/* --- START OF FILE next-step.css --- */

/* ==========================================================================
   ネクストアクション / その他の学習エリア
   ========================================================================== */

.next-action-section {
    width: 100vw;
    margin-left: calc(50% - 50vw);
    background-color: #111;
    padding: 0px 20px 0px;
    box-sizing: border-box;
    display: flex;
    justify-content: center;
    flex-grow: 1;
    position: relative;
    z-index: 20;
    margin-top: 0px; 
    background-image: linear-gradient(to bottom, #e9ecef 0%, #111 85%);
    background-size: 100% 210px;
    background-repeat: no-repeat;
    background-color: #111;
}

.next-action-inner {
    width: 100%;
    max-width: 500px;
    box-sizing: border-box;
}

/* --------------------------------------
   スクロールフェードイン
-------------------------------------- */
.scroll-fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.scroll-fade-in.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* --------------------------------------
   到達度ランプ表示
-------------------------------------- */
#milestone-lamps-section {
    padding: 25px 10px 5px;
    position: relative;
    z-index: 5;
    margin: 10px auto 15px; 
    border-radius: 25px;
    box-shadow: 0 4px 0px rgba(0, 0, 0, 1);
    background: linear-gradient(90deg, #65818f, #4b5154, #363c40, #4b5154, #65818f);
    background-size: 200% auto;
    transition: background 0.5s ease-in-out;
    width: 100%;
    max-width: 440px;
    box-sizing: border-box;
    opacity: 0;
}

#milestone-lamps-section.is-visible {
    animation: stampIn 0.5s cubic-bezier(0.39, 0.575, 0.565, 1) forwards, moveGradient 8s linear infinite;
}

#milestone-lamps-section.all-lamps-achieved {
    background: linear-gradient(90deg, #fff48f, #ffc700, #ff8c00, #ffc700, #fff48f);
    background-size: 200% auto;
    box-shadow: 0 0 20px rgba(255, 199, 0, 0.6), 0 4px 0px rgba(0, 0, 0, 1);
}

#milestone-lamps-section.all-lamps-achieved.is-visible {
    animation: stampIn 0.5s cubic-bezier(0.39, 0.575, 0.565, 1) forwards, moveGradient 4s linear infinite;
}

#milestone-lamps-section::after {
    content: '';
    position: absolute;
    top: 5px;
    left: 5px;
    right: 5px;
    bottom: 5px;
    background-color: #111;
    border-radius: 20px;
    z-index: 0;
}

#milestone-lamps-section::before {
    content: 'achievement';
    position: absolute;
    top: 10px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 11px;
    font-weight: 900;
    color: #4b5154;
    text-transform: uppercase;
    z-index: 2;
    transition: color 0.5s ease-in-out;
}

#milestone-lamps-section.all-lamps-achieved::before {
    color: #ffd700;
    text-shadow: 0 0 5px rgba(255, 215, 0, 0.5);
}

.lamp-container {
    display: flex;
    justify-content: center;
    align-items: flex-start;
    gap: 5px;
    max-width: 500px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.lamp-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 70px;
}

.lamp {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: #111;
    border: 5px solid #333;
    transition: background-color 0.5s ease, border-color 0.5s ease, box-shadow 0.5s ease;
    position: relative;
    background-repeat: no-repeat;
    background-position: center;
    background-size: 40px 40px;
    cursor: pointer;
}

#lamp-card { background-image: url('../images/indexPage-milestone-icon_card.svg'); }
#lamp-quiz-primary { background-image: url('../images/indexPage-milestone-icon_quizP.svg'); }
#lamp-quiz-secondary { background-image: url('../images/indexPage-milestone-icon_quizS.svg'); }
#lamp-list { background-image: url('../images/indexPage-milestone-icon_list.svg'); }
#lamp-details-read { background-image: url('../images/indexPage-milestone-icon_details.svg'); }

#lamp-card.is-achieved { background-image: url('../images/indexPage-milestone-icon_card-lamp.svg'); }
#lamp-quiz-primary.is-achieved { background-image: url('../images/indexPage-milestone-icon_quizP-lamp.svg'); }
#lamp-quiz-secondary.is-achieved { background-image: url('../images/indexPage-milestone-icon_quizS-lamp.svg'); }
#lamp-list.is-achieved { background-image: url('../images/indexPage-milestone-icon_list-lamp.svg'); }
#lamp-details-read.is-achieved { background-image: url('../images/indexPage-milestone-icon_details-lamp.svg'); }

.lamp.is-achieved {
    background-color: #111;
    box-shadow: inset 0 2px 10px rgba(255, 255, 255, 1);
    animation-duration: 1.5s;
    animation-iteration-count: infinite;
    animation-direction: alternate;
    animation-timing-function: ease-in-out;
}

#lamp-card.is-achieved { border-color: #ffd000; animation-name: lamp-glow-yellow; }
#lamp-quiz-primary.is-achieved { border-color: #c40e0e; animation-name: lamp-glow-red; }
#lamp-quiz-secondary.is-achieved { border-color: #2f53b5; animation-name: lamp-glow-blue; }
#lamp-list.is-achieved { border-color: #4aa5cf; animation-name: lamp-glow-lightblue; }
#lamp-details-read.is-achieved { border-color: #46d446; animation-name: lamp-glow-green; }

