a90;
  --accent: #6b83ff;
  --accent-soft: rgba(107, 131, 255, 0.16);
  --accent-strong: #8298ff;
  --success: #2bd48b;
  --success-soft: rgba(43, 212, 139, 0.16);
  --danger: #ff6169;
  --danger-soft: rgba(255, 97, 105, 0.16);
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.3), 0 12px 32px rgba(0, 0, 0, 0.35);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
}

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

body {
  font-family: "Inter", system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  transition: background 0.3s ease, color 0.3s ease;
}

/* ---------- Header ---------- */
.app-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px clamp(16px, 4vw, 48px);
  background: color-mix(in srgb, var(--bg-elev) 82%, transparent);
  backdrop-filter: saturate(160%) blur(12px);
  border-bottom: 1px solid var(--border);
}

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

.brand-mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  color: #fff;
  font-size: 22px;
  box-shadow: var(--shadow-sm);
}

.brand-text h1 { margin: 0; font-size: 1.05rem; font-weight: 700; letter-spacing: -0.01em; }
.brand-text p { margin: 0; font-size: 0.78rem; color: var(--text-faint); }

.header-actions { display: flex; align-items: center; gap: 8px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: inherit;
  font-size: 0.88rem;
  font-weight: 600;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  padding: 9px 14px;
  cursor: pointer;
  color: var(--text);
  background: transparent;
  transition: background 0.15s ease, border-color 0.15s ease, transform 0.08s ease, color 0.15s ease;
  white-space: nowrap;
}
.btn:active { transform: translateY(1px); }
.btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.btn .icon { width: 18px; height: 18px; }

.btn-ghost {
  border-color: var(--border);
  background: var(--bg-elev);
  color: var(--text-soft);
}
.btn-ghost:hover { border-color: var(--border-strong); color: var(--text); }

.btn-primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  color: #fff;
  box-shadow: var(--shadow-sm);
}
.btn-primary:hover { filter: brightness(1.06); }

.btn-icon { padding: 9px; border-color: var(--border); background: var(--bg-elev); color: var(--text-soft); }
.btn-icon:hover { color: var(--text); border-color: var(--border-strong); }

.btn-danger-ghost { border-color: transparent; background: transparent; color: var(--text-faint); }
.btn-danger-ghost:hover { color: var(--danger); background: var(--danger-soft); }

/* ---------- Theme toggle icons ---------- */
.icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: none; }
[data-theme="dark"] .icon-moon { display: block; }

/* ---------- Main ---------- */
.app-main {
  max-width: 880px;
  margin: 0 auto;
  padding: clamp(20px, 4vw, 36px) clamp(16px, 4vw, 48px) 60px;
}

/* ---------- Add panel ---------- */
.add-panel {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
  margin-bottom: 24px;
}

.add-form {
  display: grid;
  grid-template-columns: 1fr 1fr auto;
  gap: 14px;
  align-items: end;
}

.field { display: flex; flex-direction: column; gap: 6px; }
.field label {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-faint);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.field input {
  font-family: inherit;
  font-size: 0.95rem;
  color: var(--text);
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 11px 13px;
  transition: border-color 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}
.field input::placeholder { color: var(--text-faint); }
.field input:focus {
  outline: none;
  border-color: var(--accent);
  background: var(--bg-elev);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.add-form .btn-primary { height: 44px; padding: 0 20px; }

/* ---------- Summary ---------- */
.summary {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 12px;
  margin-bottom: 24px;
}
.summary-card {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.summary-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-faint);
  font-weight: 600;
}
.summary-value { font-size: 1.35rem; font-weight: 700; letter-spacing: -0.01em; font-variant-numeric: tabular-nums; }
.summary-card--live { border-color: var(--success); background: var(--success-soft); }
.summary-card--live .summary-value { color: var(--success); font-family: var(--mono); }

/* ---------- Clients ---------- */
.clients { display: flex; flex-direction: column; gap: 16px; }

.client-card {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

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

.client-toggle {
  display: flex;
  align-items: center;
  gap: 10px;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text);
  font-family: inherit;
  font-size: 1.02rem;
  font-weight: 700;
  padding: 0;
  letter-spacing: -0.01em;
  min-width: 0;
}
.client-name { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.chevron { width: 20px; height: 20px; color: var(--text-faint); transition: transform 0.2s ease; flex-shrink: 0; }
.client-card.collapsed .chevron { transform: rotate(0deg); }
.client-card:not(.collapsed) .chevron { transform: rotate(90deg); }

