/* なぜHPが必要なのか？ セクション */
.why-hp {
    padding: var(--spacing-xl) 0;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    position: relative;
    overflow: hidden;
}

/* アニメーション背景レイヤー1: 浮遊する光の粒子 */
.why-hp::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(circle at 20% 30%, rgba(255, 215, 0, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(255, 215, 0, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 50% 50%, rgba(255, 215, 0, 0.05) 0%, transparent 50%);
    pointer-events: none;
    animation: floatingLight 15s ease-in-out infinite;
}

@keyframes floatingLight {
    0%, 100% {
        opacity: 0.5;
        transform: scale(1);
    }
    50% {
        opacity: 1;
        transform: scale(1.2);
    }
}

/* アニメーション背景レイヤー2: 動く光のグラデーション */
.why-hp::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(
        ellipse at center,
        rgba(255, 215, 0, 0.08) 0%,
        transparent 50%
    );
    animation: rotatingGradient 20s linear infinite;
    pointer-events: none;
}
@keyframes rotatingGradient {
    0% {
        transform: rotate(0deg);
    }
    100% {
        transform: rotate(360deg);
    }
}

.why-hp-content {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

/* 浮遊するキラキラパーティクル */
.why-hp .sparkle-particle {
    position: absolute;
    width: 4px;
    height: 4px;
    background: var(--color-primary);
    border-radius: 50%;
    pointer-events: none;
    animation: sparkleFloat 10s ease-in-out infinite;
    box-shadow: 0 0 10px rgba(255, 215, 0, 0.8);
}

@keyframes sparkleFloat {
    0%, 100% {
        transform: translateY(0) translateX(0) scale(0.5);
        opacity: 0;
    }
    10% {
        opacity: 1;
    }
    90% {
        opacity: 1;
    }
    100% {
        transform: translateY(-100vh) translateX(50px) scale(1);
        opacity: 0;
    }
}

.why-hp .sparkle-particle:nth-child(1) { left: 10%; animation-delay: 0s; }
.why-hp .sparkle-particle:nth-child(2) { left: 20%; animation-delay: 2s; }
.why-hp .sparkle-particle:nth-child(3) { left: 30%; animation-delay: 4s; }
.why-hp .sparkle-particle:nth-child(4) { left: 40%; animation-delay: 1s; }
.why-hp .sparkle-particle:nth-child(5) { left: 50%; animation-delay: 3s; }
.why-hp .sparkle-particle:nth-child(6) { left: 60%; animation-delay: 5s; }
.why-hp .sparkle-particle:nth-child(7) { left: 70%; animation-delay: 2.5s; }
.why-hp .sparkle-particle:nth-child(8) { left: 80%; animation-delay: 4.5s; }
.why-hp .sparkle-particle:nth-child(9) { left: 90%; animation-delay: 1.5s; }
.why-hp .sparkle-particle:nth-child(10) { left: 15%; animation-delay: 3.5s; }
.why-hp .sparkle-particle:nth-child(11) { left: 25%; animation-delay: 5.5s; }
.why-hp .sparkle-particle:nth-child(12) { left: 35%; animation-delay: 0.5s; }
.why-hp .sparkle-particle:nth-child(13) { left: 45%; animation-delay: 2.8s; }
.why-hp .sparkle-particle:nth-child(14) { left: 55%; animation-delay: 4.2s; }
.why-hp .sparkle-particle:nth-child(15) { left: 65%; animation-delay: 1.8s; }
.why-hp .sparkle-particle:nth-child(16) { left: 75%; animation-delay: 3.2s; }
.why-hp .sparkle-particle:nth-child(17) { left: 85%; animation-delay: 5.2s; }
.why-hp .sparkle-particle:nth-child(18) { left: 95%; animation-delay: 0.8s; }
.why-hp .sparkle-particle:nth-child(19) { left: 12%; animation-delay: 2.2s; }
.why-hp .sparkle-particle:nth-child(20) { left: 88%; animation-delay: 4.8s; }

.why-hp-intro {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.why-hp-question {
    font-size: 1.3rem;
    color: var(--color-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.why-hp-text {
    font-size: 1.1rem;
    line-height: 1.9;
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
    text-align: left;
}

