/* ===== CSS Variables ===== */
:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-card: #ffffff;
    --bg-input: #ffffff;
    --accent-primary: #006938;
    --accent-secondary: #007bff;
    --accent-light: #e8f5e9;
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-muted: #888888;
    --border-color: #dddddd;
    --border-light: #eeeeee;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.15);
    --radius-sm: 5px;
    --radius-md: 8px;
    --radius-lg: 12px;
}

/* ===== Reset & Base ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans JP', 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', Meiryo, 'Yu Gothic', sans-serif;
    background: var(--bg-secondary);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.8;
    font-size: 16px;
}

/* ===== Container ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* ===== Portal Header ===== */
.portal-header {
    text-align: center;
    padding: 50px 20px;
    background: linear-gradient(135deg, var(--accent-primary) 0%, #004d29 100%);
    color: #ffffff;
    margin: -20px -20px 30px -20px;
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

.portal-header h1 {
    font-size: 2.2rem;
    font-weight: 700;
    margin-bottom: 10px;
}

.portal-header .subtitle {
    color: rgba(255, 255, 255, 0.85);
    font-size: 1rem;
    letter-spacing: 0.1em;
}

/* ===== Header (for tool pages) ===== */
header {
    text-align: center;
    padding: 30px 20px;
    background: var(--accent-primary);
    color: #ffffff;
    margin: -20px -20px 20px -20px;
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

header h1 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 8px;
}

header .subtitle {
    color: rgba(255, 255, 255, 0.9);
    font-size: 0.95rem;
}

.back-link {
    display: inline-block;
    color: rgba(255, 255, 255, 0.9);
    text-decoration: none;
    margin-bottom: 10px;
    font-size: 0.9rem;
    transition: color 0.2s;
}

.back-link:hover {
    color: #ffffff;
}

/* ===== Tools Grid ===== */
.tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 25px;
    margin-bottom: 40px;
}

.tool-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 28px;
    text-decoration: none;
    color: inherit;
    border: 1px solid var(--border-color);
    transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
    display: flex;
    flex-direction: column;
}

.tool-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent-primary);
}

.tool-icon {
    font-size: 2.5rem;
    margin-bottom: 15px;
}

.tool-card h2 {
    font-size: 1.3rem;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.tool-desc {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 15px;
    flex-grow: 1;
}

.tool-features {
    list-style: none;
    margin-bottom: 15px;
}

.tool-features li {
    font-size: 0.85rem;
    color: var(--text-muted);
    padding: 4px 0;
    padding-left: 18px;
    position: relative;
}

.tool-features li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--accent-primary);
    font-weight: bold;
}

.tool-status {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    align-self: flex-start;
}

.tool-status.ready {
    background: var(--accent-light);
    color: var(--accent-primary);
}

.tool-status.coming {
    background: #fff3cd;
    color: #856404;
}

/* ===== About Section ===== */
.about-section {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: 35px;
    border: 1px solid var(--border-color);
}

.about-section h2 {
    font-size: 1.3rem;
    margin-bottom: 15px;
    color: var(--accent-primary);
    padding-bottom: 10px;
    border-bottom: 2px solid var(--accent-primary);
}

.about-section>p {
    color: var(--text-secondary);
    margin-bottom: 25px;
}

.features-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.feature-item {
    display: flex;
    gap: 15px;
    align-items: flex-start;
}

.feature-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.feature-item strong {
    display: block;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.feature-item p {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin: 0;
}

/* ===== Sections (for tool pages) ===== */
section {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    padding: 25px;
    margin-bottom: 20px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
}

section h2 {
    font-size: 1.3rem;
    margin-bottom: 20px;
    color: var(--accent-primary);
    padding-bottom: 10px;
    border-bottom: 2px solid var(--accent-primary);
    display: flex;
    align-items: center;
    gap: 8px;
}

section h3 {
    font-size: 1.1rem;
    margin-bottom: 15px;
    color: var(--text-primary);
    font-weight: 600;
}

/* ===== Input Grid ===== */
.input-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 20px;
    margin-bottom: 20px;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.input-group label {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.95rem;
}

.input-group input,
.input-group select {
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 10px 12px;
    font-size: 1rem;
    color: var(--text-primary);
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.input-group input:focus,
.input-group select:focus {
    outline: none;
    border-color: var(--accent-secondary);
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.15);
}

.input-group .hint {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.input-group .unit {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-left: 5px;
}

/* ===== Inline Input ===== */
.input-inline {
    display: flex;
    align-items: center;
    gap: 10px;
}

.input-inline input {
    flex: 1;
}

.input-inline .unit-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    min-width: 50px;
}

/* ===== Calculate Button ===== */
.btn-calculate {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    width: 100%;
    padding: 14px 24px;
    font-size: 1.1rem;
    font-weight: 600;
    color: #ffffff;
    background: var(--accent-secondary);
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: background-color 0.2s ease, transform 0.1s ease;
}

