/* ===== CSS RESET & BASE ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
    font-family: 'Segoe UI', 'Inter', Arial, sans-serif;
    background: #1e1e1e; color: #e0e0e0; line-height: 1.7; overflow-x: hidden;
}
a { color: #67eb34; text-decoration: none; transition: color 0.2s; }
a:hover { color: #8dab82; }
::selection { background: #67eb34; color: #1e1e1e; }
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: #151515; }
::-webkit-scrollbar-thumb { background: #444; border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: #67eb34; }

/* ===== TOP NAV ===== */
.topnav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    background: #151515; border-bottom: 1px solid #2a2a2a;
    display: flex; align-items: center; justify-content: space-between;
    padding: 0 24px; height: 60px;
}
.topnav::after {
    content: ''; position: absolute; bottom: 0; left: 0; right: 0; height: 2px;
    background: linear-gradient(90deg, #67eb34, #2a5e15, transparent);
}
.topnav-left { display: flex; align-items: center; gap: 12px; }
.topnav-left img { width: 36px; height: 36px; }
.topnav-left .brand {
    font-family: 'Dubai', 'Segoe UI', sans-serif;
    font-size: 1.25rem; font-weight: 700; color: #67eb34;
}
.topnav-left .brand-sub { color: #666; font-size: 0.8rem; margin-left: 8px; }
.topnav-right { display: flex; align-items: center; gap: 16px; }
.topnav-right .try-link { color: #8dab82; font-weight: 600; font-size: 0.9rem; }
.topnav-right .try-link:hover { color: #67eb34; }
.btn-buy {
    background: #67eb34; color: #111; font-weight: 700; font-size: 0.85rem;
    padding: 8px 20px; border-radius: 6px; border: none; cursor: pointer;
    transition: background 0.2s, box-shadow 0.2s;
}
.btn-buy:hover { background: #8dab82; box-shadow: 0 0 16px #67eb3466; }
.hamburger { display: none; background: none; border: none; cursor: pointer; padding: 4px; }
.hamburger span { display: block; width: 24px; height: 2px; background: #e0e0e0; margin: 5px 0; transition: 0.3s; }

/* ===== LAYOUT ===== */
.page-wrapper { display: flex; margin-top: 60px; min-height: calc(100vh - 60px); }

/* ===== SIDEBAR ===== */
.sidebar {
    width: 280px; min-width: 280px; background: #151515; border-right: 1px solid #2a2a2a;
    position: fixed; top: 60px; bottom: 0; left: 0; overflow-y: auto; padding: 16px 0;
    transition: transform 0.3s ease; z-index: 900;
}
.sidebar-search { padding: 0 16px 12px; }
.sidebar-search input {
    width: 100%; padding: 8px 12px; border-radius: 6px;
    border: 1px solid #333; background: #1e1e1e; color: #e0e0e0;
    font-size: 0.85rem; outline: none; transition: border-color 0.2s;
}
.sidebar-search input:focus { border-color: #67eb34; }
.sidebar-search input::placeholder { color: #666; }
.sidebar-list { list-style: none; }
.sidebar-list a {
    display: block; padding: 8px 24px; color: #aaa; font-size: 0.85rem;
    border-left: 3px solid transparent; transition: all 0.2s;
}
.sidebar-list a:hover { color: #67eb34; background: #1e1e1e; border-left-color: #67eb34; }
.sidebar-list a.active { color: #67eb34; border-left-color: #67eb34; background: #1a2e14; font-weight: 600; }
.sidebar-list .hidden { display: none; }

/* ===== MAIN CONTENT ===== */
.main-content { margin-left: 280px; flex: 1; padding: 40px 48px 80px; max-width: 960px; }

/* Hero */
.hero {
    text-align: center; padding: 48px 0 40px; margin-bottom: 32px;
    border-bottom: 1px solid #2a2a2a; position: relative;
}
.hero::before {
    content: ''; position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%);
    width: 260px; height: 260px; border-radius: 50%;
    background: radial-gradient(circle, #67eb3422 0%, transparent 70%); pointer-events: none;
}
.hero img { width: 140px; height: 140px; position: relative; }
.hero h1 { font-family: 'Dubai','Segoe UI',sans-serif; font-size: 2.5rem; color: #67eb34; font-weight: 700; margin: 12px 0 4px; }
.hero p { color: #888; font-size: 1rem; }