@keyframes lamp-glow-yellow {
    from { box-shadow: 0 0 4px #ffdd44, inset 0 0 4px #ffdd44; }
    to { box-shadow: 0 0 10px #ffbf00, inset 0 0 10px #ffbf00; }
}
@keyframes lamp-glow-red {
    from { box-shadow: 0 0 4px #c40e0e, inset 0 0 4px #c40e0e; }
    to { box-shadow: 0 0 10px #e01b1b, inset 0 0 10px #e01b1b; }
}
@keyframes lamp-glow-blue {
    from { box-shadow: 0 0 4px #2f53b5, inset 0 0 4px #2f53b5; }
    to { box-shadow: 0 0 10px #4169d1, inset 0 0 10px #4169d1; }
}
@keyframes lamp-glow-lightblue {
    from { box-shadow: 0 0 4px #4aa5cf, inset 0 0 4px #4aa5cf; }
    to { box-shadow: 0 0 10px #5cb8e6, inset 0 0 10px #5cb8e6; }
}
@keyframes lamp-glow-green {
    from { box-shadow: 0 0 4px #46d446, inset 0 0 4px #46d446; }
    to { box-shadow: 0 0 10px #57f557, inset 0 0 10px #57f557; }
}

.lamp-label {
    font-size: 9px;
    color: #bbb;
    font-weight: bold;
    margin-top: 0px;
    text-align: center;
    line-height: 1.2;
    min-height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.lamp.is-recommended:not(.is-achieved) {
    border-color: #4a4a4a;
    animation: lamp-glow-recommend-subtle 2.5s infinite alternate ease-in-out;
}

@keyframes lamp-glow-recommend-subtle {
    from { box-shadow: 0 0 2px rgba(255,255,255,0.05), inset 0 0 2px rgba(255,255,255,0.05); }
    to { box-shadow: 0 0 6px rgba(255,255,255,0.15), inset 0 0 6px rgba(255,255,255,0.15); }
}

.milestone-clear-phrase {
    position: absolute;
    top: calc(50% + 5px);
    left: 50%;
    transform: translate(-50%, -50%);
    width: 250px;
    height: 60px;
    background-image: url('../images/milestone-lamps-clear_phrase.svg');
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    z-index: 20;
    pointer-events: none;
    opacity: 0;
}

#milestone-lamps-section.all-lamps-achieved .milestone-clear-phrase {
    animation: clearPhraseStamp 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
    animation-delay: 0.5s;
}

@keyframes clearPhraseStamp {
    0% { opacity: 0; transform: translate(-50%, -50%) scale(2.5) rotate(-5deg); }
    100% { opacity: 1; transform: translate(-50%, -50%) scale(1) rotate(0deg); }
}

/* --------------------------------------
   マイルストーン案内パネル
-------------------------------------- */
.milestone-action-panel {
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 35px;
    width: 100%;
    max-width: 440px;
    box-sizing: border-box;
    box-shadow: 0 4px 0px rgba(0,0,0,0.6);
    position: relative;
    transform: scale(1.15);
    transition: all 0.3s ease;
}

.milestone-action-panel.is-initial {
    background-color: #222;
    border: 4px solid transparent;
    border-radius: 16px;
    padding: 12px 20px;
    min-height: 48px;
    cursor: pointer;
}

.milestone-action-panel.is-all-cleared {
    cursor: default;
}

.milestone-action-panel.is-all-cleared .panel-simple-text {
    color: #ffd700;
}

.milestone-action-panel::before,
.milestone-action-panel::after {
    content: '';
    position: absolute;
    transform: translateX(-50%);
    border-style: solid;
    border-color: transparent; 
    transition: left 0.3s cubic-bezier(0.4, 0, 0.2, 1), top 0.3s ease, border-width 0.3s ease, border-bottom-color 0.3s ease;
}

.milestone-action-panel.is-initial::before {
    top: -20px;
    border-width: 0 16px 16px 16px;
    border-bottom-color: transparent;
    left: var(--tail-pos, 50%);
}

.milestone-action-panel.is-initial::after {
    top: -16px;
    border-width: 0 16px 16px 16px;
    border-bottom-color: #222;
    left: var(--tail-pos, 50%);
    z-index: 1;
}

.panel-simple-text {
    display: flex;
    align-items: center;
    justify-content: center;
    color: #ccc;
    font-size: 14px;
    font-weight: bold;
    width: 100%;
    position: relative;
}

.panel-plus-icon {
    position: absolute;
    right: 0px;
    top: 50%;
    transform: translateY(-50%);
    width: 22px;
    height: 22px;
    background-color: #444;
    border-radius: 50%;
    color: #fff;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
}

.milestone-action-panel.is-initial .panel-simple-text {
    display: flex;
}

.milestone-action-panel.is-initial .panel-expanded-content {
    display: none;
}

.milestone-action-panel.is-expanded {
    background-color: #000;
    border: 4px solid var(--panel-color, #444);
    border-radius: 24px;
    padding: 15px 15px;
    min-height: 72px;
    cursor: default;
}

.milestone-action-panel.is-expanded::before {
    top: -16px;
    border-width: 0 12px 12px 12px;
    border-bottom-color: var(--panel-color, #444);
    left: var(--tail-pos, 50%);
}

.milestone-action-panel.is-expanded::after {
    top: -10px;
    border-width: 0 10px 10px 10px;
    border-bottom-color: #000;
    left: var(--tail-pos, 50%);
    z-index: 1;
}

