/**
 * @file styles.css
 * @description Main stylesheet for the website.
 * @version 2.0.0
 *
 * Structure:
 * 1. ROOT VARIABLES      - Centralized design tokens (colors, fonts, spacing).
 * 2. GLOBAL STYLES     - Base styles for body, typography, etc.
 * 3. UTILITY CLASSES   - Reusable helper classes (e.g., gradient text).
 * 4. COMPONENT STYLES  - Self-contained styles for each component.
 * - Card
 * - Fade-in Section
 * - Comparison Slider
 * - Header & Mobile Menu
 */

/* ==========================================================================
   1. ROOT VARIABLES
   ========================================================================== */

:root {
  /* Colors */
  --color-primary: #4f46e5;
  --color-secondary: #ec4899;
  --color-text-default: #374151; /* gray-700 */
  --color-text-light: #6b7280;   /* gray-500 */
  --color-surface: #ffffff;
  --color-background: #f8f9fa;
  --color-border: #e2e8f0;      /* gray-200 */
  --color-border-light: #d1d5db;/* gray-300 */
  --color-white: #fff;

  /* Fonts */
  --font-family-base: 'Manrope', sans-serif;
  --font-weight-normal: 400;
  --font-weight-semibold: 600;

  /* Spacing & Sizing */
  --spacing-xs: 0.25rem;  /* 4px */
  --spacing-sm: 0.5rem;   /* 8px */
  --spacing-md: 1rem;     /* 16px */
  --spacing-lg: 1.25rem;  /* 20px */
  --spacing-xl: 1.5rem;   /* 24px */

  /* Borders */
  --border-radius-md: 0.5rem;
  --border-radius-lg: 0.75rem;
  --border-radius-full: 9999px;

  /* Shadows */
  --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-handle: 0 0 10px rgba(0, 0, 0, 0.3);

  /* Transitions */
  --transition-duration-fast: 0.3s;
  --transition-duration-base: 0.5s;
  --transition-duration-slow: 0.6s;
  --transition-timing-ease: ease;
  --transition-timing-ease-out: ease-out;
  --transition-timing-custom: cubic-bezier(0.4, 0.01, 0.165, 0.99);
}

/* ==========================================================================
   2. GLOBAL STYLES
   ========================================================================== */

body {
  font-family: var(--font-family-base);
  background-color: var(--color-background);
  color: var(--color-text-default);
}

/* Base styles for scalable images, can be overridden by more specific components */
img[data-scalable="true"] {
  width: 100%;
  height: auto;
  display: block;
  margin-left: auto;
  margin-right: auto;
  object-fit: contain;
}


/* ==========================================================================
   3. UTILITY CLASSES
   ========================================================================== */

.gradient-text {
  background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ==========================================================================
   4. COMPONENT STYLES
   ========================================================================== */

/* --- Card --- */
.card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  transition: transform var(--transition-duration-fast) var(--transition-timing-ease),
              box-shadow var(--transition-duration-fast) var(--transition-timing-ease);
}

.card:hover {
  transform: translateY(calc(-1 * var(--spacing-sm)));
  box-shadow: var(--shadow-lg);
}

/* --- Fade-in Section --- */
.fade-in-section {
  opacity: 0;
  transform: translateY(var(--spacing-lg));
  transition: opacity var(--transition-duration-slow) var(--transition-timing-ease-out),
              transform var(--transition-duration-slow) var(--transition-timing-ease-out);
}

.fade-in-section.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Comparison Slider --- */
.comparison-slider {
  position: relative;
  width: 100%;
  overflow: hidden;
  border-radius: var(--border-radius-lg);
  box-shadow: var(--shadow-md);
}

.comparison-slider img {
  width: 100%;
  height: auto;
  max-width: 400px;
  max-height: 600px;
  object-fit: contain;
  display: block;
  margin: 0 auto;
}

.comparison-slider .img-top {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  width: 50%; /* Initial position, controlled by JS */
  object-fit: cover;
  object-position: left;
}

.comparison-slider .slider-handle {
  position: absolute;
  top: 0;
  left: 50%; /* Initial position, controlled by JS */
  transform: translateX(-50%); /* Center the handle precisely */
  height: 100%;
  width: 4px;
  background-color: var(--color-white);
  cursor: ew-resize;
  display: flex;
  align-items: center;
  justify-content: center;
}

.comparison-slider .slider-handle .handle-icon {
  width: 40px;
  height: 40px;
  background-color: var(--color-white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-handle);
  color: var(--color-primary);
}

