/* ===========================
   RESET & BASE
=========================== */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: #1f2937;
    background-color: #f9fafb;
}

img {
    max-width: 100%;
    display: block;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

button {
    border: none;
    background: none;
    cursor: pointer;
}

/* ===========================
   VARIABLES DESIGN SYSTEM
=========================== */
:root {
    --primary: #0f766e; 
    --primary-dark: #115e59;
    --secondary: #1e40af;
    --gray-50: #f9fafb;
    --gray-200: #e5e7eb;
    --gray-500: #6b7280;
    --gray-700: #374151;
    --gray-900: #111827;
    --white: #ffffff;
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --shadow-sm: 0 4px 10px rgba(0,0,0,0.04);
    --shadow-md: 0 10px 25px rgba(0,0,0,0.06);
    --max-width: 1200px;
}

/* ===========================
   CONTAINER
=========================== */
.container {
    width: 90%;
    max-width: var(--max-width);
    margin-inline: auto;
}

/* ===========================
   HEADER / NAVBAR
=========================== */
.header {
    background: var(--white);
    border-bottom: 1px solid var(--gray-200);
    position: sticky;
    top: 0;
    z-index: 1000;
}

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

.logo-zone img {
    height: 46px;
    object-fit: contain;
}

.nav {
    display: flex;
    align-items: center;
    gap: 26px;
}

.nav a {
    font-weight: 500;
    color: var(--gray-700);
    position: relative;
    padding-bottom: 4px;
}

.nav a::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: width 0.25s ease;
}

.nav a:hover::after {
    width: 100%;
}

/* ===========================
   BUTTONS
=========================== */
.btn-primary {
    background: var(--primary);
    color: var(--white);
    padding: 10px 18px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 14.5px;
    transition: all 0.25s ease;
    box-shadow: var(--shadow-sm);
}

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

.btn-secondary {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
    padding: 9px 16px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    transition: all 0.25s ease;
}

.btn-secondary:hover {
    background: var(--primary);
    color: var(--white);
}

/* ===========================
   TYPOGRAPHY
=========================== */
h1, h2, h3, h4, h5 {
    color: var(--gray-900);
    line-height: 1.2;
    font-weight: 700;
}

h1 { font-size: clamp(32px, 4vw, 44px); }
h2 { font-size: clamp(26px, 3vw, 34px); }
h3 { font-size: 20px; }

p {
    color: var(--gray-500);
    font-size: 15.5px;
}

/* ===========================
   FOOTER
=========================== */
.footer {
    background: var(--white);
    border-top: 1px solid var(--gray-200);
    padding: 70px 0 0;
    margin-top: 80px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
    margin-bottom: 40px;
}

.footer h4 {
    font-size: 16px;
    margin-bottom: 14px;
}

.footer p,
.footer li {
    font-size: 14.5px;
    color: var(--gray-500);
    margin-bottom: 6px;
}

.footer-bottom {
    border-top: 1px solid var(--gray-200);
    padding: 18px 0;
    text-align: center;
    font-size: 13.5px;
    color: var(--gray-500);
}

/* ===========================
   UTILITIES
=========================== */
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-primary { color: var(--primary); }
.bg-white { background: var(--white); }
.mt-20 { margin-top: 20px; }
.mb-20 { margin-bottom: 20px; }

/* ===========================
   RESPONSIVE
=========================== */
@media (max-width: 1024px) {
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav { gap: 16px; font-size: 14px; }
    .footer-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
    .header-container { flex-direction: column; gap: 12px; }
    .nav { flex-wrap: wrap; justify-content: center; }
}