/* ==========================================================================
   bilen.me "Curious Grid" Design System - Core CSS
   ========================================================================== */

/* Google Fonts Import */
@import url('https://fonts.googleapis.com/css2?family=Hanken+Grotesk:wght@400;600;700;800&display=swap');
@import url('https://fonts.googleapis.com/css2?family=Material+Symbols+Outlined:opsz,wght,FILL,GRAD@20..48,100..700,0..1,-50..200');

/* --- Design Tokens --- */
:root {
  /* Color Palette */
  --bg-color: #f9f9f9;
  --on-bg-color: #1b1b1b;
  --primary-color: #000000;
  --on-primary-color: #ffffff;
  --secondary-color: #5c5e62;
  --border-subtle: #b5b5b5;
  --surface-container: #eeeeee;
  --surface-variant: #e2e2e2;
  --shadow-color: var(--primary-color);
  --dot-color: rgba(0, 0, 0, 0.05);

  /* Animation Easing Curves */
  --ease-out: cubic-bezier(0.23, 1, 0.32, 1);
  --ease-in-out: cubic-bezier(0.77, 0, 0.175, 1);
  --ease-drawer: cubic-bezier(0.32, 0.72, 0, 1);

  /* Typography Scale */
  --font-family: 'Hanken Grotesk', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;

  /* Spacing System */
  --grid-gap: 20px;
  --card-padding: 24px;
  --section-margin: 80px;
  --container-max-width: 1100px;

  /* Border System */
  --border-width: 2px;
  --border-style: solid;
  --border-color: var(--primary-color);
  --border-thick: var(--border-width) var(--border-style) var(--border-color);

  /* Border Radius */
  --radius-card: 12px;
  --radius-interactive: 8px;
  --radius-inner: 6px;
  --radius-full: 9999px;

  /* Shadow Elevation */
  --shadow-flat: 4px 4px 0px var(--shadow-color);
  --shadow-flat-hover: 6px 6px 0px var(--shadow-color);
  --shadow-flat-active: 1px 1px 0px var(--shadow-color);
  --shadow-btn: 3px 3px 0px var(--shadow-color);
  --shadow-btn-hover: 5px 5px 0px var(--shadow-color);
  --shadow-btn-active: 1px 1px 0px var(--shadow-color);
}

/* --- Base Resets --- */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html,
body {
  height: 100%;
  background-color: var(--bg-color);
  color: var(--on-bg-color);
  font-family: var(--font-family);
  font-size: 18px;
  font-weight: 400;
  line-height: 1.6;
  overflow-x: hidden;
}

/* --- Dot Pattern Background --- */
.dot-pattern {
  background-image: radial-gradient(circle, var(--dot-color) 1.5px, transparent 1.5px);
  background-size: 24px 24px;
}

/* --- Layout & Shell --- */
.app-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--grid-gap);
}

/* --- Navigation --- */
.navbar {
  width: 100%;
  position: sticky;
  top: 0;
  background-color: var(--bg-color);
  border-bottom: var(--border-thick);
  z-index: 100;
  transition: padding 0.3s ease;
}

.navbar-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 24px;
  padding-bottom: 24px;
  position: relative;
}

.nav-brand {
  font-size: 40px;
  font-weight: 800;
  color: var(--primary-color);
  text-decoration: none;
  letter-spacing: -0.04em;
  line-height: 1.1;
  transition: transform 0.2s var(--ease-out);
}

.nav-brand:hover {
  transform: scale(1.03);
}

.nav-links {
  display: flex;
  gap: 24px;
}

.nav-link {
  color: var(--secondary-color);
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 4px 8px;
  border-bottom: 2px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.nav-link:hover,
.nav-link.active {
  color: var(--primary-color);
}