.milestone-action-panel.is-expanded .panel-simple-text {
    display: none;
}

.panel-expanded-content {
    display: none;
    align-items: center;
    width: 100%;
    opacity: 0;
}

.panel-expanded-content.is-active {
    animation: fadeUpIn 0.4s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}

@keyframes fadeUpIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.milestone-action-panel .panel-icon {
    width: 44px;
    height: 44px;
    background-color: #111;
    border: 2px solid #555;
    border-radius: 50%;
    background-size: 44px 44px;
    background-position: center;
    background-repeat: no-repeat;
    flex-shrink: 0;
    margin-right: 12px;
}

.milestone-action-panel .panel-content {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.milestone-action-panel .panel-title {
    font-size: 11px;
    font-weight: bold;
    color: var(--panel-color, #fff);
    margin-bottom: 4px;
    opacity: 0.9;
}

.milestone-action-panel .panel-desc {
    font-size: 13px;
    color: #fff;
    line-height: 1.4;
}

.milestone-action-panel .panel-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background-color: #333;
    color: #fff;
    text-decoration: none;
    font-size: 12px;
    font-weight: bold;
    padding: 8px 12px;
    border-radius: 20px;
    margin-left: 10px;
    flex-shrink: 0;
    transition: all 0.2s ease;
    box-shadow: 0 2px 0px rgba(0,0,0,0.5);
}

.milestone-action-panel .panel-btn:active {
    transform: translateY(2px);
    box-shadow: 0 0px 0px rgba(0,0,0,0.5);
}

.milestone-action-panel .panel-btn .arrow {
    display: inline-block;
    width: 0;
    height: 0;
    border-top: 4px solid transparent;
    border-bottom: 4px solid transparent;
    border-left: 6px solid #fff;
    margin-left: 6px;
}

.milestone-action-panel.theme-card { --panel-color: #ffd000; }
.milestone-action-panel.theme-card .panel-icon { background-image: url('../images/indexPage-milestone-icon_card-lamp.svg'); }
.milestone-action-panel.theme-card .panel-btn { background-color: #aa8b00; }

.milestone-action-panel.theme-quiz-primary { --panel-color: #ff4d4d; }
.milestone-action-panel.theme-quiz-primary .panel-icon { background-image: url('../images/indexPage-milestone-icon_quizP-lamp.svg'); }
.milestone-action-panel.theme-quiz-primary .panel-btn { background-color: #c40e0e; }

.milestone-action-panel.theme-quiz-secondary { --panel-color: #5c85ff; }
.milestone-action-panel.theme-quiz-secondary .panel-icon { background-image: url('../images/indexPage-milestone-icon_quizS-lamp.svg'); }
.milestone-action-panel.theme-quiz-secondary .panel-btn { background-color: #2f53b5; }

.milestone-action-panel.theme-list { --panel-color: #5cb8e6; }
.milestone-action-panel.theme-list .panel-icon { background-image: url('../images/indexPage-milestone-icon_list-lamp.svg'); }
.milestone-action-panel.theme-list .panel-btn { background-color: #2a7396; }

.milestone-action-panel.theme-details { --panel-color: #57f557; }
.milestone-action-panel.theme-details .panel-icon { background-image: url('../images/indexPage-milestone-icon_details-lamp.svg'); }
.milestone-action-panel.theme-details .panel-btn { background-color: #2b912b; }

/* --------------------------------------
   見出しタイトル＆説明文
-------------------------------------- */
.next-action-title {
    width: 200px;
    height: 30px;
    margin: 0 auto 3px;
    background: url('../images/cardResultPage-btnArea-phrase-next.svg') no-repeat center;
    background-size: contain;
    opacity: 0;
}
.next-action-title.is-visible { animation: stampIn 0.5s cubic-bezier(0.39, 0.575, 0.565, 1) forwards; }

.other-action-title {
    width: 200px;
    height: 30px;
    margin: 0 auto 3px;
    background: url('../images/cardResultPage-btnArea-phrase-more.svg') no-repeat center;
    background-size: contain;
    opacity: 0;
}
.other-action-title.is-visible { animation: stampIn 0.5s cubic-bezier(0.39, 0.575, 0.565, 1) forwards; }

.next-action-desc {
    font-size: 12px;
    color: #aaa;
    text-align: center;
    margin-bottom: 20px;
    font-weight: bold;
    opacity: 0;
}
.next-action-desc.is-visible {
    animation: stampIn 0.5s cubic-bezier(0.39, 0.575, 0.565, 1) forwards;
}

/* --------------------------------------
   区切り線
-------------------------------------- */
.action-divider {
    width: 100%;
    max-width: 440px;
    height: 2px;
    background-color: #333;
    margin: 50px auto 45px;
    border-radius: 2px;
    opacity: 0;
}
.action-divider.is-visible { opacity: 1; }

/* --------------------------------------
   次の単元（大きめのボタン用ラッパー）
-------------------------------------- */
.retry-section-wrapper {
    margin: 0 auto 60px; 
    gap: 22px;
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 100%;
}

