html {
    scroll-behavior: smooth;
}


:root {
    --page-bg: #f4f6f8;
    --card-bg: #ffffff;
    --soft-bg: #f7f7f7;
    --header-bg: #eeeeee;
    --info-bg: #f0f4f7;

    --text: #222222;
    --muted-text: #666666;
    --light-text: #888888;

    --border: #dddddd;
    --row-border: #e4e4e4;

    --button-bg: #222222;
    --button-hover: #444444;
    --button-text: #ffffff;

    --preset-bg: #eeeeee;
    --preset-hover: #dddddd;

    --accent: #9BC53D;
    --accent-text: #182000;
    --accent-soft: #eef7d9;
    --accent-panel: #f6faed;
    --accent-border: #d7e9ac;

    --analysis-panel: #f4f8fb;
    --analysis-border: #d7e4ed;
    --analysis-accent: #66859a;
    --analysis-soft: #edf4f8;

    --error-bg: #fff1f1;
    --error-text: #9b1c1c;

    --success-bg: #f0f7e5;
    --success-text: #47611c;

    --shadow:
        0 4px 20px rgba(0, 0, 0, 0.08);
}


body.dark-mode {
    --page-bg: #121212;
    --card-bg: #1e1e1e;
    --soft-bg: #292929;
    --header-bg: #333333;
    --info-bg: #252c31;

    --text: #f2f2f2;
    --muted-text: #b0b0b0;
    --light-text: #888888;

    --border: #444444;
    --row-border: #3b3b3b;

    --button-bg: #f2f2f2;
    --button-hover: #d8d8d8;
    --button-text: #111111;

    --preset-bg: #333333;
    --preset-hover: #444444;

    --accent-soft: #314015;
    --accent-panel: #20291a;
    --accent-border: #465a27;

    --analysis-panel: #1d252b;
    --analysis-border: #34444f;
    --analysis-accent: #8baec4;
    --analysis-soft: #26323a;

    --error-bg: #3a2020;
    --error-text: #ffaaaa;

    --success-bg: #29351d;
    --success-text: #b9dc78;

    --shadow:
        0 4px 20px rgba(0, 0, 0, 0.35);
}


* {
    box-sizing: border-box;
}


body {
    font-family:
        Arial,
        Helvetica,
        sans-serif;

    background-color: var(--page-bg);
    color: var(--text);

    margin: 0;
    padding: 40px 20px;

    transition:
        background-color 0.25s ease,
        color 0.25s ease;
}


.container {
    max-width: 860px;
    margin: 0 auto;
}


/* ACCESSIBILITY */


.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}


button:focus-visible,
a:focus-visible {
    outline:
        3px solid var(--accent);

    outline-offset: 3px;
}


.analysis-panel button:focus-visible,
.quick-nav-button:not(.primary):focus-visible {
    outline-color:
        var(--analysis-accent);
}


input:focus-visible,
select:focus-visible {
    outline:
        3px solid var(--accent);

    outline-offset: 2px;
}


.analysis-panel input:focus-visible,
.analysis-panel select:focus-visible {
    outline-color:
        var(--analysis-accent);
}


/* HEADER */

.app-header {
    background-color: var(--card-bg);

    padding: 26px 30px;

    border-radius: 16px;

    box-shadow: var(--shadow);

    margin-bottom: 16px;
}


.top-bar {
    display: flex;

    justify-content: space-between;
    align-items: flex-start;

    gap: 20px;
}


.brand {
    display: flex;
    align-items: center;

    gap: 12px;

    min-width: 0;
}


.brand-mark {
    width: 44px;
    height: 44px;

    flex-shrink: 0;

    display: flex;

    justify-content: center;
    align-items: center;

    border-radius: 12px;

    background-color: var(--button-bg);
    color: var(--button-text);

    font-size: 22px;
}


.brand-text {
    min-width: 0;
}


h1 {
    margin: 0;

