* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: "Hiragino Sans", "Yu Gothic", sans-serif;
    background: linear-gradient(180deg, #031522 0%, #06283d 45%, #0b3a53 100%);
    color: #e8f6ff;
    min-height: 100vh;
}

.app-shell {
    width: min(920px, calc(100% - 32px));
    margin: 40px auto;
}

.app-header {
    text-align: center;
    margin-bottom: 24px;
}

.app-header h1 {
    margin: 0 0 8px;
    font-size: clamp(2rem, 4vw, 2.8rem);
    letter-spacing: 0.05em;
}

.subtitle {
    margin: 0;
    color: #a9d7ea;
    font-size: 0.95rem;
}

.app-main {
    display: grid;
    gap: 16px;
}

.input-panel,
.status-panel,
.filter-panel,
.list-panel {
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 18px;
    padding: 18px;
    backdrop-filter: blur(10px);
}

.input-panel {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr auto;
    gap: 14px;
}

#todo-input,
#category-input,
#deadline-input {
    width: 100%;
    padding: 12px 14px;
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.15);
    background: rgba(255, 255, 255, 0.10);
    color: #ffffff;
    font-size: 1rem;
    outline: none;
}

#todo-input:focus,
#category-input:focus,
#deadline-input:focus {
    border-color: #73d2ff;
    box-shadow: 0 0 0 3px rgba(115, 210, 255, 0.18);
}

#category-input option {
    background: #06283d;
    color: #e8f6ff;
}

button {
    border: none;
    border-radius: 12px;
    padding: 10px 14px;
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: 700;
    transition: transform 0.15s ease, opacity 0.15s ease;
}

button:hover {
    transform: translateY(-1px);
    opacity: 0.92;
}

#add-btn {
    background: linear-gradient(135deg, #48c6ef 0%, #1e88e5 100%);
    color: white;
    min-width: 88px;
}

.status-panel {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

#todo-count {
    margin: 0;
    color: #d9f3ff;
    font-weight: 700;
}

#filter-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

#filter-buttons button {
    background: rgba(255, 255, 255, 0.12);
    color: #e8f6ff;
    border: 1px solid rgba(255, 255, 255, 0.14);
}

#filter-buttons button.active {
    background: linear-gradient(135deg, #48c6ef 0%, #1e88e5 100%);
    color: #ffffff;
    border-color: transparent;
    box-shadow: 0 0 0 3px rgba(72, 198, 239, 0.18);
}

#todo-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    gap: 30px;
}

#todo-list li {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: 14px 16px;
    align-items: start;
    background: rgba(2, 16, 27, 0.48);
    border: 1px solid rgba(126, 211, 255, 0.10);
    border-radius: 16px;
    padding: 18px;
    box-shadow: 0  10px 24px rgba(0, 0, 0, 0.18);
}

#todo-list li > button:first-child {
    grid-row: span 2;
    align-self: center;
    background: rgba(255, 255, 255, 0.10);
    color: #fff;
    width: 44px;
    height: 44px;
    padding: 0;
    font-size: 1.1rem;
}

#todo-list li > div {
    grid-column: 2 / 3;
    background: rgba(255, 255, 255, 0.08);
    border-left: 3px solid rgba(115, 210, 255, 0.55);
    border-radius: 10px;
    padding: 10px 12px;
    line-height: 1.7;
    font-size: 0.92rem;
    color: #ffffff;
    opacity: 1;
    font-weight: 500;
}

#todo-list li > div::before {
    color: #a9d7ea;
    font-weight: 700;
}

#todo-list li > span:first-of-type {
    font-size: 1.05rem;
    font-weight: 700;
    color: #ffffff;
}

#todo-list li > span:nth-of-type(2),
#todo-list li > span:nth-of-type(3){
    display: inline-block;
    margin-right: 8px;
    font-size: 0.9rem;
}

#todo-list li > button:not(:first-child) {
    background: rgba(255, 255, 255, 0.10);
    color: #e8f6ff;
}

footer {
    text-align: center;
    margin-top: 20px;
    color: #9ec6d8;
    font-size: 0.9rem;
}

.category-仕事 {
    color: #66b3ff;
    font-weight: 700;
}

.category-勉強 {
    color: #7ee787;
    font-weight: 700;
}

.category-生活 {
    color: #ffb454;
    font-weight: 700;
}

@media (max-width: 768px) {
    .app-shell {
        width: min(100% - 20px, 100%);
        margin: 20px auto;
    }

    .input-panel {
        grid-template-columns: 1fr;
    }

    .status-panel {
        justify-content: flex-start;
    }

    #todo-list li {
        grid-template-columns: 1fr;
    }

    #todo-list li > button:first-child {
        grid-row: auto;
        width: 100%;
        height: auto;
        padding: 10px 14px;
    }

    #todo-list li > div {
        grid-column: auto;
    }
}