.why-hp-answer {
    background: linear-gradient(135deg, rgba(255, 215, 0, 0.15), rgba(255, 215, 0, 0.05));
    border: 2px solid var(--color-primary);
    border-radius: 15px;
    padding: var(--spacing-lg);
    margin: var(--spacing-lg) 0;
    position: relative;
    animation: answerPulse 3s ease-in-out infinite;
    overflow: hidden;
}

/* 流れる光のエフェクト */
.why-hp-answer::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(
        45deg,
        transparent 30%,
        rgba(255, 215, 0, 0.3) 50%,
        transparent 70%
    );
    animation: shineFlow 4s linear infinite;
}

@keyframes shineFlow {
    0% {
        transform: translate(-100%, -100%) rotate(45deg);
    }
    100% {
        transform: translate(100%, 100%) rotate(45deg);
    }
}

@keyframes answerPulse {
    0%, 100% {
        box-shadow: 0 0 30px rgba(255, 215, 0, 0.3);
    }
    50% {
        box-shadow: 0 0 50px rgba(255, 215, 0, 0.5);
    }
}

.why-hp-answer p {
    font-size: 1.4rem;
    line-height: 1.8;
    color: var(--color-primary);
    margin: 0;
    text-shadow: 0 0 20px rgba(255, 215, 0, 0.3);
    position: relative;
    z-index: 1;
}

.why-hp-section {
    background: rgba(0, 0, 0, 0.3);
    border-radius: 15px;
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    border: 1px solid rgba(255, 215, 0, 0.2);
    position: relative;
    transition: all 0.3s ease;
}

.why-hp-section::before {
    content: '';
    position: absolute;
    top: -2px;
    left: -2px;
    right: -2px;
    bottom: -2px;
    background: linear-gradient(45deg, 
        transparent, 
        rgba(255, 215, 0, 0.3), 
        transparent, 
        rgba(255, 215, 0, 0.3), 
        transparent
    );
    background-size: 200% 200%;
    border-radius: 15px;
    z-index: -1;
    opacity: 0;
    animation: borderFlow 3s linear infinite;
    transition: opacity 0.3s ease;
}

.why-hp-section:hover::before {
    opacity: 1;
}

@keyframes borderFlow {
    0% {
        background-position: 0% 0%;
    }
    100% {
        background-position: 200% 200%;
    }
}

.why-hp-section-title {
    font-size: 1.5rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.why-hp-section-title i {
    font-size: 1.3rem;
}

.why-hp-list {
    list-style: none;
    padding: 0;
    margin: var(--spacing-md) auto;
    max-width: 600px;
}

.why-hp-list li {
    position: relative;
    padding-left: 0;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
    line-height: 1.8;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    justify-content: flex-start;
}

.why-hp-list li i {
    color: var(--color-primary);
    font-size: 1.2rem;
    flex-shrink: 0;
    text-shadow: 0 0 10px rgba(255, 215, 0, 0.5);
    margin-right: var(--spacing-xs);
}

.why-hp-list li::before {
    display: none;
}

.why-hp-highlight {
    background: linear-gradient(135deg, rgba(255, 215, 0, 0.1), rgba(255, 215, 0, 0.05));
    border-left: 4px solid var(--color-primary);
    border-radius: 8px;
    padding: var(--spacing-md);
    margin: var(--spacing-md) 0;
}

.why-hp-highlight p {
    margin: 0;
    font-size: 1.2rem;
    line-height: 1.8;
    color: var(--color-primary);
}

.why-hp-checkpoints {
    list-style: none;
    padding: 0;
    margin: var(--spacing-md) auto;
    max-width: 700px;
}

.why-hp-checkpoints li {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) 0;
    color: var(--color-text);
    line-height: 1.8;
}

.why-hp-checkpoints i {
    color: var(--color-primary);
    font-size: 1.2rem;
    flex-shrink: 0;
}

.why-hp-reason-box {
    background: linear-gradient(135deg, rgba(255, 215, 0, 0.15), rgba(255, 215, 0, 0.08));
    border: 2px solid var(--color-primary);
    border-radius: 12px;
    padding: var(--spacing-md);
    margin: var(--spacing-md) 0;
    text-align: center;
}

.why-hp-reason-box p {
    margin: 0;
    font-size: 1.2rem;
    line-height: 1.8;
    color: var(--color-text);
}