.btn-next-custom {
    width: 100%;
    margin: 0 !important;
    padding: 15px 20px 15px 95px !important;
    border-radius: 30px !important;
    min-height: 100px !important;
    justify-content: flex-start;
}
@media (min-width: 420px) {
    .btn-next-custom { padding-left: 105px !important; }
}
.btn-next-custom .btn-icon {
    position: absolute; 
    left: 20px; 
    top: 50%; 
    transform: translateY(-50%); 
    width: 50px; 
    height: 50px;
    background-size: cover !important; 
    background-repeat: no-repeat; 
    background-position: center;
    border: 6px solid #000;
    box-shadow: 0 0 0 2px #bbb, 0 4px 6px rgba(0,0,0,0.5);
    border-radius: 15px !important;
    box-sizing: border-box;
    filter: none;
}
.btn-next-custom::before { border-radius: 30px !important; }
.btn-next-custom::after { border-radius: 24px !important; }


/* --------------------------------------
   その他の学習（縦並びのボタン群）
-------------------------------------- */
.btn-container-sub {
    gap: 25px !important; /* ボタン間隔の調整 */
}
.btn-container-sub .start-btn {
    padding: 20px 20px 20px 78px !important;
    min-height: auto !important;
    border-radius: 19px !important;
    margin: 0 !important; 
}
.btn-container-sub .start-btn::before {
    border-radius: 25px !important;
    top: -5px !important; left: -5px !important; right: -5px !important; bottom: -5px !important;
    box-shadow: none !important; 
}
.btn-container-sub .start-btn:hover::before { box-shadow: none !important; }
.btn-container-sub .start-btn::after {
    border-radius: 18px !important;
    background: url('../images/startBtn_arrowR-new-right.svg') no-repeat calc(100% - 10px) center / 24px 24px, #000 !important;
}
.btn-container-sub .start-btn .btn-icon {
    width: 50px !important; 
    height: 50px !important; 
    left: 12px !important;
    border-radius: 15px !important;
    background-color: #696969 !important;
    border: 5px solid #000 !important;
    box-shadow: 0 0 0 2px #555 !important;
    background-size: 100% !important;
    background-position: center !important;
    background-repeat: no-repeat !important;
}
.btn-container-sub .start-btn b { font-size: 26px !important; }
.btn-container-sub .start-btn .btn-sub-text { font-size: 12px !important; margin-top: 2px !important; }

/* --------------------------------------
   メインボタンの共通スタイル
-------------------------------------- */
.button-container { display: flex; flex-direction: column; gap: 35px; width: 100%; margin: 15px auto 40px; }
.start-btn { padding: 25px 20px 25px 110px; font-size: 18px; font-weight: bold; line-height: 1.2; transition: all 0.3s ease; border: none; background: transparent; color: white; cursor: pointer; text-decoration: none; position: relative; min-height: 100px; box-shadow: 0 5px 0px rgba(0, 0, 0, 0.5); opacity: 0; z-index: 1; margin: 6px; border-radius: 66px; display: flex; align-items: center; box-sizing: border-box; }
@media (min-width: 420px) { .start-btn { padding-left: 120px; } }
.start-btn > * { position: relative; z-index: 1; }
.start-btn .btn-text-wrapper { display: flex; flex-direction: column; justify-content: center; align-items: flex-start; }
@keyframes moveGradient { 0% { background-position: 0% 50%; } 100% { background-position: 200% 50%; } }
.start-btn::before { content: ''; position: absolute; z-index: -2; top: -6px; left: -6px; right: -6px; bottom: -6px; border-radius: 66px; background-size: 200% auto; animation: moveGradient 4s linear infinite; box-shadow: 0 0 15px var(--glow-color); transition: box-shadow 0.3s ease, filter 0.3s ease; }
.start-btn::after { content: ''; position: absolute; z-index: -1; top: 0; left: 0; right: 0; bottom: 0; border-radius: 60px; background: url('../images/startBtn_arrowR-new-right.svg') no-repeat calc(100% - 15px) center / 24px 24px, #000; pointer-events: none; }
.start-btn b { font-size: 36px; font-weight: 900; color: transparent; -webkit-background-clip: text; background-clip: text; background-size: 200% auto; animation: moveGradient 4s linear infinite; display: inline-block; line-height: 1; margin: 0; }
.start-btn .btn-sub-text { display: block; font-size: 13px; color: #bbb; font-weight: normal; margin-top: 6px; line-height: 1.4; }
.start-btn .btn-sub-text strong { color: #fff; font-size: 1.1em; }
.start-btn .btn-icon { position: absolute; left: 13px; top: 50%; transform: translateY(-50%); width: 70px; height: 70px; background-size: contain; background-repeat: no-repeat; background-position: center; }

/* --------------------------------------
   各種ボタンの色定義
-------------------------------------- */
/* 詳細学習ボタン（緑色グラデーション） */
.btn-details { --glow-color: rgba(140, 219, 140, 0.8); }
.btn-details::before { background-image: linear-gradient(90deg, #8cdb8c, #4ade4a, #85d6b3, #4ade4a, #8cdb8c); }
.btn-details b { background-image: linear-gradient(90deg, #8cdb8c, #4ade4a, #85d6b3, #4ade4a, #8cdb8c); }
.btn-details .btn-icon { background-image: url('../images/indexPageBtn_details.svg'); }

/* 暗記カードボタン（黄色グラデーション） */
.btn-card { --glow-color: rgba(245, 233, 108, 0.8); }
.btn-card::before { background-image: linear-gradient(90deg, #f5e96c, #ffd700, #ffaa00, #ffd700, #f5e96c); }
.btn-card b { background-image: linear-gradient(90deg, #f5e96c, #ffd700, #ffaa00, #ffd700, #f5e96c); }
.btn-card .btn-icon { background-image: url('../images/indexPageBtn_card.svg'); }

