:root {
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --secondary: #16a34a;
    --accent: #facc15;
    --bg: #f8fafc;
    --card: #ffffff;
    --text: #1e293b;
    --muted: #64748b;
    --border: #e2e8f0;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: Arial, Helvetica, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
}

.container {
    width: min(1100px, 92%);
    margin: 0 auto;
}

/* Header */

.site-header {
    background: #ffffff;
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 0;
}

.logo {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--primary-dark);
    text-decoration: none;
}

.main-nav {
    display: flex;
    gap: 22px;
}

.main-nav a {
    color: var(--text);
    text-decoration: none;
    font-weight: 600;
}

.main-nav a:hover {
    color: var(--primary);
}

/* Sticky heading section */

.sticky-hero {
    position: sticky;
    top: 65px;
    z-index: 900;
    background: linear-gradient(135deg, #dbeafe, #ecfdf5);
    border-bottom: 1px solid var(--border);
    padding: 28px 0;
}

.sticky-hero h1 {
    margin: 0;
    font-size: clamp(2rem, 5vw, 3.3rem);
    color: var(--primary-dark);
}

.sticky-hero p {
    margin: 8px 0 0;
    color: var(--muted);
    font-size: 1.1rem;
}

/* Main */

.main-content {
    padding: 40px 0;
}

.intro-card {
    background: var(--card);
    padding: 32px;
    border-radius: 18px;
    border: 1px solid var(--border);
    box-shadow: 0 10px 25px rgba(15, 23, 42, 0.06);
    margin-bottom: 32px;
}

.intro-card h2 {
    margin-top: 0;
    color: var(--primary-dark);
}

.btn-primary {
    display: inline-block;
    margin-top: 14px;
    background: var(--primary);
    color: #ffffff;
    padding: 12px 20px;
    border-radius: 10px;
    text-decoration: none;
    font-weight: 700;
}

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

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 22px;
}

.feature-card {
    background: var(--card);
    padding: 24px;
    border-radius: 16px;
    border: 1px solid var(--border);
}

.feature-card h3 {
    margin-top: 0;
    color: var(--secondary);
}

/* Footer */

.site-footer {
    background: #0f172a;
    color: #cbd5e1;
    padding: 24px 0;
    text-align: center;
}

/* Mobile */

@media (max-width: 768px) {
    .header-inner {
        flex-direction: column;
        gap: 14px;
    }

    .main-nav {
        flex-wrap: wrap;
        justify-content: center;
        gap: 14px;
    }

    .sticky-hero {
        top: 105px;
        padding: 22px 0;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .intro-card {
        padding: 24px;
    }
}

.tool-form {
  max-width: 750px;
  margin: 30px auto;
  padding: 28px;
  background: #ffffff;
  border-radius: 14px;
  box-shadow: 0 8px 24px rgba(0,0,0,0.08);
  font-family: Arial, sans-serif;
}

.tool-form h2 {
  margin-bottom: 22px;
  color: #1f4e79;
}

.tool-form label {
  display: block;
  margin: 14px 0 6px;
  font-weight: 600;
  color: #333;
}

.tool-form input[type="url"],
.tool-form select {
  width: 100%;
  padding: 12px;
  border: 1px solid #ccd6dd;
  border-radius: 8px;
  font-size: 16px;
}

.checkbox-group {
  margin: 18px 0;
  padding: 14px;
  background: #f4f8fb;
  border-radius: 10px;
}

.checkbox-group label {
  font-weight: normal;
  margin: 10px 0;
}

.checkbox-group input {
  margin-right: 8px;
}

.tool-form button {
  width: 100%;
  margin-top: 20px;
  padding: 14px;
  background: #2f80ed;
  color: white;
  border: none;
  border-radius: 10px;
  font-size: 17px;
  font-weight: bold;
  cursor: pointer;
}

.tool-form button:hover {
  background: #1f6fd1;
}


textarea {
    width: 100%;
    min-height: 180px;
    padding: 14px 16px;
    margin-top: 10px;
    border: 1px solid #ccd5e0;
    border-radius: 10px;
    font-size: 16px;
    font-family: Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
    resize: vertical;
    box-sizing: border-box;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

textarea:focus {
    outline: none;
    border-color: #2b6cb0;
    box-shadow: 0 0 0 3px rgba(43, 108, 176, 0.15);
}

textarea::placeholder {
    color: #888;
}

.toolkit-btn {
  display: inline-block;
  padding: 14px 26px;
  background: linear-gradient(135deg, #2f80ed, #56ccf2);
  color: #ffffff;
  font-size: 16px;
  font-weight: 700;
  text-decoration: none;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  box-shadow: 0 6px 14px rgba(47, 128, 237, 0.25);
  transition: all 0.25s ease;
}

.toolkit-btn:hover {
  background: linear-gradient(135deg, #256fd1, #40b9df);
  transform: translateY(-2px);
  box-shadow: 0 8px 18px rgba(47, 128, 237, 0.35);
}

.toolkit-btn:active {
  transform: translateY(0);
  box-shadow: 0 4px 10px rgba(47, 128, 237, 0.25);
}