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

body {
    font-family: "Inter", Helvetica, Arial, sans-serif;
    font-weight: 300;
    color: white;
    height: 100vh;
    overflow: hidden;
}

#bg-video {
    position: fixed;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center top;
    z-index: -1;
}

#ui {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
    height: 40vh;
    gap: 1rem;
    padding-left: clamp(1.5rem, 6vw, 5rem);
}

h1 {
    font-size: 1.375rem;
    font-weight: 300;
    letter-spacing: 0.18em;
    margin-bottom: 0.5rem;
}

button {
    position: relative;
    background: none;
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.5);
    padding: 10px;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: opacity 0.15s ease;
}

button:hover {
    opacity: 0.85;
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.icon-pause { display: none; }

button.playing .icon-play { display: none; }
button.playing .icon-pause { display: flex; }

button.loading .icon-play,
button.loading .icon-pause { opacity: 0; }

button.loading::after {
    content: "";
    position: absolute;
    width: 14px;
    height: 14px;
    border: 1px solid rgba(255, 255, 255, 0.25);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.75s linear infinite;
}

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

#controls {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

#progress-track {
    width: calc(100% - clamp(1.5rem, 6vw, 5rem));
    height: 1px;
    background: rgba(255, 255, 255, 0.15);
}

#progress-fill {
    height: 100%;
    width: 0%;
    background: white;
    transition: width 0.25s linear;
}

#ui p {
    max-width: 32ch;
    font-size: 0.8125rem;
    line-height: 1.8;
    color: rgba(255, 255, 255, 0.55);
    margin-top: 0.75rem;
}

#watermark {
    position: fixed;
    bottom: -0.4em;
    left: clamp(3rem, 7vw, 9rem);
    line-height: 0;
    text-align: right;
    font-size: clamp(3rem, 13vw, 11rem);
    font-weight: 600;
    letter-spacing: -0.02em;
    line-height: 1;
    white-space: nowrap;
    color: rgba(255, 255, 255, 0.02);
    pointer-events: none;
    user-select: none;
}

#watermark p {
    line-height: 0.8;
}

#watermark p span {
    font-size: 190px;
}