/* Sections */
.section { margin-bottom: 48px; padding-top: 24px; border-top: 1px solid #2a2a2a; }
.section:first-of-type { border-top: none; }
.section h2 { color: #67eb34; font-size: 1.5rem; font-weight: 700; margin-bottom: 16px; padding-bottom: 8px; border-bottom: 2px solid #2a3a20; }
.section h3 { color: #8dab82; font-size: 1.15rem; margin: 20px 0 8px; }
.section p { margin-bottom: 12px; color: #ccc; }
.section ul, .section ol { margin: 8px 0 16px 24px; color: #ccc; }
.section li { margin-bottom: 6px; }
.section li strong { color: #e0e0e0; }
.best-experience-note {
    display: inline-block;
    margin-left: 8px;
    padding: 2px 9px;
    border-radius: 999px;
    border: 1px solid #67eb34;
    background: #1f3a14;
    color: #b7ffa0;
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0.01em;
}
.section code { background: #2a2a2a; padding: 2px 6px; border-radius: 4px; font-size: 0.9em; color: #67eb34; }
.sheet-view-image {
    display: block;
    width: 100%;
    max-width: 760px;
    height: auto;
    border: 1px solid #2a2a2a;
    border-radius: 8px;
    margin: 8px 0 18px;
    background: #111;
}
kbd { background: #2a2a2a; border: 1px solid #444; border-radius: 4px; padding: 2px 7px; font-size: 0.85em; color: #e0e0e0; box-shadow: 0 1px 0 #555; }

/* Callout boxes */
.callout { border-left: 4px solid; border-radius: 6px; padding: 14px 18px; margin: 16px 0; background: #1a1a1a; }
.callout-title { font-weight: 700; margin-bottom: 4px; font-size: 0.9rem; }
.callout-tip { border-color: #67eb34; }
.callout-tip .callout-title { color: #67eb34; }
.callout-note { border-color: #a0f4ff; }
.callout-note .callout-title { color: #a0f4ff; }
.callout-warning { border-color: #e6a817; }
.callout-warning .callout-title { color: #e6a817; }
.callout-important { border-color: #e05555; }
.callout-important .callout-title { color: #e05555; }

/* FAQ */
.faq-item { border: 1px solid #2a2a2a; border-radius: 8px; margin-bottom: 10px; overflow: hidden; }
.faq-question {
    width: 100%; background: #1a1a1a; border: none; color: #e0e0e0;
    padding: 14px 18px; font-size: 0.95rem; font-weight: 600; text-align: left;
    cursor: pointer; display: flex; justify-content: space-between; align-items: center; transition: background 0.2s;
}
.faq-question:hover { background: #222; }
.faq-question .chevron { color: #67eb34; transition: transform 0.3s; font-size: 1.1rem; }
.faq-question.open .chevron { transform: rotate(90deg); }
.faq-answer { padding: 0 18px; max-height: 0; overflow: hidden; transition: max-height 0.35s ease, padding 0.35s ease; }
.faq-answer.open { max-height: 600px; padding: 14px 18px; }
.faq-answer p { color: #bbb; margin-bottom: 8px; }

/* Back to top */
.back-to-top {
    position: fixed; bottom: 28px; right: 28px; z-index: 800;
    width: 44px; height: 44px; border-radius: 50%;
    background: #67eb34; color: #111; border: none; cursor: pointer;
    font-size: 1.3rem; font-weight: 700; box-shadow: 0 0 16px #67eb3455;
    opacity: 0; pointer-events: none; transition: opacity 0.3s, transform 0.3s;
    display: flex; align-items: center; justify-content: center;
}
.back-to-top.visible { opacity: 1; pointer-events: auto; }
.back-to-top:hover { background: #8dab82; transform: scale(1.1); }

/* Glossary table */
.glossary-table { width: 100%; border-collapse: collapse; margin: 12px 0; }
.glossary-table th, .glossary-table td { padding: 10px 14px; text-align: left; border-bottom: 1px solid #2a2a2a; }
.glossary-table th { color: #67eb34; font-weight: 700; font-size: 0.9rem; border-bottom: 2px solid #2a3a20; }
.glossary-table td:first-child { color: #e0e0e0; font-weight: 600; white-space: nowrap; }
.glossary-table td:last-child { color: #bbb; }

/* ===== RESPONSIVE ===== */
@media (max-width: 900px) {
    .main-content { margin-left: 0; padding: 24px 20px 60px; }
    .sidebar { transform: translateX(-100%); }
    .sidebar.open { transform: translateX(0); box-shadow: 4px 0 24px #0008; }
    .hamburger { display: block; }
    .sidebar-overlay { display: none; position: fixed; inset: 0; z-index: 850; background: #000a; }
    .sidebar-overlay.active { display: block; }
    .hero h1 { font-size: 1.8rem; }
}
@media (max-width: 480px) {
    .topnav { padding: 0 12px; }
    .topnav-left .brand-sub { display: none; }
    .main-content { padding: 16px 12px 60px; }
}