.client-meta { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.client-total {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-soft);
  font-variant-numeric: tabular-nums;
  background: var(--bg-soft);
  padding: 4px 10px;
  border-radius: 20px;
}

.project-list { display: flex; flex-direction: column; }
.client-card.collapsed .project-list { display: none; }

/* Inline add-project form on each client card */
.client-add {
  display: flex;
  gap: 8px;
  padding: 12px 18px;
  border-top: 1px solid var(--border);
  background: var(--bg-soft);
}
.client-card.collapsed .client-add { display: none; }
.client-add-input {
  flex: 1;
  min-width: 0;
  font-family: inherit;
  font-size: 0.88rem;
  color: var(--text);
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 9px 12px;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
.client-add-input::placeholder { color: var(--text-faint); }
.client-add-input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
.btn-add-project { flex-shrink: 0; }

/* ---------- Project row ---------- */
.project-row {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 18px;
  border-top: 1px solid var(--border);
}
.project-row.running { background: var(--success-soft); }

.project-info { flex: 1; min-width: 0; display: flex; flex-direction: column; gap: 2px; }
.project-name { font-weight: 600; font-size: 0.96rem; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.project-sessions {
  font-size: 0.76rem;
  color: var(--text-faint);
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
  font-family: inherit;
  text-align: left;
  align-self: flex-start;
  transition: color 0.15s ease;
}
.project-sessions:hover { color: var(--accent); }

/* ---------- Session history ---------- */
.project-history {
  padding: 4px 18px 16px 18px;
  background: var(--bg-soft);
  border-top: 1px solid var(--border);
  animation: history-in 0.18s ease;
}
@keyframes history-in {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: translateY(0); }
}
.history-empty { margin: 8px 0; font-size: 0.82rem; color: var(--text-faint); }
.history-day { margin-top: 12px; }
.history-day-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 4px;
  padding-bottom: 4px;
  border-bottom: 1px solid var(--border);
}
.history-day-head > span:first-child {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-soft);
  text-transform: capitalize;
}
.history-day-total {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--accent);
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
}
.history-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 5px 0;
}
.history-range { font-size: 0.83rem; color: var(--text-soft); font-variant-numeric: tabular-nums; }
.history-dur {
  font-size: 0.83rem;
  font-family: var(--mono);
  color: var(--text);
  font-variant-numeric: tabular-nums;
}
.history-row.running .history-range,
.history-row.running .history-dur { color: var(--success); font-weight: 600; }

.project-timing { flex-shrink: 0; }
.project-time {
  font-family: var(--mono);
  font-size: 1.05rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  color: var(--text);
}
.project-row.running .project-time { color: var(--success); }

.project-controls { display: flex; align-items: center; gap: 6px; flex-shrink: 0; }

.btn-timer {
  background: var(--accent-soft);
  color: var(--accent-strong);
  border-color: transparent;
  min-width: 118px;
}
.btn-timer:hover { background: color-mix(in srgb, var(--accent-soft) 70%, var(--accent) 15%); }
.btn-timer .icon-stop { display: none; }
.project-row.running .btn-timer { background: var(--danger-soft); color: var(--danger); }
.project-row.running .btn-timer .icon-play { display: none; }
.project-row.running .btn-timer .icon-stop { display: block; }

/* ---------- Empty state ---------- */
.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-faint);
}
.empty-illustration {
  font-size: 3rem;
  opacity: 0.5;
  margin-bottom: 8px;
}
.empty-state h2 { margin: 0 0 6px; font-size: 1.15rem; color: var(--text-soft); }
.empty-state p { margin: 0 auto; max-width: 340px; font-size: 0.9rem; }

/* ---------- Footer ---------- */
.app-footer {
  text-align: center;
  padding: 24px 16px 40px;
  color: var(--text-faint);
  font-size: 0.8rem;
}
.app-footer p { margin: 0; }

/* ---------- Toast ---------- */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--text);
  color: var(--bg-elev);
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 500;
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease;
  z-index: 50;
  max-width: 90vw;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ---------- SVG icon defaults ---------- */
.icon {
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.icon-play, .icon-stop { fill: currentColor; stroke: none; }
.brand-mark { fill: none; }

/* ---------- Responsive ---------- */
@media (max-width: 640px) {
  .add-form { grid-template-columns: 1fr; }
  .add-form .btn-primary { width: 100%; }
  .btn-label { display: none; }
  .header-actions .btn-ghost { padding: 9px; }
  .project-row { flex-wrap: wrap; }
  .project-info { flex-basis: 100%; }
  .btn-timer { flex: 1; }
}