.nav-link.active {
  border-color: var(--primary-color);
}

.nav-mobile-btn {
  display: none;
  background: none;
  border: var(--border-thick);
  border-radius: var(--radius-interactive);
  padding: 6px;
  cursor: pointer;
  color: var(--primary-color);
  box-shadow: var(--shadow-btn);
  background-color: var(--bg-color);
  display: none;
  align-items: center;
  justify-content: center;
  transition: transform 0.15s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.15s cubic-bezier(0.16, 1, 0.3, 1);
}

.nav-mobile-btn:hover {
  transform: translate(-1px, -1px);
  box-shadow: var(--shadow-btn-hover);
}

.nav-mobile-btn:active {
  transform: translate(1px, 1px);
  box-shadow: var(--shadow-btn-active);
}

/* --- Category Switcher (Sticky Bar) --- */
.category-bar {
  width: 100%;
  position: sticky;
  top: 91px; /* standard navbar height threshold with 2px border */
  background-color: rgba(249, 249, 249, 0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1.5px solid var(--surface-variant);
  z-index: 90;
  padding: 16px 0;
  transition: top 0.3s ease;
}

.category-container {
  display: flex;
  justify-content: center;
  gap: 16px;
  position: relative;
  width: 100%;
}

/* --- Standardized Tactile Button/Tab Base --- */
.category-tab,
.card-btn {
  background-color: var(--on-primary-color);
  color: var(--on-bg-color);
  border: var(--border-thick);
  border-radius: var(--radius-interactive);
  padding: 8px 24px;
  font-family: var(--font-family);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  cursor: pointer;
  box-shadow: var(--shadow-btn);
  display: inline-block;
  text-align: center;
  text-decoration: none;
  transition: transform 0.15s var(--ease-out),
              box-shadow 0.15s var(--ease-out),
              background-color 0.2s ease,
              color 0.2s ease;
}

.category-tab:hover,
.card-btn:hover {
  transform: translate(-2px, -2px);
  box-shadow: var(--shadow-btn-hover);
  background-color: var(--surface-container);
}

.category-tab:active,
.card-btn:active {
  transform: translate(2px, 2px) scale(0.97);
  box-shadow: var(--shadow-btn-active);
}

/* Active Category Tab - Pressed Down & Disabled */
.category-tab.active {
  background-color: var(--primary-color) !important;
  color: var(--on-primary-color) !important;
  transform: translate(2px, 2px) scale(1) !important;
  box-shadow: var(--shadow-btn-active) !important;
  pointer-events: none;
}

/* --- Pin Mode Toggle Button --- */
.pin-toggle-btn {
  position: absolute;
  right: var(--grid-gap);
  top: 50%;
  transform: translateY(-50%);
  background-color: var(--bg-color);
  color: var(--primary-color);
  border: var(--border-thick);
  border-radius: var(--radius-interactive);
  width: 42px;
  height: 42px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--shadow-btn);
  z-index: 10;
  transition: background-color 0.2s cubic-bezier(0.16, 1, 0.3, 1),
              box-shadow 0.15s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.15s cubic-bezier(0.16, 1, 0.3, 1);
}

.pin-toggle-btn:hover {
  transform: translateY(-50%) translate(-2px, -2px);
  box-shadow: var(--shadow-btn-hover);
  background-color: var(--surface-container);
}

.pin-toggle-btn:active {
  transform: translateY(-50%) translate(2px, 2px);
  box-shadow: var(--shadow-btn-active);
}

/* Filled state when cards are pinned (active Pin Mode) */
.pin-toggle-btn:not(.unpinned) .material-symbols-outlined {
  font-variation-settings: 'FILL' 1, 'wght' 400, 'GRAD' 0, 'opsz' 24;
  transform: rotate(0deg);
  transition: transform 0.35s cubic-bezier(0.175, 0.885, 0.32, 1.25);
}

/* Rotated and empty state when cards are unpinned */
.pin-toggle-btn.unpinned {
  background-color: var(--surface-container);
}