/* 基本クイズボタン（赤色グラデーション） */
.btn-quiz { --glow-color: rgba(201, 54, 54, 0.8); }
.btn-quiz::before { background-image: linear-gradient(90deg, #c93636, #ff4d4d, #ff8080, #ff4d4d, #c93636); }
.btn-quiz b { background-image: linear-gradient(90deg, #c93636, #ff4d4d, #ff8080, #ff4d4d, #c93636); }
.btn-quiz .btn-icon { background-image: url('../images/indexPageBtn_quiz.svg'); }

/* 応用クイズボタン（紫色グラデーション） */
.btn-quiz-advanced { --glow-color: rgba(103, 38, 150, 0.8); }
.btn-quiz-advanced::before { background-image: linear-gradient(90deg, #60b6eb, #294799, #672696, #294799, #60b6eb); }
.btn-quiz-advanced b { background-image: linear-gradient(90deg, #60b6eb, #294799, #672696, #294799, #60b6eb); }
.btn-quiz-advanced .btn-icon { background-image: url('../images/indexPageBtn_quiz-advanced.svg'); }

/* 一覧（次の単元用）ボタン（水色グラデーション） */
.btn-list-action { --glow-color: rgba(125, 195, 227, 0.8); }
.btn-list-action::before { background-image: linear-gradient(90deg, #7dc3e3, #3bbcf0, #a4d5eb, #3bbcf0, #7dc3e3); }
.btn-list-action b { background-image: linear-gradient(90deg, #7dc3e3, #3bbcf0, #a4d5eb, #3bbcf0, #7dc3e3); }
.btn-list-action .list-icon { background-image: url('../images/indexPageBtn_list.svg'); filter: drop-shadow(0 2px 2px rgba(0,0,0,0.5)); }

/* 詳細学習（次の単元用）ボタン（緑色グラデーション） */
.btn-details-action { --glow-color: rgba(140, 219, 140, 0.8); }
.btn-details-action::before { background-image: linear-gradient(90deg, #8cdb8c, #4ade4a, #85d6b3, #4ade4a, #8cdb8c); }
.btn-details-action b { background-image: linear-gradient(90deg, #8cdb8c, #4ade4a, #85d6b3, #4ade4a, #8cdb8c); }


/* --------------------------------------
   チェックマーク（.nav-icon-check）と達成時の色変化
-------------------------------------- */
.start-btn .nav-icon-check {
    position: absolute;
    top: -8px;
    right: -8px;
    width: 22px;
    height: 22px;
    background-image: url('../images/header-iconMini_check.svg');
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    background-color: #ba8d11;
    border-radius: 50%;
    opacity: 0;
    transform: scale(0);
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    z-index: 10;
    box-shadow: 0 2px 4px rgba(0,0,0,0.5);
}

.btn-container-sub .start-btn .nav-icon-check {
    top: calc(50% - 25px - 8px);
    left: 48px;
    right: auto;
}

.start-btn.is-achieved .nav-icon-check {
    opacity: 1;
    transform: scale(1);
    z-index: 10; 
}

/* ★追加：「cleared」フレーズ画像の指定 */
.btn-cleared-phrase {
    position: absolute;
    top: -5px;
    right: 15px;
    width: 120px;
    height: 50px;
    background-image: url('../images/btnEnglish-phrase-cleared.svg');
    background-size: contain;
    background-repeat: no-repeat;
    background-position: right top;
    z-index: 10;
    pointer-events: none;
    opacity: 0;
    transform: scale(1.2) rotate(5deg);
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}
.start-btn.is-achieved .btn-cleared-phrase {
    opacity: 1;
    transform: scale(1) rotate(0deg);
}

/* 達成時のグラデーション暗色化とアニメーション停止 */
.start-btn.is-achieved::before {
    filter: brightness(0.5) grayscale(50%) !important;
    animation: none !important;
}
.start-btn.is-achieved b {
    filter: brightness(0.6) grayscale(30%) !important;
    animation: none !important;
}

/* アイコンを暗くする処理 */
.start-btn.is-achieved .btn-icon::after {
    content: '';
    position: absolute;
    top: -5px; left: -5px; right: -5px; bottom: -5px;
    background-color: rgba(0, 0, 0, 0.5);
    border-radius: inherit;
    backdrop-filter: grayscale(50%);
    z-index: 1;
}

/* 達成時は光彩パルスを非表示にする */
.start-btn.is-achieved .btn-pulse {
    display: none !important;
    animation: none !important;
}


/* --------------------------------------
   未達成ボタンの光彩（パルス）アニメーション
-------------------------------------- */
.start-btn .btn-pulse {
    position: absolute;
    top: -6px; left: -6px; right: -6px; bottom: -6px;
    border-radius: 66px;
    pointer-events: none;
    z-index: -3; 
    opacity: 1;
}

/* btn-container-sub 内のボタンは角丸が小さいのでそれに合わせる */
.btn-container-sub .start-btn .btn-pulse {
    border-radius: 25px;
}

/* 通常の光彩（弱め） */
@keyframes continuous-pulse-list {
    0% { box-shadow: 0 0 5px 0 var(--pulse-color); }
    100% { box-shadow: 0 0 20px 15px rgba(0, 0, 0, 0); }
}

/* 次の単元ボタン用の光彩（強め） */
@keyframes continuous-pulse-strong {
    0% { box-shadow: 0 0 10px 0 var(--pulse-color); }
    100% { box-shadow: 0 0 30px 20px rgba(0, 0, 0, 0); } 
}

