/* ========================
   CSS VARIABLES (THEME)
======================== */
:root {
  /* Colors */
  --bg-primary: #2e2e2e;
--bg-secondary: #1a1a1a;
  --bg-card: #2a2a2a;

  --text-primary: #ffffff;
  --text-secondary: #e5e5e5;
  --text-muted: #aaaaaa;

  --accent: #1a6fd4;
  --accent-hover: #1558a8;
  --border: #333333;

  /* Typography */
  --font-main: 'Segoe UI', sans-serif;
  --font-size-base: 16px;

  /* Spacing */
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 32px;
  --spacing-xl: 64px;

  /* Layout */
  --max-width: 1200px;
  --border-radius: 8px;
}

/* ========================
   RESET & BASE
======================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: var(--font-size-base);
  scroll-behavior: smooth;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-main);
  line-height: 1.6;
}

/* ========================
   LAYOUT UTILITY
======================== */
.container {
  width: 90%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--spacing-lg) var(--spacing-md);
}

/* ========================
   TYPOGRAPHY
======================== */
h1, h2, h3, h4 {
  color: var(--text-primary);
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }

p {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-md);
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  color: var(--accent-hover);
}

/* ========================
   BUTTONS
======================== */
.btn {
  display: inline-block;
  padding: 12px 32px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  border-radius: 0;
  font-family: var(--font-main);
  text-align: center;
}

.btn-primary {
  background: #1a6fd4;
  color: #fff;
  border: 1px solid #555;
  box-shadow:
    inset 0 2px 0 rgba(255,255,255,0.2),
    inset 0 -2px 0 rgba(0,0,0,0.35),
    inset 2px 0 0 rgba(255,255,255,0.1),
    inset -2px 0 0 rgba(0,0,0,0.25);
}

.btn-primary:hover {
  background: #1558a8;
  color: #fff;
  box-shadow:
    inset 0 2px 0 rgba(255,255,255,0.15),
    inset 0 -2px 0 rgba(0,0,0,0.4),
    inset 2px 0 0 rgba(255,255,255,0.08),
    inset -2px 0 0 rgba(0,0,0,0.3);
}

.btn-outline {
  background: transparent;
  color: #1a6fd4;
  border: 1px solid #555;
  box-shadow:
    inset 0 2px 0 rgba(255,255,255,0.05),
    inset 0 -2px 0 rgba(0,0,0,0.2),
    inset 2px 0 0 rgba(255,255,255,0.03),
    inset -2px 0 0 rgba(0,0,0,0.15);
}

.btn-outline:hover {
  background: rgba(26, 111, 212, 0.1);
  color: #fff;
}

/* ========================
   CARDS
======================== */
.card {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--border-radius);
  padding: var(--spacing-lg);
}

/* ========================
   SECTIONS
======================== */
section {
  padding: var(--spacing-xl) 0;
}

/* ========================
   RESPONSIVE BREAKPOINTS
======================== */
/* Tablet */
@media (max-width: 768px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.6rem; }
  h3 { font-size: 1.25rem; }

  .container {
    width: 95%;
  }
}

/* Phone */
@media (max-width: 480px) {
  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.4rem; }

  .btn {
    width: 100%;
    text-align: center;
  }
}

/* ========================
   HERO SECTION
======================== */
#hero {
  padding: var(--spacing-xl) 0;
  min-height: 60vh;
  display: flex;
  align-items: center;
}

.hero-content {
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
}

.hero-content h1 {
  font-size: 3.5rem;
  margin-bottom: var(--spacing-md);
}

.hero-content p {
  font-size: 1.2rem;
  max-width: 600px;
  margin: 0 auto var(--spacing-lg);
}

.hero-buttons {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  flex-wrap: wrap;
}

.accent {
  color: var(--accent);
}

/* Responsive */
@media (max-width: 768px) {
  .hero-content h1 {
    font-size: 2.5rem;
  }
  .hero-content p {
    font-size: 1rem;
  }
}