.pin-toggle-btn.unpinned .material-symbols-outlined {
  font-variation-settings: 'FILL' 0, 'wght' 400, 'GRAD' 0, 'opsz' 24;
  transform: rotate(45deg);
  transition: transform 0.35s cubic-bezier(0.175, 0.885, 0.32, 1.25);
}

/* --- Main Content Area --- */
.main-content {
  flex-grow: 1;
  position: relative;
  padding-top: 40px;
  padding-bottom: var(--section-margin);
}

.board-container {
  display: none;
  opacity: 0;
  position: relative;
  width: 100%;
  min-height: 620px;
  transition: opacity 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.board-container.active {
  display: block;
  opacity: 1;
}

/* --- Draggable Card Component --- */
.draggable {
  position: absolute;
  border: var(--border-thick);
  border-radius: var(--radius-card);
  padding: var(--card-padding);
  box-shadow: var(--shadow-flat);
  cursor: grab;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
  will-change: transform, box-shadow;
  transition: box-shadow 0.25s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.draggable:hover {
  box-shadow: var(--shadow-flat-hover);
}

.draggable:active {
  cursor: grabbing;
}

.card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.card-pill {
  background-color: #f1f2f6;
  color: var(--on-bg-color);
  border: 1.5px solid var(--primary-color);
  border-radius: var(--radius-inner);
  padding: 4px 12px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.card-icon {
  font-size: 24px;
  color: var(--primary-color);
}

.card-thumbnail {
  width: 100%;
  height: 120px;
  background-color: var(--on-primary-color);
  border: var(--border-thick);
  border-radius: var(--radius-inner);
  margin-bottom: 16px;
  overflow: hidden;
  position: relative;
}

/* Decorative Card Thumbnails */
.thumbnail-decor {
  position: absolute;
  inset: 0;
  opacity: 0.85;
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.draggable:hover .thumbnail-decor {
  transform: scale(1.06);
}

.card-title {
  font-size: 22px;
  font-weight: 800;
  color: var(--primary-color);
  margin-bottom: 8px;
  letter-spacing: -0.025em;
  line-height: 1.2;
  text-wrap: balance;
}

.card-desc {
  font-size: 14px;
  line-height: 1.6;
  color: #2b2526;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: 16px;
  text-wrap: pretty;
}

.card-btn {
  width: 100%;
  padding: 10px 16px;
  font-size: 14px;
}

.card-btn:hover {
  background-color: var(--primary-color);
  color: var(--on-primary-color);
}

/* Dark Card Styling Details (Kept as unified visual option fallback) */
.draggable-dark .card-title,
.draggable-dark .card-icon {
  color: var(--on-primary-color) !important;
}

.draggable-dark .card-desc {
  color: #c5c6ca !important;
}

.draggable-dark .card-pill {
  border-color: var(--on-primary-color) !important;
}

.draggable-dark .card-btn {
  background-color: transparent !important;
  color: var(--on-primary-color) !important;
  border-color: var(--on-primary-color) !important;
}

.draggable-dark .card-btn:hover {
  background-color: var(--on-primary-color) !important;
  color: var(--primary-color) !important;
}

/* --- Footer --- */
.footer {
  width: 100%;
  margin-top: auto;
  border-top: var(--border-thick);
  background-color: var(--bg-color);
  padding: 40px 0;
  z-index: 100;
}

.footer-container {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

.footer-copy {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-link {
  color: var(--secondary-color);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  transition: color 0.2s ease, text-decoration 0.2s ease;
}

.footer-link:hover {
  color: var(--primary-color);
  text-decoration: underline;
}

/* --- Responsive Layout Adjustments --- */
@media (min-width: 768px) {
  .navbar-container {
    padding-top: 32px;
    padding-bottom: 32px;
  }

