@import url('https://fonts.googleapis.com/css2?family=DynaPuff:wght@400;500;600;700&display=swap');

:root{
  --bg-cream: rgb(254, 248, 236);
  --green-dark: rgb(77, 125, 86);
  --green-medium: rgb(96, 128, 82);
  --green-text: rgb(81, 111, 87);
  --green-hover: rgb(60, 100, 70);
  --green-light: rgb(240, 245, 235);
  --green-border: rgb(150, 180, 140);
  --shadow: 0 10px 30px rgba(0,0,0,.18);
  --nav-h: 64px;
}

*{ box-sizing:border-box; }
html, body{ height:100%; }

body{
  margin:0;
  font-family: 'DynaPuff', ui-sans-serif, system-ui, sans-serif;
  background: var(--bg-cream);
  color: var(--green-text);
}

/* =========================
   NAVBAR (fixed, text only)
========================= */
.navbar{
  position: fixed;
  top:0; left:0; right:0;
  height: var(--nav-h);
  z-index: 10;
  background: var(--green-dark);
}

.navbar-container{
  height: 100%;
  max-width: 1050px;
  margin: 0 auto;
  padding: 0 16px;

  display:flex;
  align-items:center;
  justify-content:space-between;
  gap: 14px;
}

.logo-link{
  text-decoration:none;
  color: var(--bg-cream);
  font-weight: 800;
  font-size: 32px;
  letter-spacing: .4px;
  line-height: 1;
}

.navbar-menu{
  list-style:none;
  display:flex;
  align-items:center;
  gap: 18px;
  margin:0;
  padding:0;

  max-width: 72vw;
  overflow-x: auto;
}

.nav-item{ margin:0; padding:0; }

.nav-link{
  display:inline-flex;
  align-items:center;
  justify-content:center;

  text-decoration:none;
  color: var(--bg-cream);
  font-weight: 700;
  font-size: 22px;

  padding: 10px 14px;
  border-radius: 16px;
  border: 2px solid transparent;

  transition: transform .15s ease, background-color .15s ease, border-color .15s ease;
}

.nav-link:hover{
  background: rgba(254, 248, 236, 0.16);
  border-color: rgba(254, 248, 236, 0.35);
  transform: translateY(-1px);
}

.nav-link.active{
  background: rgba(254, 248, 236, 0.22);
  border-color: rgba(254, 248, 236, 0.55);
}

/* =========================
   MAIN LAYOUT
========================= */
.main-content{
  max-width: 1050px;
  margin: 0 auto;
  padding: calc(var(--nav-h) + 22px) 16px 28px;
}

/* =========================
   HOME: HERO + FEATURES
========================= */
.hero{
  background: var(--bg-cream);
  border: 1px solid var(--green-border);
  border-radius: 18px;
  box-shadow: var(--shadow);
  padding: 18px;
  text-align: center;
}

.hero h1{
  margin: 6px 0 8px;
  font-size: clamp(36px, 2.6vw, 56px);
  color: var(--green-medium);
}

.hero p{
  margin: 0 auto 14px;
  color: var(--green-text);
  line-height: 1.6;
  font-size: 18px;
}

.hero-image{
  width: 420px;
  max-width: 92%;
  margin: 18px auto;
  display: block;
}

.cta-button{
  display:inline-block;
  text-decoration:none;
  color: var(--bg-cream);
  font-weight: 700;
  font-size: 22px;

  background: var(--green-dark);
  border: 2px solid transparent;
  border-radius: 14px;
  padding: 12px 28px;

  transition: transform .15s ease, background-color .15s ease, border-color .15s ease;
}

.cta-button:hover{
  transform: translateY(-1px);
  background: var(--green-hover);
}

.features{
  margin-top: 16px;
  background: var(--bg-cream);
  border: 1px solid var(--green-border);
  border-radius: 18px;
  box-shadow: var(--shadow);
  padding: 18px;
}

.features h2{
  margin: 6px 0 14px;
  color: var(--green-medium);
}

.features-grid{
  display:grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.feature-card{
  background: var(--green-light);
  border: 1px solid var(--green-border);
  border-radius: 16px;
  padding: 14px;
}