    font-size: 34px;

    overflow-wrap: anywhere;
}


h2 {
    margin-top: 34px;
    margin-bottom: 10px;

    font-size: 20px;
}


p {
    line-height: 1.5;
}


.tagline {
    margin-top: 3px;
    margin-bottom: 0;

    color: var(--muted-text);

    font-size: 14px;
    font-weight: bold;
}


.subtitle {
    margin-top: 5px;
    margin-bottom: 0;

    color: var(--muted-text);
}


.theme-button {
    flex-shrink: 0;

    padding: 10px 14px;

    border:
        1px solid var(--border);

    border-radius: 10px;

    background-color: var(--soft-bg);
    color: var(--text);

    font-size: 14px;

    cursor: pointer;
}


.theme-button:hover {
    background-color:
        var(--preset-hover);
}


/* QUICK NAVIGATION */

.quick-nav {
    padding: 18px 22px;

    margin-bottom: 22px;

    border:
        1px solid var(--border);

    border-radius: 14px;

    background-color:
        var(--card-bg);

    box-shadow: var(--shadow);
}


.quick-nav-label {
    margin-bottom: 12px;

    color:
        var(--muted-text);

    font-size: 14px;
    font-weight: bold;
}


.quick-nav-buttons {
    display: flex;

    gap: 10px;
}


.quick-nav-button {
    flex: 1;

    display: flex;

    align-items: center;
    justify-content: center;

    min-height: 46px;

    padding: 12px 16px;

    border:
        1px solid var(--analysis-border);

    border-radius: 10px;

    background-color:
        var(--analysis-soft);

    color:
        var(--text);

    text-decoration: none;

    font-size: 15px;
    font-weight: bold;

    text-align: center;
}


.quick-nav-button:hover {
    opacity: 0.9;
}


.quick-nav-button.primary {
    border-color:
        var(--accent);

    background-color:
        var(--accent);

    color:
        var(--accent-text);
}


/* PANELS */

.main-panel {
    padding: 30px;

    border:
        1px solid var(--border);

    border-radius: 18px;

    background-color:
        var(--card-bg);

    box-shadow: var(--shadow);

    margin-bottom: 24px;

    scroll-margin-top: 16px;
}


.analysis-panel {
    background-color:
        var(--analysis-panel);

    border-color:
        var(--analysis-border);
}


.goal-panel {
    background-color:
        var(--accent-panel);

    border-color:
        var(--accent-border);
}


.panel-header {
    margin-bottom: 24px;
}


.panel-kicker {
    margin-bottom: 7px;

    font-size: 12px;
    font-weight: bold;

    letter-spacing: 0.08em;

    text-transform: uppercase;
}


.analysis-kicker {
    color:
        var(--analysis-accent);
}


.goal-kicker {
    color:
        var(--accent);
}


.panel-title {
    margin: 0;

    font-size: 28px;
}


.panel-description {
    margin-top: 8px;
    margin-bottom: 0;

    color: var(--muted-text);

    font-size: 15px;
}


.section-heading {
    margin-top: 34px;
    margin-bottom: 10px;

    font-size: 20px;
}


.section-heading.first {
    margin-top: 0;
}


/* INPUTS */

label {
    display: block;

    margin-top: 15px;
    margin-bottom: 6px;

    font-weight: bold;
}


input,
select {
    width: 100%;

    padding: 10px;

    border:
        1px solid var(--border);

    border-radius: 8px;

    background-color:
        var(--card-bg);

    color: var(--text);

    font-size: 16px;
}


/* DISTANCE PRESETS */

.presets {
    display: flex;
    flex-wrap: wrap;

    gap: 8px;

    margin-top: 15px;
}


.preset-button,
.target-preset-button {
    padding: 9px 15px;

    border:
        1px solid var(--border);

    border-radius: 20px;

    background-color:
        var(--preset-bg);

    color: var(--text);

    font-size: 14px;

    cursor: pointer;

    transition:
        background-color 0.2s ease,
        border-color 0.2s ease,
        color 0.2s ease;
}


