/* ==========================================================
   DonaTrainer — Landing Page Styles (with Tutorial)
   ========================================================== */

/* ---------- Security ---------- */
.no-select { -webkit-user-select: none; -ms-user-select: none; user-select: none; }

/* ---------- Theme Variables (Dark Mode) ---------- */
:root {
    --dark-bg: #0a101a;
    --panel-bg: #121a26;
    --line-color: #2a3649;
    --text-color: #cdd5e0;
    --heading-color: #ffffff;
    --accent-blue: #00aaff;
    --accent-blue-hover: #33bbff;
}

/* ---------- Base & Typography ---------- */
html { scroll-behavior: smooth; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    color: var(--text-color);
    background: var(--dark-bg);
}
h1, h2, h3 { color: var(--heading-color); font-weight: 600; }
h1 { font-size: clamp(2.5rem, 5vw, 4rem); }
h2 { font-size: 2.2rem; text-align: center; margin-bottom: 1rem; }
h3 { font-size: 1.2rem; }
a { color: var(--accent-blue); }
a:hover { color: var(--accent-blue-hover); }
.section-subtitle {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 40px;
    color: #8a9cb0;
}

/* ---------- Header ---------- */
.site-header {
  padding: 16px 0;
  background: rgba(10, 16, 26, 0.8);
  border-bottom: 1px solid var(--line-color);
  backdrop-filter: blur(10px);
  position: sticky; top: 0; z-index: 100;
}
.site-header .container { display: flex; align-items: center; justify-content: space-between; }
.brand img { height: 40px; }
.nav-actions { display: flex; align-items: center; gap: 24px; }
.nav-link { color: var(--text-color); font-weight: 500; }
.btn.primary { background-color: var(--accent-blue); color: #fff; border-radius: 4px; border: none; }
.btn.primary:hover { background-color: var(--accent-blue-hover); }

/* ---------- Hero Section ---------- */
.hero {
  text-align: center;
  padding: 100px 0;
  background: linear-gradient(180deg, var(--dark-bg) 0%, #080d14 100%);
}
.hero h1 { font-weight: 700; }
.hero .tagline {
  font-size: 1.2rem;
  color: #8a9cb0;
  max-width: 650px;
  margin: 1.5rem auto 2.5rem;
  min-height: 56px;
}
.tagline::after { content: '|'; animation: blink 1s step-end infinite; }
@keyframes blink { 50% { opacity: 0; } }
.btn.xl { padding: 14px 28px; font-size: 1.1rem; }
.hero-actions { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; }
.btn.secondary {
    background: transparent;
    border: 1px solid var(--line-color);
    color: var(--text-color);
}
.btn.secondary:hover {
    border-color: var(--accent-blue);
    background: rgba(0, 170, 255, 0.1);
}

/* ---------- Tutorial Section ---------- */
.tutorial-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 24px;
    max-width: 800px;
    margin: 0 auto;
}
.tutorial-card {
    background: var(--panel-bg);
    border: 1px solid var(--line-color);
    border-left: 4px solid var(--accent-blue);
    border-radius: var(--radius);
    padding: 2rem;
    position: relative;
}
.tutorial-step-number {
    position: absolute;
    top: 1.5rem;
    left: -25px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--accent-blue);
    color: #fff;
    font-weight: 700;
    font-size: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 4px solid var(--dark-bg);
}
.tutorial-card h3 { margin-top: 0; padding-left: 30px; }
.tutorial-card p { color: #8a9cb0; padding-left: 30px; }
.tutorial-card code {
    display: block;
    margin: 1rem 0 1rem 30px;
    padding: 1rem;
    background: var(--dark-bg);
    border: 1px solid var(--line-color);
    border-radius: var(--radius-sm);
    font-family: 'Courier New', Courier, monospace;
    font-size: 1rem;
    color: var(--text-color);
}
.tutorial-card .pro-tip {
    padding: 1rem 1rem 1rem 30px;
    margin-left: 30px;
    border-left: 2px solid var(--line-color);
    font-size: 0.9rem;
    color: #8a9cb0;
}
.tutorial-card .pro-tip strong { color: var(--text-color); }

/* ---------- Cheatsheet Tabs ---------- */
.tabs {
    background: var(--panel-bg);
    border-radius: var(--radius);
    border: 1px solid var(--line-color);
    overflow: hidden;
}
.tab-nav {
    display: flex;
    border-bottom: 1px solid var(--line-color);
    flex-wrap: wrap;
}
.tab-link {
    padding: 1rem 1.5rem;
    border: none;
    background: transparent;
    color: var(--text-color);
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
}
.tab-link.active {
    color: #fff;
    background: var(--dark-bg);
    border-bottom: 2px solid var(--accent-blue);
}
.tab-content { display: none; padding: 2rem; }
.tab-content.active { display: block; }
.tab-content ul { list-style: none; padding: 0; margin: 0; }
.tab-content li { padding: 0.6rem 0; color: #8a9cb0; }
.tab-content li strong { color: var(--text-color); font-weight: 600; font-family: 'Courier New', Courier, monospace; }

/* ---------- About & Footer ---------- */
.section { padding: 60px 0; }
.section.alt { background: #080d14; }
.about-section { max-width: 800px; text-align: center; }
.about-content p { font-size: 1.1rem; line-height: 1.7; color: #8a9cb0; margin-bottom: 1rem; }
.about-content strong { color: var(--text-color); }
.about-content .honorable-mention { margin-top: 1rem; }

.site-footer {
  padding: 20px 0;
  background: #080d14;
  text-align: center;
  color: #8a9cb0;
  font-size: 0.8rem;
  border-top: 1px solid var(--line-color);
}
.site-footer .container {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 24px;
    flex-wrap: wrap;
}
.footer-link a {
    color: var(--text-color);
    text-decoration: none;
    border: 1px solid var(--line-color);
    padding: 4px 12px;
    border-radius: 999px;
    transition: all 0.2s;
}
.footer-link a:hover {
    background: var(--accent-blue);
    border-color: var(--accent-blue);
    color: #fff;
}

/* ---------- Scroll to Top Button ---------- */
#scrollTopBtn {
    display: none;
    position: fixed;
    bottom: 20px;
    right: 30px;
    z-index: 99;
    border: none;
    outline: none;
    background-color: var(--accent-blue);
    color: white;
    cursor: pointer;
    padding: 15px;
    border-radius: 10px;
    font-size: 18px;
    line-height: 1;
}
#scrollTopBtn:hover { background-color: var(--accent-blue-hover); }

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
    .nav-link { display: none; }
}
@media (max-width: 768px) {
    .hero { padding: 60px 0; }
    .tutorial-card { padding: 1.5rem; }
    .tutorial-step-number { left: -15px; width: 40px; height: 40px; font-size: 1.2rem; }
    .tutorial-card h3, .tutorial-card p, .tutorial-card code, .tutorial-card .pro-tip { padding-left: 20px; margin-left: 10px;}
    .site-footer .container { flex-direction: column; gap: 10px; }
}