:root {
  --primary-color: #2563eb;
  --secondary-color: #f8f9fa;
  --bg-color: #ffffff;
  --text-color: #111827;
  --footer-bg: #e5e7eb;
}

[data-theme="dark"] {
  --bg-color: #111827;
  --text-color: #f3f4f6;
  --secondary-color: #1f2937;
  --footer-bg: #1c1c1e;
}

/* Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  scroll-behavior: smooth;
}

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: 'Segoe UI', sans-serif;
  line-height: 1.6;
}

a {
  text-decoration: none;
  color: var(--primary-color);
}

img {
  max-width: 100%;
  height: auto;
}

/* Navbar */
.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  background-color: var(--secondary-color);
  border-bottom: 1px solid #ccc;
  position: sticky;
  top: 0;
  z-index: 1000;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  list-style: none;
}

.nav-links li a {
  color: var(--text-color);
  font-weight: 500;
  padding: 6px 10px;
  border-radius: 6px;
  transition: background-color 0.3s;
}

.nav-links li a:hover {
  background-color: rgba(37, 99, 235, 0.1);
}

.menu-toggle {
  display: none;
}

/* Hero Section */
.hero {
  text-align: center;
  padding: 3rem 1.5rem;
  background: linear-gradient(145deg, var(--primary-color), #60a5fa);
  color: white;
}

.big-hero h1 {
  font-size: 2.4rem;
  margin-bottom: 1rem;
}

.big-hero p {
  font-size: 1.1rem;
  margin-bottom: 1.5rem;
}

.cta-button {
  display: inline-block;
  background-color: white;
  color: var(--primary-color);
  padding: 10px 18px;
  font-weight: 600;
  margin: 0.3rem;
  border-radius: 8px;
  border: none;
  transition: all 0.3s ease;
  cursor: pointer;
}

.cta-button.secondary {
  background-color: rgba(255, 255, 255, 0.2);
  color: white;
  border: 1px solid white;
}

.cta-button:hover {
  transform: scale(1.05);
}

/* Feature Grid */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
  padding: 3rem 2rem;
  background-color: var(--secondary-color);
}

.feature-card {
  background-color: var(--bg-color);
  padding: 1.5rem;
  border-radius: 12px;
  box-shadow: 0 5px 10px rgba(0, 0, 0, 0.06);
  transition: transform 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-5px);
}

/* Form Section */
.form-section {
  max-width: 600px;
  margin: 3rem auto;
  padding: 2rem;
  background-color: var(--secondary-color);
  border-radius: 12px;
  box-shadow: 0 3px 8px rgba(0, 0, 0, 0.05);
}

.form-box label {
  display: block;
  margin-top: 1rem;
  font-weight: 600;
}

.form-box input,
.form-box select {
  width: 100%;
  padding: 10px;
  margin-top: 6px;
  border-radius: 6px;
  border: 1px solid #ccc;
  background-color: white;
}

.result-box {
  margin-top: 1rem;
  font-weight: 600;
  padding: 10px;
  border-left: 4px solid var(--primary-color);
  background-color: #f0f4ff;
  border-radius: 6px;
}

/* Guide Section */
.guide-section {
  padding: 3rem 2rem;
}

.guide-box {
  background-color: var(--secondary-color);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  border-radius: 10px;
  box-shadow: 0 3px 6px rgba(0, 0, 0, 0.04);
}

/* Table Styling */
table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1rem;
  font-size: 1rem;
  background-color: var(--secondary-color);
  color: var(--text-color);
  border-radius: 8px;
  overflow: hidden;
}

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

th, td {
  padding: 14px;
  border: 1px solid #ddd;
  text-align: left;
}

tbody tr:nth-child(even) {
  background-color: rgba(0, 0, 0, 0.02);
}

/* Support Section */
.support-section {
  text-align: center;
  padding: 2.5rem 1rem;
  background-color: var(--secondary-color);
}

/* Footer */
.footer {
  text-align: center;
  background-color: var(--footer-bg);
  padding: 1.5rem;
  font-size: 0.9rem;
  color: #555;
}

/* Dark Mode Button */
.dark-toggle {
  margin-left: 1rem;
  background: none;
  border: 1.5px solid var(--text-color);
  padding: 6px 10px;
  border-radius: 8px;
  color: var(--text-color);
  cursor: pointer;
  transition: all 0.3s ease;
}

.dark-toggle:hover {
  background-color: rgba(255, 255, 255, 0.1);
}

/* Responsive */
@media (max-width: 768px) {
  .nav-links {
    flex-direction: column;
    display: none;
    gap: 0.8rem;
    background: var(--secondary-color);
    position: absolute;
    top: 60px;
    left: 0;
    width: 100%;
    padding: 1rem;
  }

  .nav-links.show {
    display: flex;
  }

  .menu-toggle {
    display: block;
    font-size: 1.5rem;
    cursor: pointer;
    margin-left: auto;
  }

  .navbar {
    flex-wrap: wrap;
  }
}

/* Logo Effects */
.logo img {
  height: 48px;
  padding: 4px;
  vertical-align: middle;
  transition: transform 0.3s ease, filter 0.3s ease;
}

.logo img:hover {
  transform: scale(1.1);
  filter: drop-shadow(0 0 6px var(--primary-color));
}