/* 
   Hola-AL Premium Design System 
   Aesthetic: Modern Spanish Premium (Red & gold accents on dark/off-white)
*/

:root {
    --spanish-red: #A93226;
    --spanish-red-dark: #8E281F;
    --spanish-gold: #D4AC0D;
    --spanish-gold-light: #F7DC6F;
    --deep-slate: #1C2833;
    --slate-grey: #2C3E50;
    --off-white: #FCF9F2;
    --pure-white: #FFFFFF;
    --text-main: #2C3E50;
    --text-light: #7F8C8D;
    --glass-bg: rgba(255, 255, 255, 0.95);
    --shadow-premium: 0 20px 40px rgba(0,0,0,0.1);
    --transition-smooth: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    -webkit-font-smoothing: antialiased;
}

body {
    font-family: 'Inter', sans-serif;
    color: var(--text-main);
    background-color: var(--off-white);
    line-height: 1.6;
    overflow-x: hidden;
}

h1, h2, h3 {
    font-family: 'Montserrat', sans-serif;
    font-weight: 700;
}

/* --- Hero Section --- */
.hero {
    position: relative;
    height: 80vh;
    min-height: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--pure-white);
    text-align: center;
    overflow: hidden;
    background-color: var(--deep-slate);
}

.hero-img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.6;
    filter: brightness(0.7);
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, rgba(28, 40, 51, 0.3), var(--deep-slate));
}

.hero-content {
    position: relative;
    z-index: 10;
    max-width: 800px;
    padding: 0 20px;
}

.hero h1 {
    font-size: clamp(2.5rem, 8vw, 4.5rem);
    margin-bottom: 1rem;
    letter-spacing: -1px;
    text-transform: uppercase;
}

.hero h1 span {
    color: var(--spanish-gold);
}

.hero p {
    font-size: clamp(1rem, 3vw, 1.25rem);
    opacity: 0.9;
    margin-bottom: 2rem;
    font-weight: 300;
    letter-spacing: 1px;
}

/* --- Textbook Cards --- */
.textbooks {
    padding: 80px 20px;
    max-width: 1200px;
    margin: -100px auto 0;
    position: relative;
    z-index: 20;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 40px;
}

.card {
    background: var(--glass-bg);
    border-radius: 20px;
    padding: 40px;
    box-shadow: var(--shadow-premium);
    transition: var(--transition-smooth);
    border: 1px solid rgba(255,255,255,0.2);
    display: flex;
    flex-direction: column;
    text-align: center;
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 30px 60px rgba(0,0,0,0.15);
}

.card h2 {
    display: none; /* Hide old text header */
}

.book-container {
    perspective: 1000px;
    margin-bottom: 30px;
    display: flex;
    justify-content: center;
}

.book-cover {
    width: 200px;
    height: auto;
    border-radius: 4px 12px 12px 4px;
    box-shadow: 10px 10px 20px rgba(0,0,0,0.2);
    transition: var(--transition-smooth);
    transform: rotateY(-15deg);
    cursor: pointer;
}

.card:hover .book-cover {
    transform: rotateY(0deg) scale(1.05);
    box-shadow: 0 15px 30px rgba(0,0,0,0.3);
}

.card p {
    color: var(--text-light);
    margin-bottom: 2rem;
    min-height: 3rem;
}

.btn-group {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-top: auto;
}

.btn {
    padding: 12px 20px;
    border-radius: 10px;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.9rem;
    transition: var(--transition-smooth);
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-primary {
    background: var(--spanish-red);
    color: var(--pure-white);
}

.btn-primary:hover {
    background: var(--spanish-red-dark);
}

.btn-secondary {
    background: transparent;
    border: 2px solid var(--spanish-gold);
    color: var(--spanish-gold);
}

.btn-secondary:hover {
    background: var(--spanish-gold);
    color: var(--pure-white);
}

/* --- Footer --- */
footer {
    padding: 60px 20px;
    text-align: center;
    color: var(--text-light);
    font-size: 0.9rem;
}

footer p {
    margin: 10px 0;
    opacity: 0.9;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.github-link {
    color: var(--text-light);
    transition: var(--transition-smooth);
    display: inline-flex;
    opacity: 0.8;
}

.github-link:hover {
    transform: scale(1.2) rotate(10deg);
    color: var(--spanish-red);
    opacity: 1;
}

.brand-link {
    color: inherit;
    text-decoration: none;
    transition: var(--transition-smooth);
}

.brand-link:hover {
    color: var(--spanish-red);
}

.footer-logo {
    font-family: 'Montserrat', sans-serif;
    font-weight: 700;
    color: var(--spanish-red);
    margin-bottom: 15px;
    font-size: 1.2rem;
}

/* --- Responsive Adjustments (Galaxy S25 & Mobile) --- */
@media (max-width: 600px) {
    .hero {
        height: 60vh;
    }
    .textbooks {
        margin-top: -50px;
        padding-top: 20px;
    }
    .card {
        padding: 30px 20px;
    }
    .btn-group {
        grid-template-columns: 1fr;
    }
}

/* Anti-aliasing rule per user preference
   (applied to specific elements if needed, but here global for clean text) */
canvas {
    image-rendering: pixelated;
}