.feature-card:first-child{
  border-color: var(--green-medium);
}

.feature-card h3{
  margin: 0 0 8px;
  color: var(--green-medium);
}

.feature-card p{
  margin: 0;
  color: var(--green-text);
  line-height: 1.6;
}

/* =========================
   FOOTER
========================= */
.footer{
  max-width: 1050px;
  margin: 0 auto;
  padding: 14px 16px 24px;
  color: var(--green-text);
  text-align: center;
}

/* =========================
   GENERIC PAGE SECTION
========================= */
.page-section{
  background: var(--bg-cream);
  border: 1px solid var(--green-border);
  border-radius: 18px;
  box-shadow: var(--shadow);
  padding: 24px;
}

.page-title{
  color: var(--green-medium);
  margin: 0 0 8px;
  font-size: clamp(28px, 4vw, 36px);
}

.page-subtitle{
  color: var(--green-text);
  margin-top: 0;
  margin-bottom: 20px;
  line-height: 1.6;
}

/* =========================
   FORMS (login/register)
========================= */
.form-card{
  background: var(--green-light);
  border: 1px solid var(--green-border);
  border-radius: 18px;
  box-shadow: var(--shadow);
  padding: 24px;
}

.form-field{
  margin-top: 14px;
}

.form-field label{
  display:block;
  margin-bottom: 8px;
  color: var(--green-medium);
  font-weight: 600;
}

.form-field input{
  width: 100%;
  padding: 12px 14px;
  border-radius: 12px;
  border: 1px solid var(--green-border);
  background: var(--bg-cream);
  color: var(--green-text);
  font-family: 'DynaPuff', sans-serif;
}

.form-field input:focus{
  outline: 2px solid var(--green-medium);
  outline-offset: 2px;
  border-color: var(--green-medium);
}

.form-field input::placeholder{
  color: rgba(81, 111, 87, 0.5);
}

.btn{
  width: 100%;
  margin-top: 16px;
  border: none;
  background: var(--green-dark);
  color: var(--bg-cream);
  padding: 12px 16px;
  border-radius: 12px;
  cursor: pointer;
  font-weight: 700;
  font-size: 16px;
  font-family: 'DynaPuff', sans-serif;
  transition: transform .15s ease, background-color .15s ease;
}

.btn:hover{
  transform: translateY(-1px);
  background: var(--green-hover);
}

/* =========================
   BUTTON GROUP
========================= */
.button-group{
  margin-top: 20px;
  display:flex;
  gap: 12px;
  flex-wrap: wrap;
}

/* =========================
   HIGH SCORES TABLE
========================= */
.score-table-card{
  background: var(--green-light);
  border: 1px solid var(--green-border);
  border-radius: 16px;
  padding: 20px;
  overflow-x: auto;
}

.score-table{
  width: 100%;
  border-collapse: collapse;
}

.score-table th{
  text-align: left;
  padding: 12px 10px;
  border-bottom: 2px solid var(--green-border);
  color: var(--green-medium);
  font-weight: 700;
}

.score-table td{
  padding: 12px 10px;
  border-bottom: 1px solid var(--green-border);
  color: var(--green-text);
}

.score-table tr:last-child td{
  border-bottom: none;
}

.score-table tr:hover{
  background: rgba(96, 128, 82, 0.06);
}

/* =========================
   RULES + CREDITS
========================= */
.rules-card{
  background: var(--green-light);
  border: 1px solid var(--green-border);
  border-radius: 16px;
  padding: 20px;
  margin-bottom: 16px;
}

.rules-card h2,
.rules-card h3{
  color: var(--green-medium);
}

.rules-card h2{
  margin: 0 0 12px;
}

.rules-card h3{
  margin: 16px 0 8px;
}

.rules-card p{
  color: var(--green-text);
  line-height: 1.6;
  margin: 8px 0;
}

.rules-card ul{
  color: var(--green-text);
  line-height: 1.7;
  margin-top: 8px;
  padding-left: 24px;
}

.rules-card li{
  margin-bottom: 6px;
}

.credits-card{ margin-top: 16px; }

.author-name{
  font-weight: 800;
  color: var(--green-medium);
}

.contact-links{
  line-height: 1.8;
  margin: 12px 0 0;
}

.contact-link{
  color: var(--green-dark);
  text-decoration: none;
  transition: color .15s ease;
}

.contact-link:hover{
  color: var(--green-medium);
  text-decoration: underline;
}

/* =========================
   SELECTION PAGE
========================= */
.selection-grid{
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-bottom: 20px;
}