.why-hp-reason-box strong {
    color: var(--color-primary);
    font-size: 1.3rem;
}

.why-hp-conclusion {
    background: linear-gradient(135deg, rgba(255, 215, 0, 0.1), rgba(255, 215, 0, 0.05));
    border: 2px solid var(--color-primary);
    border-radius: 20px;
    padding: var(--spacing-xl);
    margin-top: var(--spacing-xl);
    position: relative;
    overflow: hidden;
}

/* 結論エリアの背景アニメーション */
.why-hp-conclusion::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(
        90deg,
        transparent,
        rgba(255, 215, 0, 0.1),
        transparent
    );
    animation: scanLine 3s linear infinite;
}

@keyframes scanLine {
    0% {
        left: -100%;
    }
    100% {
        left: 100%;
    }
}

.why-hp-conclusion > * {
    position: relative;
    z-index: 1;
}

.why-hp-conclusion-title {
    font-size: 1.8rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    text-shadow: 0 0 20px rgba(255, 215, 0, 0.4);
}

.why-hp-conclusion-title i {
    font-size: 1.5rem;
}

.why-hp-final-message {
    background: rgba(0, 0, 0, 0.4);
    border-radius: 15px;
    padding: var(--spacing-lg);
    margin: var(--spacing-lg) 0;
    text-align: center;
}

.why-hp-final-message p {
    margin: var(--spacing-sm) 0;
    font-size: 1.3rem;
    line-height: 1.8;
    color: var(--color-primary);
}

.why-hp-emphasis {
    font-size: 1.5rem !important;
    font-weight: 700;
    color: var(--color-primary) !important;
    text-shadow: 0 0 20px rgba(255, 215, 0, 0.5);
}

.why-hp-flow {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-md);
    margin: var(--spacing-xl) 0;
    flex-wrap: wrap;
}

.flow-step {
    background: var(--color-dark);
    border: 2px solid var(--color-primary);
    border-radius: 15px;
    padding: var(--spacing-md);
    text-align: center;
    min-width: 150px;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

/* ホバー時のグローエフェクト */
.flow-step::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 215, 0, 0.2);
    transform: translate(-50%, -50%);
    transition: width 0.6s ease, height 0.6s ease;
}

.flow-step:hover::before {
    width: 200%;
    height: 200%;
}

.flow-step:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(255, 215, 0, 0.3);
}

.flow-step i,
.flow-step p {
    position: relative;
    z-index: 1;
}

.flow-step i {
    font-size: 2.5rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xs);
    display: block;
}

.flow-step p {
    margin: 0;
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--color-text);
}

.flow-arrow {
    font-size: 2rem;
    color: var(--color-primary);
    font-weight: 700;
}

/* レスポンシブ対応 */
@media (max-width: 768px) {
    .why-hp-question {
        font-size: 1.1rem;
    }

    .why-hp-text {
        font-size: 1rem;
    }

    .why-hp-answer p {
        font-size: 1.2rem;
    }

    .why-hp-section {
        padding: var(--spacing-md);
    }

    .why-hp-section-title {
        font-size: 1.3rem;
    }

    .why-hp-conclusion {
        padding: var(--spacing-lg);
    }

    .why-hp-conclusion-title {
        font-size: 1.5rem;
    }

    .why-hp-final-message p {
        font-size: 1.1rem;
    }

    .why-hp-emphasis {
        font-size: 1.3rem !important;
    }

    .why-hp-flow {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    .flow-arrow {
        transform: rotate(90deg);
    }

    .flow-step {
        width: 100%;
        min-width: auto;
    }
}

@media (max-width: 480px) {
    .why-hp-question {
        font-size: 1rem;
    }

    .why-hp-text {
        font-size: 0.95rem;
    }

    .why-hp-answer p {
        font-size: 1.1rem;
    }

    .why-hp-section-title {
        font-size: 1.2rem;
    }

    .why-hp-conclusion-title {
        font-size: 1.3rem;
    }

    .why-hp-final-message p {
        font-size: 1rem;
    }

    .why-hp-emphasis {
        font-size: 1.2rem !important;
    }

    .flow-step i {
        font-size: 2rem;
    }

    .flow-step p {
        font-size: 1rem;
    }
}