.btn-calculate:hover {
    background: #0056b3;
}

.btn-calculate:active {
    transform: scale(0.98);
}

/* ===== Results Cards ===== */
.results-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 15px;
    margin-bottom: 25px;
}

.result-card {
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    padding: 18px;
    display: flex;
    align-items: center;
    gap: 12px;
    border: 1px solid var(--border-light);
    transition: box-shadow 0.2s ease;
}

.result-card:hover {
    box-shadow: var(--shadow-md);
}

.result-card.primary {
    background: var(--accent-primary);
    border: none;
}

.result-card.primary .card-label,
.result-card.primary .card-value {
    color: #ffffff;
}

.result-card.accent {
    background: var(--accent-secondary);
    border: none;
}

.result-card.accent .card-label,
.result-card.accent .card-value {
    color: #ffffff;
}

.card-content {
    display: flex;
    flex-direction: column;
}

.card-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-weight: 500;
}

.card-value {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-primary);
}

.card-unit {
    font-size: 0.9rem;
    font-weight: 400;
    margin-left: 4px;
}

/* ===== Info Box ===== */
.info-box {
    background: var(--accent-light);
    border: 1px solid #c8e6c9;
    border-radius: var(--radius-sm);
    padding: 15px 20px;
    margin-bottom: 20px;
}

.info-box h4 {
    color: var(--accent-primary);
    margin-bottom: 8px;
    font-size: 0.9rem;
    font-weight: 600;
}

.info-box p,
.info-box ul {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* ===== KaTeX Formula Styling ===== */
.info-box .katex,
.info-box .katex-display,
.katex,
.katex-display {
    color: #333333;
}

.info-box .katex {
    font-size: 1.1rem;
}

.info-box .katex-display {
    margin: 10px 0;
}

.info-box .katex-display>.katex {
    font-size: 1.2rem;
}

.info-box ul {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 8px 24px;
}

/* ===== Warning Box ===== */
.warning-box {
    background: #fff3cd;
    border: 1px solid #ffc107;
    border-radius: var(--radius-sm);
    padding: 15px 20px;
    margin-bottom: 20px;
}

.warning-box p {
    font-size: 0.85rem;
    color: #856404;
    margin: 0;
}

.warning-box strong {
    color: #664d03;
}

/* ===== Chart Container ===== */
.chart-container {
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    padding: 20px;
    margin-bottom: 25px;
    border: 1px solid var(--border-light);
}

.chart-container h3 {
    text-align: center;
    margin-bottom: 15px;
}

.chart-container canvas {
    max-height: 550px;
    background: #ffffff;
    border-radius: var(--radius-sm);
}

/* ===== Table ===== */
.table-container {
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    padding: 20px;
    border: 1px solid var(--border-light);
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
    background: #ffffff;
    border-radius: var(--radius-sm);
    overflow: hidden;
}

th,
td {
    padding: 12px 16px;
    text-align: center;
    border-bottom: 1px solid var(--border-light);
}

th {
    background: var(--accent-primary);
    color: #ffffff;
    font-weight: 600;
    font-size: 0.85rem;
    letter-spacing: 0.03em;
}

td {
    color: var(--text-primary);
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 0.95rem;
}

tr:nth-child(even) {
    background: var(--bg-secondary);
}

tr:hover td {
    background: var(--accent-light);
}

/* ===== Unit Converter Specific ===== */
.converter-group {
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    padding: 20px;
    margin-bottom: 15px;
    border: 1px solid var(--border-light);
}

.converter-group h3 {
    font-size: 1rem;
    margin-bottom: 15px;
    color: var(--accent-primary);
}

.converter-row {
    display: flex;
    gap: 15px;
    align-items: center;
    flex-wrap: wrap;
}

.converter-row input {
    flex: 1;
    min-width: 120px;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 1rem;
}

.converter-row select {
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    min-width: 120px;
}

.converter-arrow {
    font-size: 1.5rem;
    color: var(--accent-primary);
}

.converter-result {
    flex: 1;
    min-width: 120px;
    padding: 10px 12px;
    background: var(--accent-light);
    border-radius: var(--radius-sm);
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 1rem;
    font-weight: 600;
    color: var(--accent-primary);
    text-align: right;
}

/* ===== Footer ===== */
footer {
    text-align: center;
    padding: 20px 0;
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* ===== Animations ===== */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(15px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.results-section {
    animation: fadeIn 0.4s ease-out;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }

    .portal-header {
        margin: -15px -15px 20px -15px;
        padding: 35px 15px;
    }

    .portal-header h1 {
        font-size: 1.6rem;
    }

    header {
        margin: -15px -15px 15px -15px;
        padding: 25px 15px;
    }

    header h1 {
        font-size: 1.5rem;
    }

    section {
        padding: 20px;
    }

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

    .tools-grid {
        grid-template-columns: 1fr;
    }

    .results-cards {
        grid-template-columns: repeat(2, 1fr);
    }

    .converter-row {
        flex-direction: column;
    }

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

@media (max-width: 480px) {
    .results-cards {
        grid-template-columns: 1fr;
    }
}