.preset-button:hover,
.target-preset-button:hover {
    background-color:
        var(--preset-hover);
}


.preset-button.active {
    border-color:
        var(--analysis-accent);

    background-color:
        var(--analysis-accent);

    color:
        #ffffff;

    font-weight: bold;
}


.target-preset-button.active {
    border-color:
        var(--accent);

    background-color:
        var(--accent);

    color:
        var(--accent-text);

    font-weight: bold;
}


/* POPULAR GOALS */

.goal-shortcuts {
    margin-top: 22px;
    padding: 16px 18px;

    border:
        1px solid var(--accent-border);

    border-radius: 14px;

    background-color:
        rgba(255, 255, 255, 0.55);
}


body.dark-mode .goal-shortcuts {
    background-color:
        rgba(255, 255, 255, 0.03);
}


.goal-shortcuts-label {
    margin-bottom: 12px;

    color:
        var(--muted-text);

    font-size: 13px;
    font-weight: bold;

    letter-spacing: 0.02em;
}


.goal-shortcut-buttons {
    display: flex;
    flex-wrap: wrap;

    gap: 10px;
}


.goal-shortcut-button {
    padding: 10px 16px;

    border:
        1px solid var(--accent-border);

    border-radius: 999px;

    background-color:
        var(--card-bg);

    color:
        var(--text);

    font-size: 14px;
    font-weight: 600;

    cursor: pointer;

    box-shadow:
        0 1px 3px rgba(0, 0, 0, 0.06);

    transition:
        transform 0.15s ease,
        background-color 0.15s ease,
        border-color 0.15s ease,
        box-shadow 0.15s ease;
}


.goal-shortcut-button:hover {
    border-color:
        var(--accent);

    background-color:
        var(--accent-soft);

    transform:
        translateY(-1px);

    box-shadow:
        0 3px 8px rgba(0, 0, 0, 0.08);
}


.goal-shortcut-button.active {
    border-color:
        var(--accent);

    background-color:
        var(--accent);

    color:
        var(--accent-text);

    box-shadow:
        0 3px 8px rgba(0, 0, 0, 0.10);
}


.goal-shortcuts.hidden {
    display: none;
}


/* FORM LAYOUT */

.distance-row {
    display: flex;

    align-items: end;

    gap: 10px;
}


.distance-field {
    flex: 3;
}


.unit-field {
    flex: 1;
}


.time-row {
    display: flex;

    gap: 10px;
}


.time-field {
    flex: 1;
}


.button-row {
    display: flex;

    gap: 10px;

    margin-top: 25px;
}


.calculate-button {
    flex: 4;

    padding: 14px;

    border: none;
    border-radius: 10px;

    background-color:
        var(--button-bg);

    color:
        var(--button-text);

    font-size: 17px;
    font-weight: bold;

    cursor: pointer;
}


.calculate-button:hover {
    background-color:
        var(--button-hover);
}


.reset-button {
    flex: 1;

    padding: 14px;

    border:
        1px solid var(--border);

    border-radius: 10px;

    background-color:
        var(--soft-bg);

    color:
        var(--text);

    font-size: 15px;

    cursor: pointer;
}


.reset-button:hover {
    background-color:
        var(--preset-hover);
}


/* MESSAGES */

.error-message {
    display: none;

    margin-top: 18px;
    padding: 14px;

    border-radius: 10px;

    background-color:
        var(--error-bg);

    color:
        var(--error-text);

    font-weight: bold;
}


.saved-message {
    min-height: 18px;

    margin-top: 10px;

    color:
        var(--muted-text);

    font-size: 13px;

    text-align: right;
}


/* RESULT CARDS */

.result-cards,
.target-results {
    display: grid;