/* スクロールして表示されたらパルス開始 */
.start-btn.is-visible .btn-pulse {
    animation: continuous-pulse-list 1.8s ease-out infinite;
}

/* is-primary-action の場合は強めのパルスを適用 */
.start-btn.is-primary-action.is-visible .btn-pulse {
    animation: continuous-pulse-strong 1.8s ease-out infinite !important;
}

.btn-next-custom.is-primary-action::before {
    animation: moveGradient 4s linear infinite !important;
}

/* ★PCのみメインボタンのホバーエフェクトを有効化 */
@media (hover: hover) and (pointer: fine) {
    .start-btn:hover {
        transform: translateY(-3px);
        box-shadow: 0 8px 20px rgba(0, 0, 0, 0.5);
    }
    .start-btn:hover::before {
        box-shadow: 0 0 25px var(--glow-color);
        filter: brightness(1.2);
    }
}

/* 押した時の反応(:active)は全デバイス共通 */
.start-btn:active {
    transform: translateY(0);
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
}

@keyframes stampIn {
    0% { transform: scale(1.15); opacity: 0; }
    50% { transform: scale(0.98); opacity: 1; }
    80% { transform: scale(1.01); }
    100% { transform: scale(1.0); opacity: 1; }
}

.start-btn.is-visible {
    animation: stampIn 0.5s cubic-bezier(0.39, 0.575, 0.565, 1) forwards;
}


/* --------------------------------------
   スクロールアニメーション用
-------------------------------------- */
.scroll-stamp-in {
    opacity: 0;
    transform: scale(1.15);
}
.scroll-stamp-in.is-visible {
    animation: stampIn 0.5s cubic-bezier(0.39, 0.575, 0.565, 1) forwards;
}

/* --------------------------------------
   「次の単元」ボタン用の追加テキストスタイル
-------------------------------------- */
.next-btn-upper-text {
    color: #fff;
    font-size: 18px;
    font-weight: bold;
    margin-bottom: 2px;
    display: block;
}

.start-btn .btn-sub-text {
    white-space: nowrap;
}


/* ==========================================================================
   一覧達成完了モーダル（ボトムシート風アレンジ）
   ========================================================================== */

/* オーバーレイ（背景の暗幕） */
.completion-modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6); 
    z-index: 5000;
    
    display: flex;
    justify-content: center;
    align-items: flex-end; 
    
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.4s ease, visibility 0.4s ease;
    backdrop-filter: blur(2px); 
}

.completion-modal-overlay.is-visible {
    opacity: 1;
    visibility: visible;
}

/* モーダル本体（ボトムシート） */
.completion-modal-content {
    background: #111;
    width: 100%; 
    max-width: 550px; 
    
    border-radius: 25px 25px 0 0; 
    padding: 10px 25px 25px;
    text-align: center;
    position: relative;
    box-shadow: 0 -10px 40px rgba(0,0,0,0.2);
    
    transform: translateY(100%);
    opacity: 1; 
    transition: transform 0.5s cubic-bezier(0.19, 1, 0.22, 1);
    overflow: visible; 
}

/* ドラッグハンドル */
.modal-drag-handle {
    width: 60px;
    height: 4px;
    background-color: #444;
    border-radius: 2px;
    margin: 0 auto 40px;
    opacity: 0.8;
}

.completion-modal-overlay.is-visible .completion-modal-content {
    transform: translateY(0);
}

/* PC/タブレット向けの調整 */
@media (min-width: 600px) {
    .completion-modal-overlay {
        align-items: center; 
    }

    .completion-modal-content {
        width: 90%;
        max-width: 500px;
        border-radius: 25px; 
        padding: 30px 25px;
        
        transform: scale(0.9) translateY(20px);
        box-shadow: 0 10px 40px rgba(0,0,0,0.3);
    }
    
    .modal-drag-handle {
        display: none; 
    }

    .completion-modal-overlay.is-visible .completion-modal-content {
        transform: scale(1) translateY(0);
    }
}

/* 右上の閉じるボタン（×アイコン） */
.modal-close-icon {
    position: absolute;
    top: 15px;
    right: 15px;
    width: 36px;
    height: 36px;
    background-color: #a30b22;
    border-radius: 50%;
    cursor: pointer;
    z-index: 10;
    transition: background-color 0.2s;
}
.modal-close-icon:hover { background-color: #8a091d; }
.modal-close-icon::before,
.modal-close-icon::after {
    content: '';
    position: absolute; top: 50%; left: 50%; width: 16px; height: 2px;
    background-color: #000; border-radius: 1px;
}
.modal-close-icon::before { transform: translate(-50%, -50%) rotate(45deg); }
.modal-close-icon::after { transform: translate(-50%, -50%) rotate(-45deg); }


/* モーダル内ヘッダー */
.completion-header {
    margin-bottom: 30px;
}

.completion-phrase-image {
    width: 100%;
    max-width: 400px;
    height: 130px;
    margin: 0 auto;
    background-image: url('../images/modal-lamp-phrase-cleared.svg');
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    opacity: 0; 
}
.completion-phrase-image.is-all {
    background-image: url('../images/modal-lamp-phrase-all.svg');
}

