:root {
    --main-color: #ff3399;
    --text-color: #012f89;
    --bg-color: #0061d3;
    --accent-bg: rgba(255,255,255,0.8);
    --accent-color:#980000;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html, body {
  height: 100%;
}

html {
  scroll-behavior: smooth;
}


body {
    font-family: "Noto Sans JP",-apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    color: var(--text-color);
    background: var(--bg-color) url("../img/bg.jpg") fixed;
    margin: 0;
    line-height: 1.6;
    font-size: clamp(16px, 1.8vw, 20px);
    color: var(text-color);
    font-weight: 700;
}


a {
    text-decoration: none;
    background: linear-gradient(transparent 80%, #f4fb41 80%);
    background-size: 0% 100%;
    background-repeat: no-repeat;
    transition: background-size .3s ease;
    color: #0078d4;
}

a:hover {
    background-size: 100% 100%;
}

a:visited {
    color: #0078d4;
}


img {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 0 auto;
}

br.sp-only {
    display: none;
}

ul {
  margin: 0;
  padding: 0;
}

.container {
    width: min(100%, 1200px);
    margin: 0 auto;
    padding: 10px;
}

section {
    padding: 40px 0;
}

section:last-of-type p {
  margin-bottom: 0;
}


h1, h2 {
    margin-bottom: 16px;
    line-height: 1.3;
}

h1 {
    font-size: clamp(26px, 6.2vw, 48px);
    font-weight: 900;
}

h2 {
    font-size: clamp(24px, 5vw, 36px);
    font-weight: 900;
    display: flex;
    justify-content: center;
}

h2 > span {
  position: relative;
  display: inline-block;
  height: 68px;
  line-height: 68px;
  padding: 0 20px;
  background: var(--main-color);
  color: #fff;
}


h2 > span::before,
h2 > span::after {
  content: '';
  position: absolute;
  width: 0;
  height: 0;
  top: 0;
}

h2 > span::before {
  border-bottom: 68px solid transparent;
  border-left: 30px solid var(--main-color);
  right: -30px;
}

h2 > span::after {
  border-top: 68px solid transparent;
  border-right: 30px solid var(--main-color);
  left: -30px;
}

h3 {
    font-size: clamp(20px, 4vw, 32px);
    font-weight: 900;
    color: #012f89;
}

h3.line span {
    display: inline-block;
    border-top: solid 2px #012f89;
    border-bottom: solid 2px #012f89;
}

h3.line2 {
    display: inline;
    background: linear-gradient(transparent 65%, var(--main-color) 65%);
    -webkit-box-decoration-break: clone;
    box-decoration-break: clone;
    padding: 0 2px;
    word-break: keep-all;
}

h3.line2 span {
    white-space: nowrap;
}

p.big {
    font-size: clamp(20px, 4vw, 32px);
}

ul.aten li {    
    padding-left: 1em;
    text-indent: -1em;
    list-style: none;
    color: #333;
    font-weight: 400;
}

.card {
    background: var(--accent-bg);
    padding: 30px 40px;
    box-shadow: 5px 5px 5px #5f95fd;
    border-bottom: solid 10px #012f89;
}

.button {
    display: inline-block;
    padding: 16px 24px;
    background: var(--main-color);
    color: #fff;
    text-decoration: none;
    border-radius: 8px;
    font-weight: bold;
    
    position: relative;
    overflow: hidden;
    z-index: 1;
}

.button::before {
    content: "";
    position: absolute;
    inset: 0;
    background: #333;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    z-index: -1;
}

.button:hover::before {
  transform: translateX(0);
}

.cnt {
    text-align: center;
}

/* --- ここまで共通style --- */

header {
    border-top: solid 5px var(--main-color);
}

header div.sns {
    display: flex;
    justify-content: flex-end;
    align-items: center;
    background: var(--main-color);
    padding: 5px;
    color: #FFF;
}

header div.sns p {
    margin: 0;
    font-size: clamp(14px, 2vw, 16px);
}

header div.sns li {
    display: inline-block;
    width: clamp(40px, 3vw, 44px);
    height: clamp(40px, 3vw, 44px);
    transition: opacity 300ms ease-in-out;
    margin-left: 10px;
}

header div.sns a {
    transition: .5s;
}

header div.sns a:hover {
    opacity: .6;
}

header h1 {
    background-image: url("../img/main.png");
    background-size: cover;
    background-position: center;
    aspect-ratio: 1192 / 532;
    text-indent: -9999px;
}

div.date {
    background-color: #FFF;
    border-top: 5px solid var(--accent-color);
    border-bottom: 5px solid var(--accent-color);
    color: var(--accent-color);
    font-weight: 700;
}

div.date p {
    font-size: clamp(24px, 5vw, 36px);
    margin: 0;
}

div.date p span.period {
    display: inline-block;
    padding: 0 10px;
    margin-right: 10px;
    background-color: var(--accent-color);
    border-radius: 5px;
    color: #FFF;
}

div.date p span.mini {
    font-size: clamp(18px, 3.5vw, 30px);
}

.twitter-tweet {
    width: min(100%, 550px);
    margin: 0 auto;
}

.way {
    display: flex;
    gap: 24px;
    justify-content: center;
    margin:0;
}

.step-box {
    flex: 1;
    max-width: 550px;
}

.step-box.bg {
    padding: 15px 30px 30px;
}

.step-box.bg h2 {
    font-size: clamp(14px, 2.6vw, 22px)
}

.step-box.bg img {
    display: block;
    box-shadow: 3px 3px 3px #012f89;
    transition: transform 0.3s ease;
}

.step-box.bg img:hover {
    transform: translateY(-5px);
}

.img {
    display: flex;
    align-items: center;
    justify-content: center;
}

.mb5 {
    margin-bottom: 5px;
}

.grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

p.white {
    color: #FFF;
}

.rules ul {
    margin-left: 1.2em;
}

.rules h3 {
    display: inline-block;
    margin-bottom: 15px;
    border-bottom: #012f89 solid 2px;
}

footer {
    padding: 20px;
    background: var(--main-color);
    text-align: center;
}

footer p {
  margin: 0;
}

footer .container {
  padding-bottom: 0;
}


@media (max-width: 980px) {

    section {
        padding: 10px 0;
    }

    br.sp-only {
        display: inline-block;
    }

    header div.sns p {
        display: none;
    }

    header h1 {
    background-image: url("../img/main_s.png");
    aspect-ratio: 760 / 600;
}
    
    h2 > span {
        height: 44px;
        line-height: 44px;
        padding: 0 14px;
        font-size: 1.1rem;
    }

    h2 > span::before {
        border-bottom: 44px solid transparent;
        border-left: 14px solid var(--main-color);
        right: -14px;
    }

    h2 > span::after {
        border-top: 44px solid transparent;
        border-right: 14px solid var(--main-color);
        left: -14px;
    }

    .card {
        padding: 10px 20px;
    }

    .way {
        flex-direction: column;
        gap: 16px;
        padding: 0 16px;
    }

    .step-box {
        max-width: 100%;
    }

    .step-box.bg {
        padding: 5px 10px 10px;
    }


    .grid-2 {
        display: block;
    }

}