    grid-template-columns:
        repeat(4, 1fr);

    gap: 12px;

    margin-top: 20px;
}


.result-card,
.target-card {
    padding: 18px;

    border-radius: 12px;

    background-color:
        var(--card-bg);

    text-align: center;
}


.result-card {
    border:
        1px solid var(--analysis-border);
}


.target-card {
    border:
        1px solid var(--accent-border);
}


.result-label,
.target-label {
    margin-bottom: 8px;

    color:
        var(--muted-text);

    font-size: 14px;
}


.result-value,
.target-value {
    font-size: 23px;
    font-weight: bold;
}


/* TABLES */

.table-wrapper {
    width: 100%;
    margin-top: 20px;
    overflow-x: auto;
    border-radius: 12px;
}

.data-table,
.split-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    background-color: var(--card-bg);
    overflow: hidden;
    font-size: 16px;
}

.analysis-panel .data-table {
    border: 1px solid var(--analysis-border);
    border-radius: 12px;
}

.goal-panel .split-table {
    border: 1px solid var(--accent-border);
    border-radius: 12px;
}

.data-table th,
.data-table td,
.split-table th,
.split-table td {
    padding: 14px 18px;
    border-bottom: 1px solid var(--row-border);
    text-align: left;
}

.data-table tbody tr:last-child th,
.data-table tbody tr:last-child td,
.split-table tbody tr:last-child th,
.split-table tbody tr:last-child td {
    border-bottom: none;
}

.data-table thead th,
.split-table thead th {
    background-color: var(--header-bg);
    color: var(--muted-text);
    font-size: 13px;
    font-weight: bold;
}

.data-table tbody th,
.split-table tbody th {
    background-color: transparent;
    color: var(--text);
    font-size: inherit;
}

.distance-name {
    font-weight: bold;
}

.time-value,
.pace-value,
.split-time {
    text-align: right !important;
    font-variant-numeric: tabular-nums;
}

.pace-value {
    color: var(--muted-text);
}

.split-table tbody tr.finish th,
.split-table tbody tr.finish td {
    background-color: var(--accent-soft);
    font-weight: bold;
}

.split-table tbody tr.finish .split-time {
    color: var(--accent);
    font-size: 17px;
}


.note {
    margin-top: 10px;

    color:
        var(--muted-text);

    font-size: 14px;
}


/* INFO BOXES */

.info-box {
    margin-top: 18px;
    padding: 16px 18px;

    border-radius: 12px;

    background-color:
        var(--card-bg);
}


.analysis-panel .info-box {
    border:
        1px solid var(--analysis-border);
}


.goal-panel .info-box {
    border:
        1px solid var(--accent-border);
}


.info-box strong {
    display: block;

    margin-bottom: 5px;
}


/* TRAINING */

.training-grid {
    display: grid;

    grid-template-columns:
        repeat(2, 1fr);

    gap: 12px;

    margin-top: 20px;
}


.training-card {
    padding: 18px;

    border:
        1px solid var(--analysis-border);

    border-radius: 12px;

    background-color:
        var(--card-bg);
}


.training-title {
    margin-bottom: 5px;

    font-size: 17px;
    font-weight: bold;
}


.training-purpose {
    margin-bottom: 14px;

    color:
        var(--muted-text);

    font-size: 14px;
}


.training-pace {
    margin-bottom: 4px;

    font-size: 24px;
    font-weight: bold;
}


.training-mile {
    color:
        var(--muted-text);

    font-size: 14px;
}


/* RACE STRATEGY */

.strategy-section {
    margin-top: 38px;
    padding-top: 30px;

    border-top:
        1px solid var(--accent-border);
}


.strategy-header {
    display: flex;

    justify-content: space-between;
    align-items: flex-start;

    gap: 20px;
}


.strategy-title {
    margin: 0;

    font-size: 24px;
}


.strategy-intro {
    margin-top: 8px;
    margin-bottom: 0;

