:root {
    --primary-color: #f97316;
    /* Orange 500 */
    --primary-hover: #ea580c;
    --primary-light: #ffedd5;

    --success-color: #f97316;
    /* このアプリではメインを成功色とする */
    --success-dark: #c2410c;
    /* Orange 700 */
    --success-light: #fff7ed;
    /* Orange 50 */

    --danger-color: #ef4444;
    --danger-light: #fef2f2;
    --danger-dark: #b91c1c;

    --bg-color: #fff7ed;
    /* Orange 50 */
    --card-bg: #ffffff;
    --text-main: #431407;
    /* Orange 950 */
    --text-muted: #78350f;
    /* Orange 900 */
    --border-color: #fed7aa;
    /* Orange 200 */

    --radius-sm: 8px;
    --radius-md: 16px;
    --radius-lg: 20px;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.05), 0 2px 4px -2px rgb(0 0 0 / 0.05);

    --font-family: 'Inter', 'Noto Sans JP', sans-serif;
}

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

img,
input,
select,
textarea {
    max-width: 100%;
}

html,
body {
    overflow-x: hidden !important;
    width: 100% !important;
    position: relative;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    padding: 16px;
    padding-bottom: 40px;
}

.app-container {
    max-width: 500px !important;
    margin: 0 auto;
}

/* 入力が少ないため少し幅を狭く */

/* Header */
.app-header {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    gap: 12px;
    margin-top: 10px;
    margin-bottom: 24px;
    padding: 0;
}

.app-header .header-icon img {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
}

.app-header h1 {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-main);
    letter-spacing: -0.01em;
}

/* Cards */
.card {
    background-color: var(--card-bg);
    border-radius: var(--radius-md);
    padding: 24px;
    margin-bottom: 20px;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

/* Date Inputs */
.date-inputs-container {
    display: flex;
    flex-direction: column;
    gap: 0;
    position: relative;
}

.date-row {
    background-color: #fff;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 16px;
    box-shadow: var(--shadow-sm);
    z-index: 2;
}

.footer-text {
    text-align: center;
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--text-muted);
}

/* Back Button */
.back-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 12px;
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    text-decoration: none;
    font-size: 1.3rem;
    margin-right: 8px;
    flex-shrink: 0;
    transition: transform 0.2s;
    box-shadow: var(--shadow-sm);
}

.back-btn:active {
    transform: scale(0.95);
    background: #f1f5f9;
}

.date-label {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 6px;
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text-main);
    word-break: break-all;
}

.date-label .emoji {
    font-size: 1.1rem;
}

.input-wrapper {
    position: relative;
    width: 100%;
    margin-top: 8px;
}

.input-wrapper input {
    display: block;
    width: 100% !important;
    max-width: 100% !important;
    min-width: 0 !important;
    -webkit-appearance: none;
    appearance: none;
    padding: 12px;
    font-size: 16px !important;
    /* iOSでズームさせない最小サイズ */
    font-family: inherit;
    font-weight: 700;
    color: var(--text-main);
    border: 2px solid #fdba74;
    border-radius: var(--radius-sm);
    outline: none;
    transition: all 0.2s ease;
    background-color: #fffaf0;
}

.input-wrapper input.target-date {
    border-color: var(--primary-color);
    background-color: #fff;
}

.input-wrapper input:focus {
    border-color: var(--primary-hover);
    background-color: #ffffff;
    box-shadow: 0 0 0 3px rgba(249, 115, 22, 0.15);
}

/* Connect Line (Arrow between From and To) */
.connect-line {
    height: 30px;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    z-index: 1;
    margin: -5px 0;
}

.arrow-down {
    width: 0;
    height: 0;
    border-left: 10px solid transparent;
    border-right: 10px solid transparent;
    border-top: 15px solid var(--border-color);
    animation: bounce 2s infinite ease-in-out;
}

@keyframes bounce {

    0%,
    100% {
        transform: translateY(0);
    }

    50% {
        transform: translateY(4px);
    }
}

/* Actions */
.action-row {
    text-align: right;
    margin-top: 24px;
}

.clear-btn {
    background: transparent;
    border: 2px solid #fed7aa;
    color: var(--text-muted);
    font-size: 0.95rem;
    font-weight: 700;
    padding: 8px 16px;
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: all 0.2s;
}

.clear-btn:hover,
.clear-btn:active {
    color: var(--primary-dark);
    background: #ffedd5;
    border-color: #fdba74;
}

/* Results Section */
.results-card {
    border: 2px solid var(--primary-color);
    background-color: var(--success-light);
    padding: 0;
    overflow: hidden;
    transition: all 0.3s ease;
}

.results-header {
    background-color: var(--primary-light);
    padding: 16px;
    text-align: center;
    border-bottom: 1px solid #fdba74;
}

.results-header h2 {
    font-size: 1.15rem;
    color: var(--primary-hover);
    font-weight: 800;
}

.results-main {
    padding: 32px 20px;
    text-align: center;
}

.value-large {
    font-size: 4.5rem;
    line-height: 1;
    font-weight: 800;
    color: var(--success-dark);
    margin-bottom: 12px;
}

.value-large .unit {
    font-size: 1.4rem;
    font-weight: 700;
    margin-left: 4px;
}

.result-details {
    font-size: 1rem;
    font-weight: 600;
}

/* エラー状態 (日付が逆の場合) */
.results-card.is-error {
    border-color: var(--danger-color);
    background-color: var(--danger-light);
    animation: shake 0.5s;
}

.results-card.is-error .results-header {
    background-color: #fecdd3;
    border-bottom-color: #fda4af;
}

.results-card.is-error .results-header h2 {
    color: var(--danger-dark);
}

.results-card.is-error .value-large {
    color: var(--danger-color);
    font-size: 2rem;
    padding: 20px 0;
}

.results-card.is-error .unit {
    display: none;
}

.results-card.is-error .result-details {
    display: none;
}

@keyframes shake {

    0%,
    100% {
        transform: translateX(0);
    }

    25% {
        transform: translateX(-5px);
    }

    75% {
        transform: translateX(5px);
    }
}

/* Responsive adjustments for smaller iPhones */
@media (max-width: 375px) {
    body {
        padding: 8px;
    }

    .app-header {
        gap: 8px;
        margin-bottom: 20px;
    }

    .app-header h1 {
        font-size: 1.1rem;
    }

    .app-header .header-icon img {
        width: 34px;
        height: 34px;
    }

    .back-btn {
        width: 38px;
        height: 38px;
        margin-right: 4px;
    }

    .card {
        padding: 12px 10px;
        overflow: hidden;
    }

    .date-row {
        padding: 8px;
    }

    .input-wrapper input {
        font-size: 0.95rem;
        padding: 8px;
    }

    .value-large {
        font-size: 2.6rem;
    }

    .results-main {
        padding: 20px 8px;
    }

    .result-details {
        font-size: 0.85rem;
    }
}