:root {
  --bg: #f7f4ef;
  --ink: #121212;
  --muted: #606060;
  --accent: #0f766e;
  --accent-light: #14b8a6;
  --accent-2: #f59e0b;
  --card: #ffffff;
  --card-glass: rgba(255, 255, 255, 0.85);
  --shadow: 0 22px 60px rgba(10, 10, 10, 0.14);
  --shadow-sm: 0 10px 22px rgba(10, 10, 10, 0.08);
  --radius: 22px;
  --radius-sm: 14px;
  --nav-height: 68px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0a0a0a;
    --ink: #f5f5f5;
    --muted: #a0a0a0;
    --card: #141414;
    --card-glass: rgba(20, 20, 20, 0.9);
    --shadow: 0 22px 60px rgba(0, 0, 0, 0.5);
    --shadow-sm: 0 10px 22px rgba(0, 0, 0, 0.3);
  }
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-tap-highlight-color: transparent;
}

body {
  margin: 0;
  font-family: "Manrope", "Segoe UI", sans-serif;
  color: var(--ink);
  min-height: 100vh;
  padding-bottom: calc(var(--nav-height) + 8px);
  -webkit-font-smoothing: antialiased;
  background: 
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(15, 118, 110, 0.15) 0%, transparent 50%),
    radial-gradient(ellipse 60% 40% at 100% 0%, rgba(245, 158, 11, 0.1) 0%, transparent 40%),
    radial-gradient(ellipse 50% 50% at 0% 100%, rgba(15, 118, 110, 0.08) 0%, transparent 50%),
    linear-gradient(180deg, #fefdfb 0%, #f7f4ef 30%, #eef2f6 100%);
  background-attachment: fixed;
}

@media (prefers-color-scheme: dark) {
  body {
    background: 
      radial-gradient(ellipse 80% 50% at 50% -20%, rgba(15, 118, 110, 0.2) 0%, transparent 50%),
      radial-gradient(ellipse 60% 40% at 100% 0%, rgba(245, 158, 11, 0.08) 0%, transparent 40%),
      linear-gradient(180deg, #0f0f0f 0%, #0a0a0a 100%);
    background-attachment: fixed;
  }
}

.app {
  max-width: 1140px;
  margin: 0 auto;
  padding: 20px 16px 24px;
}

/* ========== Header ========== */
header {
  display: flex;
  justify-content: flex-start;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}

.brand h1 {
  margin: 0 0 4px;
  font-size: clamp(24px, 5vw, 38px);
  letter-spacing: 0.02em;
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.brand p {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

h1 {
  margin: 0 0 8px;
  font-size: clamp(24px, 5vw, 38px);
}

p {
  margin: 0;
  color: var(--muted);
}

/* ========== Buttons ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 18px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  text-decoration: none;
  color: var(--ink);
  background: var(--card);
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.btn.primary {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-light) 100%);
  color: #fff;
}

.btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 14px 26px rgba(10, 10, 10, 0.14);
}

.btn:active {
  transform: translateY(0);
}

/* ========== Hero / Tips ========== */
.hero {
  margin: 0 0 16px;
  padding: 16px;
  border-radius: var(--radius);
  background: var(--card-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: var(--shadow);
  display: grid;
  gap: 10px;
}

.hero .tip {
  display: flex;
  gap: 8px;
  align-items: flex-start;
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.45;
}

.tip strong {
  color: var(--ink);
}

/* ========== Status ========== */
.status {
  margin: 14px 0;
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  background: #fff8e7;
  color: #8a5b00;
  display: none;
  font-size: 0.92rem;
}

@media (prefers-color-scheme: dark) {
  .status {
    background: #3d3000;
    color: #ffd666;
  }
}

.status.error {
  background: #ffe8e8;
  color: #8c1d1d;
}

@media (prefers-color-scheme: dark) {
  .status.error {
    background: #3d0000;
    color: #ff8888;
  }
}

/* ========== Cards ========== */
.card {
  background: var(--card-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-radius: var(--radius);
  padding: 16px;
  box-shadow: var(--shadow);
  overflow: hidden;
}

/* ========== Tables ========== */
.table {
  width: 100%;
  border-collapse: collapse;
}

.table th,
.table td {
  padding: 12px 8px;
  border-bottom: 1px solid rgba(128, 128, 128, 0.15);
  text-align: left;
  font-size: 0.92rem;
}

.table th {
  font-weight: 600;
  color: var(--muted);
}

.table a {
  color: var(--accent);
  text-decoration: none;
}

.table a:hover {
  text-decoration: underline;
}

.row-highlight {
  background: rgba(15, 118, 110, 0.1);
}

@media (prefers-color-scheme: dark) {
  .row-highlight {
    background: rgba(20, 184, 166, 0.15);
  }
}

