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

/* Theme variables */
:root {
  --bg: #f4f6fb;
  --text: #2c3e50;
  --card-bg: #ffffff;
  --card-border: rgba(7,41,99,0.10);
  --muted: #5e6b78;
  --accent: #21ba45;
  --accent-contrast: #ffffff;
}

.theme-dark {
  --bg: #0b1220;
  --text: #e6eef7;
  --card-bg: #111a2b;
  --card-border: rgba(255,255,255,0.14);
  --muted: #9fb0c4;
  --accent: #1a8a36;
  --accent-contrast: #ffffff;
}

html, body, .container, header, footer, .content h3, .content h4, .content hr, .main-title { transition: background 220ms ease, color 220ms ease, border-color 220ms ease, box-shadow 220ms ease; }

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  color: var(--text);
  background-color: var(--bg);
  line-height: 1.6;
  padding: 20px;
}

header {
  background: linear-gradient(45deg, #21ba45, #1e9a3f, #17833a);
  color: var(--accent-contrast);
  padding: 1.5rem 2rem;
  text-align: center;
  border-radius: 8px;
  margin-bottom: 2rem;
  box-shadow: 0 6px 18px rgba(0,0,0,0.10);
  position: relative;
}

header h1 {
  font-weight: 700;
  letter-spacing: 1px;
  font-size: 2rem;
}

.container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 2rem;
  background: linear-gradient(180deg, rgba(255,255,255,0.95), rgba(246,251,255,0.95)), var(--card-bg);
  box-shadow: 0 8px 26px rgba(0,0,0,0.10);
  border: 1px solid var(--card-border);
  border-radius: 14px;
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}

.main-title {
  margin-bottom: 2rem;
  text-align: center;
  border-bottom: 2px solid var(--card-border);
  padding-bottom: 1rem;
}

.main-title h2 {
  font-weight: 700;
  font-size: 2rem;
  color: var(--text);
  text-transform: uppercase;
  position: relative;
}

.main-title h2::after {
  content: "";
  display: block;
  width: 80px;
  height: 4px;
  margin: 10px auto 0 auto;
  background: linear-gradient(90deg, #ffa000, #21ba45);
  border-radius: 2px;
}

/* Headings inside content */
.content h3 {
  margin-top: 2rem;
  margin-bottom: 1rem;
  font-weight: 600;
  color: var(--text);
  border-bottom: 1px solid var(--card-border);
  padding-bottom: 0.5rem;
}

.content h4 {
  margin-top: 1.5rem;
  margin-bottom: 0.75rem;
  font-weight: 600;
  color: var(--text);
}

.content p {
  margin-bottom: 1rem;
  text-align: justify;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--text);
}

.content a { color: #0077ff; text-decoration: none; }
.content a:hover { color: #005bba; text-decoration: underline; }

.content strong {
  font-weight: bold;
}

.content hr {
  margin: 2rem 0;
  border: none;
  border-top: 1px solid #e0e0e0;
}

.content ul {
  margin: 1rem 0 1rem 0;
  list-style: none;
}

.content li {
  margin-bottom: 0.5rem;
  font-size: 1rem;
  position: relative;
  padding-left: 1.5rem;
}

.content li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.6rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: linear-gradient(135deg, #21ba45, #0077ff);
  box-shadow: 0 0 0 3px rgba(33,186,69,0.12);
}

footer {
  text-align: center;
  padding: 1.5rem 2rem;
  background: linear-gradient(45deg, #21ba45, #1e9a3f, #17833a);
  color: var(--accent-contrast);
  border-radius: 8px;
  margin-top: 2rem;
  font-size: 0.9rem;
  box-shadow: 0 6px 18px rgba(0,0,0,0.10);
}

/* A simple responsive layout tweak for smaller screens */
@media (max-width: 768px) {
  .container {
    padding: 1rem;
  }

  .main-title h2 {
    font-size: 1.5rem;
  }

  header h1 {
    font-size: 1.5rem;
  }
}

/* Dark theme overrides */
.theme-dark header, .theme-dark footer {
  background: linear-gradient(45deg, #0e1a2f, #0c1a2a, #0b1a24);
  color: var(--accent-contrast);
}

.theme-dark .container {
  background: linear-gradient(180deg, rgba(28,36,54,0.92), rgba(22,30,48,0.92)), var(--card-bg);
  box-shadow: 0 10px 30px rgba(0,0,0,0.35);
  border-color: var(--card-border);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.theme-dark .main-title { border-bottom-color: var(--card-border); }
.theme-dark .content h3 { border-bottom-color: var(--card-border); }
.theme-dark .content a { color: #7db0ff; }
.theme-dark .content a:hover { color: #a5c5ff; }

/* Theme toggle (premium) */
.theme-toggle {
  position: absolute;
  top: 10px;
  right: 10px;
  z-index: 10;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 10px;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,0.28);
  background: rgba(255,255,255,0.10);
  color: #fff;
  cursor: pointer;
  box-shadow: 0 6px 14px rgba(0,0,0,0.18);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  transition: transform 160ms ease, background 160ms ease, box-shadow 160ms ease, border-color 160ms ease;
}
.theme-toggle:hover { transform: translateY(-1px); background: rgba(255,255,255,0.14); box-shadow: 0 8px 18px rgba(0,0,0,0.22); }
.theme-toggle .icon { display: inline-block; }
.theme-toggle .moon { opacity: 0.6; }
.theme-dark .theme-toggle .sun { opacity: 0.5; }
.theme-dark .theme-toggle .moon { opacity: 1; }
.theme-dark .theme-toggle { border-color: rgba(255,255,255,0.22); background: rgba(0,0,0,0.25); }