    color:
        var(--muted-text);

    font-size: 14px;
}


.strategy-buttons {
    display: grid;

    grid-template-columns:
        repeat(2, 1fr);

    gap: 12px;

    margin-top: 20px;
}


.strategy-button {
    display: flex;
    flex-direction: column;

    align-items: flex-start;

    min-height: 88px;

    padding: 16px 18px;

    border:
        1px solid var(--accent-border);

    border-radius: 14px;

    background-color:
        var(--card-bg);

    color:
        var(--text);

    text-align: left;

    cursor: pointer;

    transition:
        border-color 0.15s ease,
        background-color 0.15s ease,
        transform 0.15s ease,
        box-shadow 0.15s ease;
}


.strategy-button:hover {
    border-color:
        var(--accent);

    background-color:
        var(--accent-soft);

    transform:
        translateY(-1px);
}


.strategy-button.active {
    border-color:
        var(--accent);

    background-color:
        var(--accent-soft);

    box-shadow:
        inset 0 0 0 1px var(--accent);
}


.strategy-button-title {
    font-size: 16px;
    font-weight: bold;
}


.strategy-button-description {
    margin-top: 6px;

    color:
        var(--muted-text);

    font-size: 13px;

    line-height: 1.35;
}


.strategy-explanation {
    margin-top: 16px;
    padding: 14px 16px;

    border:
        1px solid var(--accent-border);

    border-radius: 11px;

    background-color:
        var(--card-bg);

    color:
        var(--muted-text);

    font-size: 14px;

    line-height: 1.5;
}


.strategy-pace-cards {
    display: grid;

    grid-template-columns:
        repeat(3, 1fr);

    gap: 10px;

    margin-top: 14px;
}


.strategy-pace-card {
    padding: 15px;

    border:
        1px solid var(--accent-border);

    border-radius: 11px;

    background-color:
        var(--card-bg);

    text-align: center;
}


.strategy-pace-label {
    margin-bottom: 7px;

    color:
        var(--muted-text);

    font-size: 12px;
    font-weight: bold;

    text-transform: uppercase;

    letter-spacing: 0.04em;
}


.strategy-pace-value {
    font-size: 20px;
    font-weight: bold;

    font-variant-numeric:
        tabular-nums;
}


.strategy-pace-distance {
    margin-top: 5px;

    color:
        var(--muted-text);

    font-size: 12px;
}


/* SPLITS */

.split-section {
    margin-top: 36px;
    padding-top: 30px;

    border-top:
        1px solid var(--accent-border);
}


.split-header {
    display: flex;

    justify-content: space-between;
    align-items: center;

    gap: 15px;
}


.split-header h2 {
    margin: 0;
}


.split-toggle {
    flex-shrink: 0;

    padding: 10px 14px;

    border:
        1px solid var(--accent-border);

    border-radius: 10px;

    background-color:
        var(--card-bg);

    color:
        var(--text);

    font-size: 14px;
    font-weight: bold;

    cursor: pointer;
}


.split-toggle:hover {
    background-color:
        var(--accent-soft);
}


.split-summary {
    margin-top: 10px;

    color:
        var(--muted-text);

    font-size: 14px;
}




/* SHARE */

.share-section {
    margin-top: 36px;
    padding-top: 28px;
}


.analysis-panel .share-section {
    border-top:
        1px solid var(--analysis-border);
}


.goal-panel .share-section {
    border-top:
        1px solid var(--accent-border);
}


