/* ===== Base ===== */
* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #0b1020;
  color: #f5f6ff;
  line-height: 1.6;
}

[hidden] {
  display: none !important;
}

/* ===== Header and Navigation ===== */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 18px 8%;
  background: #10172a;
  border-bottom: 1px solid #252d45;
}

.logo {
  margin: 0;
  font-size: 27px;
  font-weight: 800;
  letter-spacing: -1px;
}

.logo span,
h1 span {
  color: #927bff;
}

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 24px;
}

nav a {
  color: #c1c7db;
  text-decoration: none;
  font-size: 14px;
  transition: color 0.2s ease;
}

nav a:hover {
  color: #a99aff;
}

/* ===== Main Hero Section ===== */
main {
  width: 100%;
  max-width: 1000px;
  margin: 0 auto;
  padding: 76px 22px;
  text-align: center;
}

.tag {
  display: inline-block;
  margin: 0;
  padding: 7px 15px;
  border: 1px solid #443a79;
  border-radius: 30px;
  background: #1d1940;
  color: #b9adff;
  font-size: 12px;
  font-weight: bold;
  letter-spacing: 1px;
}

h1 {
  margin: 25px 0 16px;
  font-size: clamp(36px, 6vw, 60px);
  line-height: 1.12;
  letter-spacing: -2px;
}

.intro {
  max-width: 580px;
  margin: 0 auto 30px;
  color: #a7b0c8;
  font-size: 16px;
}

/* ===== URL Form Card ===== */
form {
  width: 100%;
  max-width: 600px;
  margin: 30px auto;
  padding: 30px;
  background: #141c31;
  border: 1px solid #2a3552;
  border-radius: 18px;
  text-align: left;
  box-shadow: 0 20px 55px rgba(0, 0, 0, 0.22);
}

label {
  display: block;
  margin: 14px 0 8px;
  color: #e2e6f5;
  font-size: 14px;
  font-weight: bold;
}

input,
select {
  display: block;
  width: 100%;
  min-width: 0;
  padding: 14px;
  border: 1px solid #35415f;
  border-radius: 9px;
  outline: none;
  background: #0d1426;
  color: #f5f6ff;
  font-size: 14px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

input::placeholder {
  color: #78839e;
}

input:focus,
select:focus {
  border-color: #927bff;
  box-shadow: 0 0 0 3px rgba(146, 123, 255, 0.15);
}

/* ===== Analyze Button ===== */
button {
  display: block;
  width: 100%;
  margin-top: 20px;
  padding: 15px;
  border: none;
  border-radius: 9px;
  background: linear-gradient(135deg, #8065ff, #6245e8);
  color: white;
  font-size: 15px;
  font-weight: bold;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

button:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 22px rgba(113, 84, 255, 0.28);
}

button:active {
  transform: translateY(0);
}

button:focus-visible,
nav a:focus-visible,
input:focus-visible,
select:focus-visible {
  outline: 2px solid #b9adff;
  outline-offset: 3px;
}

/* ===== Link Analysis Result ===== */
.result-card {
  width: 100%;
  min-width: 0;
  margin-top: 18px;
  padding: 20px;
  background: #10172a;
  border: 1px solid #443a79;
  border-radius: 12px;
  text-align: left;
  overflow: hidden;
}

.result-card h3 {
  margin: 0 0 10px;
  color: #b9adff;
  font-size: 17px;
}

#message {
  margin: 0;
  color: #c8d0e7;
  font-size: 14px;
  line-height: 1.7;
  overflow-wrap: anywhere;
}

/* ===== Video Preview ===== */
.video-preview {
  width: 100%;
  max-width: 360px;
  min-width: 0;
  margin: 22px auto 0;
  padding-top: 18px;
  border-top: 1px solid #2a3552;
  overflow: hidden;
}

.video-preview h4 {
  margin: 0 0 14px;
  color: #f5f6ff;
  font-size: 16px;
}

.video-preview video {
  display: block;
  width: 100%;
  max-width: 360px;
  height: 200px;
  margin: 0 auto;
  border: 1px solid #35415f;
  border-radius: 12px;
  background: #080c16;
  object-fit: contain;
}

/* ===== Notice ===== */
.notice {
  max-width: 600px;
  margin: 18px auto;
  color: #8e9ab6;
  font-size: 12px;
}

/* ===== How It Works ===== */
#how-it-works {
  margin-top: 75px;
  padding: 30px 20px;
  border: 1px solid #252f49;
  border-radius: 18px;
  background: #10172a;
}

#how-it-works h2 {
  margin-top: 0;
  font-size: 27px;
}

.section-intro {
  margin-bottom: 28px;
  color: #a7b0c8;
}

.steps-container {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin-top: 28px;
  text-align: left;
}

.step-card {
  padding: 22px 18px;
  background: #141c31;
  border: 1px solid #2a3552;
  border-radius: 14px;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.step-card:hover {
  transform: translateY(-4px);
  border-color: #8065ff;
}

.step-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  margin-bottom: 18px;
  border-radius: 12px;
  background: #28204e;
  color: #b9adff;
  font-size: 16px;
  font-weight: bold;
}

.step-card h3 {
  margin: 0 0 10px;
  color: #f5f6ff;
  font-size: 17px;
}

.step-card p {
  margin: 0;
  color: #a7b0c8;
  font-size: 13px;
  line-height: 1.7;
}

/* ===== Footer ===== */
footer {
  padding: 22px;
  border-top: 1px solid #252d45;
  background: #10172a;
  color: #8e9ab6;
  text-align: center;
  font-size: 12px;
}

/* ===== Tablet and Mobile ===== */
@media (max-width: 700px) {
  .steps-container {
    grid-template-columns: 1fr;
  }

  .step-card {
    padding: 20px;
  }
}

@media (max-width: 600px) {
  header {
    padding: 16px 5%;
    flex-wrap: wrap;
    gap: 12px;
  }

  .logo {
    font-size: 24px;
  }

  nav {
    gap: 15px;
  }

  nav a {
    font-size: 13px;
  }

  main {
    padding: 48px 16px;
  }

  h1 {
    letter-spacing: -1px;
  }

  .intro {
    font-size: 14px;
  }

  form {
    padding: 20px;
    border-radius: 14px;
  }

  #how-it-works {
    margin-top: 50px;
    padding: 24px 16px;
  }

  .result-card {
    padding: 16px;
  }

  .video-preview video {
    height: 190px;
  }
}