:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --border: #d1d5db;
  --bg: #f3f4f6;
  --card-bg: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --danger: #dc2626;
  --danger-bg: #fef2f2;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Segoe UI", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

/* --- Login --- */
.login-body {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
}
.login-box {
  background: var(--card-bg);
  padding: 2.5rem;
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
  width: 100%;
  max-width: 360px;
}
.login-box h1 { font-size: 1.3rem; margin: 0 0 0.25rem; text-align: center; }
.login-box .subtitle { text-align: center; color: var(--muted); margin: 0 0 1.5rem; font-size: 0.9rem; }
.login-box label { display: block; margin: 0.75rem 0 0.25rem; font-size: 0.9rem; }
.login-box input {
  width: 100%; padding: 0.6rem 0.75rem; border: 1px solid var(--border);
  border-radius: 8px; font-size: 1rem;
}
.login-box button {
  margin-top: 1.5rem; width: 100%; padding: 0.7rem; background: var(--primary);
  color: white; border: none; border-radius: 8px; font-size: 1rem; cursor: pointer;
}
.login-box button:hover { background: var(--primary-dark); }

/* --- App header --- */
.app-header {
  background: var(--card-bg);
  padding: 1rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border);
}
.app-header h1 { font-size: 1.2rem; margin: 0; }
.logout-link { color: var(--muted); text-decoration: none; font-size: 0.9rem; }
.logout-link:hover { color: var(--text); }

main {
  max-width: 1100px;
  margin: 1.5rem auto;
  padding: 0 1rem 3rem;
}

.card {
  background: var(--card-bg);
  border-radius: 12px;
  padding: 1.5rem;
  margin-bottom: 1.25rem;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}
.card h2 { margin-top: 0; font-size: 1.05rem; }

.field-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}
.field { display: flex; flex-direction: column; position: relative; }
.field.span-2 { grid-column: span 2; }
.field label { font-size: 0.85rem; color: var(--muted); margin-bottom: 0.3rem; }
.field input {
  padding: 0.55rem 0.7rem; border: 1px solid var(--border); border-radius: 8px; font-size: 0.95rem;
}
.field input:focus { outline: 2px solid var(--primary); outline-offset: -1px; }

.autocomplete-field { position: relative; }
/* Cac o goi y duoc JS chuyen ra document.body va dinh vi bang position:fixed,
   de khong bi bo hep/cat theo chieu rong cot bang hay vung scroll cha. */
.suggestions {
  display: none;
  position: fixed;
  background: white;
  border: 1px solid var(--border);
  border-radius: 8px;
  max-height: 260px;
  overflow-y: auto;
  overflow-x: hidden;
  z-index: 1000;
  box-shadow: 0 4px 16px rgba(0,0,0,0.15);
}
.suggestion-item {
  padding: 0.5rem 0.8rem;
  cursor: pointer;
  font-size: 0.9rem;
  white-space: nowrap;
}
.suggestion-item:hover, .suggestion-item.active { background: #eff6ff; }
.suggestion-item .s-main { color: var(--text); }
.suggestion-item .s-sub { color: var(--muted); font-size: 0.82rem; margin-left: 0.4rem; }

.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; min-width: 900px; }
th, td { border: 1px solid var(--border); padding: 0.4rem; vertical-align: top; }
th { background: #f9fafb; font-size: 0.8rem; color: var(--muted); text-align: left; }
td input { width: 100%; border: 1px solid transparent; padding: 0.35rem; font-size: 0.9rem; border-radius: 6px; }
td input:focus { border-color: var(--primary); outline: none; }
.col-stt { width: 34px; text-align: center; }
.col-sl, .col-gia, .col-thanhtien { width: 100px; }
.col-xoa { width: 32px; text-align: center; }
.thanh_tien { background: #f9fafb; font-weight: 600; }
.ghi_chu_tu_do { margin-top: 4px; }

.remove-row {
  border: none; background: var(--danger-bg); color: var(--danger);
  width: 24px; height: 24px; border-radius: 50%; cursor: pointer; font-size: 1rem; line-height: 1;
}
.remove-row:hover { background: #fee2e2; }

.btn-secondary {
  margin-top: 0.75rem;
  background: #eef2ff; color: var(--primary-dark); border: none;
  padding: 0.5rem 1rem; border-radius: 8px; cursor: pointer; font-size: 0.9rem;
}
.btn-secondary:hover { background: #e0e7ff; }

.btn-primary {
  background: var(--primary); color: white; border: none;
  padding: 0.75rem 1.5rem; border-radius: 8px; font-size: 1rem; cursor: pointer;
  text-decoration: none; display: inline-block; text-align: center;
}
.btn-primary:hover { background: var(--primary-dark); }
.btn-primary:disabled { opacity: 0.6; cursor: not-allowed; }

.tong-cong {
  margin-top: 1rem; font-size: 1.1rem; font-weight: 600; text-align: right;
}

.error-msg {
  background: var(--danger-bg); color: var(--danger);
  padding: 0.75rem 1rem; border-radius: 8px; margin-bottom: 1rem; font-size: 0.9rem;
}

.result-card { text-align: center; }
.result-actions { display: flex; gap: 0.75rem; justify-content: center; flex-wrap: wrap; margin-top: 1rem; }

@media (max-width: 700px) {
  .field-grid { grid-template-columns: 1fr; }
  .field.span-2 { grid-column: span 1; }
}