/* ========================
   SECTION TITLES
======================== */
.section-title {
  text-align: center;
  margin-bottom: var(--spacing-md);
}

.section-subtitle {
  text-align: center;
  max-width: 600px;
  margin: 0 auto var(--spacing-lg);
}

.section-title span {
  color: var(--accent);
}

/* ========================
   FLIP CARDS
======================== */
.cards-col {
  display: flex;
  flex-direction: column;
  gap: 20px;
  width: 100%;
  margin: 0 auto;
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  padding: var(--spacing-lg);
  border-radius: var(--border-radius);
}

.flip-card {
  width: 100%;
  aspect-ratio: 2.8 / 1;
  perspective: 1200px;
  cursor: pointer;
}

.flip-inner {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.7s cubic-bezier(0.4, 0.2, 0.2, 1);
}

.flip-card.flipped .flip-inner {
  transform: rotateY(180deg);
}

.flip-front,
.flip-back {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  background: #f5f0e8;
  border: 1px solid #555;
  box-sizing: border-box;
  padding: 28px 32px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  overflow: hidden;
}

.flip-back {
  transform: rotateY(180deg);
  align-items: center;
  justify-content: center;
}

.card-title {
  font-family: var(--font-main);
  font-size: 1.15rem;
  font-weight: 700;
  color: #111;
  margin: 0 0 10px;
}

.card-text {
  font-family: var(--font-main);
  font-size: 0.9rem;
  color: #333;
  margin: 0;
  line-height: 1.6;
}

.card-back-placeholder {
  width: 90%;
  height: 70%;
  background: #e0d9cc;
  display: flex;
  align-items: center;
  justify-content: center;
}

.card-back-placeholder span {
  font-family: monospace;
  font-size: 0.85rem;
  color: #888;
}

@media (max-width: 768px) {
  .cards-col {
    padding: var(--spacing-sm);
  }

  .container {
    padding: var(--spacing-md) var(--spacing-sm);
  }
}
/* ========================
   PAGE CURL
======================== */
.peel {
  position: absolute;
  bottom: 0;
  right: 0;
  width: 60px;
  height: 60px;
  pointer-events: none;
}

.peel::after {
  content: '';
  position: absolute;
  bottom: 0;
  right: 0;
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 0 0 60px 60px;
  border-color: transparent transparent rgba(0,0,0,0.12) transparent;
  transition: border-width 0.4s ease;
}

.peel-flap {
  position: absolute;
  bottom: 0;
  right: 0;
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 0 0 60px 60px;
  border-color: transparent transparent #d4cdc0 transparent;
  transition: border-width 0.4s ease, filter 0.4s ease;
  filter: drop-shadow(-3px -3px 4px rgba(0,0,0,0.25));
}

@keyframes peekCurl {
  0%   { border-width: 0 0 60px 60px; }
  40%  { border-width: 0 0 100px 100px; filter: drop-shadow(-6px -6px 8px rgba(0,0,0,0.35)); }
  100% { border-width: 0 0 60px 60px; }
}

.do-peek .peel-flap {
  animation: peekCurl 1s ease both;
}

.flip-card:hover .peel-flap {
  border-width: 0 0 90px 90px;
  filter: drop-shadow(-5px -5px 7px rgba(0,0,0,0.35));
}

.flip-card:hover .peel::after {
  border-width: 0 0 90px 90px;
}

/* ========================
   MOBILE TAP HINT
======================== */
.tap-hint {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(0,0,0,0.75);
  color: #fff;
  padding: 10px 20px;
  font-size: 0.85rem;
  font-family: var(--font-main);
  border-radius: 20px;
  pointer-events: none;
  opacity: 1;
  transition: opacity 0.5s ease;
  z-index: 9999;
}

.tap-hint.hidden {
  opacity: 0;
}

/* ========================
   CTA SECTION
======================== */
#cta .container {
  text-align: center;
}

#cta p {
  max-width: 600px;
  margin: 0 auto var(--spacing-lg);
}

#cta {
  padding-bottom: var(--spacing-lg);
}