/* style.css */
:root {
    --primary: #B22222; /* แดงปลาร้าแซ่บ */
    --primary-light: #FFD1D1;
    --secondary: #DAA520; /* ทองพรีเมียม */
    --text-dark: #333333;
    --text-light: #666666;
    --bg-light: #FFFDF8;
    --border: #F0E0E0;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: 'Sarabun', sans-serif; background-color: var(--bg-light); color: var(--text-dark); line-height: 1.6; }
h1, h2, h3, h4, .logo { font-family: 'Mitr', sans-serif; color: var(--primary); }
a { text-decoration: none; color: var(--primary); transition: 0.3s; }
img { max-width: 100%; display: block; }

/* Header & Nav */
.main-header { background: #fff; box-shadow: 0 2px 10px rgba(0,0,0,0.05); position: sticky; top: 0; z-index: 100; }
.nav-container { max-width: 1200px; margin: 0 auto; padding: 15px 20px; display: flex; justify-content: space-between; align-items: center; }
.logo { font-size: 1.5rem; font-weight: 600; color: var(--primary); }
.nav-links { list-style: none; display: flex; gap: 20px; }
.nav-links a { color: var(--text-dark); font-weight: 500; }
.nav-links a:hover { color: var(--primary); }

/* Buttons */
.btn-line { display: inline-block; background: #06C755; color: #fff; padding: 12px 25px; border-radius: 30px; font-weight: 600; box-shadow: 0 4px 10px rgba(6,199,85,0.3); }
.btn-call { display: inline-block; background: var(--secondary); color: #fff; padding: 12px 25px; border-radius: 30px; font-weight: 600; box-shadow: 0 4px 10px rgba(218,165,32,0.3); }
.btn-outline { display: inline-block; background: #fff; color: var(--primary); border: 2px solid var(--primary); padding: 10px 25px; border-radius: 30px; font-weight: 600; }
.btn-line:hover, .btn-call:hover { transform: translateY(-2px); color: #fff; }

/* Layouts */
.container { max-width: 1200px; margin: 0 auto; padding: 60px 20px; }
.text-center { text-align: center; }
.section-title { font-size: 2.2rem; margin-bottom: 20px; text-align: center; }

/* Grids */
.grid-2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 30px; }
.grid-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 30px; }
.grid-4 { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 20px; }

/* Cards & Images */
.card { background: #fff; border-radius: 15px; padding: 25px; border: 1px solid var(--border); box-shadow: 0 4px 15px rgba(0,0,0,0.03); transition: 0.3s; text-align: center; }
.card:hover { transform: translateY(-5px); box-shadow: 0 8px 25px rgba(178,34,34,0.1); border-color: var(--primary-light); }
.img-1-1 { width: 100%; aspect-ratio: 1/1; object-fit: cover; border-radius: 12px; margin-bottom: 15px; }

/* Calculator */
.calculator-box { max-width: 800px; margin: 0 auto; background: #fff; padding: 40px; border-radius: 20px; box-shadow: 0 10px 30px rgba(0,0,0,0.08); border: 2px solid var(--primary-light); }
.form-group { margin-bottom: 20px; text-align: left; }
.form-group label { display: block; font-weight: 600; margin-bottom: 8px; color: var(--text-dark); }
.form-control { width: 100%; padding: 12px 15px; border: 1px solid #ddd; border-radius: 8px; font-family: 'Sarabun', sans-serif; font-size: 1rem; }
.form-control:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px var(--primary-light); }

/* Footer */
.main-footer { background: var(--text-dark); color: #fff; padding: 40px 20px; text-align: center; }
.main-footer p { color: #ccc; }

/* Lightbox */
.lightbox { position: fixed; inset: 0; background: rgba(0,0,0,0.9); z-index: 9999; display: none; align-items: center; justify-content: center; opacity: 0; transition: 0.3s; }
.lightbox.active { display: flex; opacity: 1; }
.lightbox-img { max-width: 90vw; max-height: 85vh; border-radius: 10px; }
.lightbox-close { position: absolute; top: 20px; right: 30px; color: #fff; font-size: 40px; cursor: pointer; }