  .footer-container {
    flex-direction: row;
  }
}

@media (max-width: 768px) {
  .nav-mobile-btn {
    display: flex;
  }

  /* Neo-Brutalist Mobile Menu Dropdown Drawer */
  .nav-links {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background-color: var(--bg-color);
    border-bottom: var(--border-thick);
    border-left: var(--border-thick);
    border-right: var(--border-thick);
    border-radius: 0 0 var(--radius-card) var(--radius-card);
    padding: 24px;
    gap: 16px;
    z-index: 99;
    box-shadow: 6px 6px 0px var(--primary-color);
    opacity: 0;
    transform: translateY(-10px);
    transition: opacity 0.25s ease, transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
    pointer-events: none;
  }

  .nav-links.open {
    display: flex;
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
  }

  .nav-link {
    width: 100%;
    padding: 12px 16px;
    border: var(--border-thick);
    border-radius: var(--radius-interactive);
    background-color: var(--on-primary-color);
    box-shadow: var(--shadow-btn);
    transition: transform 0.15s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.15s cubic-bezier(0.16, 1, 0.3, 1);
  }

  .nav-link:hover {
    transform: translate(-1px, -1px);
    box-shadow: var(--shadow-btn-hover);
  }

  .nav-link.active {
    background-color: var(--primary-color);
    color: var(--on-primary-color);
    transform: translate(1px, 1px);
    box-shadow: var(--shadow-btn-active);
  }

  /* Mobile Category Switcher Placement Adjustment */
  .category-bar {
    top: 85px; /* adjust top to match navbar size on mobile */
    padding: 12px 0;
  }

  /* Grid system for smaller screens */
  .board-container {
    display: none;
    opacity: 0;
    min-height: auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    padding: 16px 0;
  }

  .board-container.active {
    display: grid;
    opacity: 1;
  }

  .draggable {
    position: relative !important;
    top: auto !important;
    left: auto !important;
    right: auto !important;
    bottom: auto !important;
    transform: none !important;
    margin: 0 auto;
    width: 100% !important;
    max-width: 360px;
    cursor: default;
  }

  .draggable:hover {
    box-shadow: var(--shadow-flat);
  }

  .draggable:active {
    cursor: default;
  }

  .pin-toggle-btn {
    display: none !important;
  }
}

@media (max-width: 480px) {
  .nav-brand {
    font-size: 32px;
  }

  .category-tab {
    padding: 6px 16px;
    font-size: 11px;
  }

  .category-bar {
    top: 76px;
  }
}

/* ==========================================================================
   Info Drawer (About & Contact Slide-out Panel)
   ========================================================================== */

/* Drawer Backdrop */
.info-drawer-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 1999;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s var(--ease-out);
}

.info-drawer-backdrop.open {
  opacity: 1;
  pointer-events: auto;
}

/* Sidebar Drawer Panel */
.info-drawer {
  position: fixed;
  top: 0;
  right: 0;
  width: 480px;
  max-width: 100%;
  height: 100vh;
  background-color: var(--bg-color);
  border-left: var(--border-thick);
  box-shadow: -8px 0px 0px var(--primary-color);
  z-index: 2000;
  transform: translateX(100%);
  transition: transform 380ms var(--ease-drawer);
  display: flex;
  flex-direction: column;
}

.info-drawer.open {
  transform: translateX(0);
}

/* Drawer Header */
.info-drawer-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 24px;
  border-bottom: var(--border-thick);
}

.info-drawer-title {
  font-size: 28px;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin: 0;
}

.info-drawer-close {
  background: none;
  border: var(--border-thick);
  border-radius: var(--radius-interactive);
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--shadow-btn);
  color: var(--primary-color);
  transition: transform 0.15s var(--ease-out), box-shadow 0.15s var(--ease-out);
}

.info-drawer-close:hover {
  transform: translate(-1px, -1px);
  box-shadow: var(--shadow-btn-hover);
  background-color: var(--surface-container);
}

.info-drawer-close:active {
  transform: translate(1px, 1px) scale(0.95);
  box-shadow: var(--shadow-btn-active);
}

/* Drawer Body Scrollable Content */
.info-drawer-body {
  flex-grow: 1;
  overflow-y: auto;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.info-drawer-section {
  display: flex;
  flex-direction: column;
}

