/* ================= BASE ================= */

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background-color: #FAF6EF;
    color: #1E1E1E;
    font-size: 16px;
    line-height: 1.7;
    animation: fadeIn 0.6s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* ================= HERO (INDEX PAGE) ================= */

.hero {
    text-align: center;
    padding: 90px 20px;
}

.logo {
    width: 250px;
    margin-bottom: 30px;
}

h1 {
    font-weight: 700;
}

.subtitle {
    font-size: 18px;
    max-width: 700px;
    margin: 0 auto 40px;
    line-height: 1.6;
    color: #555;
}

.buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

/* ================= HERO BANNER (Proposal + Technical) ================= */

.hero-banner {
    background: linear-gradient(135deg, #FAF6EF, #F3EFE6);
    padding: 90px 20px 70px 20px;
    text-align: center;
    border-radius: 14px;
    margin-bottom: 70px;
}

.hero-content h1 {
    font-size: 36px;
    color: #2E7D32;
    margin-bottom: 15px;
}

.hero-content p {
    font-size: 18px;
    color: #555;
    max-width: 720px;
    margin: 0 auto;
    line-height: 1.6;
}

/* ================= BUTTONS ================= */

.btn-primary {
    background-color: #E65100;
    color: white;
    padding: 14px 28px;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.2s ease;
}

.btn-secondary {
    border: 2px solid #2E7D32;
    color: #2E7D32;
    padding: 12px 26px;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.2s ease;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0,0,0,0.12);
}

.btn-secondary:hover {
    background-color: #2E7D32;
    color: white;
    transform: translateY(-2px);
}

/* ================= NAVIGATION ================= */

.navbar {
    background-color: white;
    border-bottom: 1px solid #eaeaea;
    padding: 18px 40px;
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.brand {
    font-size: 20px;
    font-weight: 700;
    text-decoration: none;
    color: #2E7D32;
}

.nav-buttons {
    display: flex;
    gap: 16px;
}

.nav-btn {
    padding: 10px 18px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-size: 14px;
    border: 2px solid #E65100;
    color: #E65100;
    transition: all 0.2s ease;
}

.nav-btn:hover {
    background-color: #E65100;
    color: white;
    transform: translateY(-2px);
}

.nav-btn.active {
    background-color: #E65100;
    color: white;
}

/* ================= CONTAINER ================= */

.container {
    max-width: 950px;
    margin: 80px auto;
    padding: 0 25px;
}

/* ================= TYPOGRAPHY ================= */

h2 {
    font-size: 26px;
    margin-bottom: 15px;
    color: #E65100;
}

h3 {
    font-size: 18px;
    margin-top: 25px;
    margin-bottom: 10px;
    color: #2E7D32;
    font-weight: 600;
}

p {
    margin-bottom: 18px;
}

ul, ol {
    margin-bottom: 20px;
    padding-left: 20px;
}

/* ================= CARDS ================= */

.card {
    background: white;
    padding: 35px;
    margin-bottom: 35px;
    border-radius: 14px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.08);
}

/* ================= DIAGRAM ================= */

.diagram {
    background-color: #F3EFE6;
    padding: 20px;
    border-radius: 10px;
    font-family: monospace;
    font-size: 14px;
    overflow-x: auto;
    margin-top: 20px;
}

/* ================= FOOTER ================= */

footer {
    text-align: center;
    padding: 50px 20px;
    font-size: 14px;
    color: #777;
}