:root {
  --primary: #0f172a;
  --primary-accent: #2563eb;
  --primary-hover: #1d4ed8;
  --bg: #f8fafc;
  --surface: #ffffff;
  --text-main: #0f172a;
  --text-muted: #64748b;
  --border: #e2e8f0;
  --radius: 0.75rem;
  --shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
  --font: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

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

body {
  font-family: var(--font);
  background-color: var(--bg);
  color: var(--text-main);
  line-height: 1.6;
}

.container {
  width: 90%;
  max-width: 1200px;
  margin: 0 auto;
}

/* Header & Nav */
header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 50;
}

nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0;
}

.logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-muted);
  font-weight: 500;
  transition: color 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--primary-accent);
}

/* Hero Section */
.hero {
  padding: 5rem 0 3rem;
  text-align: center;
}

.hero h1 {
  font-size: 2.75rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 1rem;
}

.hero p {
  color: var(--text-muted);
  font-size: 1.15rem;
  max-width: 700px;
  margin: 0 auto 2rem;
}

/* UI Elements */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-weight: 600;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
  background-color: var(--primary-accent);
  color: #ffffff;
  text-decoration: none;
}

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

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin: 3rem 0;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow);
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.card:hover {
  border-color: var(--primary-accent);
  transform: translateY(-2px);
}

.card h3 {
  margin-bottom: 0.75rem;
  font-size: 1.25rem;
}

.card p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* Forms */
.form-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2.5rem;
  max-width: 600px;
  margin: 2rem auto;
  box-shadow: var(--shadow);
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.form-control {
  width: 100%;
  padding: 0.75rem 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 1rem;
  font-family: inherit;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.form-control:focus {
  border-color: var(--primary-accent);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

textarea.form-control {
  resize: vertical;
  min-height: 120px;
}

.toast {
  display: none;
  padding: 1rem;
  border-radius: var(--radius);
  margin-bottom: 1rem;
  font-weight: 500;
}

.toast.success {
  background: #dcfce7;
  color: #15803d;
}

.toast.error {
  background: #fee2e2;
  color: #b91c1c;
}

footer {
  border-top: 1px solid var(--border);
  background: var(--surface);
  padding: 2.5rem 0;
  margin-top: 5rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
}