.game-card{
  background: var(--green-light);
  border: 1px solid var(--green-border);
  border-radius: 16px;
  padding: 20px;
  text-decoration: none;
  display: block;
  transition: transform .15s ease, box-shadow .15s ease, border-color .15s ease;
}

.game-card:hover{
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(96, 128, 82, 0.18);
  border-color: var(--green-medium);
}

.game-card h3{
  color: var(--green-medium);
  margin: 0 0 10px;
  font-size: 20px;
}

.game-author{
  color: var(--green-text);
  font-size: 14px;
  margin: 0;
}

/* =========================
   GAME PAGES (easy/hard)
========================= */
.game-section{
  background: var(--bg-cream);
  border: 1px solid var(--green-border);
  border-radius: 18px;
  box-shadow: var(--shadow);
  padding: 24px;
}

.game-controls{
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  align-items: center;
  margin: 12px 0 20px;
}

.timer-display{
  padding: 10px 14px;
  border-radius: 12px;
  border: 1px solid var(--green-border);
  background: var(--green-light);
  color: var(--green-text);
  font-weight: 700;
}

.timer-value{
  color: var(--green-medium);
  font-weight: 800;
  margin-left: 6px;
}

/* =========================
   SUDOKU BOARD
========================= */
.board{
  display: grid;
  border: 2px solid var(--green-border);
  border-radius: 16px;
  overflow: hidden;
  background: var(--bg-cream);
  max-width: 620px;
  margin: 0 auto;
}

.board--9{ grid-template-columns: repeat(9, 1fr); }
.board--6{ grid-template-columns: repeat(6, 1fr); }

.cell{
  width: 100%;
  aspect-ratio: 1 / 1;
  border: 1px solid var(--green-border);
  background: var(--bg-cream);
  color: var(--green-text);
  text-align: center;
  font-weight: 700;
  font-size: clamp(14px, 1.6vw, 18px);
  font-family: 'DynaPuff', sans-serif;
  padding: 0;
}

.cell:hover{
  background: rgba(96, 128, 82, 0.10);
}

.cell:focus{
  outline: 2px solid var(--green-medium);
  outline-offset: -2px;
  background: rgba(96, 128, 82, 0.05);
}

.cell.fixed{
  background: var(--green-light);
  color: var(--green-medium);
  font-weight: 800;
}

/* 9x9 subgrid separators (3x3) */
.board--9 .cell:nth-child(9n+3),
.board--9 .cell:nth-child(9n+6){
  border-right: 2px solid var(--green-medium);
}
.board--9 .cell:nth-child(n+19):nth-child(-n+27),
.board--9 .cell:nth-child(n+46):nth-child(-n+54){
  border-bottom: 2px solid var(--green-medium);
}

/* 6x6 subgrid separators (2x3 blocks) */
.board--6 .cell:nth-child(6n+3){
  border-right: 2px solid var(--green-medium);
}
.board--6 .cell:nth-child(n+7):nth-child(-n+12),
.board--6 .cell:nth-child(n+19):nth-child(-n+24){
  border-bottom: 2px solid var(--green-medium);
}

/* =========================
   MOBILE (iPhone 12 Pro)
========================= */
@media (max-width: 430px){
  :root{ --nav-h: 74px; }

  .navbar{
    top: auto;
    bottom: 0;
  }

  .main-content{
    padding-top: 18px;
    padding-bottom: calc(var(--nav-h) + 18px);
  }

  .logo-link{
    font-size: 22px;
  }

  .navbar-menu{
    gap: 10px;
    max-width: 78vw;
  }

  .nav-link{
    font-size: 16px;
    padding: 9px 10px;
    border-radius: 14px;
    white-space: nowrap;
  }

  .features-grid{
    grid-template-columns: 1fr;
  }

  .selection-grid{
    grid-template-columns: 1fr;
  }

  .page-section,
  .game-section{
    padding: 18px;
  }

  .button-group{
    flex-direction: column;
  }

  .button-group .cta-button{
    width: 100%;
    text-align: center;
  }

  .game-controls{
    flex-direction: column;
    align-items: stretch;
  }

  .game-controls .cta-button{
    width: 100%;
    text-align: center;
  }

  .timer-display{
    text-align: center;
  }

  .score-table-card{
    padding: 14px;
  }

  .score-table th,
  .score-table td{
    padding: 10px 8px;
    font-size: 14px;
  }
}