:root {
    --color-background: #0f172a;
    --color-surface: #1e293b;
    --color-text: #f1f5f9;
    --color-text-secondary: #cbd5e1;
    --color-primary: #60a5fa;
    --color-primary-hover: #3b82f6;
    --color-accent: #a855f7;
    --color-border: #334155;
    --color-success: #22c55e;
    --color-warning: #fbbf24;
    --neon-blue: #00f3ff;
    --neon-purple: #bd00ff;
}

@media (prefers-color-scheme: dark) {
    :root {
        --color-background: #0f172a;
        --color-surface: #1e293b;
        --color-text: #f1f5f9;
        --color-text-secondary: #cbd5e1;
        --color-border: #334155;
    }
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: #020617;
    color: var(--color-text);
    line-height: 1.6;
    overflow-x: hidden;
}

/* Header */
header {
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    color: white;
    padding: 80px 20px;
    text-align: center;
    position: relative;
    overflow: hidden;
    border-bottom: 1px solid rgba(96, 165, 250, 0.2);
}

header::before {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 0% 0%, rgba(96, 165, 250, 0.1), transparent 50%), 
                radial-gradient(circle at 100% 100%, rgba(168, 85, 247, 0.1), transparent 50%);
    pointer-events: none;
}

header h1 {
    font-size: 3.4em;
    margin-bottom: 10px;
    font-weight: 900;
    letter-spacing: -0.03em;
    background: linear-gradient(90deg, #60a5fa, #a78bfa, #22d3ee);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    position: relative;
    z-index: 2;
}

header p {
    font-size: 1.1em;
    opacity: 0.8;
    font-weight: 300;
    color: #cbd5e1;
    position: relative;
    z-index: 2;
}

/* Navigation - Tab Style */
nav {
    position: sticky;
    top: 0;
    background: rgba(15, 23, 42, 0.9);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(96, 165, 250, 0.3);
    padding: 16px 20px;
    z-index: 100;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
}

nav ul {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
    max-width: 1200px;
    margin: 0 auto;
}

nav a {
    color: #cbd5e1;
    text-decoration: none;
    padding: 10px 20px;
    border-radius: 40px;
    transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    font-size: 0.9em;
    font-weight: 500;
    position: relative;
    white-space: nowrap;
}

nav a:hover {
    background: rgba(96, 165, 250, 0.2);
    color: #00f3ff;
    transform: translateY(-2px);
    box-shadow: 0 0 20px rgba(96, 165, 250, 0.4);
}

nav a.active {
    background: linear-gradient(135deg, #60a5fa, #a855f7);
    color: white;
    box-shadow: 0 8px 20px rgba(96, 165, 250, 0.3);
}

/* Main Container */
main {
    max-width: 900px;
    margin: 0 auto;
    padding: 40px 20px;
}

/* Section Styles */
section {
    background: radial-gradient(circle at top left, rgba(56, 189, 248, 0.08), rgba(30, 41, 59, 0.96));
    border-radius: 20px;
    padding: 40px;
    margin-bottom: 30px;
    box-shadow: 0 18px 60px rgba(15, 23, 42, 0.9), inset 0 0 0 1px rgba(148, 163, 184, 0.3);
    border: 1px solid rgba(96, 165, 250, 0.2);
    backdrop-filter: blur(12px);
    transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    position: relative;
    overflow: hidden;
}

section::before {
    content: "";
    position: absolute;
    inset: -50%;
    background: radial-gradient(circle at 0% 0%, rgba(96, 165, 250, 0.1), transparent 60%);
    pointer-events: none;
}

section:hover {
    transform: translateY(-6px);
    box-shadow: 0 32px 90px rgba(15, 23, 42, 0.95), 0 0 40px rgba(96, 165, 250, 0.2);
    border-color: rgba(96, 165, 250, 0.4);
}

h2 {
    background: linear-gradient(90deg, #60a5fa, #a78bfa, #22d3ee);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-size: 2.2rem;
    margin-bottom: 20px;
    font-weight: 900;
    padding-bottom: 15px;
    border-bottom: 2px solid rgba(96, 165, 250, 0.3);
    letter-spacing: -0.02em;
    position: relative;
    z-index: 1;
}

h3 {
    color: var(--color-text);
    font-size: 1.3rem;
    margin-top: 25px;
    margin-bottom: 12px;
    font-weight: 600;
}

h3:first-child {
    margin-top: 0;
}

p {
    margin-bottom: 15px;
    color: var(--color-text-secondary);
    line-height: 1.8;
}

ul, ol {
    margin-left: 25px;
    margin-bottom: 15px;
}

li {
    margin-bottom: 10px;
    color: var(--color-text-secondary);
    line-height: 1.8;
}

strong {
    color: var(--color-text);
    font-weight: 600;
}

/* Contact Box */
.contact-box {
    background: radial-gradient(circle at 0 0, rgba(56, 189, 248, 0.35), rgba(30, 41, 59, 0.98));
    color: white;
    padding: 30px;
    border-radius: 16px;
    margin: 20px 0;
    font-size: 1.05rem;
    border: 1px solid rgba(96, 165, 250, 0.4);
    backdrop-filter: blur(16px);
    box-shadow: 0 14px 40px rgba(15, 23, 42, 0.9), 0 0 30px rgba(96, 165, 250, 0.2);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.contact-box::before {
    content: "";
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(96, 165, 250, 0.1), rgba(168, 85, 247, 0.1));
    opacity: 0;
    transition: opacity 0.3s ease;
}