/* --- Header & Mobile Menu --- */
.header {
  transition: all var(--transition-duration-base) var(--transition-timing-custom),
              background 1s var(--transition-timing-custom);
  transition-delay: 0.2s;
}

.burger-container {
  position: relative;
  display: inline-block;
  height: 50px;
  width: 50px;
  cursor: pointer;
  transform: rotate(0deg);
  transition: all var(--transition-duration-fast) var(--transition-timing-custom);
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

#burger {
  width: 18px;
  height: 8px;
  position: relative;
  display: block;
  margin: -4px auto 0;
  top: 50%;
}

#burger .bar {
  width: 100%;
  height: 1px;
  display: block;
  position: relative;
  background: var(--color-text-default);
  transition: all var(--transition-duration-fast) var(--transition-timing-custom);
}

#burger .bar.topBar {
  transform: translateY(0px) rotate(0deg);
}

#burger .bar.btmBar {
  transform: translateY(6px) rotate(0deg);
}

.menu {
  width: 100%;
  list-style: none;
  padding: 0 48px;
  margin: 0;
  text-align: center;
  background-color: inherit;
  visibility: hidden;
  opacity: 0;
  height: 0;
  overflow: hidden;
  transition: visibility 0s 0.5s, opacity 0s 0.5s, height 0s 0.5s;
}

.menu-item {
  border-bottom: 1px solid var(--color-border-light);
  margin-top: 5px;
  transform: scale(1.15) translateY(-30px);
  opacity: 0;
  transition: transform var(--transition-duration-base) var(--transition-timing-custom),
              opacity var(--transition-duration-slow) var(--transition-timing-custom);
}

.menu-item a {
  display: block;
  position: relative;
  color: var(--color-text-default);
  font-family: var(--font-family-base);
  font-weight: var(--font-weight-semibold);
  text-decoration: none;
  font-size: 22px;
  line-height: 2.35;
  width: 100%;
}

.menu-item.highlight {
  background: linear-gradient(to right, var(--color-primary), var(--color-secondary));
  border-radius: var(--border-radius-full);
  border-bottom: none;
  margin-top: 20px;
}

.menu-item.highlight a {
  line-height: 1;
  padding: var(--spacing-md) 0;
  color: var(--color-white);
}

/* Staggered transition delays for menu items closing */
.menu-item:nth-child(1) { transition-delay: 0.44s; }
.menu-item:nth-child(2) { transition-delay: 0.37s; }
.menu-item:nth-child(3) { transition-delay: 0.30s; }
.menu-item:nth-child(4) { transition-delay: 0.23s; }
.menu-item:nth-child(5) { transition-delay: 0.16s; }

/* Menu Opened State */
.header.menu-opened {
  height: 100vh;
  background-color: rgba(255, 255, 255, 0.8);
  -webkit-backdrop-filter: blur(4px);
  backdrop-filter: blur(4px);
  transition: all var(--transition-duration-fast) ease-in, background var(--transition-duration-base) ease-in;
  transition-delay: 0.25s;
}

.header.menu-opened .menu {
  visibility: visible;
  opacity: 1;
  height: auto;
  transition: visibility 0s 0s, opacity 0s 0s, height 0s 0s;
}

.header.menu-opened .burger-container {
  transform: rotate(90deg);
}

.header.menu-opened #burger .bar {
  transition: all 0.4s var(--transition-timing-custom);
  transition-delay: 0.2s;
}

.header.menu-opened #burger .bar.topBar {
  transform: translateY(4px) rotate(45deg);
}

.header.menu-opened #burger .bar.btmBar {
  transform: translateY(3px) rotate(-45deg);
}

.header.menu-opened .menu-item {
  transform: scale(1) translateY(0px);
  opacity: 1;
}

/* Staggered transition delays for menu items opening */
.header.menu-opened .menu-item:nth-child(1) { transition-delay: 0.22s; }
.header.menu-opened .menu-item:nth-child(2) { transition-delay: 0.29s; }
.header.menu-opened .menu-item:nth-child(3) { transition-delay: 0.36s; }
.header.menu-opened .menu-item:nth-child(4) { transition-delay: 0.43s; }
.header.menu-opened .menu-item:nth-child(5) { transition-delay: 0.50s; }

.telegram-btn img[alt="Telegram"] {
  filter: brightness(0) invert(1); /* black → white */
  /* optional: keep size */
  width: 20px;
  height: 20px;
}