:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --success-color: #10b981;
    --error-color: #ef4444;
    --border-color: #e5e7eb;
    --text-color: #1f2937;
    --bg-color: #f9fafb;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Hiragino Sans', 'Hiragino Kaku Gothic ProN', 'Meiryo', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    padding: 20px;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    background-color: white;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    padding: 40px;
}

h1 {
    font-size: 2em;
    margin-bottom: 8px;
    color: var(--primary-color);
}

.subtitle {
    color: #6b7280;
    margin-bottom: 30px;
    font-size: 0.95em;
}

h2 {
    font-size: 1.3em;
    margin-bottom: 20px;
    color: var(--text-color);
}

h3 {
    font-size: 1.1em;
    margin-bottom: 12px;
}

.section {
    margin-bottom: 25px;
    padding-bottom: 25px;
    border-bottom: 1px solid var(--border-color);
}

.section:last-of-type {
    border-bottom: none;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    font-size: 0.95em;
}

.input-field {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.95em;
    font-family: inherit;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.input-field:focus,
select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%232563eb' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 10px center;
    padding-right: 32px;
}

.textarea {
    min-height: 100px;
    resize: vertical;
    font-family: 'Monaco', 'Menlo', monospace;
    font-size: 0.9em;
}

.search-field {
    position: relative;
}

.search-wrapper {
    position: relative;
}

/* 変換前の座標系表示（読み取り専用） */
.system-display-box {
    padding: 12px;
    background-color: #f3f4f6;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.95em;
    min-height: 40px;
    display: flex;
    align-items: center;
    color: var(--text-color);
    font-weight: 500;
}

.hint {
    display: block;
    margin-top: 6px;
    font-size: 0.85em;
    color: #6b7280;
}

.hint a {
    color: var(--primary-color);
    text-decoration: none;
}

.hint a:hover {
    text-decoration: underline;
}

/* Coordinate System Selection */
.coordinate-system-row {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 15px;
    align-items: flex-start;
}

.coordinate-system {
    flex: 1;
}

.swap-button {
    align-self: flex-end;
    margin-bottom: 0;
    padding: 10px 12px;
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    cursor: pointer;
    font-size: 1.2em;
    transition: all 0.2s;
}

.swap-button:hover {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.swap-button:active {
    transform: scale(0.95);
}

.suggestions {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: white;
    border: 1px solid var(--border-color);
    border-top: none;
    border-radius: 0 0 6px 6px;
    max-height: 200px;
    overflow-y: auto;
    z-index: 10;
    display: none;
}

.suggestions.active {
    display: block;
}

.suggestion-item {
    padding: 10px 12px;
    cursor: pointer;
    transition: background-color 0.2s;
    border-bottom: 1px solid var(--border-color);
}

.suggestion-item:last-child {
    border-bottom: none;
}

.suggestion-item:hover {
    background-color: var(--bg-color);
}

.suggestion-item strong {
    color: var(--primary-color);
}

.system-display {
    margin-top: 8px;
    padding: 8px 10px;
    background-color: var(--bg-color);
    border-radius: 4px;
    font-size: 0.85em;
    color: #6b7280;
    min-height: 20px;
}

.system-description {
    margin-top: 8px;
    padding: 8px 10px;
    background-color: #f3f4f6;
    border-radius: 4px;
    font-size: 0.82em;
    color: #9ca3af;
    line-height: 1.5;
}

/* Buttons */
.convert-button {
    width: 100%;
    padding: 12px 20px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 1em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    margin-bottom: 25px;
}

.convert-button:hover {
    background-color: var(--primary-dark);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.4);
}

.convert-button:active {
    transform: translateY(2px);
}

.convert-button:disabled {
    background-color: #d1d5db;
    cursor: not-allowed;
}

/* Results */
.results-section {
    background-color: #f0fdf4;
    border-left: 4px solid var(--success-color);
    padding: 20px;
    border-radius: 6px;
    margin-bottom: 25px;
}

.results-container {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.result-item {
    background-color: white;
    padding: 12px;
    border-radius: 4px;
    border: 1px solid var(--border-color);
    font-family: 'Monaco', 'Menlo', monospace;
    font-size: 0.9em;
}

.result-item .label {
    color: #6b7280;
    font-size: 0.85em;
    margin-bottom: 4px;
}

.result-item .value {
    color: var(--primary-color);
    font-weight: 600;
}

/* Error */
.error-section {
    background-color: #fef2f2;
    border-left: 4px solid var(--error-color);
    padding: 20px;
    border-radius: 6px;
    margin-bottom: 25px;
}

.error-message {
    color: var(--error-color);
    font-size: 0.95em;
    line-height: 1.5;
}

/* Loading */
.loading-indicator {
    text-align: center;
    padding: 30px;
}

.spinner {
    width: 40px;
    height: 40px;
    margin: 0 auto 15px;
    border: 4px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* File Upload */
.file-input {
    display: none;
}

.file-upload-area {
    position: relative;
    border: 2px dashed var(--border-color);
    border-radius: 8px;
    padding: 40px 20px;
    text-align: center;
    transition: all 0.2s;
    background-color: var(--bg-color);
}

.file-upload-area:hover {
    border-color: var(--primary-color);
    background-color: #f0f9ff;
}

.file-upload-area.drag-over {
    border-color: var(--primary-color);
    background-color: rgba(37, 99, 235, 0.05);
}

.file-upload-label {
    display: flex;
    flex-direction: column;
    align-items: center;
    cursor: pointer;
    font-weight: normal;
    margin-bottom: 0;
}

.upload-icon {
    width: 48px;
    height: 48px;
    color: var(--primary-color);
    margin-bottom: 12px;
}

.file-upload-label span {
    color: var(--text-color);
    font-size: 0.95em;
    line-height: 1.4;
}

.file-info {
    margin-top: 15px;
    padding: 12px;
    background-color: var(--bg-color);
    border-radius: 6px;
    font-size: 0.9em;
}

.file-info-item {
    margin: 4px 0;
}

.file-info-label {
    font-weight: 600;
    color: #6b7280;
}

.file-preview {
    margin-top: 15px;
    padding: 12px;
    background-color: var(--bg-color);
    border-radius: 6px;
    max-height: 200px;
    overflow-y: auto;
    font-size: 0.85em;
    font-family: 'Monaco', 'Menlo', monospace;
}

.preview-item {
    padding: 4px 0;
    word-break: break-all;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 20px;
    }

    h1 {
        font-size: 1.5em;
    }

    .coordinate-system-row {
        grid-template-columns: 1fr;
    }

    .swap-button {
        align-self: center;
        padding: 8px 10px;
        font-size: 1em;
    }

    .suggestions {
        position: static;
        border: 1px solid var(--border-color);
        max-height: 150px;
    }

    .file-upload-area {
        padding: 30px 15px;
    }

    .upload-icon {
        width: 40px;
        height: 40px;
    }
}