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

html,
body {
  min-height: 100%;
  width: 100%;
}

html {
  font-family:
    system-ui,
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    Roboto,
    Oxygen,
    Ubuntu,
    Cantarell,
    "Open Sans",
    sans-serif;
}

/* =========================
   THEME VARIABLES
========================= */

:root {
  --bg-color: #0f0f0f;
  --primary-text-color: #f4f4f4;

  --bg-task-color: #252525;
  --bg-column-color: #191919;
  --bg-button-color: #222222;

  --border-color: #333333;

  --delete-color: #ff4d4d;

  --input-bg: #252525;
  --modal-bg: #191919;

  --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);

  --nav-padding: 15px 30px;

  --section-padding: 15px 30px;

  --padding-s: 5px;
  --padding-m: 10px;
  --padding-l: 15px;
  --padding-xl: 20px;
  --padding-xxl: 30px;

  --border-radius-s: 5px;
  --border-radius-m: 10px;
  --border-radius-l: 15px;
}

/* LIGHT THEME */

body.light-theme {
  --bg-color: #f4f5f7;
  --primary-text-color: #181818;

  --bg-task-color: #ffffff;
  --bg-column-color: #e8eaf0;
  --bg-button-color: #ffffff;

  --border-color: #d5d7dc;

  --input-bg: #f1f2f4;
  --modal-bg: #ffffff;

  --shadow: 0 10px 30px rgba(0, 0, 0, 0.12);
}

/* =========================
   BODY
========================= */

body {
  background-color: var(--bg-color);
  color: var(--primary-text-color);

  transition:
    background-color 0.3s ease,
    color 0.3s ease;
}

/* =========================
   MAIN
========================= */

main {
  min-height: 100vh;

  display: flex;
  flex-direction: column;
}

/* =========================
   NAVBAR
========================= */

nav {
  padding: var(--nav-padding);

  display: flex;
  align-items: center;
  justify-content: space-between;

  position: sticky;
  top: 0;

  background-color: var(--bg-color);

  z-index: 50;

  border-bottom: 1px solid var(--border-color);

  transition: background-color 0.3s ease;
}

/* Brand section */

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: -0.5px;
}

/* Theme button */

.theme-btn {
  width: 38px;
  height: 38px;

  display: flex;
  align-items: center;
  justify-content: center;

  border: 1px solid var(--border-color);
  border-radius: 50%;

  background-color: var(--bg-button-color);

  color: var(--primary-text-color);

  cursor: pointer;

  font-size: 17px;

  transition:
    transform 0.2s ease,
    background-color 0.3s ease;
}

.theme-btn:hover {
  transform: rotate(20deg) scale(1.05);
}

/* Buttons */

nav button {
  border: none;
  outline: none;

  color: var(--primary-text-color);

  cursor: pointer;
}

.new-task-btn {
  background-color: var(--bg-button-color);

  border: 1px solid var(--border-color) !important;

  padding: 10px 16px;

  border-radius: var(--border-radius-m);

  transition:
    transform 0.2s ease,
    background-color 0.3s ease;
}

.new-task-btn:hover {
  transform: translateY(-2px);
}

/* =========================
   BOARD
========================= */

.board {
  padding: var(--section-padding);

  display: flex;

  gap: var(--padding-xxl);

  flex-grow: 1;

  align-items: stretch;
}

/* =========================
   TASK COLUMN
========================= */

.task-column {
  background-color: var(--bg-column-color);

  flex: 1;

  min-width: 0;

  padding: var(--padding-m);

  display: flex;
  flex-direction: column;

  gap: var(--padding-m);

  border-radius: var(--border-radius-m);

  border: 2px solid transparent;

  transition:
    background-color 0.3s ease,
    transform 0.3s ease,
    border 0.3s ease;
}

/* Drag over */

.task-column.hover-over {
  border: 2px dashed var(--primary-text-color);

  transform: scale(1.02);
}

/* =========================
   COLUMN HEADING
========================= */

.task-column .heading {
  width: 100%;

  display: flex;

  align-items: center;

  justify-content: space-between;

  padding: 5px;
}

.heading .left {
  display: flex;

  align-items: center;

  gap: 8px;

  font-weight: 600;
}

/* Column dots */

.column-dot {
  width: 9px;
  height: 9px;

  border-radius: 50%;

  display: inline-block;
}

.todo-dot {
  background-color: #ffb84d;
}

.progress-dot {
  background-color: #5b8cff;
}

.done-dot {
  background-color: #4ade80;
}

/* Count */

.count {
  min-width: 28px;
  height: 28px;

  display: flex;

  align-items: center;
  justify-content: center;

  border-radius: 50%;

  background-color: var(--bg-button-color);

  font-size: 13px;
}

/* =========================
   TASK
========================= */

.task-column .task {
  background-color: var(--bg-task-color);

  padding: var(--padding-m);

  border-radius: var(--border-radius-m);

  display: flex;

  flex-direction: column;

  gap: var(--padding-s);

  cursor: grab;

  border: 1px solid var(--border-color);