.completion-phrase-image.stamp-in {
    animation: phrase-stamp-in 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}
@keyframes phrase-stamp-in {
    0% { opacity: 0; transform: scale(2.5); }
    50% { opacity: 1; transform: scale(0.9); }
    75% { transform: scale(1.05); }
    100% { opacity: 1; transform: scale(1); }
}


/* ランプセクション共通 */
.completion-lamp-section {
    display: flex;
    justify-content: center;
    margin-bottom: 20px;
}
.completion-lamp-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
}

/* 共通ランプ形状 */
.completion-lamp {
    border-radius: 50%;
    background-color: #111;
    border: 5px solid #333;
    background-repeat: no-repeat;
    background-position: center;
    position: relative;
    z-index: 2;
    transition: all 0.5s ease;
}

/* ================== メインランプ ================== */
.completion-lamp-wrapper.main {
    width: 130px; 
}
.completion-lamp-wrapper.main .completion-lamp {
    width: 120px;
    height: 120px;
    background-size: 96px 96px;
    border-width: 8px;
    opacity: 0.5;
}

/* list.html用 メインランプ */
.completion-lamp-wrapper.main #modal-lamp-list {
    background-image: url('../images/indexPage-milestone-icon_list.svg');
}
.completion-lamp-wrapper.main #modal-lamp-list.is-achieved {
    opacity: 1;
    border-color: #4aa5cf;
    background-image: url('../images/indexPage-milestone-icon_list-lamp.svg');
    box-shadow: 0 0 15px #4aa5cf, inset 0 0 10px #4aa5cf;
    animation: modal-lamp-glow-list 1.5s infinite alternate;
}

/* details.html用 メインランプ */
.completion-lamp-wrapper.main #modal-lamp-details {
    background-image: url('../images/indexPage-milestone-icon_details.svg');
}
.completion-lamp-wrapper.main #modal-lamp-details.is-achieved {
    opacity: 1;
    border-color: #46d446;
    background-image: url('../images/indexPage-milestone-icon_details-lamp.svg');
    box-shadow: 0 0 15px #46d446, inset 0 0 10px #46d446;
    animation: modal-lamp-glow-details 1.5s infinite alternate;
}

@keyframes modal-lamp-glow-list {
    from { box-shadow: 0 0 5px #4aa5cf, inset 0 0 5px #4aa5cf; }
    to { box-shadow: 0 0 20px #5cb8e6, inset 0 0 15px #5cb8e6; }
}

@keyframes modal-lamp-glow-details {
    from { box-shadow: 0 0 5px #46d446, inset 0 0 5px #46d446; }
    to { box-shadow: 0 0 20px #57f557, inset 0 0 15px #57f557; }
}


/* ================== サブランプ ================== */
.completion-lamp-section.sub-section {
    gap: 18px;
    margin-bottom: 30px;
    flex-wrap: wrap; 
    justify-content: center;
}
.completion-lamp-wrapper.sub .completion-lamp {
    width: 60px;
    height: 60px;
    background-size: 48px 48px;
    border-width: 6px;
    opacity: 0.3; 
    filter: grayscale(100%);
}

.completion-lamp-wrapper.sub .completion-lamp.is-achieved {
    opacity: 1;
    filter: grayscale(0%);
    background-color: #111; 
    box-shadow: inset 0 2px 10px rgba(255, 255, 255, 1);
}

#modal-lamp-card { background-image: url('../images/indexPage-milestone-icon_card.svg'); }
#modal-lamp-quiz-p { background-image: url('../images/indexPage-milestone-icon_quizP.svg'); }
#modal-lamp-quiz-s { background-image: url('../images/indexPage-milestone-icon_quizS.svg'); }
.completion-lamp-wrapper.sub #modal-lamp-list { background-image: url('../images/indexPage-milestone-icon_list.svg'); }
.completion-lamp-wrapper.sub #modal-lamp-details { background-image: url('../images/indexPage-milestone-icon_details.svg'); }

#modal-lamp-card.is-achieved { 
    border-color: #ffd000; 
    background-image: url('../images/indexPage-milestone-icon_card-lamp.svg');
    box-shadow: 0 0 8px #ffd000, inset 0 0 8px #ffd000;
}
#modal-lamp-quiz-p.is-achieved { 
    border-color: #c40e0e; 
    background-image: url('../images/indexPage-milestone-icon_quizP-lamp.svg');
    box-shadow: 0 0 8px #c40e0e, inset 0 0 8px #c40e0e;
}
#modal-lamp-quiz-s.is-achieved { 
    border-color: #2f53b5; 
    background-image: url('../images/indexPage-milestone-icon_quizS-lamp.svg');
    box-shadow: 0 0 8px #2f53b5, inset 0 0 8px #2f53b5;
}
.completion-lamp-wrapper.sub #modal-lamp-list.is-achieved { 
    border-color: #4aa5cf; 
    background-image: url('../images/indexPage-milestone-icon_list-lamp.svg');
    box-shadow: 0 0 8px #4aa5cf, inset 0 0 8px #4aa5cf;
}
.completion-lamp-wrapper.sub #modal-lamp-details.is-achieved {
    border-color: #46d446;
    background-image: url('../images/indexPage-milestone-icon_details-lamp.svg');
    box-shadow: 0 0 8px #46d446, inset 0 0 8px #46d446;
}

/* ラベルスタイル */
.completion-lamp-label {
    margin-top: 8px;
    font-size: 14px;
    font-weight: bold;
    color: #ccc;
}
.completion-lamp-label.small {
    font-size: 13px;
    margin-top: 5px;
}