.info-drawer-section-title {
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -0.015em;
  margin-bottom: 12px;
  text-transform: uppercase;
  border-bottom: 1.5px solid var(--surface-variant);
  padding-bottom: 6px;
  color: var(--primary-color);
}

.info-drawer-text {
  font-size: 15px;
  line-height: 1.6;
  color: #2b2526;
  margin-bottom: 16px;
  text-wrap: pretty;
}

.info-drawer-text strong {
  font-weight: 700;
  color: var(--primary-color);
}

/* Contact Form Neo-Brutalist Layout */
.contact-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-label {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--secondary-color);
}

.form-input,
.form-textarea {
  font-family: var(--font-family);
  font-size: 14px;
  padding: 10px 14px;
  border: var(--border-thick);
  border-radius: var(--radius-interactive);
  background-color: var(--on-primary-color);
  color: var(--on-bg-color);
  transition: border-color 0.2s var(--ease-out), box-shadow 0.2s var(--ease-out);
}

.form-input:focus,
.form-textarea:focus {
  outline: none;
  box-shadow: 0 0 0 3px rgba(0, 0, 0, 0.1);
  border-color: var(--primary-color);
}

.form-textarea {
  resize: vertical;
  min-height: 100px;
}

.form-submit-btn {
  width: 100%;
  padding: 12px;
  margin-top: 8px;
}

/* Form Alert Statuses */
.form-status-message {
  display: none;
  background-color: #d4edda;
  color: #155724;
  border: var(--border-thick);
  border-color: #c3e6cb;
  border-radius: var(--radius-interactive);
  padding: 12px;
  font-size: 14px;
  font-weight: 700;
  text-align: center;
  margin-top: 8px;
  box-shadow: var(--shadow-btn-active);
}

/* Ensure drawer borders merge cleanly on small widths */
@media (max-width: 480px) {
  .info-drawer {
    border-left: none;
    box-shadow: none;
  }
}

/* ==========================================================================
   Language Switcher Styles (DE & EN)
   ========================================================================== */

/* Align nav elements vertically */
.nav-links {
  align-items: center;
}

.lang-switch-pill {
  display: inline-flex;
  align-items: center;
  border: var(--border-thick);
  border-radius: var(--radius-interactive);
  background-color: var(--on-primary-color);
  padding: 2px;
  box-shadow: var(--shadow-btn);
  transition: transform 0.15s var(--ease-out), box-shadow 0.15s var(--ease-out);
  height: 38px;
}

.lang-switch-pill:hover {
  transform: translate(-1px, -1px);
  box-shadow: var(--shadow-btn-hover);
}

.lang-switch-pill:active {
  transform: translate(1px, 1px);
  box-shadow: var(--shadow-btn-active);
}

.lang-switch-btn {
  background: none;
  border: none;
  font-family: var(--font-family);
  font-size: 12px;
  font-weight: 800;
  text-transform: uppercase;
  color: var(--secondary-color);
  padding: 4px 10px;
  cursor: pointer;
  border-radius: var(--radius-inner);
  transition: background-color 0.2s ease, color 0.2s ease;
  line-height: 1;
}

.lang-switch-btn:hover {
  color: var(--primary-color);
}

.lang-switch-btn.active {
  background-color: var(--primary-color);
  color: var(--on-primary-color);
  pointer-events: none;
}

.lang-switch-divider {
  width: 2px;
  height: 16px;
  background-color: var(--border-subtle);
  margin: 0 2px;
}

/* Responsive language switcher for mobile menu drawer */
@media (max-width: 768px) {
  .lang-switch-pill {
    width: 100%;
    justify-content: center;
    box-sizing: border-box;
    margin-top: 8px;
    height: 48px;
  }
  
  .lang-switch-btn {
    flex: 1;
    font-size: 14px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-interactive);
  }
  
  .lang-switch-divider {
    display: none;
  }
}