/* =========================================================
   HYPERTRANSLATOR MAIN STYLESHEET
   ========================================================= */

:root {
  /* ===== Color Palette ===== */
  --blue-dark: #031323;
  --blue-mid: #061c33;
  --blue-light: #064686;
  --blue-accent: #093c70;
  --blue-hover: #004c99;
  --blue-soft: rgba(0, 32, 63, .5);

  --teal-accent: #66c0ff;
  --teal-glow: rgba(102, 192, 255, .25);

  --orange: #b36c00;
  --orange-light: #e09626;

  --green: #00aa66;
  --green-soft: rgba(0, 170, 102, .25);

  --red: #cc3333;
  --red-soft: rgba(204, 51, 51, .25);

  --white: #fff;
  --white-soft: rgba(255, 255, 255, .84);
  --white-muted: rgba(255, 255, 255, .6);
  --white-faint: rgba(255, 255, 255, .25);

  --black-soft: rgba(0, 0, 0, .3);

  /* ===== Shadows ===== */
  --shadow-strong: 0 8px 20px rgba(0, 0, 0, .4);
  --shadow-soft: 0 4px 15px rgba(0, 0, 0, .3);
  --shadow-nav: 0 10px 28px rgba(0, 0, 0, .45);

  /* ===== Transitions ===== */
  --transition-fast: all .3s ease-in 0s;
  --transition-mid: all .4s ease-in-out;
}

/* =========================================================
   GENERAL
   ========================================================= */

body {
  min-width: 340px;
  font: 400 .9rem/1.75 'Poppins', sans-serif;
  color: var(--white-soft);
  background: #032040 linear-gradient(to bottom,
      var(--blue-light) 0%,
      var(--blue-light) 20%,
      var(--blue-light) 33%,
      var(--blue-dark) 66%,
      var(--blue-dark) 75%,
      var(--blue-dark) 100%);
  overflow-x: hidden;
  scroll-behavior: smooth;
}

/* =========================================================
   TYPOGRAPHY
   ========================================================= */

h1,
h2,
h3,
h4,
h5,
h6,
p {
  font-family: 'Poppins', sans-serif;
  margin-bottom: 1em;
  color: var(--white-soft);
}

h1 {
  font: 700 2rem/1.4 'Poppins', sans-serif;
}

h2 {
  font: 600 1.6rem/1.4 'Poppins', sans-serif;
}

h3 {
  font: 600 1.33rem/1.4 'Poppins', sans-serif;
}

h4 {
  font: 500 1.25rem/1.4 'Poppins', sans-serif;
}

h5 {
  font: 500 1.125rem/1.4 'Poppins', sans-serif;
}

h6 {
  font: 500 1rem/1.4 'Poppins', sans-serif;
  text-transform: uppercase;
  letter-spacing: .5px;
}

a {
  color: var(--white);
  text-decoration: none;
  transition: var(--transition-fast);
}

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

a:active {
  color: var(--orange-light);
}

p {
  margin-bottom: 1.5rem;
  font: 400 1rem/1.75 'Poppins', sans-serif;
  color: var(--white-soft);
}

blockquote {
  border-left: 4px solid var(--teal-accent);
  padding-left: 1rem;
  font-style: italic;
  color: var(--white-soft);
  margin: 2rem 0;
}

::selection {
  background-color: var(--orange);
  color: var(--white);
}

::-moz-selection {
  background-color: var(--orange);
  color: var(--white);
}

/* =========================================================
   HEADER
   ========================================================= */

header {
  background: var(--blue-mid);
}

.logo {
  display: block;
  width: 153px;
  height: auto;
  margin-left: -.5rem;
}

.navbar {
  margin-right: -.5rem;
}

.navbar-brand {
  display: block;
}

.navbar-nav {
  padding-top: 1.25rem;
}

.nav-link {
  margin: 0 .5rem;
  padding: 1rem 0;
  font-size: 1rem;
  color: var(--white-soft);
}

.nav-item .nav-link:hover {
  color: var(--teal-accent);
}

.nav-item .nav-link:active {
  color: var(--orange-light);
}

.btn-blue {
  background: var(--blue-accent);
  border-radius: .5rem;
  color: var(--white-soft);
  padding: .5rem 1rem;
}

