:root {
  --bg-main: #f5f7fb;
  --bg-card: #ffffff;
  --bg-dark: #111827;
  --text-main: #1f2937;
  --text-muted: #6b7280;
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --border: #e5e7eb;
  --danger: #dc2626;
  --danger-dark: #b91c1c;
  --shadow: 0 18px 40px rgba(15, 23, 42, 0.08);
  --radius: 18px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: Arial, Helvetica, sans-serif;
  background: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
}

a {
  text-decoration: none;
  color: inherit;
}

.hero {
  background: linear-gradient(135deg, #0f172a, #1e3a8a);
  color: white;
  padding: 24px 8%;
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 70px;
}

.logo {
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.5px;
}

.nav-links {
  display: flex;
  gap: 24px;
}

.nav-links a {
  color: #dbeafe;
  font-size: 0.95rem;
}

.nav-links a:hover {
  color: white;
}

.hero-content {
  display: grid;
  grid-template-columns: 1.4fr 0.8fr;
  gap: 40px;
  align-items: center;
  padding-bottom: 70px;
}

.eyebrow {
  color: #60a5fa;
  text-transform: uppercase;
  font-weight: 700;
  letter-spacing: 1.5px;
  font-size: 0.75rem;
  margin-bottom: 10px;
}

.hero h1 {
  font-size: clamp(2.3rem, 6vw, 4.8rem);
  line-height: 1.05;
  max-width: 800px;
  margin-bottom: 22px;
}

.hero-text {
  color: #dbeafe;
  max-width: 650px;
  font-size: 1.1rem;
  margin-bottom: 28px;
}

.hero-buttons {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.primary-btn,
.secondary-btn,
.danger-btn {
  border: none;
  padding: 13px 18px;
  border-radius: 999px;
  cursor: pointer;
  font-weight: 700;
  transition: 0.2s ease;
  display: inline-block;
  text-align: center;
}

.primary-btn {
  background: var(--primary);
  color: white;
}

.primary-btn:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
}

.secondary-btn {
  background: white;
  color: var(--primary);
  border: 1px solid var(--border);
}

.secondary-btn:hover {
  background: #eff6ff;
  transform: translateY(-1px);
}

.danger-btn {
  background: var(--danger);
  color: white;
}

.danger-btn:hover {
  background: var(--danger-dark);
}

.full-width {
  width: 100%;
  margin-top: 12px;
}

.hero-card {
  background: rgba(255, 255, 255, 0.12);
  padding: 28px;
  border-radius: var(--radius);
  border: 1px solid rgba(255, 255, 255, 0.18);
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow);
}

.hero-card h2 {
  margin-bottom: 20px;
}

.hero-card p {
  color: #dbeafe;
  margin-top: 18px;
}

.hero-card strong {
  font-size: 2.4rem;
  display: block;
}

main {
  padding: 60px 8%;
}

.section-heading {
  max-width: 750px;
  margin-bottom: 28px;
}

.section-heading h2 {
  font-size: clamp(2rem, 4vw, 3rem);
  margin-bottom: 10px;
  letter-spacing: -1px;
}

.section-heading p {
  color: var(--text-muted);
}

.dashboard {
  margin-bottom: 55px;
}

.dashboard-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-bottom: 20px;
}

.stat-card,
.card,
.status-box {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
}

.stat-card span {
  color: var(--text-muted);
  font-weight: 700;
}

.stat-card strong {
  font-size: 2.4rem;
  display: block;
  margin: 8px 0;
}

.stat-card p,
.status-box p {
  color: var(--text-muted);
}

.status-box h3 {
  margin-bottom: 8px;
}

.tabs-section {
  display: flex;
  justify-content: center;
  margin-bottom: 35px;
}

.tab-buttons {
  background: white;
  border: 1px solid var(--border);
  padding: 8px;
  border-radius: 999px;
  box-shadow: var(--shadow);
  display: flex;
  gap: 8px;
}

