/* PZKDQ.com - University Mathematics Theme */
@import url('https://fonts.googleapis.com/css2?family=Roboto+Mono:wght@400;500;700&family=Libre+Baskerville:wght@400;700&display=swap');

:root {
    --primary: #2563EB;
    --secondary: #1D4ED8;
    --accent: #F59E0B;
    --dark: #1e293b;
    --darker: #0f172a;
    --light: #f1f5f9;
    --blue: #3B82F6;
    --shadow: rgba(37, 99, 235, 0.3);
}

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

body {
    font-family: 'Libre Baskerville', serif;
    background: var(--darker);
    color: var(--light);
    min-height: 100vh;
    background-image: 
        radial-gradient(ellipse at 20% 20%, rgba(37, 99, 235, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(245, 158, 11, 0.1) 0%, transparent 50%),
        linear-gradient(180deg, var(--darker) 0%, var(--dark) 100%);
}

.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

header {
    background: linear-gradient(90deg, var(--dark), rgba(37,99,235,0.2), var(--dark));
    padding: 15px 0;
    box-shadow: 0 5px 30px var(--shadow);
    border-bottom: 2px solid var(--blue);
}

header .container { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; }

.logo {
    font-family: 'Roboto Mono', monospace;
    font-size: 24px;
    color: var(--accent);
    text-decoration: none;
    font-weight: 700;
    letter-spacing: 1px;
}

nav { display: flex; gap: 10px; flex-wrap: wrap; }

nav a {
    color: var(--light);
    text-decoration: none;
    padding: 10px 20px;
    border-radius: 6px;
    font-family: 'Roboto Mono', monospace;
    font-weight: 500;
    font-size: 14px;
    transition: all 0.3s;
    border: 1px solid transparent;
}

nav a:hover, nav a.active {
    border-color: var(--accent);
    color: var(--accent);
    background: rgba(245, 158, 11, 0.1);
}

.hero {
    text-align: center;
    padding: 70px 20px;
    background: linear-gradient(180deg, transparent, rgba(37, 99, 235, 0.1));
}

.hero h1 {
    font-family: 'Roboto Mono', monospace;
    font-size: 40px;
    font-weight: 700;
    background: linear-gradient(90deg, #fff, var(--blue), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 15px;
}

.hero p { font-size: 20px; color: var(--light); opacity: 0.8; }

.main { padding: 40px 20px; min-height: 60vh; }

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.card {
    background: linear-gradient(145deg, rgba(37, 99, 235, 0.12), rgba(15, 23, 42, 0.95));
    border-radius: 14px;
    overflow: hidden;
    transition: all 0.3s;
    box-shadow: 0 10px 30px rgba(0,0,0,0.4);
    border: 2px solid rgba(37, 99, 235, 0.3);
}

.card:hover {
    transform: translateY(-8px);
    border-color: var(--accent);
    box-shadow: 0 20px 50px var(--shadow);
}

.card-icon {
    font-size: 44px;
    padding: 20px;
    text-align: center;
    background: rgba(0,0,0,0.3);
}

.card-body { padding: 18px; text-align: center; }

.card-body h3 {
    font-family: 'Roboto Mono', monospace;
    font-size: 14px;
    margin-bottom: 10px;
    color: var(--light);
}

.card-body p { font-size: 13px; color: rgba(255,255,255,0.7); }

.btn {
    display: inline-block;
    padding: 10px 24px;
    background: linear-gradient(90deg, var(--secondary), var(--blue));
    color: white;
    text-decoration: none;
    border-radius: 6px;
    font-family: 'Roboto Mono', monospace;
    font-weight: 600;
    font-size: 14px;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
}

.btn:hover {
    transform: scale(1.05);
    box-shadow: 0 0 20px var(--shadow);
}

.tool-page, .article-page {
    max-width: 700px;
    margin: 0 auto;
    background: linear-gradient(145deg, rgba(37, 99, 235, 0.08), rgba(15, 23, 42, 0.95));
    border-radius: 18px;
    padding: 38px;
    box-shadow: 0 15px 50px rgba(0,0,0,0.5);
    border: 2px solid var(--blue);
}

.tool-page h1, .article-page h1 {
    font-family: 'Roboto Mono', monospace;
    font-size: 26px;
    text-align: center;
    margin-bottom: 22px;
    color: var(--light);
}

.article-page h1 { font-size: 30px; }

.article-page .meta { color: var(--accent); margin-bottom: 28px; padding-bottom: 18px; border-bottom: 2px dashed rgba(37,99,235,0.3); }

.article-page h2 {
    font-family: 'Roboto Mono', monospace;
    font-size: 20px;
    margin: 28px 0 14px;
    color: var(--blue);
}

.article-page p { line-height: 1.85; margin-bottom: 16px; font-size: 16px; }

input, select, textarea {
    width: 100%;
    padding: 12px;
    margin-bottom: 14px;
    background: rgba(0,0,0,0.4);
    border: 2px solid rgba(37, 99, 235, 0.4);
    border-radius: 6px;
    color: var(--light);
    font-size: 15px;
    font-family: 'Roboto Mono', monospace;
}

input:focus, textarea:focus { border-color: var(--accent); outline: none; }

.result {
    margin-top: 22px;
    padding: 22px;
    background: rgba(37, 99, 235, 0.15);
    border-radius: 10px;
    text-align: center;
    font-size: 17px;
    color: var(--light);
    border: 2px solid var(--blue);
    font-family: 'Roboto Mono', monospace;
}

.result.error { border-color: #ef4444; color: #fca5a5; }

footer {
    background: linear-gradient(90deg, var(--dark), rgba(37,99,235,0.2), var(--dark));
    padding: 28px 0;
    margin-top: 55px;
    text-align: center;
    border-top: 2px solid var(--blue);
}

footer p { color: var(--light); font-size: 14px; }
footer a { color: var(--accent); text-decoration: none; margin: 0 10px; }

.text-center { text-align: center; }
.mt-20 { margin-top: 20px; }
.breadcrumb { margin-bottom: 22px; color: var(--light); opacity: 0.7; }
.breadcrumb a { color: var(--accent); text-decoration: none; }

h2 { font-family: 'Roboto Mono', monospace; font-size: 24px; margin: 38px 0 18px; color: var(--light); }

@media (max-width: 768px) {
    .hero h1 { font-size: 30px; }
    .grid { grid-template-columns: 1fr; }
    .tool-page, .article-page { padding: 24px; }
    .logo { font-size: 20px; }
}