/* ==========================================================================
   1. FONTS & ROOT
   ========================================================================== */
@font-face {
  font-family: "Roboto Slab";
  src: url("./fonts/RobotoSlab/RobotoSlab-VariableFont_wght.ttf") format("truetype");
  font-weight: 100 900;
  font-display: swap;
}

html { 
  font-size: 112.5%; 
  font-family: Arial, sans-serif; 
  box-sizing: border-box; 
  scroll-behavior: smooth; 
}

*, *::before, *::after { box-sizing: inherit; }

body { 
  margin: 0; 
  overflow-x: hidden; 
  width: 100%;
}

/* ==========================================================================
   2. HEADER & NAVIGATION
   ========================================================================== */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 68.75rem;
  margin: 0 auto;
  padding: 0 1rem;
}

nav { display: flex; }

header nav a {
  padding: 0 1rem;
  height: 3rem;
  display: flex;
  align-items: center;
  color: #1a73e8;
  text-decoration: none; 
  font-size: 0.95rem;
}

header nav a:hover {
  color: #000;
}

header > a[href*="github.com"] {
  padding: 0 1rem;
  color: #1a73e8;
  text-decoration: underline;
  font-size: 0.95rem;
}

.disabled {
  color: #888 !important; 
  opacity: 0.6;
  pointer-events: none;
  text-decoration: none !important;
}

/* ==========================================================================
   3. HERO / SPLASH (Desktop Grid)
   ========================================================================== */
#splash {
  grid-column: 1 / -1;
  height: 940px;
  background: url("./angola.jpg") no-repeat center bottom / cover;
  display: grid;
  grid-template-columns: 1fr repeat(3, 21.58rem) 1fr;
  align-items: center;
  text-align: center;
}

#splash h1 {
  grid-column: 2 / -2;
  color: white;
  font-family: "Roboto Slab", serif;
  font-weight: 800; 
  font-size: 4.5rem;
  line-height: 1.1;
  letter-spacing: 0.02em;
  margin-bottom: 2rem;
}

/* ==========================================================================
   4. BUTTON CARDS (Tightened Icon & Centering)
   ========================================================================== */
.buttons {
  background: white;
  border-radius: 8px;
  display: flex;
  flex-direction: column;
  justify-content: center; 
  align-items: center; 
  min-height: 140px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
  margin: 0 10px;
}

.buttons a {
  display: inline-flex; 
  align-items: center;
  justify-content: center;
  width: 100%;
  color: black;
  text-decoration: none;
  font-size: 1.4rem;
  padding: 5px 0;
}

.buttons i { 
  margin-left: 8px; 
  font-size: 1.25rem; 
}

/* Add this below .buttons i */
.tud-logo {
    height: 2.8rem;    /* Since your button text is 1.4rem, 2.8rem is exactly twice the height */
    width: auto;       /* Keeps the logo proportional */
    margin-left: 10px; /* Space between the word "Textbook" and the logo */
}

/* This ensures the larger logo doesn't touch the top/bottom of the card */
#buttons-textbook {
    padding: 10px 0;
}

#buttons-textbook { grid-column: 2; }
#buttons-codebook  { grid-column: 3; }
#buttons-quizbook  { grid-column: 4; }

/* ==========================================================================
   5. CONTENT AREA (Minimized Gaps)
   ========================================================================== */
main {
  display: grid;
  grid-template-columns: 1fr minmax(0, 68.75rem) 1fr;
}

main > section {
  grid-column: 2;
  padding: 0 1.5rem; 
}

h2 {
  font-family: "Roboto Slab", serif;
  font-weight: 700;
  font-size: 2rem;
  margin: 2rem 0 0.8rem 0; 
}

p { 
  margin: 0 0 1rem 0; 
  line-height: 1.6; 
}

address p { margin-bottom: 0 !important; }

footer { 
  text-align: center; 
  padding: 3rem 0; 
  color: #666; 
  font-size: 0.9rem; 
}

/* ==========================================================================
   6. RESPONSIVE DESIGN (Slimmed Mobile Buttons)
   ========================================================================== */
@media (max-width: 1600px) {
  #splash {
    display: flex;
    flex-direction: column;
    height: auto;
    min-height: 100vh;
    padding: 6rem 1rem 4rem 1rem;
  }
  #splash h1 { font-size: 3.5rem; }
  .buttons { width: 320px; margin: 0 auto 1.2rem auto; }
}

@media (max-width: 600px) {
  html { font-size: 15px; } 
  header { flex-direction: column; padding: 0.5rem; }

  /* Synced Nav Font Sizes */
  header nav a, 
  header > a[href*="github.com"] { 
    height: 1.8rem; 
    font-size: 0.8rem; 
  }

  #splash h1 { font-size: 2.3rem; }

  /* SLIMMER BUTTONS FOR MOBILE */
  .buttons { 
    width: 90%; 
    max-width: 300px; 
    min-height: 90px; /* Reduced from 110px back to original slim height */
    margin: 0 auto 1rem auto;
  }

  .buttons a {
    font-size: 1.2rem; /* Slightly smaller text so it doesn't feel cramped */
  }

  .buttons i {
    font-size: 1.1rem; /* Proportional icon resize */
  }

  h2 { margin: 1.5rem 0 0.5rem 0; font-size: 1.6rem; }
}