/* --- RESET & GLOBAL --- */
body {
    font-family: Arial, Helvetica, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f0f2f5;
    color: #333;
    transition: background-color 0.3s;
}

.hidden { display: none !important; }

/* Tombol Back Home (Pojok Kiri Atas) */
#btn-back-home {
    position: fixed;
    top: 15px;
    left: 15px;
    z-index: 1000;
    padding: 10px 15px;
    background: #333;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-weight: bold;
}

/* --- HOME PAGE STYLE --- */
#home {
    text-align: center;
    padding-top: 50px;
}

.menu-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
    max-width: 900px;
    margin: 40px auto;
    padding: 20px;
}

/* Style Umum untuk Tombol Menu (Baik <button> maupun <a>) */
.menu-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 30px;
    font-size: 18px;
    font-weight: bold;
    border: none;
    border-radius: 15px;
    color: white;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    text-decoration: none; /* Hilangkan garis bawah untuk Link */
    text-align: center;
}

.menu-btn:hover { 
    transform: translateY(-5px); 
    box-shadow: 0 8px 15px rgba(0,0,0,0.2);
}

/* Warna-warna Tombol */
.gizi { background: linear-gradient(135deg, #e74c3c, #c0392b); }
.word { background: linear-gradient(135deg, #3498db, #2980b9); }
.presentasi { background: linear-gradient(135deg, #2ecc71, #27ae60); }
.kalkulator { background: linear-gradient(135deg, #f1c40f, #f39c12); color: #2c3e50; }

/* --- CEK GIZI STYLE --- */
.section-gizi {
    max-width: 400px;
    margin: 80px auto;
    background: white;
    padding: 30px;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}
.form-group { margin-bottom: 15px; text-align: left; }
.form-group input { width: 100%; padding: 10px; box-sizing: border-box; border: 1px solid #ccc; border-radius: 5px; }
.section-gizi button {
    background: #e74c3c; color: white; border: none; padding: 10px 20px;
    border-radius: 5px; cursor: pointer; width: 100%; font-size: 16px;
}
.result-box { margin-top: 20px; font-weight: bold; line-height: 1.5; }

/* --- CALCULATOR STYLE --- */
.section-kalkulator {
    max-width: 320px;
    margin: 80px auto;
    background: #2c3e50;
    padding: 20px;
    border-radius: 15px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.3);
}
.section-kalkulator h2 { color: white; text-align: center; margin-bottom: 15px; }
#calc-display {
    width: 100%; height: 60px; font-size: 28px; text-align: right;
    margin-bottom: 15px; padding: 10px; box-sizing: border-box;
    border-radius: 5px; border: none; background: #ecf0f1;
}
.calc-keys {
    display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px;
}
.calc-keys button {
    padding: 15px; font-size: 20px; border: none; border-radius: 8px;
    cursor: pointer; background: #ecf0f1; color: #333; font-weight: bold;
}
.calc-keys button.operator { background: #f39c12; color: white; }
.calc-keys button.equal { background: #27ae60; color: white; grid-column: span 2; }
.calc-keys button.clear { background: #c0392b; color: white; grid-column: span 2; }

/* --- PRESENTASI STYLE --- */
.section-presentasi header {
    background: #2ecc71; color: white; padding: 30px 20px; text-align: center;
}
.pres-nav {
    background: #27ae60; padding: 15px; text-align: center; position: sticky; top: 0;
}
.pres-nav a {
    color: white; margin: 0 15px; text-decoration: none; font-weight: bold; display: inline-block;
}
.pres-nav a:hover { text-decoration: underline; }

.section-presentasi section {
    padding: 40px 30px; max-width: 900px; margin: 30px auto;
    background: white; border-radius: 10px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}
.section-presentasi h2 { color: #27ae60; border-bottom: 2px solid #eee; padding-bottom: 10px; }
.section-presentasi table {
    width: 100%; border-collapse: collapse; margin-top: 20px;
}
.section-presentasi th, .section-presentasi td {
    border: 1px solid #ddd; padding: 12px; text-align: center;
}
.section-presentasi th { background: #2ecc71; color: white; }
.section-presentasi tr:nth-child(even) { background-color: #f9f9f9; }
.section-presentasi tr:hover { background-color: #f1f1f1; }

.section-presentasi footer {
    text-align: center; padding: 20px; margin-top: 40px;
    background: #27ae60; color: white;
}