/* ========================================
   Flat Design — Variables & Reset
   ======================================== */
:root {
  --primary: #1a365d;
  --primary-mid: #2c5282;
  --primary-light: #2b6cb0;
  --accent: #2b6cb0;
  --accent-light: #4299e1;
  --accent-soft: #ebf4ff;

  --phase-start: #2b6cb0;
  --phase-input: #2f855a;
  --phase-process: #b7791f;
  --phase-output: #6b46c1;
  --phase-support: #c05621;
  --phase-analysis: #c53030;

  --bg: #f8f9fa;
  --bg-card: #ffffff;
  --text: #1a202c;
  --text-muted: #4a5568;
  --border: #cbd5e0;
  --border-strong: #a0aec0;

  --sidebar-w: 270px;
  --header-h: 64px;
  --timeline-w: 2px;
  --node-gap: 2rem;
  --card-max: 520px;

  --radius: 4px;
  --radius-sm: 4px;
  --transition: 0.2s ease;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 20px);
}

body {
  font-family: "Noto Sans Bengali", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 15px;
}

a { color: inherit; text-decoration: none; }
ul { list-style: none; }

/* ========================================
   Layout
   ======================================== */
.layout { display: flex; min-height: 100vh; }

.main-wrapper {
  flex: 1;
  margin-left: var(--sidebar-w);
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.main-content {
  flex: 1;
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 2rem 2rem 3rem;
}

/* ========================================
   Sidebar — solid flat
   ======================================== */
.sidebar {
  position: fixed;
  top: 0; left: 0;
  width: var(--sidebar-w);
  height: 100vh;
  background: var(--primary);
  color: #e2e8f0;
  display: flex;
  flex-direction: column;
  z-index: 200;
  transition: transform var(--transition);
  border-right: 2px solid #0f2744;
}

.sidebar-header {
  padding: 1.25rem 1rem 1rem;
  border-bottom: 1px solid rgba(255,255,255,0.12);
  text-align: center;
}

.sidebar-logo {
  width: 44px; height: 44px;
  margin: 0 auto 0.6rem;
  background: #2c5282;
  border: 2px solid #4299e1;
  border-radius: var(--radius);
  display: grid;
  place-items: center;
  font-size: 1.2rem;
  color: #fff;
}

.sidebar-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: #fff;
}

.sidebar-subtitle {
  font-size: 0.7rem;
  color: #90cdf4;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-top: 0.15rem;
}

.sidebar-nav {
  flex: 1;
  overflow-y: auto;
  padding: 0.5rem 0 1rem;
  scrollbar-width: thin;
  scrollbar-color: rgba(255,255,255,0.2) transparent;
}

.nav-group { margin-bottom: 0.5rem; }

.nav-group-label {
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: #718096;
  padding: 0.5rem 1rem 0.25rem;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.45rem 1rem;
  font-size: 0.82rem;
  color: #a0aec0;
  border-left: 3px solid transparent;
  transition: background var(--transition), color var(--transition);
  line-height: 1.3;
}

.nav-item i {
  width: 16px;
  text-align: center;
  font-size: 0.75rem;
}

.nav-item:hover {
  background: #2c5282;
  color: #fff;
}

.nav-item.active {
  background: #2c5282;
  color: #fff;
  border-left-color: #4299e1;
  font-weight: 600;
}

.nav-item.active i { color: #90cdf4; }

.sidebar-overlay {
  display: none;
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.45);
  z-index: 150;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition);
}

.sidebar-overlay.visible { opacity: 1; pointer-events: auto; }

/* ========================================
   Mobile Header
   ======================================== */
.top-header {
  display: none;
  position: sticky; top: 0; z-index: 100;
  background: var(--bg-card);
  border-bottom: 2px solid var(--border);
  padding: 0.65rem 1rem;
  align-items: center;
  gap: 0.75rem;
  min-height: var(--header-h);
}

.menu-toggle {
  display: flex; flex-direction: column; gap: 5px;
  background: none; border: none; cursor: pointer; padding: 4px;
}

.menu-toggle span {
  display: block; width: 22px; height: 2px;
  background: var(--primary);
  transition: var(--transition);
}

.menu-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle.open span:nth-child(2) { opacity: 0; }
.menu-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.top-label {
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
  font-weight: 600;
}

.top-title {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--primary);
  line-height: 1.3;
}

/* ========================================
   Hero — solid flat
   ======================================== */
.hero-section {
  background: var(--primary);
  color: #fff;
  border: 2px solid #0f2744;
  border-radius: var(--radius);
  padding: 2.5rem 2rem;
  margin-bottom: 2.5rem;
  text-align: center;
}

.hero-icon {
  font-size: 2.25rem;
  color: #90cdf4;
  margin-bottom: 0.75rem;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: #2c5282;
  border: 1px solid #4299e1;
  border-radius: var(--radius);
  padding: 0.35rem 0.85rem;
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 1rem;
}

.hero-section h1 {
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 700;
  color: #fff;
  margin-bottom: 0.75rem;
  line-height: 1.35;
}

