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

body {
  margin: 0;
  font-family: "Inter", "Hiragino Kaku Gothic ProN", "Meiryo", sans-serif;
  color: #0f172a;
  line-height: 1.7;
  background:
    linear-gradient(
      rgba(2,6,23,0.65),
      rgba(2,6,23,0.85)
    ),
    url("https://images.unsplash.com/photo-1586528116311-ad8dd3c8310d?auto=format&fit=crop&w=1600&q=80");
  background-size: cover;
  background-position: center;
  background-attachment: fixed;
}

/* =========================
   Header
========================= */
header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(2,6,23,0.75);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255,255,255,0.1);
  padding: 18px 36px;
}

header h1 {
  margin: 0;
  font-size: 20px;
  letter-spacing: 0.08em;
  color: #e5e7eb;
}

nav {
  margin-top: 10px;
}

nav a {
  color: #cbd5f5;
  margin-right: 26px;
  text-decoration: none;
  font-size: 13px;
  letter-spacing: 0.08em;
  position: relative;
}

nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -6px;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, #38bdf8, #2563eb);
  transition: width 0.3s ease;
}

nav a:hover::after {
  width: 100%;
}

/* =========================
   Main Container (Glass)
========================= */
.container {
  max-width: 1100px;
  margin: 120px auto 100px;
  padding: 64px 56px;
  background: rgba(255,255,255,0.9);
  backdrop-filter: blur(18px) saturate(140%);
  border-radius: 28px;
  box-shadow:
    0 40px 80px rgba(0,0,0,0.45),
    inset 0 1px 0 rgba(255,255,255,0.6);
  animation: fadeUp 0.8s ease;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* =========================
   Headings
========================= */
h2 {
  margin-top: 0;
  font-size: 22px;
  letter-spacing: 0.05em;
  color: #0f172a;
  padding-left: 16px;
  border-left: 5px solid #2563eb;
}

p {
  color: #334155;
  font-size: 15px;
}

/* =========================
   List
========================= */
ul {
  padding-left: 20px;
}

li {
  margin-bottom: 10px;
  color: #334155;
}

/* =========================
   Button Area
========================= */
.btn-area {
  display: flex;
  gap: 24px;
  margin: 40px 0 56px;
  flex-wrap: wrap;
}

/* =========================
   Buttons (Main)
========================= */
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 18px 42px;
  border-radius: 999px;
  background: linear-gradient(
    135deg,
    #38bdf8 0%,
    #2563eb 60%,
    #1e3a8a 100%
  );
  color: #fff;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.12em;
  border: 1px solid rgba(255,255,255,0.35);
  text-decoration: none;
  box-shadow:
    0 16px 36px rgba(37,99,235,0.55),
    inset 0 1px 0 rgba(255,255,255,0.5);
  transition: all 0.35s ease;
}

.button:hover {
  transform: translateY(-6px) scale(1.04);
  box-shadow:
    0 28px 60px rgba(56,189,248,0.8),
    inset 0 1px 0 rgba(255,255,255,0.7);
}

/* =========================
   Forms
========================= */
form {
  margin-top: 40px;
}

label {
  display: block;
  font-size: 13px;
  letter-spacing: 0.08em;
  margin-bottom: 6px;
  color: #1e293b;
}

input,
select,
textarea {
  width: 100%;
  padding: 14px 16px;
  border-radius: 12px;
  border: 1px solid #cbd5f5;
  background: #f8fafc;
  font-size: 14px;
  margin-bottom: 22px;
}

input:focus,
select:focus,
textarea:focus {
  outline: none;
  border-color: #2563eb;
  box-shadow: 0 0 0 2px rgba(37,99,235,0.2);
}

/* =========================
   Footer
========================= */
footer {
  text-align: center;
  padding: 40px 20px;
  font-size: 12px;
  color: #cbd5f5;
  background: rgba(2,6,23,0.75);
  letter-spacing: 0.08em;
}