.tab-btn {
  border: none;
  padding: 12px 18px;
  border-radius: 999px;
  cursor: pointer;
  background: transparent;
  color: var(--text-muted);
  font-weight: 700;
}

.tab-btn.active {
  background: var(--primary);
  color: white;
}

.tool-section {
  display: none;
  margin-bottom: 55px;
}

.tool-section.active-tool {
  display: block;
}

.tool-layout {
  display: grid;
  grid-template-columns: 0.85fr 1.35fr;
  gap: 24px;
  align-items: start;
}

.card h3 {
  margin-bottom: 16px;
}

label {
  display: block;
  margin: 14px 0 6px;
  font-weight: 700;
  font-size: 0.92rem;
}

input,
select {
  width: 100%;
  padding: 13px 14px;
  border-radius: 12px;
  border: 1px solid var(--border);
  font-size: 1rem;
  outline: none;
}

input:focus,
select:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.12);
}

.table-wrapper {
  overflow-x: auto;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 8px;
}

th,
td {
  padding: 14px;
  border-bottom: 1px solid var(--border);
  text-align: left;
}

th {
  color: var(--text-muted);
  font-size: 0.88rem;
}

.empty-message {
  text-align: center;
  color: var(--text-muted);
}

.delete-small-btn {
  border: none;
  background: #fee2e2;
  color: var(--danger);
  padding: 8px 10px;
  border-radius: 10px;
  cursor: pointer;
  font-weight: 700;
}

.delete-small-btn:hover {
  background: #fecaca;
}

.final-calculator {
  margin-top: 28px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}

.gpa-summary-box {
  margin-top: 28px;
  background: #eff6ff;
  border-radius: var(--radius);
  padding: 22px;
}

.gpa-summary-box p {
  color: var(--text-muted);
}

.gpa-summary-box strong {
  font-size: 2.5rem;
  color: var(--primary);
}

.actions-section {
  display: flex;
  justify-content: center;
  gap: 14px;
  margin: 50px 0 20px;
  flex-wrap: wrap;
}

.helper-text {
  color: var(--text-muted);
  font-size: 0.92rem;
  margin-bottom: 14px;
}

footer {
  text-align: center;
  padding: 25px;
  color: var(--text-muted);
  background: white;
  border-top: 1px solid var(--border);
}

@media (max-width: 900px) {
  .hero-content,
  .tool-layout,
  .dashboard-grid {
    grid-template-columns: 1fr;
  }

  .navbar {
    flex-direction: column;
    gap: 18px;
    align-items: flex-start;
  }

  .nav-links {
    flex-wrap: wrap;
  }
}

@media (max-width: 600px) {
  .hero,
  main {
    padding-left: 5%;
    padding-right: 5%;
  }

  .tab-buttons {
    flex-direction: column;
    border-radius: 18px;
    width: 100%;
  }

  .tab-btn {
    width: 100%;
  }

  .hero-buttons,
  .actions-section {
    flex-direction: column;
  }

  .primary-btn,
  .secondary-btn,
  .danger-btn {
    width: 100%;
  }
}

/* Dashboard Layout Split */
.dashboard-split {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 24px;
  margin-bottom: 20px;
}

.dashboard-grid.two-col {
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}

.dashboard-grid.one-col {
  grid-template-columns: 1fr;
  gap: 18px;
}

/* Tool Data Color Coding */
.course-card {
  border-top: 4px solid var(--primary);
}

.gpa-card {
  border-top: 4px solid #10b981;
}

/* Mobile Responsiveness for Split Layout */
@media (max-width: 900px) {
  .dashboard-split {
    grid-template-columns: 1fr;
  }
}

/* GPA Tool Specific Coloring */
.gpa-hero-btn {
  color: #10b981;
  border-color: #10b981;
}

.gpa-hero-btn:hover {
  background: #ecfdf5;
  color: #10b981;
}

.tab-btn.gpa-tab.active {
  background: #10b981;
  color: white;
}

.primary-btn.gpa-btn {
  background: #10b981;
}

.primary-btn.gpa-btn:hover {
  background: #059669;
}