.hero-subtitle {
  font-size: 1rem;
  color: #cbd5e0;
  max-width: 640px;
  margin: 0 auto 1.5rem;
  line-height: 1.65;
}

.hero-flow-preview {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  background: #2c5282;
  border: 1px solid #4299e1;
  border-radius: var(--radius);
  padding: 0.6rem 1rem;
  font-size: 0.82rem;
}

.hero-flow-preview span {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  white-space: nowrap;
}

.hero-flow-preview i.fa-arrow-right {
  font-size: 0.65rem;
  opacity: 0.7;
}

/* ========================================
   Workflow Timeline — flat line
   ======================================== */
.workflow-timeline {
  position: relative;
  padding: 0 0 2rem;
}

.workflow-timeline::before {
  content: "";
  position: absolute;
  top: 0; bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: var(--timeline-w);
  background: var(--border-strong);
  z-index: 0;
}

/* Phase Labels — flat text blocks */
.phase-label {
  position: relative;
  z-index: 2;
  display: flex;
  justify-content: center;
  margin: 2rem 0 1.25rem;
}

.phase-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  background: var(--bg-card);
  border: 2px solid var(--border-strong);
  border-left: 4px solid var(--phase-start);
  color: var(--primary);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 0.45rem 1rem;
  border-radius: var(--radius);
}

.phase-badge--input { border-left-color: var(--phase-input); }
.phase-badge--process { border-left-color: var(--phase-process); }
.phase-badge--output { border-left-color: var(--phase-output); }
.phase-badge--support { border-left-color: var(--phase-support); }
.phase-badge--analysis { border-left-color: var(--phase-analysis); }

/* Flow Nodes */
.flow-node {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: start;
  margin-bottom: var(--node-gap);
  scroll-margin-top: calc(var(--header-h) + 20px);
}

.flow-node--center {
  grid-template-columns: 1fr;
  justify-items: center;
}

.flow-node--center .flow-marker {
  position: relative;
  left: auto;
  transform: none;
  margin: 0 auto 0.75rem;
}

.flow-node--center .flow-card {
  max-width: 680px;
  width: 100%;
}

.flow-node--left .flow-card {
  grid-column: 1;
  justify-self: end;
  max-width: var(--card-max);
  width: 100%;
  margin-right: 1.5rem;
}

.flow-node--right .flow-card {
  grid-column: 3;
  justify-self: start;
  max-width: var(--card-max);
  width: 100%;
  margin-left: 1.5rem;
}

.flow-marker {
  grid-column: 2;
  position: relative;
  z-index: 3;
  width: 40px; height: 40px;
  background: var(--bg-card);
  border: 2px solid var(--accent);
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent);
  flex-shrink: 0;
  margin-top: 1.25rem;
}

.flow-marker--final {
  border-color: var(--phase-analysis);
  color: var(--phase-analysis);
  font-size: 0.9rem;
}

.flow-node--left .flow-card::after,
.flow-node--right .flow-card::after {
  content: "";
  position: absolute;
  top: 2rem;
  width: 1.5rem;
  height: 2px;
  background: var(--border-strong);
}

.flow-node--left .flow-card::after { right: -1.5rem; }
.flow-node--right .flow-card::after { left: -1.5rem; }

/* Flow Cards — border only, no shadow */
.flow-card {
  position: relative;
  background: var(--bg-card);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem 1.75rem;
  transition: border-color var(--transition);
}

.flow-card:hover {
  border-color: var(--border-strong);
}

.flow-card--accent {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.flow-card--warn {
  border-color: #d69e2e;
  background: #fffff0;
}

.flow-card--final {
  border-color: var(--phase-analysis);
  background: #fff5f5;
}

.flow-card-header {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  margin-bottom: 1rem;
  padding-bottom: 0.85rem;
  border-bottom: 2px solid var(--border);
}

.flow-icon {
  width: 44px; height: 44px;
  background: var(--accent-soft);
  border: 2px solid var(--accent);
  border-radius: var(--radius);
  display: grid;
  place-items: center;
  font-size: 1.1rem;
  color: var(--accent);
  flex-shrink: 0;
}

.flow-card h2 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--primary);
  line-height: 1.35;
}

.flow-card p { margin-bottom: 0.75rem; color: var(--text); }
.flow-text-muted { color: var(--text-muted); font-size: 0.92rem; }

/* Feature Lists */
.feature-list li {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  margin-bottom: 0.45rem;
  font-size: 0.92rem;
}

.feature-list li i {
  color: var(--phase-input);
  margin-top: 0.2rem;
  flex-shrink: 0;
}

/* Check Grid */
.check-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 0.5rem;
  margin: 0.75rem 0;
}

.check-grid--3 { grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); }

.check-grid span {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.45rem 0.7rem;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--primary-mid);
}

.check-grid span i { color: var(--phase-input); font-size: 0.75rem; }

/* Metric Grid */
.metric-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 0.5rem;
  margin-top: 0.5rem;
}

.metric-grid--6 { grid-template-columns: repeat(auto-fill, minmax(120px, 1fr)); }

.metric-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.35rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.75rem 0.5rem;
  text-align: center;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--primary-mid);
  transition: border-color var(--transition);
}