.share-heading {
    margin: 0 0 6px;

    font-size: 20px;
}


.share-description {
    margin: 0;

    color:
        var(--muted-text);

    font-size: 14px;
}


.share-actions {
    display: flex;

    gap: 10px;

    margin-top: 16px;
}


.copy-button,
.share-button {
    flex: 1;

    min-height: 46px;

    padding: 12px 16px;

    border-radius: 10px;

    font-size: 15px;
    font-weight: bold;

    cursor: pointer;
}


.analysis-panel .copy-button {
    border:
        1px solid var(--analysis-border);

    background-color:
        var(--card-bg);

    color:
        var(--text);
}


.analysis-panel .share-button {
    border:
        1px solid var(--analysis-accent);

    background-color:
        var(--analysis-accent);

    color:
        #ffffff;
}


.goal-panel .copy-button {
    border:
        1px solid var(--accent-border);

    background-color:
        var(--card-bg);

    color:
        var(--text);
}


.goal-panel .share-button {
    border:
        1px solid var(--accent);

    background-color:
        var(--accent);

    color:
        var(--accent-text);
}


.copy-button:hover,
.share-button:hover {
    opacity: 0.9;
}


.action-message {
    display: none;

    margin-top: 12px;
    padding: 10px 12px;

    border-radius: 8px;

    background-color:
        var(--success-bg);

    color:
        var(--success-text);

    font-size: 13px;
    font-weight: bold;
}


/* FOOTER */

.footer {
    padding: 20px 0 8px;

    text-align: center;
}


.footer-brand {
    color:
        var(--muted-text);

    font-size: 13px;
    font-weight: bold;
}


.footer-domain {
    margin-top: 4px;

    color:
        var(--light-text);

    font-size: 12px;
}


.version {
    margin-top: 6px;

    color:
        var(--light-text);

    font-size: 12px;
}


/* RESPONSIVE */

@media (max-width: 700px) {

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


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

}


@media (max-width: 600px) {

    body {
        padding: 10px;
    }


    .app-header,
    .main-panel,
    .quick-nav {
        padding: 18px;

        border-radius: 14px;
    }


    .top-bar {
        align-items: flex-start;

        gap: 10px;
    }


    .brand {
        gap: 9px;
    }


    .brand-mark {
        width: 38px;
        height: 38px;

        border-radius: 10px;

        font-size: 19px;
    }


    h1 {
        font-size: 23px;

        line-height: 1.08;
    }


    .tagline {
        margin-top: 4px;

        font-size: 12px;
    }


    .subtitle {
        display: none;
    }


    .theme-button {
        padding: 8px 10px;

        font-size: 12px;
    }


    .quick-nav-buttons,
    .share-actions {
        flex-direction: column;
    }


    .panel-title {
        font-size: 24px;
    }


    .distance-row,
    .time-row {
        flex-direction: column;
    }


    .distance-field,
    .unit-field,
    .time-field {
        width: 100%;
    }


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


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


    .goal-shortcut-button {
        flex: 1 1 auto;
    }


    .strategy-buttons {
        grid-template-columns: 1fr;
    }


    .strategy-pace-cards {
        grid-template-columns: 1fr;
    }


    .strategy-pace-card {
        display: grid;

        grid-template-columns:
            1fr auto;

        align-items: center;

        text-align: left;
    }


    .strategy-pace-label {
        margin-bottom: 0;
    }


    .strategy-pace-value {
        grid-row:
            1 / span 2;

        grid-column: 2;

        text-align: right;
    }


    .strategy-pace-distance {
        margin-top: 3px;
    }


    .split-header {
        align-items: stretch;
        flex-direction: column;
    }


    .split-toggle {
        width: 100%;
    }


    .data-table,
    .split-table {
        font-size: 14px;
    }

    .data-table th,
    .data-table td,
    .split-table th,
    .split-table td {
        padding: 13px 12px;
    }

}


@media (max-width: 400px) {

    h1 {
        font-size: 21px;
    }


    .result-cards,
    .target-results {
        grid-template-columns: 1fr;
    }


    .preset-button,
    .target-preset-button {
        padding: 8px 12px;

        font-size: 13px;
    }


    .data-table th,
    .data-table td,
    .split-table th,
    .split-table td {
        padding: 12px 8px;
    }

}