.btn-blue:hover,
.btn-blue:active {
  color: var(--white);
  background: var(--blue-hover);
}

/* =========================================================
   BURGER MENU
   ========================================================= */

.navbar-toggler {
  border: none;
}

.navbar-toggler:focus {
  box-shadow: none !important;
  outline: none !important;
}

.navbar-toggler.collapsed i.fa-bars {
  display: inline;
  font-size: 1.5rem;
  color: rgba(255, 255, 255, .75);
}

.navbar-toggler.collapsed i.fa-xmark {
  display: none;
}

.navbar-toggler:not(.collapsed) i.fa-bars {
  display: none;
}

.navbar-toggler:not(.collapsed) i.fa-xmark {
  display: inline;
  font-size: 1.5rem;
  color: rgba(255, 255, 255, .75);
}

/* =========================================================
   LANGUAGE SWITCH
   ========================================================= */

.lang-switch {
  position: absolute;
  top: 26px;
  left: 60%;
  z-index: 99;
}

.lang-flag {
  display: inline-block;
  width: 24px;
  height: 24px;
  margin: -1px 8px 1px 0;
  vertical-align: middle;
  border: 1px solid #033366;
  border-top-color: #062c50;
  border-bottom-color: #1363ac;
  border-radius: 50%;
  box-shadow: inset 3px 3px 9px var(--black-soft);
}

.flag-bg {
  background: url(img/flag_bg.svg) no-repeat;
  background-size: contain;
}

.flag-en {
  background: url(img/flag_uk.svg) no-repeat;
  background-size: contain;
}

/* =========================================================
   DROPDOWN MENU
   ========================================================= */

.dropdown-menu {
  background: rgba(6, 28, 51, 0.96);
  border: 1px solid rgba(255, 255, 255, .067);
  border-radius: .6rem;
  backdrop-filter: blur(8px);
  box-shadow: var(--shadow-nav);
  margin-top: .5rem;
  min-width: 220px;
}

.dropdown-item {
  color: rgba(255, 255, 255, .9);
  padding: .65rem 1rem;
  transition: background .3s ease, color .3s ease;
}

.dropdown-item i {
  color: var(--teal-accent);
}

.dropdown-item:hover {
  background: rgba(102, 192, 255, .1);
  color: var(--teal-accent);
}

.dropdown-item.current, 
.dropdown-item.current i {
  color: var(--orange-light);
  cursor: default;
}

/* =========================================================
   INTRO SECTION
   ========================================================= */

.intro {
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: #062649 url(img/intro.jpg) no-repeat center / cover scroll;
  padding: 6rem 1rem;
  text-align: center;
  transition: var(--transition-fast);
}

.intro.transcription {
  background-image: url(img/intro_transcription.jpg);
}

.intro.translation {
  background-image: url(img/intro_translation.jpg);
}

.overlay {
  background-image: url(img/intro_overlay.jpg);
}

.demucs {
  background-image: url(img/intro_demucs.jpg);
}

.text-to-speech {
  background-image: url(img/intro_text_to_speech.jpg);
}

.speech-to-speech {
  background-image: url(img/intro_speech_to_speech.jpg);
}

.intro h1 {
  font-size: 1.67rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.intro p {
  font-size: 1.25rem;
  margin: 2em 0;
}

.btn-cta {
  background: linear-gradient(45deg, var(--orange), var(--orange-light));
  color: var(--white-soft);
  padding: .75rem 1.5rem;
  border-radius: .5rem;
  font-weight: 600;
  text-decoration: none;
}

.btn-cta:hover,
.btn-cta:active {
  color: var(--white);
  background: linear-gradient(45deg, var(--orange-light), var(--orange));
  box-shadow: var(--shadow-soft);
}

/* =========================================================
   SECTIONS
   ========================================================= */

section {
  padding: 2rem .5rem;
}

.section-title {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
}

.section-title::before,
.section-title::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--white-faint);
}