.metric-card i { font-size: 1rem; color: var(--accent); }
.metric-card:hover { border-color: var(--border-strong); }

.metric-card--warn { border-color: #d69e2e; }
.metric-card--warn i { color: #b7791f; }

.metric-card--profit {
  background: #f0fff4;
  border-color: #38a169;
  color: #276749;
}

.metric-card--profit i { color: #38a169; }

/* Sub Blocks */
.sub-blocks {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin: 0.75rem 0;
}

.sub-block {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.85rem 1rem;
}

.sub-block h3 {
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--primary-light);
  margin-bottom: 0.4rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.sub-block p { font-size: 0.88rem; margin: 0; color: var(--text-muted); }

/* Formula Box */
.formula-box {
  background: var(--bg);
  border: 2px dashed var(--accent);
  border-radius: var(--radius-sm);
  padding: 1rem 1.25rem;
  margin-top: 0.5rem;
}

.formula-title {
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.formula-eq {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 0.5rem;
}

.formula-results {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: 0.75rem;
}

.formula-results span {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.4rem 0.85rem;
  font-size: 0.85rem;
}

.formula-gap { border-color: #e53e3e !important; color: #c53030; }

/* Status Flow */
.status-flow {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin: 0.75rem 0;
  padding: 0.75rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.78rem;
}

.status-flow span {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.25rem 0.65rem;
  font-weight: 600;
  color: var(--primary-light);
  white-space: nowrap;
}

.status-flow i { font-size: 0.6rem; color: var(--text-muted); }
.status-flow--wrap { justify-content: center; }

/* Approval Flow */
.approval-flow {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.35rem;
  margin: 0.75rem 0;
}

.approval-step {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.55rem 1rem;
  font-size: 0.88rem;
  font-weight: 600;
  width: 100%;
  max-width: 320px;
}

.approval-step span {
  width: 24px; height: 24px;
  background: var(--accent);
  color: #fff;
  border-radius: var(--radius-sm);
  display: grid;
  place-items: center;
  font-size: 0.72rem;
  flex-shrink: 0;
}

.approval-step--final span { background: var(--phase-input); }

.approval-flow > i { color: var(--text-muted); font-size: 0.75rem; }

/* Tags */
.courier-tags, .role-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 0.75rem 0;
}

.courier-tags span, .role-tags span {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.3rem 0.75rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--primary-light);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

/* Highlight & Note */
.highlight-box {
  display: flex;
  align-items: flex-start;
  gap: 0.65rem;
  background: var(--accent-soft);
  border: 2px solid #90cdf4;
  border-radius: var(--radius-sm);
  padding: 0.85rem 1rem;
  margin-top: 0.75rem;
}

.highlight-box i { color: var(--accent); margin-top: 0.15rem; flex-shrink: 0; }
.highlight-box p { margin: 0; color: var(--primary); font-weight: 500; font-size: 0.92rem; }

.note {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  background: #fffff0;
  border: 1px solid #d69e2e;
  border-left: 4px solid #d69e2e;
  padding: 0.65rem 0.85rem;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  color: #744210;
  margin-top: 0.75rem;
}

.note i { margin-top: 0.1rem; flex-shrink: 0; }

/* Footer */
.footer {
  background: var(--primary);
  color: #90cdf4;
  text-align: center;
  padding: 1.1rem;
  font-size: 0.82rem;
  margin-top: auto;
  border-top: 2px solid #0f2744;
}

.footer i { margin-right: 0.35rem; }

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 960px) {
  .main-wrapper { margin-left: 0; }
  .top-header { display: flex; }
  .sidebar { transform: translateX(-100%); }
  .sidebar.open { transform: translateX(0); }
  .sidebar-overlay { display: block; }
  .main-content { padding: 1.25rem 1rem 2rem; }

  .workflow-timeline::before { left: 22px; transform: none; }

  .flow-node,
  .flow-node--left,
  .flow-node--right,
  .flow-node--center {
    grid-template-columns: 40px 1fr;
    gap: 0 1rem;
  }

  .flow-node--center { justify-items: stretch; }

  .flow-marker {
    grid-column: 1;
    grid-row: 1;
    margin-top: 0.5rem;
    width: 34px; height: 34px;
    font-size: 0.68rem;
  }

  .flow-node--center .flow-marker { margin: 0.5rem 0 0; }

  .flow-card,
  .flow-node--left .flow-card,
  .flow-node--right .flow-card,
  .flow-node--center .flow-card {
    grid-column: 2;
    grid-row: 1;
    max-width: 100%;
    margin: 0;
    justify-self: stretch;
  }

  .flow-node--left .flow-card::after,
  .flow-node--right .flow-card::after { display: none; }

  .phase-label { justify-content: flex-start; padding-left: 3.5rem; }

  .sub-blocks { grid-template-columns: 1fr; }
  .hero-flow-preview { font-size: 0.75rem; padding: 0.5rem 0.85rem; }
}

@media (max-width: 480px) {
  .check-grid, .metric-grid { grid-template-columns: 1fr 1fr; }
  .flow-card { padding: 1.15rem; }
  .hero-section { padding: 1.75rem 1.25rem; }
}