/* ========== Card Layout for Mobile ========== */
@media (max-width: 600px) {
  .table thead {
    display: none;
  }
  .table,
  .table tbody,
  .table tr {
    display: block;
  }
  .table tr {
    background: var(--card);
    border-radius: var(--radius-sm);
    padding: 12px;
    margin-bottom: 10px;
    box-shadow: var(--shadow-sm);
    border: 1px solid rgba(128, 128, 128, 0.1);
  }
  .table td {
    display: flex;
    justify-content: space-between;
    padding: 6px 0;
    border-bottom: 1px solid rgba(128, 128, 128, 0.08);
    font-size: 0.9rem;
  }
  .table td:last-child {
    border-bottom: none;
  }
  .table td::before {
    content: attr(data-label);
    font-weight: 600;
    color: var(--muted);
    margin-right: 10px;
  }
}

/* ========== Action Buttons ========== */
.fav,
.remove {
  border: none;
  background: rgba(128, 128, 128, 0.12);
  border-radius: 999px;
  padding: 6px 12px;
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--ink);
  transition: background 0.2s ease;
}

.fav:hover,
.remove:hover {
  background: rgba(128, 128, 128, 0.2);
}

/* ========== Manual Input ========== */
.manual {
  margin-top: 10px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}

.manual input {
  border: 1px solid rgba(128, 128, 128, 0.3);
  border-radius: 10px;
  padding: 10px 12px;
  min-width: 130px;
  font-family: inherit;
  font-size: 0.92rem;
  background: var(--card);
  color: var(--ink);
}

/* ========== Bottom Navigation ========== */
.nav-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: var(--card-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: 0 -4px 30px rgba(0, 0, 0, 0.1);
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 4px;
  z-index: 1000;
  padding: 0 12px;
  padding-bottom: env(safe-area-inset-bottom, 0);
}

@media (prefers-color-scheme: dark) {
  .nav-bar {
    box-shadow: 0 -4px 30px rgba(0, 0, 0, 0.4);
  }
}

.nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  text-decoration: none;
  color: var(--muted);
  font-size: 0.68rem;
  font-weight: 600;
  padding: 8px 14px;
  border-radius: 14px;
  transition: color 0.2s ease, background 0.2s ease, transform 0.15s ease;
  min-width: 56px;
}

.nav-item svg {
  width: 22px;
  height: 22px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.nav-item.active {
  background: rgba(128, 128, 128, 0.08);
}

.nav-item.active.diesel {
  color: #2563eb;
  background: rgba(37, 99, 235, 0.1);
}

.nav-item.active.e10 {
  color: #16a34a;
  background: rgba(22, 163, 74, 0.1);
}

.nav-item.active svg {
  stroke: currentColor;
}

.nav-item:hover {
  background: rgba(128, 128, 128, 0.08);
  transform: translateY(-1px);
}

.nav-item.active:hover {
  background: rgba(15, 118, 110, 0.15);
}

/* Desktop nav adjustments */
@media (min-width: 768px) {
  .nav-bar {
    gap: 8px;
  }
  .nav-item {
    flex-direction: row;
    gap: 8px;
    padding: 10px 20px;
    font-size: 0.85rem;
  }
}

/* ========== Chart Page ========== */
.chart-card {
  padding: 18px;
}

.chart-title {
  margin: 0 0 6px;
  font-size: clamp(20px, 4vw, 30px);
}

.chart-sub {
  margin: 0 0 16px;
  color: var(--muted);
  font-size: 0.92rem;
}

.chart-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 14px;
}

canvas {
  width: 100% !important;
  height: 380px !important;
  display: block;
}

@media (max-width: 720px) {
  canvas {
    height: 300px !important;
  }
}

/* ========== Management Page ========== */
.toolbar {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 14px;
}

.toolbar .left {
  display: grid;
  gap: 4px;
}

.toolbar h2 {
  margin: 0;
  font-size: clamp(16px, 3vw, 22px);
}

.toolbar .meta {
  color: var(--muted);
  font-size: 0.88rem;
}

.fuel-tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.date-nav {
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
}

.date-nav input[type="date"] {
  border: 1px solid rgba(128, 128, 128, 0.3);
  border-radius: 999px;
  padding: 9px 14px;
  font: inherit;
  font-size: 0.92rem;
  background: var(--card);
  color: var(--ink);
  box-shadow: var(--shadow-sm);
}

.chart-wrap {
  margin-top: 10px;
}

#plot {
  width: 100%;
  height: 420px;
  display: block;
}

@media (max-width: 720px) {
  #plot {
    height: 320px;
  }
}

.note {
  margin-top: 12px;
  color: var(--muted);
  font-size: 0.88rem;
  line-height: 1.5;
}

.note code {
  background: rgba(128, 128, 128, 0.12);
  padding: 2px 6px;
  border-radius: 6px;
  font-size: 0.85em;
}

/* ========== Info Page ========== */
.info-section {
  margin-bottom: 24px;
}

.info-section h2 {
  font-size: 1.25rem;
  margin: 0 0 12px;
  color: var(--ink);
}

.info-section p {
  margin: 0 0 8px;
  line-height: 1.6;
}

.info-section a {
  color: var(--accent);
  text-decoration: none;
}

.info-section a:hover {
  text-decoration: underline;
}

/* ========== Responsive adjustments ========== */
@media (max-width: 720px) {
  .app {
    padding: 16px 12px 20px;
  }
  .card {
    padding: 14px;
  }
  header {
    gap: 12px;
  }
}

/* ========== Utility: Hidden ========== */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}