.section-title::before {
  margin-right: 1.66rem;
}

.section-title::after {
  margin-left: 1.66rem;
}

/* =========================================================
   FEATURES
   ========================================================= */

.feature-box {
  display: block;
  background: var(--blue-soft);
  color: #f0f0f0;
  padding: 2rem 1.5rem 1.5rem;
  border-radius: 1rem;
  text-align: center;
  height: 100%;
  text-decoration: none;
  transition: transform .4s cubic-bezier(.25, .8, .25, 1), box-shadow .4s, background .4s;
  position: relative;
}

.feature-box:hover {
  background: #00203f;
  box-shadow: var(--shadow-strong);
  transform: translateY(-8px);
}

.icon-circle {
  width: 84px;
  height: 84px;
  background: var(--blue-mid);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: -40px auto 1rem auto;
  transition: var(--transition-fast);
}

.feature-box:hover .icon-circle {
  background: var(--blue-dark);
}

.icon-circle i {
  font-size: 2rem;
  color: var(--teal-accent);
}

/* =========================================================
   CONTACT FORM
   ========================================================= */

.lead {
  letter-spacing: .3px;
}

.contact-form {
  border-radius: 1rem;
  padding: 1rem;
  max-width: 600px;
  margin: 0 auto;
  background: linear-gradient(to bottom, #062646, #063360);
  border-top: 1px solid #063360;
}

.contact-form .form-control {
  background: #031629;
  border: 1px solid var(--blue-accent);
  color: var(--white-soft);
  border-radius: .5rem;
  padding: .75rem 1rem;
  transition: var(--transition-mid);
}

.contact-form .form-control:focus {
  background: var(--blue-mid);
  border-color: var(--teal-accent);
  box-shadow: 0 0 0 .2rem var(--teal-glow);
  color: var(--white-soft);
  outline: none;
}

.contact-form label {
  font-weight: 500;
  margin-bottom: .5rem;
  color: var(--white-soft);
}

/* =========================================================
   FORMS VALIDATION FEEDBACK
   ========================================================= */

.form-feedback {
  text-align: center;
  font-weight: 500;
  margin-top: 1rem;
  padding: .75rem 1rem;
  border-radius: .5rem;
  transition: opacity .3s ease-in-out, transform .3s ease-in-out;
  opacity: 1;
  transform: translateY(0);
}

.form-feedback.success {
  background: rgba(0, 64, 32, .4);
  color: #7cffb2;
  border: 1px solid var(--green);
}

.form-feedback.error {
  background: rgba(64, 0, 0, .4);
  color: #ff8080;
  border: 1px solid var(--red);
}

.form-feedback.fade-out {
  opacity: 0;
  transform: translateY(-6px);
}

/* =========================================================
   INPUT VALIDATION STATES
   ========================================================= */

.form-control.is-valid {
  border-color: var(--green);
  box-shadow: 0 0 0 .2rem var(--green-soft);
}

.form-control.is-invalid {
  border-color: var(--red);
  box-shadow: 0 0 0 .2rem var(--red-soft);
}

#loginModal .form-control.is-valid {
  border-color: var(--green);
  box-shadow: 0 0 0 .2rem rgba(0, 170, 102, .4);
}

#loginModal .form-control.is-invalid {
  border-color: var(--red);
  box-shadow: 0 0 0 .2rem rgba(204, 51, 51, .4);
}

/* =========================================================
   FOOTER
   ========================================================= */

footer {
  padding: 1.5rem 0;
  line-height: 2rem;
  text-align: center;
  background: var(--blue-mid);
}

footer p {
  font-size: .75rem;
  color: var(--white-muted);
  margin: 0;
}

footer .footer-nav {
  margin-bottom: 1.5rem;
}

footer a {
  margin: 0 .75rem;
  white-space: nowrap;
  color: var(--white-muted);
}

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

.footer-brand-sign {
  display: flex;
  justify-content: center;
  padding: 1rem 0 3rem;
}