.contact-box:hover {
    box-shadow: 0 22px 60px rgba(15, 23, 42, 1), 0 0 40px rgba(96, 165, 250, 0.3);
    border-color: rgba(96, 165, 250, 0.6);
}

.contact-box a {
    color: #00f3ff;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    position: relative;
    z-index: 1;
}

.contact-box a:hover {
    color: #60a5fa;
    text-shadow: 0 0 10px rgba(96, 165, 250, 0.5);
}

/* Summary Box */
.summary-box {
    background: rgba(30, 41, 59, 0.8);
    border-left: 4px solid #60a5fa;
    padding: 25px;
    border-radius: 12px;
    margin: 20px 0;
    border: 1px solid rgba(96, 165, 250, 0.2);
    backdrop-filter: blur(10px);
    box-shadow: inset 0 0 20px rgba(96, 165, 250, 0.05);
    color: #f1f5f9;
    transition: all 0.3s ease;
}

.summary-box:hover {
    border-color: rgba(96, 165, 250, 0.3);
    box-shadow: inset 0 0 30px rgba(96, 165, 250, 0.1);
}

[data-color-scheme="dark"] .summary-box {
    color: #f1f5f9;
}

@media (prefers-color-scheme: dark) {
    .summary-box {
        color: #f1f5f9;
    }
}

/* Highlight Text */
.highlight {
    background-color: var(--color-primary);
    color: white;
    padding: 2px 6px;
    border-radius: 4px;
    font-weight: 500;
}

/* Table */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    background: var(--color-surface);
}

th {
    background-color: #1e40af;
    color: white;
    padding: 12px;
    text-align: left;
    font-weight: 600;
}

td {
    padding: 12px;
    border-bottom: 1px solid var(--color-border);
}

tr:hover {
    background-color: var(--color-background);
}

.site-footer {
  width: 100%;
  padding: 40px 0;
  background: rgba(2, 6, 23, 0.8);
  backdrop-filter: blur(10px);
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  position: relative;
  overflow: hidden;
  text-align: center;
}
.footer-line {
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 50%;
  height: 1px;
  background: linear-gradient(90deg, transparent, #60a5fa, #a855f7, transparent);
}
.footer-content { display:flex; flex-direction:column; gap:10px; }
.footer-content a { color: inherit; text-decoration:none; margin-left:0px; font-size:0.9em; opacity:0.8; transition:opacity 0.3s ease; }
.footer-content a:hover { opacity:1; text-decoration:underline; color: var(--neon-blue); }
.footer-content p { color: #64748b; font-size: 0.85rem; letter-spacing: 0.05em; }
.footer-brand { color: #94a3b8; font-weight: 600; }
.footer-status { font-family: 'JetBrains Mono', monospace; font-size:0.7rem !important; color: #22c55e !important; opacity:0.8; }
.footer-status::before { content: '●'; margin-right:6px; animation: pulse-dot 2s infinite; }
@keyframes pulse-dot { 0%,100%{opacity:1;}50%{opacity:0.3;} }
@media (max-width: 768px) {
  .site-footer {
    padding-bottom: 120px; /* 👈 space for side nav */
  }
}


/* Back to Top Button */
#backToTop {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background-color: var(--color-primary);
    color: white;
    border: none;
    padding: 15px 18px;
    border-radius: 50%;
    font-size: 20px;
    cursor: pointer;
    display: none;
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
    transition: all 0.3s ease;
    z-index: 99;
}

#backToTop:hover {
    background-color: var(--color-primary-hover);
    transform: translateY(-3px);
    box-shadow: 0 6px 16px rgba(0,0,0,0.3);
}

/* Quick Links */
.quick-links {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin: 20px 0;
}

.quick-links a {
    background: radial-gradient(circle at 0% 0%, rgba(96, 165, 250, 0.2), rgba(30, 41, 59, 0.95));
    color: #60a5fa;
    padding: 14px 24px;
    border-radius: 12px;
    text-decoration: none;
    text-align: center;
    transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    font-weight: 600;
    border: 1px solid rgba(96, 165, 250, 0.3);
    backdrop-filter: blur(8px);
}

.quick-links a:hover {
    background: rgba(96, 165, 250, 0.15);
    transform: translateY(-4px);
    box-shadow: 0 12px 32px rgba(96, 165, 250, 0.3), 0 0 20px rgba(96, 165, 250, 0.2);
    border-color: rgba(96, 165, 250, 0.6);
    color: #00f3ff;
}

/* Responsive */
@media (max-width: 768px) {
    header h1 {
        font-size: 2em;
    }

    nav ul {
        flex-direction: column;
        gap: 5px;
    }

    nav a {
        padding: 10px 12px;
        font-size: 0.9em;
    }

    main {
        padding: 20px 10px;
    }

    section {
        padding: 20px;
    }

    h2 {
        font-size: 1.5em;
    }

    #backToTop {
        bottom: 20px;
        right: 20px;
        padding: 12px 14px;
        font-size: 18px;
    }
}

/* Print Styles */
@media print {
    nav {
        display: none;
    }

    #backToTop {
        display: none;
    }

    section {
        page-break-inside: avoid;
    }
}