  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);

  transition:
    transform 0.2s ease,
    box-shadow 0.2s ease;
}

.task-column .task:hover {
  transform: translateY(-2px);

  box-shadow: var(--shadow);
}

.task-column .task:active {
  cursor: grabbing;
}

.task h2 {
  font-size: 17px;

  overflow-wrap: anywhere;
}

.task p {
  color: var(--primary-text-color);

  opacity: 0.7;

  font-size: 14px;

  line-height: 1.5;

  overflow-wrap: anywhere;
}

/* Delete button */

.task-column .task button {
  align-self: flex-end;

  cursor: pointer;

  padding: var(--padding-s) var(--padding-m);

  border-radius: var(--border-radius-s);

  border: none;

  outline: none;

  background-color: var(--delete-color);

  color: white;

  transition: opacity 0.2s ease;
}

.task-column .task button:hover {
  opacity: 0.8;
}

/* =========================
   MODAL
========================= */

.modal {
  position: fixed;

  height: 100vh;
  width: 100vw;

  top: 0;
  left: 0;

  display: none;

  align-items: center;
  justify-content: center;

  z-index: 100;
}

.modal.active {
  display: flex;
}

/* Background */

.modal .bg {
  position: absolute;

  height: 100%;
  width: 100%;

  background-color: rgba(0, 0, 0, 0.5);

  backdrop-filter: blur(6px);
}

/* Modal box */

.modal .center {
  position: relative;

  width: min(450px, calc(100% - 30px));

  background-color: var(--modal-bg);

  padding: var(--padding-xxl);

  border-radius: var(--border-radius-l);

  display: flex;

  flex-direction: column;

  gap: var(--padding-m);

  z-index: 10;

  box-shadow: var(--shadow);

  border: 1px solid var(--border-color);

  animation: modalIn 0.25s ease;
}

@keyframes modalIn {
  from {
    opacity: 0;
    transform: translateY(20px) scale(0.97);
  }

  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

/* Modal header */

.modal-header {
  display: flex;

  align-items: center;

  justify-content: space-between;

  margin-bottom: 5px;
}

.modal-header h2 {
  font-size: 20px;
}

/* Close */

.close-btn {
  width: 32px;
  height: 32px;

  border: none;

  border-radius: 50%;

  background-color: var(--bg-task-color);

  color: var(--primary-text-color);

  font-size: 22px;

  cursor: pointer;

  display: flex;

  align-items: center;
  justify-content: center;
}

/* Inputs */

.modal .center input,
.modal .center textarea {
  background-color: var(--input-bg);

  border: 1px solid var(--border-color);

  outline: none;

  color: var(--primary-text-color);

  padding: var(--padding-m);

  border-radius: var(--border-radius-s);

  font-family: inherit;

  width: 100%;
}

.modal .center textarea {
  resize: vertical;

  min-height: 120px;
}

.modal .center input:focus,
.modal .center textarea:focus {
  border-color: #777;
}

/* Add button */

.modal .center button.add-task-btn {
  background-color: var(--primary-text-color);

  color: var(--bg-color);

  border: none;

  outline: none;

  padding: var(--padding-m) var(--padding-l);

  cursor: pointer;

  border-radius: var(--border-radius-m);

  width: fit-content;

  align-self: flex-end;

  font-weight: 600;

  transition: transform 0.2s ease;
}

.modal .center button.add-task-btn:hover {
  transform: translateY(-2px);
}

/* =========================
   TABLET
========================= */

@media (max-width: 900px) {
  .board {
    gap: 15px;
  }

  .task-column {
    padding: 8px;
  }

  .task h2 {
    font-size: 15px;
  }

  .task p {
    font-size: 13px;
  }
}

/* =========================
   MOBILE
========================= */

@media (max-width: 700px) {
  nav {
    padding: 12px 15px;
  }

  .logo {
    font-size: 21px;
  }

  .theme-btn {
    width: 34px;
    height: 34px;

    font-size: 15px;
  }

  .new-task-btn {
    padding: 9px 12px;

    font-size: 13px;
  }

  .board {
    padding: 15px;

    flex-direction: column;

    gap: 15px;
  }

  .task-column {
    width: 100%;

    min-height: 180px;

    flex: none;
  }

  .task-column.hover-over {
    transform: none;
  }

  .task {
    width: 100%;
  }

  .modal .center {
    padding: 20px;

    width: calc(100% - 24px);
  }
}

/* =========================
   SMALL PHONES
========================= */

@media (max-width: 400px) {
  nav {
    gap: 10px;
  }

  .brand {
    gap: 7px;
  }

  .logo {
    font-size: 19px;
  }

  .new-task-btn {
    font-size: 12px;

    padding: 8px 10px;
  }

  .board {
    padding: 10px;
  }

  .task-column {
    min-height: 160px;
  }

  .modal .center {
    padding: 16px;
  }
}
.task {
  touch-action: none;
}

@media (max-width: 700px) {
  .task {
    cursor: grab;
  }

  .task:active {
    cursor: grabbing;
  }
}