.logo-sign {
  display: block;
  width: 54px;
  height: auto;
  opacity: .5;
}

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

.modal {
  background-color: rgba(3, 19, 35, .84);
}

.login-form {
  border-radius: 1rem;
  color: var(--white-soft);
  box-shadow: var(--shadow-strong);
  background: linear-gradient(to bottom, #062646, #063360);
  border-top: 1px solid #063360;
}

.modal-header {
  border: none;
}

.login-form .form-control {
  background: #031629;
  border: 1px solid var(--blue-accent);
  color: var(--white-soft);
  border-radius: .5rem;
  padding: .75rem 1rem;
  transition: var(--transition-mid);
}

.login-form .form-control:focus {
  background: var(--blue-mid);
  border-color: var(--teal-accent);
  box-shadow: 0 0 0 .2rem var(--teal-glow);
  color: var(--white-soft);
}

.login-form label {
  font-weight: 500;
  margin-bottom: .5rem;
  color: var(--white-soft);
}

/* =========================================================
   BACK TO TOP BUTTON
   ========================================================= */

#backToTop {
  position: fixed;
  bottom: 20px;
  right: 20px;
  background: var(--blue-accent);
  color: var(--white-soft);
  border: none;
  border-radius: .5rem;
  padding: .75rem 1rem;
  display: none;
  cursor: pointer;
  z-index: 999;
}

#backToTop:hover {
  background: var(--blue-hover);
}

/* =========================================================
   ACCESSIBILITY
   ========================================================= */

.visually-hidden {
  position: absolute !important;
  height: 1px;
  width: 1px;
  overflow: hidden;
  clip: rect(1px, 1px, 1px, 1px);
  white-space: nowrap;
}

/* =========================================================
   MEDIA QUERIES
   ========================================================= */

@media (min-width: 768px) {
  h1 {
    font-size: 2.75rem;
  }

  .intro h1 {
    font-size: 2rem;
  }

  h2 {
    font-size: 2rem;
  }

  h3 {
    font-size: 1.5rem;
  }

  section {
    padding: 3rem .75rem;
  }

  .contact-form,
  .login-form {
    padding: 2rem;
  }

  footer {
    padding: 2.25rem 0;
  }

  .footer-brand-sign {
    padding-top: 1.33rem;
  }

  .logo-sign {
    width: 81px;
  }
}

@media (min-width: 992px) {

  body,
  p {
    font-size: .9rem;
  }

  .logo {
    width: 204px;
  }

  .header-row {
    display: flex;
    justify-content: space-between;
    position: relative;
    padding: .25rem 0;
  }

  .navbar {
    flex-grow: 1;
    justify-content: flex-end;
    margin-right: 0;
  }

  .navbar-collapse {
    display: flex !important;
    flex-basis: auto;
  }

  .navbar-nav {
    flex-direction: row;
    padding-top: 0;
  }

  .navbar-nav .nav-link {
    padding: .75rem 1rem;
  }

  .navbar-nav .nav-item:has(.btn),
  .nav-item-btn {
    display: flex;
    align-items: center;
  }

  .navbar-toggler {
    display: none;
  }
  
  .dropdown:hover>.dropdown-menu {
    display: block;
    margin-top: .5rem;
  }

  .dropdown-menu {
    opacity: 0;
    visibility: hidden;
    transform: translateY(-6px);
    transition: opacity .25s ease, transform .25s ease;
  }

  .dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  .navbar-nav .dropdown-menu {
    position: absolute;
    top: 81%;
  }

  .lang-switch {
    top: 22px;
    left: auto;
    right: 520px;
  }

  .intro {
    min-height: 620px;
    background-attachment: fixed;
  }

  .intro h1 {
    font-size: 2.5rem;
  }

  section {
    padding: 4rem 1rem;
  }

  h1,
  h2,
  h3,
  h4,
  h5,
  h6 {
    break-inside: avoid;
  }

  #features .row {
    justify-content: center;
  }

  .cols-desktop {
    column-count: 2;
    column-gap: 4rem;
  }

  .contact-form {
    padding: 2.33rem;
  }

  footer {
    padding: 3rem 0;
  }
}

@media (min-width: 1400px) {
  .lang-switch {
    right: 48%;
    right: calc(50% - 42.5px);
  }
}