/* キャラクター演出 */
.completion-character-area {
    display: flex;
    flex-direction: column; 
    justify-content: center;
    align-items: center; 
    margin-bottom: 0px;
    gap: 10px;
    margin-top: 25px; 
}

.completion-character {
    width: 220px; 
    height: 140px; 
    max-width: 70%;
    background-image: url('../images/modal-lamp-takokichi.svg');
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center bottom;
    opacity: 0; 
    transform: translateY(20px) scale(0.8);
}
.completion-character.is-all {
    background-image: url('../images/modal-lamp-takokichi-all.svg');
}

.completion-character.bounce-in {
    opacity: 1;
    animation: bounce-in-bottom 0.8s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

@keyframes bounce-in-bottom {
    0% { transform: translateY(100px) scale(0.5); opacity: 0; }
    50% { transform: translateY(-20px) scale(1.1); opacity: 1; }
    70% { transform: translateY(10px) scale(0.95); }
    100% { transform: translateY(0) scale(1); opacity: 1; }
}

.completion-message {
    background: #fff;
    color: #111;
    padding: 10px 15px;
    border-radius: 15px;
    position: relative;
    font-size: 14px;
    font-weight: bold;
    line-height: 1.5;
    text-align: center;
    max-width: 300px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    
    opacity: 0;
    transform: translateY(10px) scale(0.9);
    transition: opacity 0.4s ease, transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.completion-message.show-message {
    opacity: 1;
    transform: translateY(0) scale(1);
}
.completion-message::before {
    content: '';
    position: absolute;
    bottom: -8px; 
    left: 50%;
    transform: translateX(-50%);
    border-top: 8px solid #fff;
    border-left: 8px solid transparent;
    border-right: 8px solid transparent;
}


/* 紙吹雪エフェクト */
.completion-confetti {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    overflow: hidden;
    z-index: 1;
    border-radius: 25px 25px 0 0; 
}
@media (min-width: 600px) {
    .completion-confetti {
        border-radius: 25px;
    }
}
.confetti-dot {
    position: absolute;
    top: -20px;
    box-shadow: 0 0 4px rgba(255, 215, 0, 0.6), inset 0 0 2px rgba(255, 255, 255, 0.4); 
    animation: confetti-fall linear forwards;
}

@keyframes confetti-fall {
    0%   { transform: translate(0, 0) rotate(0deg); opacity: 0; }
    15%  { opacity: 0.8; }
    25%  { transform: translate(var(--sway-x), 125px) rotate(90deg); opacity: 0.3; }
    50%  { transform: translate(0, 250px) rotate(180deg); opacity: 0.7; }
    75%  { transform: translate(calc(var(--sway-x) * -1), 375px) rotate(270deg); opacity: 0.2; }
    100% { transform: translate(0, 500px) rotate(360deg); opacity: 0; }
}

/* ==========================================================================
   単元一覧へ戻るエリア
   ========================================================================== */
.back-to-chapter-area {
    max-width: 500px;
    margin: 80px auto 0px;
    text-align: center;
    border-bottom: 1px solid #444;
    border-top: 1px solid #444;
}
.back-to-chapter-button {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-decoration: none;
    color: #333;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    flex: 1;
    padding: 15px 5px;
    border-radius: 12px;
    opacity: 0; 
}
.back-to-chapter-button.is-visible {
    animation: stampIn 0.5s cubic-bezier(0.39, 0.575, 0.565, 1) forwards;
    animation-delay: 0.2s; 
}
.back-to-chapter-icon {
    width: 90px;
    height: 90px;
    border-radius: 50%;
    background-color: #000;
    background-repeat: no-repeat;
    background-position: center;
    margin-bottom: 12px;
    border: 7px solid #4c788a;
    box-shadow: 0 4px 0px rgba(0, 0, 0, 0.2);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.back-to-chapter-label {
    font-size: 16px;
    font-weight: bold;
    color: #aaa;
    line-height: 1.3;
}
.chapter-label-subject {
    color: #fff;
    font-size: 1.2em;
}
.chapter-label-particle {
    font-size: 0.85em;
    margin: 0 0.2em;
}
.back-to-chapter-wrapper { 
    margin-top: 20px; 
}
.back-to-chapter-wrapper .back-to-chapter-button {
    display: inline-flex;
    flex: none;
    max-width: 400px;
    padding-top: 20px;
    padding-bottom: 30px;
}
.back-to-chapter-icon.chapter-icon {
    position: relative;
    background-color: #111;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    overflow: hidden; 
}
.back-to-chapter-icon.chapter-icon::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background-color: rgba(0, 0, 0, 0.6);
    border-radius: 50%;
    box-shadow: inset 0 0 12px rgba(0, 0, 0, 0.5);
    z-index: 1;
}
.back-to-chapter-icon.chapter-icon::after {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background-image: url(../images/next-stepIcon_chapter.svg);
    background-size: contain;
    background-position: center;
    background-repeat: no-repeat;
    z-index: 2;
}

.back-to-chapter-button:hover .back-to-chapter-icon {
    transform: translateY(-3px);
    box-shadow: 0 7px 10px rgba(0, 0, 0, 0.2);
}
.back-to-chapter-button:active .back-to-chapter-icon {
    transform: translateY(0);
    box-shadow: 0 4px 0px rgba(0, 0, 0, 0.2);
}

/* --- END OF FILE next-step.css --- */